- devel - example.com

[Patch v4] Static PIE support for i386, x86_64, and arm
by linted 26 Jul '22

26 Jul '22

Hello, I first want to apologize for so many patch versions. This version of the patch correctly adjusts the offset of the TLS initimage used by __libc_setup_tls when copying. I would love feedback on my modifications to libc-tls.c as I had to use a new global variable defined in reloc_static_pie.c containing the load address. Originally I attempted to copy how glibc pulls the load address from a memory map when initializing the TLS, however I could not find a similar structure available in __libc_setup_tls. I would love to know if there is a better method which I overlooked. From 30b435a0b7a7f2d4323eafea2bcebb087cc62462 Mon Sep 17 00:00:00 2001 From: linted <linted(a)users.noreply.github.com> Date: Sat, 23 Jul 2022 16:25:41 -0400 Subject: [PATCH] Added support for creation of Static Position-Independent Executables (PIE) on i386, x86_64, and arm. This patch adds the generation of rcrt1.o which is used by gcc when compiling with the --static-pie flag. rcrt1.o differs from crt1.o and Scrt1.o in that it the executable has a dynamic section but no relocations have been performed prior to _start being called. crt1.o assumes there to be no dynamic relocations, and Scrt1.o has all relocations performed prior to execution by lsdo. The new reloc_static_pie function handles parsing the dynamic section, and performing the relocations in a architecture agnostic method. It also sets _dl_load_base which is used when initalizing TLS to ensure loading from the proper location. This allows for easier porting of static-pie support to additional architectures as only modifications to crt1.S to find the load address are required. Signed-off-by: linted <linted(a)users.noreply.github.com> --- Makerules | 5 +++ extra/Configs/Config.in | 5 +++ libc/misc/internals/Makefile.in | 1 + libc/misc/internals/reloc_static_pie.c | 47 +++++++++++++++++++++ libc/sysdeps/linux/arm/crt1.S | 19 +++++++++ libc/sysdeps/linux/i386/crt1.S | 20 +++++++++ libc/sysdeps/linux/x86_64/crt1.S | 16 ++++++- libpthread/nptl/sysdeps/generic/Makefile.in | 4 ++ libpthread/nptl/sysdeps/generic/libc-tls.c | 4 ++ 9 files changed, 120 insertions(+), 1 deletion(-) create mode 100644 libc/misc/internals/reloc_static_pie.c diff --git a/Makerules b/Makerules index fd40e6c7b..845d81897 100644 --- a/Makerules +++ b/Makerules @@ -405,8 +405,13 @@ else CRTS=$(top_builddir)lib/$(CRT).o endif +ifeq ($(STATIC_PIE),y) +CRTS+=$(top_builddir)lib/r$(CRT).o +endif + ASFLAGS-$(CRT).o := -DL_$(CRT) ASFLAGS-S$(CRT).o := $(PIEFLAG) -DL_S$(CRT) +ASFLAGS-r$(CRT).o := $(PIEFLAG) -DL_r$(CRT) $(CRTS): $(top_srcdir)libc/sysdeps/linux/$(TARGET_ARCH)/$(CRT).S $(compile.S) $(Q)$(STRIPTOOL) -x -R .note -R .comment $@ diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in index a58ceb265..a49278b30 100644 --- a/extra/Configs/Config.in +++ b/extra/Configs/Config.in @@ -301,6 +301,11 @@ config DOPIC If you wish to build all of uClibc as PIC objects, then answer Y here. If you are unsure, then you should answer N. +config STATIC_PIE + bool "Add support for Static Position Independent Executables (PIE)" + default n + depends on DOPIC && !UCLIBC_FORMAT_FDPIC_ELF && (TARGET_arm || TARGET_i386 || TARGET_x86_64) + config ARCH_HAS_NO_SHARED bool diff --git a/libc/misc/internals/Makefile.in b/libc/misc/internals/Makefile.in index a8e4e36f9..4a6e73d2d 100644 --- a/libc/misc/internals/Makefile.in +++ b/libc/misc/internals/Makefile.in @@ -34,6 +34,7 @@ libc-static-$(UCLIBC_FORMAT_FLAT_SEP_DATA) += \ libc-static-$(UCLIBC_FORMAT_SHARED_FLAT) += \ $(MISC_INTERNALS_OUT)/shared_flat_initfini.o \ $(MISC_INTERNALS_OUT)/shared_flat_add_library.o +libc-static-$(STATIC_PIE) += $(MISC_INTERNALS_OUT)/reloc_static_pie.o libc-shared-$(UCLIBC_FORMAT_SHARED_FLAT) += \ $(MISC_INTERNALS_OUT)/shared_flat_initfini.os \ $(MISC_INTERNALS_OUT)/shared_flat_add_library.os diff --git a/libc/misc/internals/reloc_static_pie.c b/libc/misc/internals/reloc_static_pie.c new file mode 100644 index 000000000..578202d23 --- /dev/null +++ b/libc/misc/internals/reloc_static_pie.c @@ -0,0 +1,47 @@ +/* Support for relocating static PIE. + Copyright (C) 2017-2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <link.h> +#include <elf.h> +#include <dl-elf.h> + +ElfW(Addr) _dl_load_base = NULL; + +void +reloc_static_pie (ElfW(Addr) load_addr); + +void +reloc_static_pie (ElfW(Addr) load_addr) +{ + ElfW(Word) relative_count = 0; + ElfW(Addr) rel_addr = 0; + ElfW(Dyn) * dyn_addr = NULL; + unsigned long dynamic_info[DYNAMIC_SIZE] = {0}; + + /* Read our own dynamic section and fill in the info array. */ + dyn_addr = ((void *) load_addr + elf_machine_dynamic ()); + + /* Use the underlying function to avoid TLS access before initialization */ + __dl_parse_dynamic_info(dyn_addr, dynamic_info, NULL, load_addr); + + /* Perform relocations */ + relative_count = dynamic_info[DT_RELCONT_IDX]; + rel_addr = dynamic_info[DT_RELOC_TABLE_ADDR]; + elf_machine_relative(load_addr, rel_addr, relative_count); + _dl_load_base = load_addr; +} diff --git a/libc/sysdeps/linux/arm/crt1.S b/libc/sysdeps/linux/arm/crt1.S index a1d7f0f23..fade1d25c 100644 --- a/libc/sysdeps/linux/arm/crt1.S +++ b/libc/sysdeps/linux/arm/crt1.S @@ -246,6 +246,22 @@ _start: mov lr, #0 #ifdef __ARCH_USE_MMU__ +#ifdef L_rcrt1 + /* We don't need to save a1 since no dynamic linker should have run */ + ldr a1, .L_GOT /* Get value at .L_GOT + 0 (offset to GOT)*/ + adr a2, .L_GOT /* Get address of .L_GOT */ + ldr a3, .L_GOT+16 /* Get value of _start(GOT) stored in .L_GOT */ + adr a4, _start /* Get address of _start after relocation (changes to pc - ~30 or so) */ + add a1, a1, a2 /* Calculate where the GOT is */ + ldr a2, [a1, a3] /* GOT + _start(GOT) = offset of _start from begin of file */ + sub a1, a4, a2 /* Current addr of _start - offset from beginning of file = load addr */ + bl reloc_static_pie + mov a1, #0 /* Clean up a1 so that a random address won't get called at the end of program */ + + /* Clear the frame pointer and link register again since it might be modified by previous call */ + mov fp, #0 + mov lr, #0 +#endif /* Pop argc off the stack and save a pointer to argv */ ldr a2, [sp], #4 mov a3, sp @@ -309,6 +325,9 @@ _start: .word _fini(GOT) .word _init(GOT) .word main(GOT) +#ifdef L_rcrt1 + .word _start(GOT) +#endif #endif #endif diff --git a/libc/sysdeps/linux/i386/crt1.S b/libc/sysdeps/linux/i386/crt1.S index 35a6552e8..decc68967 100644 --- a/libc/sysdeps/linux/i386/crt1.S +++ b/libc/sysdeps/linux/i386/crt1.S @@ -67,6 +67,9 @@ #endif .type main,%function .type __uClibc_main,%function +#ifdef L_rcrt1 +.type reloc_static_pie,%function +#endif _start: /* Clear the frame pointer. The ABI suggests this be done, to mark the outermost frame obviously. */ @@ -100,6 +103,23 @@ _start: pop %ebx addl $_GLOBAL_OFFSET_TABLE_+[.-.L0],%ebx +#ifdef L_rcrt1 + /* We cannot rely on _DYNAMIC being usable here due to RELRO. + Instead we calculate the load address based off a symbol + that we know will exist, _start. */ + pushl %ecx /* Save ecx so it won't get clobbered */ + pushl %ebx /* Save ebx so it won't get clobbered */ + xorl %ecx, %ecx /* Clear ecx */ + addl _start@GOT(%ebx), %ecx /* Get the offset of _start */ + movl _start@GOT(%ebx), %eax /* Get the run time address of _start */ + subl %ecx, %eax /* Subtract to find the load address */ + pushl %eax /* Pass the load address */ + call reloc_static_pie@PLT + popl %eax /* Clean up from function call */ + popl %ebx /* Restore the GOT address */ + popl %ecx /* restore ecx */ +#endif + /* Push address of our own entry points to .fini and .init. */ pushl _fini@GOT(%ebx) pushl _init@GOT(%ebx) diff --git a/libc/sysdeps/linux/x86_64/crt1.S b/libc/sysdeps/linux/x86_64/crt1.S index 87777dd5d..701cbf2f6 100644 --- a/libc/sysdeps/linux/x86_64/crt1.S +++ b/libc/sysdeps/linux/x86_64/crt1.S @@ -80,6 +80,20 @@ _start: the outermost frame obviously. */ xorl %ebp, %ebp +#ifdef L_rcrt1 + pushq %rdi /* save rdi (but should be 0...) */ + pushq %rdx /* store rdx (rtld_fini) */ + xorq %rcx, %rcx /* ensure rcx is 0 */ + addq _start@GOTPCREL(%rip), %rcx /* get offset of _start from beginning of file */ + movq _start@GOTPCREL(%rip), %rax /* get run time address of _start */ + subq %rcx, %rax /* calculate run time load offset */ + movq %rax, %rdi /* load offset -> param 1 */ + call reloc_static_pie /* relocate dynamic addrs */ + xorq %rax, %rax /* cleanup */ + popq %rdx + popq %rdi +#endif + /* Extract the arguments as encoded on the stack and set up the arguments for __libc_start_main (int (*main) (int, char **, char **), int argc, char *argv, @@ -107,7 +121,7 @@ _start: which grow downwards). */ pushq %rsp -#if defined(L_Scrt1) +#if defined(L_Scrt1) || defined(L_rcrt1) /* Give address for main() */ movq main@GOTPCREL(%rip), %rdi diff --git a/libpthread/nptl/sysdeps/generic/Makefile.in b/libpthread/nptl/sysdeps/generic/Makefile.in index eb656ee17..a5ba9bbe8 100644 --- a/libpthread/nptl/sysdeps/generic/Makefile.in +++ b/libpthread/nptl/sysdeps/generic/Makefile.in @@ -13,6 +13,10 @@ subdirs += libpthread/nptl/sysdeps/generic libpthread_generic_DIR := $(top_srcdir)libpthread/nptl/sysdeps/generic libpthread_generic_OUT := $(top_builddir)libpthread/nptl/sysdeps/generic +ifeq ($(STATIC_PIE),y) +CFLAGS-libc-tls.c := -DSTATIC_PIE +endif + libpthread_generic_libc_a_CSRC = libc-tls.c libpthread_generic_libc_a_COBJ = $(patsubst %.c,$(libpthread_generic_OUT)/%.o,$(libpthread_generic_libc_a_CSRC)) libpthread_generic_libc_a_OBJS = $(libpthread_generic_libc_a_COBJ) diff --git a/libpthread/nptl/sysdeps/generic/libc-tls.c b/libpthread/nptl/sysdeps/generic/libc-tls.c index d746c9a38..0c8c558d0 100644 --- a/libpthread/nptl/sysdeps/generic/libc-tls.c +++ b/libpthread/nptl/sysdeps/generic/libc-tls.c @@ -142,6 +142,10 @@ __libc_setup_tls (size_t tcbsize, size_t tcbalign) initimage = (void *) &__tdata_start; #else initimage = (void *) phdr->p_vaddr; +#if !defined(SHARED) && defined(STATIC_PIE) + extern ElfW(Addr) _dl_load_base; + initimage += _dl_load_base; +#endif #endif align = phdr->p_align; if (phdr->p_align > max_align) -- 2.34.1

3 2

[Patch v3] Static PIE support for i386, x86_64, and arm
by linted 22 Jul '22

22 Jul '22

Hello, This is an updated patch for static pie support. I have corrected formatting and code standard issues which appeared in my previous patches. I also updated the commit message to be clearer on what is occurring and why. -linted From 92056b7db87be00e6daea59a4f82d022bfc7f223 Mon Sep 17 00:00:00 2001 From: linted <linted(a)users.noreply.github.com> Date: Sun, 17 Jul 2022 13:38:49 -0400 Subject: [PATCH] Added support for creation of Static Position-Independent Executables (PIE) on i386, x86_64, and arm. This patch adds the generation of rcrt1.o which is used by gcc when compiling with the --static-pie flag. rcrt1.o differs from crt1.o and Scrt1.o in that it the executable has a dynamic section but no relocations have been performed prior to _start being called. crt1.o assumes there to be no dynamic relocations, and Scrt1.o has all relocations performed prior to execution by lsdo. The new reloc_static_pie function handles parsing the elf headers, locating the dynamic section, and performing the relocations in a architecture agnostic method. This allows for easier porting of static-pie support to additional architectures. Signed-off-by: linted <linted(a)users.noreply.github.com> --- Makerules | 5 ++++ extra/Configs/Config.in | 5 ++++ libc/misc/internals/Makefile.in | 1 + libc/misc/internals/reloc_static_pie.c | 41 ++++++++++++++++++++++++++ libc/sysdeps/linux/arm/crt1.S | 15 ++++++++++ libc/sysdeps/linux/i386/crt1.S | 20 +++++++++++++ libc/sysdeps/linux/x86_64/crt1.S | 16 +++++++++- 7 files changed, 102 insertions(+), 1 deletion(-) create mode 100644 libc/misc/internals/reloc_static_pie.c diff --git a/Makerules b/Makerules index fd40e6c7b..845d81897 100644 --- a/Makerules +++ b/Makerules @@ -405,8 +405,13 @@ else CRTS=$(top_builddir)lib/$(CRT).o endif +ifeq ($(STATIC_PIE),y) +CRTS+=$(top_builddir)lib/r$(CRT).o +endif + ASFLAGS-$(CRT).o := -DL_$(CRT) ASFLAGS-S$(CRT).o := $(PIEFLAG) -DL_S$(CRT) +ASFLAGS-r$(CRT).o := $(PIEFLAG) -DL_r$(CRT) $(CRTS): $(top_srcdir)libc/sysdeps/linux/$(TARGET_ARCH)/$(CRT).S $(compile.S) $(Q)$(STRIPTOOL) -x -R .note -R .comment $@ diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in index a58ceb265..a49278b30 100644 --- a/extra/Configs/Config.in +++ b/extra/Configs/Config.in @@ -301,6 +301,11 @@ config DOPIC If you wish to build all of uClibc as PIC objects, then answer Y here. If you are unsure, then you should answer N. +config STATIC_PIE + bool "Add support for Static Position Independent Executables (PIE)" + default n + depends on DOPIC && !UCLIBC_FORMAT_FDPIC_ELF && (TARGET_arm || TARGET_i386 || TARGET_x86_64) + config ARCH_HAS_NO_SHARED bool diff --git a/libc/misc/internals/Makefile.in b/libc/misc/internals/Makefile.in index a8e4e36f9..4a6e73d2d 100644 --- a/libc/misc/internals/Makefile.in +++ b/libc/misc/internals/Makefile.in @@ -34,6 +34,7 @@ libc-static-$(UCLIBC_FORMAT_FLAT_SEP_DATA) += \ libc-static-$(UCLIBC_FORMAT_SHARED_FLAT) += \ $(MISC_INTERNALS_OUT)/shared_flat_initfini.o \ $(MISC_INTERNALS_OUT)/shared_flat_add_library.o +libc-static-$(STATIC_PIE) += $(MISC_INTERNALS_OUT)/reloc_static_pie.o libc-shared-$(UCLIBC_FORMAT_SHARED_FLAT) += \ $(MISC_INTERNALS_OUT)/shared_flat_initfini.os \ $(MISC_INTERNALS_OUT)/shared_flat_add_library.os diff --git a/libc/misc/internals/reloc_static_pie.c b/libc/misc/internals/reloc_static_pie.c new file mode 100644 index 000000000..9a8066b84 --- /dev/null +++ b/libc/misc/internals/reloc_static_pie.c @@ -0,0 +1,41 @@ +/* Support for relocating static PIE. + Copyright (C) 2017-2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <link.h> +#include <elf.h> +#include <dl-elf.h> + +void +reloc_static_pie (ElfW(Addr) load_addr) +{ + ElfW(Word) relative_count = 0; + ElfW(Addr) rel_addr = NULL; + ElfW(Dyn) * dyn_addr = NULL; + unsigned long dynamic_info[DYNAMIC_SIZE] = {0}; + + /* Read our own dynamic section and fill in the info array. */ + dyn_addr = ((void *) load_addr + elf_machine_dynamic ()); + + /* Use the underlying function to avoid TLS access before initialization */ + __dl_parse_dynamic_info(dyn_addr, dynamic_info, NULL, load_addr); + + /* Perform relocations */ + relative_count = dynamic_info[DT_RELCONT_IDX]; + rel_addr = dynamic_info[DT_RELOC_TABLE_ADDR]; + elf_machine_relative(load_addr, rel_addr, relative_count); +} diff --git a/libc/sysdeps/linux/arm/crt1.S b/libc/sysdeps/linux/arm/crt1.S index a1d7f0f23..2aa2a5234 100644 --- a/libc/sysdeps/linux/arm/crt1.S +++ b/libc/sysdeps/linux/arm/crt1.S @@ -246,6 +246,18 @@ _start: mov lr, #0 #ifdef __ARCH_USE_MMU__ +#ifdef L_rcrt1 + /* We don't need to save a1 since no dynamic linker should have run */ + ldr a1, .L_GOT /* Get value at .L_GOT + 0 (offset to GOT)*/ + adr a2, .L_GOT /* Get address of .L_GOT */ + ldr a3, .L_GOT+16 /* get value of _start(GOT) stored in .L_GOT */ + adr a4, _start /* get address of _start after relocation (changes to pc - ~30 or so) */ + add a1, a1, a2 /* calculate where the GOT is */ + ldr a2, [a1, a3] /* GOT + _start(GOT) = offset of _start from begin of file */ + sub a1, a4, a2 /* current addr of _start - offset from beginning of file = load addr */ + bl reloc_static_pie + mov a1, #0 /* Clean up a1 so that a random address won't get called at the end of program */ +#endif /* Pop argc off the stack and save a pointer to argv */ ldr a2, [sp], #4 mov a3, sp @@ -309,6 +321,9 @@ _start: .word _fini(GOT) .word _init(GOT) .word main(GOT) +#ifdef L_rcrt1 + .word _start(GOT) +#endif #endif #endif diff --git a/libc/sysdeps/linux/i386/crt1.S b/libc/sysdeps/linux/i386/crt1.S index 35a6552e8..decc68967 100644 --- a/libc/sysdeps/linux/i386/crt1.S +++ b/libc/sysdeps/linux/i386/crt1.S @@ -67,6 +67,9 @@ #endif .type main,%function .type __uClibc_main,%function +#ifdef L_rcrt1 +.type reloc_static_pie,%function +#endif _start: /* Clear the frame pointer. The ABI suggests this be done, to mark the outermost frame obviously. */ @@ -100,6 +103,23 @@ _start: pop %ebx addl $_GLOBAL_OFFSET_TABLE_+[.-.L0],%ebx +#ifdef L_rcrt1 + /* We cannot rely on _DYNAMIC being usable here due to RELRO. + Instead we calculate the load address based off a symbol + that we know will exist, _start. */ + pushl %ecx /* Save ecx so it won't get clobbered */ + pushl %ebx /* Save ebx so it won't get clobbered */ + xorl %ecx, %ecx /* Clear ecx */ + addl _start@GOT(%ebx), %ecx /* Get the offset of _start */ + movl _start@GOT(%ebx), %eax /* Get the run time address of _start */ + subl %ecx, %eax /* Subtract to find the load address */ + pushl %eax /* Pass the load address */ + call reloc_static_pie@PLT + popl %eax /* Clean up from function call */ + popl %ebx /* Restore the GOT address */ + popl %ecx /* restore ecx */ +#endif + /* Push address of our own entry points to .fini and .init. */ pushl _fini@GOT(%ebx) pushl _init@GOT(%ebx) diff --git a/libc/sysdeps/linux/x86_64/crt1.S b/libc/sysdeps/linux/x86_64/crt1.S index 87777dd5d..701cbf2f6 100644 --- a/libc/sysdeps/linux/x86_64/crt1.S +++ b/libc/sysdeps/linux/x86_64/crt1.S @@ -80,6 +80,20 @@ _start: the outermost frame obviously. */ xorl %ebp, %ebp +#ifdef L_rcrt1 + pushq %rdi /* save rdi (but should be 0...) */ + pushq %rdx /* store rdx (rtld_fini) */ + xorq %rcx, %rcx /* ensure rcx is 0 */ + addq _start@GOTPCREL(%rip), %rcx /* get offset of _start from beginning of file */ + movq _start@GOTPCREL(%rip), %rax /* get run time address of _start */ + subq %rcx, %rax /* calculate run time load offset */ + movq %rax, %rdi /* load offset -> param 1 */ + call reloc_static_pie /* relocate dynamic addrs */ + xorq %rax, %rax /* cleanup */ + popq %rdx + popq %rdi +#endif + /* Extract the arguments as encoded on the stack and set up the arguments for __libc_start_main (int (*main) (int, char **, char **), int argc, char *argv, @@ -107,7 +121,7 @@ _start: which grow downwards). */ pushq %rsp -#if defined(L_Scrt1) +#if defined(L_Scrt1) || defined(L_rcrt1) /* Give address for main() */ movq main@GOTPCREL(%rip), %rdi -- 2.34.1

4 10

Building uClibc-ng for ARM32 targetting an ARMv8 core fails
by Thomas Petazzoni 18 Jul '22

18 Jul '22

Hello, Buildroot supports building ARM 32-bit systems for ARMv8 cores (even though those would more classically run an AArch64 system). Unfortunately, it seems like uClibc-ng doesn't support this situation, as it exhibits the following build failure: CC libpthread/linuxthreads/mutex.os /tmp/ccn8SFKU.s: Assembler messages: /tmp/ccn8SFKU.s:162: Error: swp{b} use is obsoleted for ARMv8 and later /tmp/ccn8SFKU.s:186: Error: swp{b} use is obsoleted for ARMv8 and later /tmp/ccn8SFKU.s:203: Error: swp{b} use is obsoleted for ARMv8 and later /tmp/ccn8SFKU.s:224: Error: swp{b} use is obsoleted for ARMv8 and later make[1]: *** [Makerules:369: libpthread/linuxthreads/mutex.os] Error 1 See http://autobuild.buildroot.net/results/1e2e5e6c752901a818630d0c0816f43874bf… for a more detailed log. This is due to libpthread/linuxthreads/sysdeps/arm/pt-machine.h which uses the swp instruction that is not allowed on ARMv8. Best regards, Thomas -- Thomas Petazzoni, co-owner and CEO, Bootlin Embedded Linux and Kernel engineering and training https://bootlin.com

1 0

[Patch v2] Static PIE support for i386, x86_64, and arm
by linted 16 Jul '22

16 Jul '22

Hello, This is an updated patch for static pie support on i386, x86_64, and arm. I added dependency checks to ensure it only affects supported architectures. I also added a check to ensure an MMU is present on arm since there is no support for FDPIC yet.

2 2

Static PIE support for i386, x86_64, and arm
by linted 15 Jul '22

15 Jul '22

Hello, I implemented support for static pie generation on i386, x86_64, and arm. This patch adds the generation of rcrt1.o which is used by gcc when compiling with the --static-pie flag. The main difference in rcrt1.o is that it is required to perform dynamic relocations which would normally occur in ldso. The new reloc_static_pie function handles parsing the elf headers, locating the dynamic section, and performing the relocations.

2 2

[PATCH] assert: Add static_assert macro
by Nicolas Cavallari 29 Jun '22

29 Jun '22

See the C11 standard 7.2 §3 The definition is copied from glibc. --- include/assert.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/assert.h b/include/assert.h index ee8e85fa2..fd71e833b 100644 --- a/include/assert.h +++ b/include/assert.h @@ -76,3 +76,8 @@ __END_DECLS # endif #endif /* NDEBUG. */ + +#if defined __USE_ISOC11 && !defined __cplusplus +# undef static_assert +# define static_assert _Static_assert +#endif -- 2.36.1

2 1

[PATCH] inet: gethostid: only accept v4 addresses
by наб 20 Jun '22

20 Jun '22

getaddrinfo() returns addresses from, at least, ip(7) and ipv6(7), but _addr() always uses sin_addr from struct sockaddr_in; we're saved from wild unsoundness (or incompatibility) by virtue of struct sockaddr_in6 having an always-0 u32 sin6_flowinfo at the same offset, so we end up returning 0 anyway, but in a round-about and definitely unintended way Instead, limit the request to AF_INET, and fall through to the end early, returning the default id=0 --- diff -ur uClibc-ng-1.0.41.orig/libc/inet/hostid.c uClibc-ng-1.0.41/libc/inet/hostid.c --- uClibc-ng-1.0.41.orig/libc/inet/hostid.c 2022-05-20 17:07:47.000000000 +0200 +++ uClibc-ng-1.0.41/libc/inet/hostid.c 2022-06-01 19:09:21.971253011 +0200 @@ -61,8 +61,7 @@ * Mitch */ if (gethostname(host, HOST_NAME_MAX) >= 0 && *host) { - struct addrinfo hints, *results, *addr; - memset(&hints, 0, sizeof(struct addrinfo)); + struct addrinfo hints = {.ai_family = AF_INET}, *results, *addr; if (!getaddrinfo(host, NULL, &hints, &results)) { for (addr = results; addr; addr = results->ai_next) { /* Just so it doesn't look exactly like the

2 1

[PATCH v3] xtensa: implement user context manipulation functions
by Max Filippov 20 Jun '22

20 Jun '22

Implement getcontext, makecontext, setcontext and swapcontext. Signed-off-by: Max Filippov <jcmvbkbc(a)gmail.com> --- Changes v2->v3: - use explicit SIG_BLOCK in getcontext instead of 0 Changes v1->v2: - drop wrong comment from __start_context extra/Configs/Config.xtensa | 3 +- libc/sysdeps/linux/xtensa/Makefile.arch | 3 + libc/sysdeps/linux/xtensa/__start_context.S | 100 +++++++++++ libc/sysdeps/linux/xtensa/getcontext.S | 99 +++++++++++ libc/sysdeps/linux/xtensa/makecontext.c | 179 ++++++++++++++++++++ libc/sysdeps/linux/xtensa/setcontext.S | 116 +++++++++++++ libc/sysdeps/linux/xtensa/swapcontext.S | 173 +++++++++++++++++++ libc/sysdeps/linux/xtensa/sysdep.h | 7 +- libc/sysdeps/linux/xtensa/ucontext_i.sym | 15 ++ 9 files changed, 692 insertions(+), 3 deletions(-) create mode 100644 libc/sysdeps/linux/xtensa/__start_context.S create mode 100644 libc/sysdeps/linux/xtensa/getcontext.S create mode 100644 libc/sysdeps/linux/xtensa/makecontext.c create mode 100644 libc/sysdeps/linux/xtensa/setcontext.S create mode 100644 libc/sysdeps/linux/xtensa/swapcontext.S create mode 100644 libc/sysdeps/linux/xtensa/ucontext_i.sym diff --git a/extra/Configs/Config.xtensa b/extra/Configs/Config.xtensa index 3ee8817ba1a2..7316c542d896 100644 --- a/extra/Configs/Config.xtensa +++ b/extra/Configs/Config.xtensa @@ -10,5 +10,6 @@ config TARGET_ARCH config FORCE_OPTIONS_FOR_ARCH bool default y - select ARCH_HAS_DEPRECATED_SYSCALLS select ARCH_ANY_ENDIAN + select ARCH_HAS_DEPRECATED_SYSCALLS + select ARCH_HAS_UCONTEXT diff --git a/libc/sysdeps/linux/xtensa/Makefile.arch b/libc/sysdeps/linux/xtensa/Makefile.arch index 23cd08ee5687..f3a93caaafb1 100644 --- a/libc/sysdeps/linux/xtensa/Makefile.arch +++ b/libc/sysdeps/linux/xtensa/Makefile.arch @@ -10,3 +10,6 @@ SSRC-y := bsd-_setjmp.S bsd-setjmp.S setjmp.S clone.S \ sigrestorer.S syscall.S mmap.S windowspill.S __longjmp.S vfork.S CSRC-$(if $(UCLIBC_HAS_THREADS_NATIVE),,y) += fork.c + +CSRC-$(UCLIBC_HAS_CONTEXT_FUNCS) += makecontext.c +SSRC-$(UCLIBC_HAS_CONTEXT_FUNCS) += setcontext.S getcontext.S swapcontext.S __start_context.S diff --git a/libc/sysdeps/linux/xtensa/__start_context.S b/libc/sysdeps/linux/xtensa/__start_context.S new file mode 100644 index 000000000000..a30d7b6188ad --- /dev/null +++ b/libc/sysdeps/linux/xtensa/__start_context.S @@ -0,0 +1,100 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +#if defined(__XTENSA_CALL0_ABI__) +/* + * There's no entry instruction, makecontext sets up ucontext_t as if + * getcontext was called above and is about to return here. + * Registers on entry to this function: + * a12: func to call + * a13: ucp->uc_link, next context to activate if func returns + * a14: func argc + */ + .literal_position + +ENTRY_PREFIX(__start_context) + + beqz a14, 1f + + /* load func arguments 0..1 from stack and free that space */ + l32i a2, a1, 8 + l32i a3, a1, 12 + addi a1, a1, 16 + bltui a14, 3, 1f + + /* load func arguments 2..5 from stack and free that space */ + l32i a4, a1, 0 + l32i a5, a1, 4 + l32i a6, a1, 8 + l32i a7, a1, 12 + addi a1, a1, 16 + /* func arguments 6..argc - 1 are now at the top of the stack */ +1: + callx0 a12 + beqz a13, 1f + mov a2, a13 + movi a4, JUMPTARGET (setcontext) + callx0 a4 +1: + movi a4, JUMPTARGET (_exit) + movi a2, 0 + callx0 a4 + ill +END(__start_context) +#elif defined(__XTENSA_WINDOWED_ABI__) +/* + * There's no entry instruction, makecontext sets up ucontext_t as if + * getcontext was called above and is about to return here. + * Registers on entry to this function: + * a2: func to call + * a3: ucp->uc_link, next context to activate if func returns + * a4: func argc + * a5..a7: func arguments 0..2 + */ + .literal_position + +ENTRY_PREFIX(__start_context) + + mov a10, a5 + mov a11, a6 + mov a12, a7 + bltui a4, 4, 1f + + /* load func arguments 3..5 from stack and free that space */ + l32i a13, a1, 4 + l32i a14, a1, 8 + l32i a15, a1, 12 + addi a5, a1, 16 + movsp a1, a5 + /* func arguments 6..argc - 1 are now at the top of the stack */ +1: + callx8 a2 + beqz a3, 1f + mov a6, a3 + movi a4, JUMPTARGET (setcontext) + callx4 a4 +1: + movi a4, JUMPTARGET (_exit) + movi a6, 0 + callx4 a4 + ill +END(__start_context) +#else +#error Unsupported Xtensa ABI +#endif diff --git a/libc/sysdeps/linux/xtensa/getcontext.S b/libc/sysdeps/linux/xtensa/getcontext.S new file mode 100644 index 000000000000..7588a91b33b3 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/getcontext.S @@ -0,0 +1,99 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "ucontext_i.h" + +#if defined(__XTENSA_CALL0_ABI__) +ENTRY(__getcontext) + s32i a0, a2, MCONTEXT_SC_PC + s32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* save callee-saved registers in the context */ + s32i a12, a2, MCONTEXT_SC_A_0 + 48 + s32i a13, a2, MCONTEXT_SC_A_0 + 52 + s32i a14, a2, MCONTEXT_SC_A_0 + 56 + s32i a15, a2, MCONTEXT_SC_A_0 + 60 + + movi a3, 0 + addi a4, a2, UCONTEXT_SIGMASK + movi a2, SIG_BLOCK + movi a5, JUMPTARGET (sigprocmask) + jx a5 +END(__getcontext) +#elif defined(__XTENSA_WINDOWED_ABI__) +ENTRY(__getcontext) + movi a4, __window_spill + callx4 a4 + s32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 from spill area */ + addi a3, a1, -16 + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 0 + s32i a5, a2, MCONTEXT_SC_A_0 + 4 + s32i a6, a2, MCONTEXT_SC_A_0 + 8 + s32i a7, a2, MCONTEXT_SC_A_0 + 12 + + /* if it was call4 then register saving is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 from spill overflow area */ + addi a3, a3, -16 + l32i a4, a3, 16 + l32i a5, a3, 20 + l32i a6, a3, 24 + l32i a7, a3, 28 + s32i a4, a2, MCONTEXT_SC_A_0 + 32 + s32i a5, a2, MCONTEXT_SC_A_0 + 36 + s32i a6, a2, MCONTEXT_SC_A_0 + 40 + s32i a7, a2, MCONTEXT_SC_A_0 + 44 + + /* copy registers a4..a7 from spill overflow area */ +2: + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 16 + s32i a5, a2, MCONTEXT_SC_A_0 + 20 + s32i a6, a2, MCONTEXT_SC_A_0 + 24 + s32i a7, a2, MCONTEXT_SC_A_0 + 28 +1: + movi a6, SIG_BLOCK + movi a7, 0 + addi a8, a2, UCONTEXT_SIGMASK + movi a4, JUMPTARGET (sigprocmask) + callx4 a4 + mov a2, a6 + retw +END(__getcontext) +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__getcontext, getcontext) diff --git a/libc/sysdeps/linux/xtensa/makecontext.c b/libc/sysdeps/linux/xtensa/makecontext.c new file mode 100644 index 000000000000..da26a0130325 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/makecontext.c @@ -0,0 +1,179 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include <stdarg.h> +#include <stdint.h> +#include <string.h> +#include <ucontext.h> + +extern void __start_context (void); + +#if defined(__XTENSA_CALL0_ABI__) +/* + * makecontext sets up new stack like this: + * + * +------------------ stack top (uc_stack.ss_sp + uc_stack.ss_size) + * | optional alignment + * +------------------ CFA of __start_context, initial sp points here + * | optional padding + * +------------------ Optional arguments 6..argc - 1 + * | func arg argc - 1 + * | func arg argc - 2 + * | ... + * | func arg 6 + * +------------------ Optional arguments 2..5 + * | func arg 5 + * 16 | func arg 4 + * | func arg 3 + * | func arg 2 + * +------------------ Optional arguments 0..1 + * | func arg 1 + * 16 | func arg 0 + * | padding + * | padding + * +------------------ CFA of pseudo getcontext + * | + * +------------------ stack bottom (uc_stack.ss_sp) + * + * When argc is 0 arguments areas are not allocated, + * when 1 <= argc < 3 only area for arguments 0..1 is allocated, + * when 3 <= argc < 7 areas for arguments 0..1 and 2..5 is allocated, + * when argc >= 7 all three arguments areas are allocated. + * Arguments 0..5 area is deallocated by the __start_context after + * arguments are loaded into registers. + * uc_mcontext registers are set as if __start_context made call0 + * to getcontext, sp points to that pseudo getcontext CFA. + * setcontext/swapcontext will arrange for restoring regiters + * a1, a12..a15 of __start_context. + */ + +void +__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) +{ + unsigned long sp = ((unsigned long) ucp->uc_stack.ss_sp + + ucp->uc_stack.ss_size) & -16; + int i; + + if (argc > 0) + sp -= 4 * (argc + 2); + sp &= -16; + + ucp->uc_mcontext.sc_pc = (unsigned long) __start_context; + ucp->uc_mcontext.sc_a[1] = sp; + ucp->uc_mcontext.sc_a[12] = (unsigned long) func; + ucp->uc_mcontext.sc_a[13] = (unsigned long) ucp->uc_link; + ucp->uc_mcontext.sc_a[14] = argc; + + if (argc) + { + va_list ap; + + va_start (ap, argc); + for (i = 0; i < argc; ++i) + ((int *) sp)[i + 2] = va_arg (ap, int); + va_end (ap); + } +} +#elif defined(__XTENSA_WINDOWED_ABI__) +/* + * makecontext sets up new stack like this: + * + * +------------------ stack top (uc_stack.ss_sp + uc_stack.ss_size) + * | optional alignment + * +------------------ CFA of __start_context + * 16 | Outermost caller spill area + * +------------------ + * 16 | __start_context overflow area + * +------------------ initial sp points here + * | optional padding + * +------------------ Optional arguments 6..argc - 1 + * | func arg argc - 1 + * | func arg argc - 2 + * | ... + * | func arg 6 + * +------------------ Optional arguments 3..5 + * | func arg 5 + * 16 | func arg 4 + * | func arg 3 + * | padding + * +------------------ CFA of pseudo getcontext + * 16 | __start_context caller spill area + * +------------------ + * | + * +------------------ stack bottom (uc_stack.ss_sp) + * + * When argc < 4 both arguments areas are not allocated, + * when 4 <= argc < 7 only area for arguments 3..5 is allocated, + * when argc >= 7 both arguments areas are allocated. + * Arguments 3..5 area is deallocated by the __start_context after + * arguments are loaded into registers. + * uc_mcontext registers are set as if __start_context made call8 + * to getcontext, sp points to that pseudo getcontext CFA, spill + * area under that sp has a1 pointing to the __start_context CFA + * at the top of the stack. setcontext/swapcontext will arrange for + * restoring regiters a0..a7 of __start_context. + */ + +void +__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) +{ + unsigned long sp = ((unsigned long) ucp->uc_stack.ss_sp + + ucp->uc_stack.ss_size - 32) & -16; + unsigned long spill0[4] = + { + 0, sp + 32, 0, 0, + }; + int i; + + memset ((void *) sp, 0, 32); + + if (argc > 2) + sp -= 4 * (argc - 2); + sp &= -16; + + ucp->uc_mcontext.sc_pc = + ((unsigned long) __start_context & 0x3fffffff) + 0x80000000; + ucp->uc_mcontext.sc_a[0] = 0; + ucp->uc_mcontext.sc_a[1] = sp; + ucp->uc_mcontext.sc_a[2] = (unsigned long) func; + ucp->uc_mcontext.sc_a[3] = (unsigned long) ucp->uc_link; + ucp->uc_mcontext.sc_a[4] = argc; + + if (argc) + { + va_list ap; + + va_start (ap, argc); + for (i = 0; i < argc; ++i) + { + if (i < 3) + ucp->uc_mcontext.sc_a[5 + i] = va_arg (ap, int); + else + ((int *) sp)[i - 2] = va_arg (ap, int); + } + va_end (ap); + } + + sp -= 16; + memcpy ((void *) sp, spill0, sizeof (spill0)); +} +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__makecontext, makecontext) diff --git a/libc/sysdeps/linux/xtensa/setcontext.S b/libc/sysdeps/linux/xtensa/setcontext.S new file mode 100644 index 000000000000..4df7cc049006 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/setcontext.S @@ -0,0 +1,116 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "ucontext_i.h" + +#if defined(__XTENSA_CALL0_ABI__) +ENTRY(__setcontext) + addi sp, sp, -16 + s32i a0, sp, 0 + s32i a2, sp, 4 + + addi a3, a2, UCONTEXT_SIGMASK + movi a4, 0 + movi a2, SIG_SETMASK + movi a5, JUMPTARGET (sigprocmask) + callx0 a5 + bnez a2, .Lerror + + l32i a2, sp, 4 + l32i a0, a2, MCONTEXT_SC_PC + l32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* load callee-saved registers from the context */ + l32i a12, a2, MCONTEXT_SC_A_0 + 48 + l32i a13, a2, MCONTEXT_SC_A_0 + 52 + l32i a14, a2, MCONTEXT_SC_A_0 + 56 + l32i a15, a2, MCONTEXT_SC_A_0 + 60 + movi a2, 0 + ret +.Lerror: + l32i a0, sp, 0 + addi sp, sp, 16 + ret +END(__setcontext) +#elif defined(__XTENSA_WINDOWED_ABI__) +ENTRY(__setcontext) + movi a6, SIG_SETMASK + addi a7, a2, UCONTEXT_SIGMASK + movi a8, 0 + movi a4, JUMPTARGET (sigprocmask) + callx4 a4 + bnez a6, .Lerror + movi a4, __window_spill + callx4 a4 + + l32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 to spill area */ + addi a3, a1, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 0 + l32i a5, a2, MCONTEXT_SC_A_0 + 4 + l32i a6, a2, MCONTEXT_SC_A_0 + 8 + l32i a7, a2, MCONTEXT_SC_A_0 + 12 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 + + /* if it was call4 then register setup is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 to spill overflow area */ + addi a3, a3, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 32 + l32i a5, a2, MCONTEXT_SC_A_0 + 36 + l32i a6, a2, MCONTEXT_SC_A_0 + 40 + l32i a7, a2, MCONTEXT_SC_A_0 + 44 + s32i a4, a3, 16 + s32i a5, a3, 20 + s32i a6, a3, 24 + s32i a7, a3, 28 + + /* copy registers a4..a7 to spill overflow area */ +2: + l32i a4, a2, MCONTEXT_SC_A_0 + 16 + l32i a5, a2, MCONTEXT_SC_A_0 + 20 + l32i a6, a2, MCONTEXT_SC_A_0 + 24 + l32i a7, a2, MCONTEXT_SC_A_0 + 28 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 +1: + movi a2, 0 + retw +.Lerror: + mov a2, a6 + retw +END(__setcontext) +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__setcontext, setcontext) diff --git a/libc/sysdeps/linux/xtensa/swapcontext.S b/libc/sysdeps/linux/xtensa/swapcontext.S new file mode 100644 index 000000000000..a215edc6d54a --- /dev/null +++ b/libc/sysdeps/linux/xtensa/swapcontext.S @@ -0,0 +1,173 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "ucontext_i.h" + +#if defined(__XTENSA_CALL0_ABI__) +ENTRY(__swapcontext) + s32i a0, a2, MCONTEXT_SC_PC + s32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* save callee-saved registers in the context */ + s32i a12, a2, MCONTEXT_SC_A_0 + 48 + s32i a13, a2, MCONTEXT_SC_A_0 + 52 + s32i a14, a2, MCONTEXT_SC_A_0 + 56 + s32i a15, a2, MCONTEXT_SC_A_0 + 60 + + mov a12, a3 + mov a13, a2 + + addi a3, a3, UCONTEXT_SIGMASK + addi a4, a2, UCONTEXT_SIGMASK + movi a2, SIG_SETMASK + movi a5, JUMPTARGET (sigprocmask) + callx0 a5 + bnez a2, .Lerror + + mov a2, a12 + l32i a0, a2, MCONTEXT_SC_PC + l32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* load callee-saved registers from the context */ + l32i a12, a2, MCONTEXT_SC_A_0 + 48 + l32i a13, a2, MCONTEXT_SC_A_0 + 52 + l32i a14, a2, MCONTEXT_SC_A_0 + 56 + l32i a15, a2, MCONTEXT_SC_A_0 + 60 + + movi a2, 0 + ret +.Lerror: + l32i a0, a13, MCONTEXT_SC_PC + l32i a12, a13, MCONTEXT_SC_A_0 + 48 + l32i a13, a13, MCONTEXT_SC_A_0 + 52 + ret +END(__swapcontext) +#elif defined(__XTENSA_WINDOWED_ABI__) +ENTRY(__swapcontext) + movi a4, __window_spill + callx4 a4 + mov a9, a3 + s32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 from spill area */ + addi a3, a1, -16 + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 0 + s32i a5, a2, MCONTEXT_SC_A_0 + 4 + s32i a6, a2, MCONTEXT_SC_A_0 + 8 + s32i a7, a2, MCONTEXT_SC_A_0 + 12 + + /* if it was call4 then register saving is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 from spill overflow area */ + addi a3, a3, -16 + l32i a4, a3, 16 + l32i a5, a3, 20 + l32i a6, a3, 24 + l32i a7, a3, 28 + s32i a4, a2, MCONTEXT_SC_A_0 + 32 + s32i a5, a2, MCONTEXT_SC_A_0 + 36 + s32i a6, a2, MCONTEXT_SC_A_0 + 40 + s32i a7, a2, MCONTEXT_SC_A_0 + 44 + + /* copy registers a4..a7 from spill overflow area */ +2: + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 16 + s32i a5, a2, MCONTEXT_SC_A_0 + 20 + s32i a6, a2, MCONTEXT_SC_A_0 + 24 + s32i a7, a2, MCONTEXT_SC_A_0 + 28 +1: + movi a6, SIG_SETMASK + addi a7, a9, UCONTEXT_SIGMASK + addi a8, a2, UCONTEXT_SIGMASK + mov a2, a9 + movi a4, JUMPTARGET (sigprocmask) + callx4 a4 + bnez a6, .Lerror + + l32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 to spill area */ + addi a3, a1, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 0 + l32i a5, a2, MCONTEXT_SC_A_0 + 4 + l32i a6, a2, MCONTEXT_SC_A_0 + 8 + l32i a7, a2, MCONTEXT_SC_A_0 + 12 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 + + /* if it was call4 then register setup is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 to spill overflow area */ + addi a3, a3, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 32 + l32i a5, a2, MCONTEXT_SC_A_0 + 36 + l32i a6, a2, MCONTEXT_SC_A_0 + 40 + l32i a7, a2, MCONTEXT_SC_A_0 + 44 + s32i a4, a3, 16 + s32i a5, a3, 20 + s32i a6, a3, 24 + s32i a7, a3, 28 + + /* copy registers a4..a7 to spill overflow area */ +2: + l32i a4, a2, MCONTEXT_SC_A_0 + 16 + l32i a5, a2, MCONTEXT_SC_A_0 + 20 + l32i a6, a2, MCONTEXT_SC_A_0 + 24 + l32i a7, a2, MCONTEXT_SC_A_0 + 28 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 +1: + movi a2, 0 + retw +.Lerror: + mov a2, a6 + retw +END(__swapcontext) +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__swapcontext, swapcontext) diff --git a/libc/sysdeps/linux/xtensa/sysdep.h b/libc/sysdeps/linux/xtensa/sysdep.h index 0671f0783477..80b3f30fcc5d 100644 --- a/libc/sysdeps/linux/xtensa/sysdep.h +++ b/libc/sysdeps/linux/xtensa/sysdep.h @@ -39,12 +39,15 @@ #endif -#define ENTRY(name) \ +#define ENTRY_PREFIX(name) \ .globl C_SYMBOL_NAME(name); \ ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name), @function); \ .align ALIGNARG(2); \ LITERAL_POSITION; \ - C_LABEL(name) \ + C_LABEL(name) + +#define ENTRY(name) \ + ENTRY_PREFIX(name) \ abi_entry(sp, FRAMESIZE); #define HIDDEN_ENTRY(name) \ diff --git a/libc/sysdeps/linux/xtensa/ucontext_i.sym b/libc/sysdeps/linux/xtensa/ucontext_i.sym new file mode 100644 index 000000000000..4770c36c9e1d --- /dev/null +++ b/libc/sysdeps/linux/xtensa/ucontext_i.sym @@ -0,0 +1,15 @@ +#include <inttypes.h> +#include <signal.h> +#include <stddef.h> +#include <sys/ucontext.h> + +SIG_BLOCK +SIG_SETMASK + +-- Offsets of the fields in the ucontext_t structure. +#define ucontext(member) offsetof (ucontext_t, member) +#define mcontext(member) ucontext (uc_mcontext.member) + +UCONTEXT_SIGMASK ucontext (uc_sigmask) +MCONTEXT_SC_A_0 mcontext (sc_a[0]) +MCONTEXT_SC_PC mcontext (sc_pc) -- 2.30.2

2 1

[PATCH v2] xtensa: implement user context manipulation functions
by Max Filippov 17 Jun '22

17 Jun '22

Implement getcontext, makecontext, setcontext and swapcontext. Signed-off-by: Max Filippov <jcmvbkbc(a)gmail.com> --- Changes v1->v2: - drop wrong comment from __start_context extra/Configs/Config.xtensa | 3 +- libc/sysdeps/linux/xtensa/Makefile.arch | 3 + libc/sysdeps/linux/xtensa/__start_context.S | 100 +++++++++++ libc/sysdeps/linux/xtensa/getcontext.S | 99 +++++++++++ libc/sysdeps/linux/xtensa/makecontext.c | 179 ++++++++++++++++++++ libc/sysdeps/linux/xtensa/setcontext.S | 116 +++++++++++++ libc/sysdeps/linux/xtensa/swapcontext.S | 173 +++++++++++++++++++ libc/sysdeps/linux/xtensa/sysdep.h | 7 +- libc/sysdeps/linux/xtensa/ucontext_i.sym | 15 ++ 9 files changed, 692 insertions(+), 3 deletions(-) create mode 100644 libc/sysdeps/linux/xtensa/__start_context.S create mode 100644 libc/sysdeps/linux/xtensa/getcontext.S create mode 100644 libc/sysdeps/linux/xtensa/makecontext.c create mode 100644 libc/sysdeps/linux/xtensa/setcontext.S create mode 100644 libc/sysdeps/linux/xtensa/swapcontext.S create mode 100644 libc/sysdeps/linux/xtensa/ucontext_i.sym diff --git a/extra/Configs/Config.xtensa b/extra/Configs/Config.xtensa index 3ee8817ba1a2..7316c542d896 100644 --- a/extra/Configs/Config.xtensa +++ b/extra/Configs/Config.xtensa @@ -10,5 +10,6 @@ config TARGET_ARCH config FORCE_OPTIONS_FOR_ARCH bool default y - select ARCH_HAS_DEPRECATED_SYSCALLS select ARCH_ANY_ENDIAN + select ARCH_HAS_DEPRECATED_SYSCALLS + select ARCH_HAS_UCONTEXT diff --git a/libc/sysdeps/linux/xtensa/Makefile.arch b/libc/sysdeps/linux/xtensa/Makefile.arch index 23cd08ee5687..f3a93caaafb1 100644 --- a/libc/sysdeps/linux/xtensa/Makefile.arch +++ b/libc/sysdeps/linux/xtensa/Makefile.arch @@ -10,3 +10,6 @@ SSRC-y := bsd-_setjmp.S bsd-setjmp.S setjmp.S clone.S \ sigrestorer.S syscall.S mmap.S windowspill.S __longjmp.S vfork.S CSRC-$(if $(UCLIBC_HAS_THREADS_NATIVE),,y) += fork.c + +CSRC-$(UCLIBC_HAS_CONTEXT_FUNCS) += makecontext.c +SSRC-$(UCLIBC_HAS_CONTEXT_FUNCS) += setcontext.S getcontext.S swapcontext.S __start_context.S diff --git a/libc/sysdeps/linux/xtensa/__start_context.S b/libc/sysdeps/linux/xtensa/__start_context.S new file mode 100644 index 000000000000..a30d7b6188ad --- /dev/null +++ b/libc/sysdeps/linux/xtensa/__start_context.S @@ -0,0 +1,100 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +#if defined(__XTENSA_CALL0_ABI__) +/* + * There's no entry instruction, makecontext sets up ucontext_t as if + * getcontext was called above and is about to return here. + * Registers on entry to this function: + * a12: func to call + * a13: ucp->uc_link, next context to activate if func returns + * a14: func argc + */ + .literal_position + +ENTRY_PREFIX(__start_context) + + beqz a14, 1f + + /* load func arguments 0..1 from stack and free that space */ + l32i a2, a1, 8 + l32i a3, a1, 12 + addi a1, a1, 16 + bltui a14, 3, 1f + + /* load func arguments 2..5 from stack and free that space */ + l32i a4, a1, 0 + l32i a5, a1, 4 + l32i a6, a1, 8 + l32i a7, a1, 12 + addi a1, a1, 16 + /* func arguments 6..argc - 1 are now at the top of the stack */ +1: + callx0 a12 + beqz a13, 1f + mov a2, a13 + movi a4, JUMPTARGET (setcontext) + callx0 a4 +1: + movi a4, JUMPTARGET (_exit) + movi a2, 0 + callx0 a4 + ill +END(__start_context) +#elif defined(__XTENSA_WINDOWED_ABI__) +/* + * There's no entry instruction, makecontext sets up ucontext_t as if + * getcontext was called above and is about to return here. + * Registers on entry to this function: + * a2: func to call + * a3: ucp->uc_link, next context to activate if func returns + * a4: func argc + * a5..a7: func arguments 0..2 + */ + .literal_position + +ENTRY_PREFIX(__start_context) + + mov a10, a5 + mov a11, a6 + mov a12, a7 + bltui a4, 4, 1f + + /* load func arguments 3..5 from stack and free that space */ + l32i a13, a1, 4 + l32i a14, a1, 8 + l32i a15, a1, 12 + addi a5, a1, 16 + movsp a1, a5 + /* func arguments 6..argc - 1 are now at the top of the stack */ +1: + callx8 a2 + beqz a3, 1f + mov a6, a3 + movi a4, JUMPTARGET (setcontext) + callx4 a4 +1: + movi a4, JUMPTARGET (_exit) + movi a6, 0 + callx4 a4 + ill +END(__start_context) +#else +#error Unsupported Xtensa ABI +#endif diff --git a/libc/sysdeps/linux/xtensa/getcontext.S b/libc/sysdeps/linux/xtensa/getcontext.S new file mode 100644 index 000000000000..fbb70c3f8720 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/getcontext.S @@ -0,0 +1,99 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "ucontext_i.h" + +#if defined(__XTENSA_CALL0_ABI__) +ENTRY(__getcontext) + s32i a0, a2, MCONTEXT_SC_PC + s32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* save callee-saved registers in the context */ + s32i a12, a2, MCONTEXT_SC_A_0 + 48 + s32i a13, a2, MCONTEXT_SC_A_0 + 52 + s32i a14, a2, MCONTEXT_SC_A_0 + 56 + s32i a15, a2, MCONTEXT_SC_A_0 + 60 + + movi a3, 0 + addi a4, a2, UCONTEXT_SIGMASK + movi a2, 0 + movi a5, JUMPTARGET (sigprocmask) + jx a5 +END(__getcontext) +#elif defined(__XTENSA_WINDOWED_ABI__) +ENTRY(__getcontext) + movi a4, __window_spill + callx4 a4 + s32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 from spill area */ + addi a3, a1, -16 + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 0 + s32i a5, a2, MCONTEXT_SC_A_0 + 4 + s32i a6, a2, MCONTEXT_SC_A_0 + 8 + s32i a7, a2, MCONTEXT_SC_A_0 + 12 + + /* if it was call4 then register saving is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 from spill overflow area */ + addi a3, a3, -16 + l32i a4, a3, 16 + l32i a5, a3, 20 + l32i a6, a3, 24 + l32i a7, a3, 28 + s32i a4, a2, MCONTEXT_SC_A_0 + 32 + s32i a5, a2, MCONTEXT_SC_A_0 + 36 + s32i a6, a2, MCONTEXT_SC_A_0 + 40 + s32i a7, a2, MCONTEXT_SC_A_0 + 44 + + /* copy registers a4..a7 from spill overflow area */ +2: + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 16 + s32i a5, a2, MCONTEXT_SC_A_0 + 20 + s32i a6, a2, MCONTEXT_SC_A_0 + 24 + s32i a7, a2, MCONTEXT_SC_A_0 + 28 +1: + movi a6, 0 + movi a7, 0 + addi a8, a2, UCONTEXT_SIGMASK + movi a4, JUMPTARGET (sigprocmask) + callx4 a4 + mov a2, a6 + retw +END(__getcontext) +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__getcontext, getcontext) diff --git a/libc/sysdeps/linux/xtensa/makecontext.c b/libc/sysdeps/linux/xtensa/makecontext.c new file mode 100644 index 000000000000..da26a0130325 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/makecontext.c @@ -0,0 +1,179 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include <stdarg.h> +#include <stdint.h> +#include <string.h> +#include <ucontext.h> + +extern void __start_context (void); + +#if defined(__XTENSA_CALL0_ABI__) +/* + * makecontext sets up new stack like this: + * + * +------------------ stack top (uc_stack.ss_sp + uc_stack.ss_size) + * | optional alignment + * +------------------ CFA of __start_context, initial sp points here + * | optional padding + * +------------------ Optional arguments 6..argc - 1 + * | func arg argc - 1 + * | func arg argc - 2 + * | ... + * | func arg 6 + * +------------------ Optional arguments 2..5 + * | func arg 5 + * 16 | func arg 4 + * | func arg 3 + * | func arg 2 + * +------------------ Optional arguments 0..1 + * | func arg 1 + * 16 | func arg 0 + * | padding + * | padding + * +------------------ CFA of pseudo getcontext + * | + * +------------------ stack bottom (uc_stack.ss_sp) + * + * When argc is 0 arguments areas are not allocated, + * when 1 <= argc < 3 only area for arguments 0..1 is allocated, + * when 3 <= argc < 7 areas for arguments 0..1 and 2..5 is allocated, + * when argc >= 7 all three arguments areas are allocated. + * Arguments 0..5 area is deallocated by the __start_context after + * arguments are loaded into registers. + * uc_mcontext registers are set as if __start_context made call0 + * to getcontext, sp points to that pseudo getcontext CFA. + * setcontext/swapcontext will arrange for restoring regiters + * a1, a12..a15 of __start_context. + */ + +void +__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) +{ + unsigned long sp = ((unsigned long) ucp->uc_stack.ss_sp + + ucp->uc_stack.ss_size) & -16; + int i; + + if (argc > 0) + sp -= 4 * (argc + 2); + sp &= -16; + + ucp->uc_mcontext.sc_pc = (unsigned long) __start_context; + ucp->uc_mcontext.sc_a[1] = sp; + ucp->uc_mcontext.sc_a[12] = (unsigned long) func; + ucp->uc_mcontext.sc_a[13] = (unsigned long) ucp->uc_link; + ucp->uc_mcontext.sc_a[14] = argc; + + if (argc) + { + va_list ap; + + va_start (ap, argc); + for (i = 0; i < argc; ++i) + ((int *) sp)[i + 2] = va_arg (ap, int); + va_end (ap); + } +} +#elif defined(__XTENSA_WINDOWED_ABI__) +/* + * makecontext sets up new stack like this: + * + * +------------------ stack top (uc_stack.ss_sp + uc_stack.ss_size) + * | optional alignment + * +------------------ CFA of __start_context + * 16 | Outermost caller spill area + * +------------------ + * 16 | __start_context overflow area + * +------------------ initial sp points here + * | optional padding + * +------------------ Optional arguments 6..argc - 1 + * | func arg argc - 1 + * | func arg argc - 2 + * | ... + * | func arg 6 + * +------------------ Optional arguments 3..5 + * | func arg 5 + * 16 | func arg 4 + * | func arg 3 + * | padding + * +------------------ CFA of pseudo getcontext + * 16 | __start_context caller spill area + * +------------------ + * | + * +------------------ stack bottom (uc_stack.ss_sp) + * + * When argc < 4 both arguments areas are not allocated, + * when 4 <= argc < 7 only area for arguments 3..5 is allocated, + * when argc >= 7 both arguments areas are allocated. + * Arguments 3..5 area is deallocated by the __start_context after + * arguments are loaded into registers. + * uc_mcontext registers are set as if __start_context made call8 + * to getcontext, sp points to that pseudo getcontext CFA, spill + * area under that sp has a1 pointing to the __start_context CFA + * at the top of the stack. setcontext/swapcontext will arrange for + * restoring regiters a0..a7 of __start_context. + */ + +void +__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) +{ + unsigned long sp = ((unsigned long) ucp->uc_stack.ss_sp + + ucp->uc_stack.ss_size - 32) & -16; + unsigned long spill0[4] = + { + 0, sp + 32, 0, 0, + }; + int i; + + memset ((void *) sp, 0, 32); + + if (argc > 2) + sp -= 4 * (argc - 2); + sp &= -16; + + ucp->uc_mcontext.sc_pc = + ((unsigned long) __start_context & 0x3fffffff) + 0x80000000; + ucp->uc_mcontext.sc_a[0] = 0; + ucp->uc_mcontext.sc_a[1] = sp; + ucp->uc_mcontext.sc_a[2] = (unsigned long) func; + ucp->uc_mcontext.sc_a[3] = (unsigned long) ucp->uc_link; + ucp->uc_mcontext.sc_a[4] = argc; + + if (argc) + { + va_list ap; + + va_start (ap, argc); + for (i = 0; i < argc; ++i) + { + if (i < 3) + ucp->uc_mcontext.sc_a[5 + i] = va_arg (ap, int); + else + ((int *) sp)[i - 2] = va_arg (ap, int); + } + va_end (ap); + } + + sp -= 16; + memcpy ((void *) sp, spill0, sizeof (spill0)); +} +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__makecontext, makecontext) diff --git a/libc/sysdeps/linux/xtensa/setcontext.S b/libc/sysdeps/linux/xtensa/setcontext.S new file mode 100644 index 000000000000..4df7cc049006 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/setcontext.S @@ -0,0 +1,116 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "ucontext_i.h" + +#if defined(__XTENSA_CALL0_ABI__) +ENTRY(__setcontext) + addi sp, sp, -16 + s32i a0, sp, 0 + s32i a2, sp, 4 + + addi a3, a2, UCONTEXT_SIGMASK + movi a4, 0 + movi a2, SIG_SETMASK + movi a5, JUMPTARGET (sigprocmask) + callx0 a5 + bnez a2, .Lerror + + l32i a2, sp, 4 + l32i a0, a2, MCONTEXT_SC_PC + l32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* load callee-saved registers from the context */ + l32i a12, a2, MCONTEXT_SC_A_0 + 48 + l32i a13, a2, MCONTEXT_SC_A_0 + 52 + l32i a14, a2, MCONTEXT_SC_A_0 + 56 + l32i a15, a2, MCONTEXT_SC_A_0 + 60 + movi a2, 0 + ret +.Lerror: + l32i a0, sp, 0 + addi sp, sp, 16 + ret +END(__setcontext) +#elif defined(__XTENSA_WINDOWED_ABI__) +ENTRY(__setcontext) + movi a6, SIG_SETMASK + addi a7, a2, UCONTEXT_SIGMASK + movi a8, 0 + movi a4, JUMPTARGET (sigprocmask) + callx4 a4 + bnez a6, .Lerror + movi a4, __window_spill + callx4 a4 + + l32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 to spill area */ + addi a3, a1, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 0 + l32i a5, a2, MCONTEXT_SC_A_0 + 4 + l32i a6, a2, MCONTEXT_SC_A_0 + 8 + l32i a7, a2, MCONTEXT_SC_A_0 + 12 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 + + /* if it was call4 then register setup is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 to spill overflow area */ + addi a3, a3, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 32 + l32i a5, a2, MCONTEXT_SC_A_0 + 36 + l32i a6, a2, MCONTEXT_SC_A_0 + 40 + l32i a7, a2, MCONTEXT_SC_A_0 + 44 + s32i a4, a3, 16 + s32i a5, a3, 20 + s32i a6, a3, 24 + s32i a7, a3, 28 + + /* copy registers a4..a7 to spill overflow area */ +2: + l32i a4, a2, MCONTEXT_SC_A_0 + 16 + l32i a5, a2, MCONTEXT_SC_A_0 + 20 + l32i a6, a2, MCONTEXT_SC_A_0 + 24 + l32i a7, a2, MCONTEXT_SC_A_0 + 28 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 +1: + movi a2, 0 + retw +.Lerror: + mov a2, a6 + retw +END(__setcontext) +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__setcontext, setcontext) diff --git a/libc/sysdeps/linux/xtensa/swapcontext.S b/libc/sysdeps/linux/xtensa/swapcontext.S new file mode 100644 index 000000000000..a215edc6d54a --- /dev/null +++ b/libc/sysdeps/linux/xtensa/swapcontext.S @@ -0,0 +1,173 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "ucontext_i.h" + +#if defined(__XTENSA_CALL0_ABI__) +ENTRY(__swapcontext) + s32i a0, a2, MCONTEXT_SC_PC + s32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* save callee-saved registers in the context */ + s32i a12, a2, MCONTEXT_SC_A_0 + 48 + s32i a13, a2, MCONTEXT_SC_A_0 + 52 + s32i a14, a2, MCONTEXT_SC_A_0 + 56 + s32i a15, a2, MCONTEXT_SC_A_0 + 60 + + mov a12, a3 + mov a13, a2 + + addi a3, a3, UCONTEXT_SIGMASK + addi a4, a2, UCONTEXT_SIGMASK + movi a2, SIG_SETMASK + movi a5, JUMPTARGET (sigprocmask) + callx0 a5 + bnez a2, .Lerror + + mov a2, a12 + l32i a0, a2, MCONTEXT_SC_PC + l32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* load callee-saved registers from the context */ + l32i a12, a2, MCONTEXT_SC_A_0 + 48 + l32i a13, a2, MCONTEXT_SC_A_0 + 52 + l32i a14, a2, MCONTEXT_SC_A_0 + 56 + l32i a15, a2, MCONTEXT_SC_A_0 + 60 + + movi a2, 0 + ret +.Lerror: + l32i a0, a13, MCONTEXT_SC_PC + l32i a12, a13, MCONTEXT_SC_A_0 + 48 + l32i a13, a13, MCONTEXT_SC_A_0 + 52 + ret +END(__swapcontext) +#elif defined(__XTENSA_WINDOWED_ABI__) +ENTRY(__swapcontext) + movi a4, __window_spill + callx4 a4 + mov a9, a3 + s32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 from spill area */ + addi a3, a1, -16 + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 0 + s32i a5, a2, MCONTEXT_SC_A_0 + 4 + s32i a6, a2, MCONTEXT_SC_A_0 + 8 + s32i a7, a2, MCONTEXT_SC_A_0 + 12 + + /* if it was call4 then register saving is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 from spill overflow area */ + addi a3, a3, -16 + l32i a4, a3, 16 + l32i a5, a3, 20 + l32i a6, a3, 24 + l32i a7, a3, 28 + s32i a4, a2, MCONTEXT_SC_A_0 + 32 + s32i a5, a2, MCONTEXT_SC_A_0 + 36 + s32i a6, a2, MCONTEXT_SC_A_0 + 40 + s32i a7, a2, MCONTEXT_SC_A_0 + 44 + + /* copy registers a4..a7 from spill overflow area */ +2: + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 16 + s32i a5, a2, MCONTEXT_SC_A_0 + 20 + s32i a6, a2, MCONTEXT_SC_A_0 + 24 + s32i a7, a2, MCONTEXT_SC_A_0 + 28 +1: + movi a6, SIG_SETMASK + addi a7, a9, UCONTEXT_SIGMASK + addi a8, a2, UCONTEXT_SIGMASK + mov a2, a9 + movi a4, JUMPTARGET (sigprocmask) + callx4 a4 + bnez a6, .Lerror + + l32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 to spill area */ + addi a3, a1, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 0 + l32i a5, a2, MCONTEXT_SC_A_0 + 4 + l32i a6, a2, MCONTEXT_SC_A_0 + 8 + l32i a7, a2, MCONTEXT_SC_A_0 + 12 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 + + /* if it was call4 then register setup is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 to spill overflow area */ + addi a3, a3, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 32 + l32i a5, a2, MCONTEXT_SC_A_0 + 36 + l32i a6, a2, MCONTEXT_SC_A_0 + 40 + l32i a7, a2, MCONTEXT_SC_A_0 + 44 + s32i a4, a3, 16 + s32i a5, a3, 20 + s32i a6, a3, 24 + s32i a7, a3, 28 + + /* copy registers a4..a7 to spill overflow area */ +2: + l32i a4, a2, MCONTEXT_SC_A_0 + 16 + l32i a5, a2, MCONTEXT_SC_A_0 + 20 + l32i a6, a2, MCONTEXT_SC_A_0 + 24 + l32i a7, a2, MCONTEXT_SC_A_0 + 28 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 +1: + movi a2, 0 + retw +.Lerror: + mov a2, a6 + retw +END(__swapcontext) +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__swapcontext, swapcontext) diff --git a/libc/sysdeps/linux/xtensa/sysdep.h b/libc/sysdeps/linux/xtensa/sysdep.h index 0671f0783477..80b3f30fcc5d 100644 --- a/libc/sysdeps/linux/xtensa/sysdep.h +++ b/libc/sysdeps/linux/xtensa/sysdep.h @@ -39,12 +39,15 @@ #endif -#define ENTRY(name) \ +#define ENTRY_PREFIX(name) \ .globl C_SYMBOL_NAME(name); \ ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name), @function); \ .align ALIGNARG(2); \ LITERAL_POSITION; \ - C_LABEL(name) \ + C_LABEL(name) + +#define ENTRY(name) \ + ENTRY_PREFIX(name) \ abi_entry(sp, FRAMESIZE); #define HIDDEN_ENTRY(name) \ diff --git a/libc/sysdeps/linux/xtensa/ucontext_i.sym b/libc/sysdeps/linux/xtensa/ucontext_i.sym new file mode 100644 index 000000000000..4770c36c9e1d --- /dev/null +++ b/libc/sysdeps/linux/xtensa/ucontext_i.sym @@ -0,0 +1,15 @@ +#include <inttypes.h> +#include <signal.h> +#include <stddef.h> +#include <sys/ucontext.h> + +SIG_BLOCK +SIG_SETMASK + +-- Offsets of the fields in the ucontext_t structure. +#define ucontext(member) offsetof (ucontext_t, member) +#define mcontext(member) ucontext (uc_mcontext.member) + +UCONTEXT_SIGMASK ucontext (uc_sigmask) +MCONTEXT_SC_A_0 mcontext (sc_a[0]) +MCONTEXT_SC_PC mcontext (sc_pc) -- 2.30.2

1 0

[PATCH] xtensa: implement user context manipulation functions
by Max Filippov 17 Jun '22

17 Jun '22

Implement getcontext, makecontext, setcontext and swapcontext. Signed-off-by: Max Filippov <jcmvbkbc(a)gmail.com> --- extra/Configs/Config.xtensa | 3 +- libc/sysdeps/linux/xtensa/Makefile.arch | 3 + libc/sysdeps/linux/xtensa/__start_context.S | 103 +++++++++++ libc/sysdeps/linux/xtensa/getcontext.S | 99 +++++++++++ libc/sysdeps/linux/xtensa/makecontext.c | 179 ++++++++++++++++++++ libc/sysdeps/linux/xtensa/setcontext.S | 116 +++++++++++++ libc/sysdeps/linux/xtensa/swapcontext.S | 173 +++++++++++++++++++ libc/sysdeps/linux/xtensa/sysdep.h | 7 +- libc/sysdeps/linux/xtensa/ucontext_i.sym | 15 ++ 9 files changed, 695 insertions(+), 3 deletions(-) create mode 100644 libc/sysdeps/linux/xtensa/__start_context.S create mode 100644 libc/sysdeps/linux/xtensa/getcontext.S create mode 100644 libc/sysdeps/linux/xtensa/makecontext.c create mode 100644 libc/sysdeps/linux/xtensa/setcontext.S create mode 100644 libc/sysdeps/linux/xtensa/swapcontext.S create mode 100644 libc/sysdeps/linux/xtensa/ucontext_i.sym diff --git a/extra/Configs/Config.xtensa b/extra/Configs/Config.xtensa index 3ee8817ba1a2..7316c542d896 100644 --- a/extra/Configs/Config.xtensa +++ b/extra/Configs/Config.xtensa @@ -10,5 +10,6 @@ config TARGET_ARCH config FORCE_OPTIONS_FOR_ARCH bool default y - select ARCH_HAS_DEPRECATED_SYSCALLS select ARCH_ANY_ENDIAN + select ARCH_HAS_DEPRECATED_SYSCALLS + select ARCH_HAS_UCONTEXT diff --git a/libc/sysdeps/linux/xtensa/Makefile.arch b/libc/sysdeps/linux/xtensa/Makefile.arch index 23cd08ee5687..f3a93caaafb1 100644 --- a/libc/sysdeps/linux/xtensa/Makefile.arch +++ b/libc/sysdeps/linux/xtensa/Makefile.arch @@ -10,3 +10,6 @@ SSRC-y := bsd-_setjmp.S bsd-setjmp.S setjmp.S clone.S \ sigrestorer.S syscall.S mmap.S windowspill.S __longjmp.S vfork.S CSRC-$(if $(UCLIBC_HAS_THREADS_NATIVE),,y) += fork.c + +CSRC-$(UCLIBC_HAS_CONTEXT_FUNCS) += makecontext.c +SSRC-$(UCLIBC_HAS_CONTEXT_FUNCS) += setcontext.S getcontext.S swapcontext.S __start_context.S diff --git a/libc/sysdeps/linux/xtensa/__start_context.S b/libc/sysdeps/linux/xtensa/__start_context.S new file mode 100644 index 000000000000..f92c01112fa7 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/__start_context.S @@ -0,0 +1,103 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +#if defined(__XTENSA_CALL0_ABI__) +/* + * There's no entry instruction, makecontext sets up ucontext_t as if + * getcontext was called above and is about to return here. + * Registers on entry to this function: + * a12: func to call + * a13: ucp->uc_link, next context to activate if func returns + * a14: func argc + * a2..a4: func arguments 0..2 + * + */ + .literal_position + +ENTRY_PREFIX(__start_context) + + beqz a14, 1f + + /* load func arguments 0..1 from stack and free that space */ + l32i a2, a1, 8 + l32i a3, a1, 12 + addi a1, a1, 16 + bltui a14, 3, 1f + + /* load func arguments 2..5 from stack and free that space */ + l32i a4, a1, 0 + l32i a5, a1, 4 + l32i a6, a1, 8 + l32i a7, a1, 12 + addi a1, a1, 16 + /* func arguments 6..argc - 1 are now at the top of the stack */ +1: + callx0 a12 + beqz a13, 1f + mov a2, a13 + movi a4, JUMPTARGET (setcontext) + callx0 a4 +1: + movi a4, JUMPTARGET (_exit) + movi a2, 0 + callx0 a4 + ill +END(__start_context) +#elif defined(__XTENSA_WINDOWED_ABI__) +/* + * There's no entry instruction, makecontext sets up ucontext_t as if + * getcontext was called above and is about to return here. + * Registers on entry to this function: + * a2: func to call + * a3: ucp->uc_link, next context to activate if func returns + * a4: func argc + * a5..a7: func arguments 0..2 + * + */ + .literal_position + +ENTRY_PREFIX(__start_context) + + mov a10, a5 + mov a11, a6 + mov a12, a7 + bltui a4, 4, 1f + + /* load func arguments 3..5 from stack and free that space */ + l32i a13, a1, 4 + l32i a14, a1, 8 + l32i a15, a1, 12 + addi a5, a1, 16 + movsp a1, a5 + /* func arguments 6..argc - 1 are now at the top of the stack */ +1: + callx8 a2 + beqz a3, 1f + mov a6, a3 + movi a4, JUMPTARGET (setcontext) + callx4 a4 +1: + movi a4, JUMPTARGET (_exit) + movi a6, 0 + callx4 a4 + ill +END(__start_context) +#else +#error Unsupported Xtensa ABI +#endif diff --git a/libc/sysdeps/linux/xtensa/getcontext.S b/libc/sysdeps/linux/xtensa/getcontext.S new file mode 100644 index 000000000000..fbb70c3f8720 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/getcontext.S @@ -0,0 +1,99 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "ucontext_i.h" + +#if defined(__XTENSA_CALL0_ABI__) +ENTRY(__getcontext) + s32i a0, a2, MCONTEXT_SC_PC + s32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* save callee-saved registers in the context */ + s32i a12, a2, MCONTEXT_SC_A_0 + 48 + s32i a13, a2, MCONTEXT_SC_A_0 + 52 + s32i a14, a2, MCONTEXT_SC_A_0 + 56 + s32i a15, a2, MCONTEXT_SC_A_0 + 60 + + movi a3, 0 + addi a4, a2, UCONTEXT_SIGMASK + movi a2, 0 + movi a5, JUMPTARGET (sigprocmask) + jx a5 +END(__getcontext) +#elif defined(__XTENSA_WINDOWED_ABI__) +ENTRY(__getcontext) + movi a4, __window_spill + callx4 a4 + s32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 from spill area */ + addi a3, a1, -16 + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 0 + s32i a5, a2, MCONTEXT_SC_A_0 + 4 + s32i a6, a2, MCONTEXT_SC_A_0 + 8 + s32i a7, a2, MCONTEXT_SC_A_0 + 12 + + /* if it was call4 then register saving is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 from spill overflow area */ + addi a3, a3, -16 + l32i a4, a3, 16 + l32i a5, a3, 20 + l32i a6, a3, 24 + l32i a7, a3, 28 + s32i a4, a2, MCONTEXT_SC_A_0 + 32 + s32i a5, a2, MCONTEXT_SC_A_0 + 36 + s32i a6, a2, MCONTEXT_SC_A_0 + 40 + s32i a7, a2, MCONTEXT_SC_A_0 + 44 + + /* copy registers a4..a7 from spill overflow area */ +2: + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 16 + s32i a5, a2, MCONTEXT_SC_A_0 + 20 + s32i a6, a2, MCONTEXT_SC_A_0 + 24 + s32i a7, a2, MCONTEXT_SC_A_0 + 28 +1: + movi a6, 0 + movi a7, 0 + addi a8, a2, UCONTEXT_SIGMASK + movi a4, JUMPTARGET (sigprocmask) + callx4 a4 + mov a2, a6 + retw +END(__getcontext) +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__getcontext, getcontext) diff --git a/libc/sysdeps/linux/xtensa/makecontext.c b/libc/sysdeps/linux/xtensa/makecontext.c new file mode 100644 index 000000000000..da26a0130325 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/makecontext.c @@ -0,0 +1,179 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include <stdarg.h> +#include <stdint.h> +#include <string.h> +#include <ucontext.h> + +extern void __start_context (void); + +#if defined(__XTENSA_CALL0_ABI__) +/* + * makecontext sets up new stack like this: + * + * +------------------ stack top (uc_stack.ss_sp + uc_stack.ss_size) + * | optional alignment + * +------------------ CFA of __start_context, initial sp points here + * | optional padding + * +------------------ Optional arguments 6..argc - 1 + * | func arg argc - 1 + * | func arg argc - 2 + * | ... + * | func arg 6 + * +------------------ Optional arguments 2..5 + * | func arg 5 + * 16 | func arg 4 + * | func arg 3 + * | func arg 2 + * +------------------ Optional arguments 0..1 + * | func arg 1 + * 16 | func arg 0 + * | padding + * | padding + * +------------------ CFA of pseudo getcontext + * | + * +------------------ stack bottom (uc_stack.ss_sp) + * + * When argc is 0 arguments areas are not allocated, + * when 1 <= argc < 3 only area for arguments 0..1 is allocated, + * when 3 <= argc < 7 areas for arguments 0..1 and 2..5 is allocated, + * when argc >= 7 all three arguments areas are allocated. + * Arguments 0..5 area is deallocated by the __start_context after + * arguments are loaded into registers. + * uc_mcontext registers are set as if __start_context made call0 + * to getcontext, sp points to that pseudo getcontext CFA. + * setcontext/swapcontext will arrange for restoring regiters + * a1, a12..a15 of __start_context. + */ + +void +__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) +{ + unsigned long sp = ((unsigned long) ucp->uc_stack.ss_sp + + ucp->uc_stack.ss_size) & -16; + int i; + + if (argc > 0) + sp -= 4 * (argc + 2); + sp &= -16; + + ucp->uc_mcontext.sc_pc = (unsigned long) __start_context; + ucp->uc_mcontext.sc_a[1] = sp; + ucp->uc_mcontext.sc_a[12] = (unsigned long) func; + ucp->uc_mcontext.sc_a[13] = (unsigned long) ucp->uc_link; + ucp->uc_mcontext.sc_a[14] = argc; + + if (argc) + { + va_list ap; + + va_start (ap, argc); + for (i = 0; i < argc; ++i) + ((int *) sp)[i + 2] = va_arg (ap, int); + va_end (ap); + } +} +#elif defined(__XTENSA_WINDOWED_ABI__) +/* + * makecontext sets up new stack like this: + * + * +------------------ stack top (uc_stack.ss_sp + uc_stack.ss_size) + * | optional alignment + * +------------------ CFA of __start_context + * 16 | Outermost caller spill area + * +------------------ + * 16 | __start_context overflow area + * +------------------ initial sp points here + * | optional padding + * +------------------ Optional arguments 6..argc - 1 + * | func arg argc - 1 + * | func arg argc - 2 + * | ... + * | func arg 6 + * +------------------ Optional arguments 3..5 + * | func arg 5 + * 16 | func arg 4 + * | func arg 3 + * | padding + * +------------------ CFA of pseudo getcontext + * 16 | __start_context caller spill area + * +------------------ + * | + * +------------------ stack bottom (uc_stack.ss_sp) + * + * When argc < 4 both arguments areas are not allocated, + * when 4 <= argc < 7 only area for arguments 3..5 is allocated, + * when argc >= 7 both arguments areas are allocated. + * Arguments 3..5 area is deallocated by the __start_context after + * arguments are loaded into registers. + * uc_mcontext registers are set as if __start_context made call8 + * to getcontext, sp points to that pseudo getcontext CFA, spill + * area under that sp has a1 pointing to the __start_context CFA + * at the top of the stack. setcontext/swapcontext will arrange for + * restoring regiters a0..a7 of __start_context. + */ + +void +__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) +{ + unsigned long sp = ((unsigned long) ucp->uc_stack.ss_sp + + ucp->uc_stack.ss_size - 32) & -16; + unsigned long spill0[4] = + { + 0, sp + 32, 0, 0, + }; + int i; + + memset ((void *) sp, 0, 32); + + if (argc > 2) + sp -= 4 * (argc - 2); + sp &= -16; + + ucp->uc_mcontext.sc_pc = + ((unsigned long) __start_context & 0x3fffffff) + 0x80000000; + ucp->uc_mcontext.sc_a[0] = 0; + ucp->uc_mcontext.sc_a[1] = sp; + ucp->uc_mcontext.sc_a[2] = (unsigned long) func; + ucp->uc_mcontext.sc_a[3] = (unsigned long) ucp->uc_link; + ucp->uc_mcontext.sc_a[4] = argc; + + if (argc) + { + va_list ap; + + va_start (ap, argc); + for (i = 0; i < argc; ++i) + { + if (i < 3) + ucp->uc_mcontext.sc_a[5 + i] = va_arg (ap, int); + else + ((int *) sp)[i - 2] = va_arg (ap, int); + } + va_end (ap); + } + + sp -= 16; + memcpy ((void *) sp, spill0, sizeof (spill0)); +} +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__makecontext, makecontext) diff --git a/libc/sysdeps/linux/xtensa/setcontext.S b/libc/sysdeps/linux/xtensa/setcontext.S new file mode 100644 index 000000000000..4df7cc049006 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/setcontext.S @@ -0,0 +1,116 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "ucontext_i.h" + +#if defined(__XTENSA_CALL0_ABI__) +ENTRY(__setcontext) + addi sp, sp, -16 + s32i a0, sp, 0 + s32i a2, sp, 4 + + addi a3, a2, UCONTEXT_SIGMASK + movi a4, 0 + movi a2, SIG_SETMASK + movi a5, JUMPTARGET (sigprocmask) + callx0 a5 + bnez a2, .Lerror + + l32i a2, sp, 4 + l32i a0, a2, MCONTEXT_SC_PC + l32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* load callee-saved registers from the context */ + l32i a12, a2, MCONTEXT_SC_A_0 + 48 + l32i a13, a2, MCONTEXT_SC_A_0 + 52 + l32i a14, a2, MCONTEXT_SC_A_0 + 56 + l32i a15, a2, MCONTEXT_SC_A_0 + 60 + movi a2, 0 + ret +.Lerror: + l32i a0, sp, 0 + addi sp, sp, 16 + ret +END(__setcontext) +#elif defined(__XTENSA_WINDOWED_ABI__) +ENTRY(__setcontext) + movi a6, SIG_SETMASK + addi a7, a2, UCONTEXT_SIGMASK + movi a8, 0 + movi a4, JUMPTARGET (sigprocmask) + callx4 a4 + bnez a6, .Lerror + movi a4, __window_spill + callx4 a4 + + l32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 to spill area */ + addi a3, a1, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 0 + l32i a5, a2, MCONTEXT_SC_A_0 + 4 + l32i a6, a2, MCONTEXT_SC_A_0 + 8 + l32i a7, a2, MCONTEXT_SC_A_0 + 12 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 + + /* if it was call4 then register setup is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 to spill overflow area */ + addi a3, a3, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 32 + l32i a5, a2, MCONTEXT_SC_A_0 + 36 + l32i a6, a2, MCONTEXT_SC_A_0 + 40 + l32i a7, a2, MCONTEXT_SC_A_0 + 44 + s32i a4, a3, 16 + s32i a5, a3, 20 + s32i a6, a3, 24 + s32i a7, a3, 28 + + /* copy registers a4..a7 to spill overflow area */ +2: + l32i a4, a2, MCONTEXT_SC_A_0 + 16 + l32i a5, a2, MCONTEXT_SC_A_0 + 20 + l32i a6, a2, MCONTEXT_SC_A_0 + 24 + l32i a7, a2, MCONTEXT_SC_A_0 + 28 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 +1: + movi a2, 0 + retw +.Lerror: + mov a2, a6 + retw +END(__setcontext) +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__setcontext, setcontext) diff --git a/libc/sysdeps/linux/xtensa/swapcontext.S b/libc/sysdeps/linux/xtensa/swapcontext.S new file mode 100644 index 000000000000..a215edc6d54a --- /dev/null +++ b/libc/sysdeps/linux/xtensa/swapcontext.S @@ -0,0 +1,173 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "ucontext_i.h" + +#if defined(__XTENSA_CALL0_ABI__) +ENTRY(__swapcontext) + s32i a0, a2, MCONTEXT_SC_PC + s32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* save callee-saved registers in the context */ + s32i a12, a2, MCONTEXT_SC_A_0 + 48 + s32i a13, a2, MCONTEXT_SC_A_0 + 52 + s32i a14, a2, MCONTEXT_SC_A_0 + 56 + s32i a15, a2, MCONTEXT_SC_A_0 + 60 + + mov a12, a3 + mov a13, a2 + + addi a3, a3, UCONTEXT_SIGMASK + addi a4, a2, UCONTEXT_SIGMASK + movi a2, SIG_SETMASK + movi a5, JUMPTARGET (sigprocmask) + callx0 a5 + bnez a2, .Lerror + + mov a2, a12 + l32i a0, a2, MCONTEXT_SC_PC + l32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* load callee-saved registers from the context */ + l32i a12, a2, MCONTEXT_SC_A_0 + 48 + l32i a13, a2, MCONTEXT_SC_A_0 + 52 + l32i a14, a2, MCONTEXT_SC_A_0 + 56 + l32i a15, a2, MCONTEXT_SC_A_0 + 60 + + movi a2, 0 + ret +.Lerror: + l32i a0, a13, MCONTEXT_SC_PC + l32i a12, a13, MCONTEXT_SC_A_0 + 48 + l32i a13, a13, MCONTEXT_SC_A_0 + 52 + ret +END(__swapcontext) +#elif defined(__XTENSA_WINDOWED_ABI__) +ENTRY(__swapcontext) + movi a4, __window_spill + callx4 a4 + mov a9, a3 + s32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 from spill area */ + addi a3, a1, -16 + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 0 + s32i a5, a2, MCONTEXT_SC_A_0 + 4 + s32i a6, a2, MCONTEXT_SC_A_0 + 8 + s32i a7, a2, MCONTEXT_SC_A_0 + 12 + + /* if it was call4 then register saving is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 from spill overflow area */ + addi a3, a3, -16 + l32i a4, a3, 16 + l32i a5, a3, 20 + l32i a6, a3, 24 + l32i a7, a3, 28 + s32i a4, a2, MCONTEXT_SC_A_0 + 32 + s32i a5, a2, MCONTEXT_SC_A_0 + 36 + s32i a6, a2, MCONTEXT_SC_A_0 + 40 + s32i a7, a2, MCONTEXT_SC_A_0 + 44 + + /* copy registers a4..a7 from spill overflow area */ +2: + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 16 + s32i a5, a2, MCONTEXT_SC_A_0 + 20 + s32i a6, a2, MCONTEXT_SC_A_0 + 24 + s32i a7, a2, MCONTEXT_SC_A_0 + 28 +1: + movi a6, SIG_SETMASK + addi a7, a9, UCONTEXT_SIGMASK + addi a8, a2, UCONTEXT_SIGMASK + mov a2, a9 + movi a4, JUMPTARGET (sigprocmask) + callx4 a4 + bnez a6, .Lerror + + l32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 to spill area */ + addi a3, a1, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 0 + l32i a5, a2, MCONTEXT_SC_A_0 + 4 + l32i a6, a2, MCONTEXT_SC_A_0 + 8 + l32i a7, a2, MCONTEXT_SC_A_0 + 12 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 + + /* if it was call4 then register setup is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 to spill overflow area */ + addi a3, a3, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 32 + l32i a5, a2, MCONTEXT_SC_A_0 + 36 + l32i a6, a2, MCONTEXT_SC_A_0 + 40 + l32i a7, a2, MCONTEXT_SC_A_0 + 44 + s32i a4, a3, 16 + s32i a5, a3, 20 + s32i a6, a3, 24 + s32i a7, a3, 28 + + /* copy registers a4..a7 to spill overflow area */ +2: + l32i a4, a2, MCONTEXT_SC_A_0 + 16 + l32i a5, a2, MCONTEXT_SC_A_0 + 20 + l32i a6, a2, MCONTEXT_SC_A_0 + 24 + l32i a7, a2, MCONTEXT_SC_A_0 + 28 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 +1: + movi a2, 0 + retw +.Lerror: + mov a2, a6 + retw +END(__swapcontext) +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__swapcontext, swapcontext) diff --git a/libc/sysdeps/linux/xtensa/sysdep.h b/libc/sysdeps/linux/xtensa/sysdep.h index 0671f0783477..80b3f30fcc5d 100644 --- a/libc/sysdeps/linux/xtensa/sysdep.h +++ b/libc/sysdeps/linux/xtensa/sysdep.h @@ -39,12 +39,15 @@ #endif -#define ENTRY(name) \ +#define ENTRY_PREFIX(name) \ .globl C_SYMBOL_NAME(name); \ ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name), @function); \ .align ALIGNARG(2); \ LITERAL_POSITION; \ - C_LABEL(name) \ + C_LABEL(name) + +#define ENTRY(name) \ + ENTRY_PREFIX(name) \ abi_entry(sp, FRAMESIZE); #define HIDDEN_ENTRY(name) \ diff --git a/libc/sysdeps/linux/xtensa/ucontext_i.sym b/libc/sysdeps/linux/xtensa/ucontext_i.sym new file mode 100644 index 000000000000..4770c36c9e1d --- /dev/null +++ b/libc/sysdeps/linux/xtensa/ucontext_i.sym @@ -0,0 +1,15 @@ +#include <inttypes.h> +#include <signal.h> +#include <stddef.h> +#include <sys/ucontext.h> + +SIG_BLOCK +SIG_SETMASK + +-- Offsets of the fields in the ucontext_t structure. +#define ucontext(member) offsetof (ucontext_t, member) +#define mcontext(member) ucontext (uc_mcontext.member) + +UCONTEXT_SIGMASK ucontext (uc_sigmask) +MCONTEXT_SC_A_0 mcontext (sc_a[0]) +MCONTEXT_SC_PC mcontext (sc_pc) -- 2.30.2

1 0