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build error for x86_64 with NPTL
by Kirill Makurin 26 May '25

26 May '25

Hello, I recently tried to build uclibc-ng configured with NPTL posix threads implementation for x86_64 system. Build fails, which I believe is a bug. The error occurs when compiling `libpthread/nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S`, it takes the false branch in ``` #if USE___THREAD ... #else ... #endif ``` which contains #error preprocessor directive. I tried to understand why it happens. Turns out the `USE___THREAD` macro is not defined when compiling this file and false branch in always taken. This macro is defined in tls.h, however this header files in not included directly or indirectly. This issue should affect all assembler code in `libpthread/nptl/sysdeps/unix/sysv/linux/x86_64` since it all have preprocessor conditions depending on `USE___THREAD` macro. Directly including tls.h fixes the build error. - Kirill Makurin

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[PATCH v1] include/uchar.h: only typedef mbstate_t if __mbstate_t exists
by Thomas Devoogdt 17 Apr '25

17 Apr '25

In file included from /home/thomas/br-test-pkg/br-powerpc-603e-basic-cpp/build/fluent-bit-4.0.0/include/fluent-bit/simdutf/flb_simdutf_connector.h:32, from /home/thomas/br-test-pkg/br-powerpc-603e-basic-cpp/build/fluent-bit-4.0.0/include/fluent-bit/flb_unicode.h:26, from /home/thomas/br-test-pkg/br-powerpc-603e-basic-cpp/build/fluent-bit-4.0.0/plugins/in_tail/tail_file.c:52: /home/thomas/br-test-pkg/br-powerpc-603e-basic-cpp/host/powerpc-buildroot-linux-uclibc/sysroot/usr/include/uchar.h:36:9: error: unknown type name ‘__mbstate_t’ 36 | typedef __mbstate_t mbstate_t; | ^~~~~~~~~~~ The __mbstate_t type is created in wchar.h, and there, __mbstate_t_defined gets defined, and __need_mbstate_t gets undefined. The mbstate_t type is not created in wchar.h, since __need_mbstate_t is defined in uchar.h. Its not yet clear why __mbstate_t_defined is not defined in uchar.h after the wchar.h include, but the fact is, if it's not, that we can't define mbstate_t. Signed-off-by: Thomas Devoogdt <thomas(a)devoogdt.com> --- Beware that I'm not completly sure about the __mbstate_t_defined and __need_mbstate_t, so please review the patch carefully. --- include/uchar.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/include/uchar.h b/include/uchar.h index 5e10196d7..58cf1918f 100644 --- a/include/uchar.h +++ b/include/uchar.h @@ -30,12 +30,11 @@ #define __need_mbstate_t #include <wchar.h> -#ifndef __mbstate_t_defined +#ifdef __mbstate_t_defined __BEGIN_NAMESPACE_C99 /* Public type. */ typedef __mbstate_t mbstate_t; __END_NAMESPACE_C99 -# define __mbstate_t_defined 1 #endif -- 2.43.0

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New Release 1.0.52 is out
by Waldemar Brodkorb 06 Apr '25

06 Apr '25

Hi Embedded Hackers, I released 1.0.52 today. Here is the shortlog: Frank Mehnert (4): nan.h: define NAN only if not already defined libc/string/x86_64: fix p2align max number of bytes to skip stdint.h: don't define __INT64_C / __UINT64_C if already defined spawn.h: fix compiler warning about unused variable Georg Kotheimer (2): Make getauxval work with static linking Support non-cached entries in getauxval Jan Klötzke (4): inet/resolv.c: set h_errnop if /etc/hosts cannot be opened Do not rely on unrelocated GOT entries Use __ehdr_start to compute load address Use __ehdr_start as known zero link address symbol Jeffrey H. Johnson (1): Rename variable to fix compilation with GCC 15 Marcus Haehnel (2): Fix missing include in __uClibc_main ldso.h: factor out _dl_auxvt from ldso.h Peter Seiderer (1): m68k: fix SUPPORT_LD_DEBUG null pointer access Thomas Devoogdt (1): mount.h: fix MS_{} being seen as an identifier iso a variable Thomas Petazzoni (1): include/stdlib.h: only expose reallocarray() prototype when implementation is available Thorsten Glaser (1): m68k: fix alignment in NPTL code Waldemar Brodkorb (4): bfin: fix compile and linking errors with gcc 14.2.0 aarch64: add fenv support from glibc arm: add fenv support from glibc bump version for 1.0.52 release Thanks to all Contributors. Extra Thanks to Kernconcept for there continous work on good clang support. Sunshine! Waldemar

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[PATCH] mount.h: fix MS_{} being seen as an identifier iso a variable
by Thomas Devoogdt 05 Apr '25

05 Apr '25

In file included from /home/thomas/external/buildroot2/output/host/mips64-buildroot-linux-uclibc/sysroot/usr/include/linux/fs.h:19, from /home/thomas/external/buildroot2/output/host/mips64-buildroot-linux-uclibc/sysroot/usr/include/linux/btrfs.h:29, from libmount/src/btrfs.c:22: /home/thomas/external/buildroot2/output/host/mips64-buildroot-linux-uclibc/sysroot/usr/include/sys/mount.h:38:3: error: expected identifier before numeric constant 38 | MS_NOSUID = 2, /* Ignore suid and sgid bits. */ | ^~~~~~~~~ Fixes: - https://github.com/util-linux/util-linux/issues/3501 - https://lore.kernel.org/buildroot/CACXRmJioVq7PUwBkCPNj0k-47hrJ_vtgVYtzp+_8… Signed-off-by: Thomas Devoogdt <thomas(a)devoogdt.com> --- include/sys/mount.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/include/sys/mount.h b/include/sys/mount.h index c0e7b84f8..f9edbeba3 100644 --- a/include/sys/mount.h +++ b/include/sys/mount.h @@ -32,54 +32,79 @@ supported */ enum { +#undef MS_RDONLY MS_RDONLY = 1, /* Mount read-only. */ #define MS_RDONLY MS_RDONLY +#undef MS_NOSUID MS_NOSUID = 2, /* Ignore suid and sgid bits. */ #define MS_NOSUID MS_NOSUID +#undef MS_NODEV MS_NODEV = 4, /* Disallow access to device special files. */ #define MS_NODEV MS_NODEV +#undef MS_NOEXEC MS_NOEXEC = 8, /* Disallow program execution. */ #define MS_NOEXEC MS_NOEXEC +#undef MS_SYNCHRONOUS MS_SYNCHRONOUS = 16, /* Writes are synced at once. */ #define MS_SYNCHRONOUS MS_SYNCHRONOUS +#undef MS_REMOUNT MS_REMOUNT = 32, /* Alter flags of a mounted FS. */ #define MS_REMOUNT MS_REMOUNT +#undef MS_MANDLOCK MS_MANDLOCK = 64, /* Allow mandatory locks on an FS. */ #define MS_MANDLOCK MS_MANDLOCK +#undef MS_DIRSYNC MS_DIRSYNC = 128, /* Directory modifications are synchronous. */ #define MS_DIRSYNC MS_DIRSYNC +#undef MS_NOATIME MS_NOATIME = 1024, /* Do not update access times. */ #define MS_NOATIME MS_NOATIME +#undef MS_NODIRATIME MS_NODIRATIME = 2048, /* Do not update directory access times. */ #define MS_NODIRATIME MS_NODIRATIME +#undef MS_BIND MS_BIND = 4096, /* Bind directory at different place. */ #define MS_BIND MS_BIND +#undef MS_MOVE MS_MOVE = 8192, #define MS_MOVE MS_MOVE +#undef MS_REC MS_REC = 16384, #define MS_REC MS_REC +#undef MS_SILENT MS_SILENT = 32768, #define MS_SILENT MS_SILENT +#undef MS_POSIXACL MS_POSIXACL = 1 << 16, /* VFS does not apply the umask. */ #define MS_POSIXACL MS_POSIXACL +#undef MS_UNBINDABLE MS_UNBINDABLE = 1 << 17, /* Change to unbindable. */ #define MS_UNBINDABLE MS_UNBINDABLE +#undef MS_PRIVATE MS_PRIVATE = 1 << 18, /* Change to private. */ #define MS_PRIVATE MS_PRIVATE +#undef MS_SLAVE MS_SLAVE = 1 << 19, /* Change to slave. */ #define MS_SLAVE MS_SLAVE +#undef MS_SHARED MS_SHARED = 1 << 20, /* Change to shared. */ #define MS_SHARED MS_SHARED +#undef MS_RELATIME MS_RELATIME = 1 << 21, /* Update atime relative to mtime/ctime. */ #define MS_RELATIME MS_RELATIME +#undef MS_KERNMOUNT MS_KERNMOUNT = 1 << 22, /* This is a kern_mount call. */ #define MS_KERNMOUNT MS_KERNMOUNT +#undef MS_I_VERSION MS_I_VERSION = 1 << 23, /* Update inode I_version field. */ #define MS_I_VERSION MS_I_VERSION +#undef MS_STRICTATIME MS_STRICTATIME = 1 << 24, /* Always perform atime updates. */ #define MS_STRICTATIME MS_STRICTATIME +#undef MS_ACTIVE MS_ACTIVE = 1 << 30, #define MS_ACTIVE MS_ACTIVE +#undef MS_NOUSER MS_NOUSER = 1 << 31 #define MS_NOUSER MS_NOUSER }; -- 2.43.0

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[PATCH] include/stdlib.h: only expose reallocarray() prototype when implementation is available
by Thomas Petazzoni 04 Apr '25

04 Apr '25

The reallocarray() primitive is only provided by the malloc-standard implementation: neither malloc nor malloc-simple provide it. This causes issues when building for example util-linux on noMMU platforms as: - noMMU platforms can't use malloc-standard, so either malloc or malloc-simple are used, which means reallocarray() is not implemented - util-linux detects the absence of reallocarray(), and provides its own implementation, but the prototype clashes with the prototype in uClibc's <stdlib.h> The combination of which causes the following build failure: In file included from lib/color-names.c:7: ./include/c.h:586:21: error: static declaration of ‘reallocarray’ follows non-static declaration 586 | static inline void *reallocarray(void *ptr, size_t nmemb, size_t size) | ^~~~~~~~~~~~ In file included from ./include/c.h:16: /home/thomas/projets/buildroot/output/host/arm-buildroot-uclinux-uclibcgnueabi/sysroot/usr/include/stdlib.h:898:14: note: previous declaration of ‘reallocarray’ with type ‘void *(void *, size_t, size_t)’ {aka ‘void *(void *, unsigned int, unsigned int)’} 898 | extern void *reallocarray (void *__ptr, size_t __m, size_t __n); | ^~~~~~~~~~~~ make[3]: *** [Makefile:12354: lib/libtcolors_la-color-names.lo] Error 1 To fix this, let's not expose the prototype of reallocarray() if we don't provide the implementation for it. Signed-off-by: Thomas Petazzoni <thomas.petazzoni(a)bootlin.com> --- include/stdlib.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/stdlib.h b/include/stdlib.h index d4e0b75e7..448c5e336 100644 --- a/include/stdlib.h +++ b/include/stdlib.h @@ -986,9 +986,13 @@ extern int getpt (void); extern int getloadavg (double __loadavg[], int __nelem) __THROW __nonnull ((1)); +/* reallocarray() only provided by the malloc-standard implementation */ +#if defined(__MALLOC_STANDARD__) extern void *reallocarray (void *__ptr, size_t __m, size_t __n); #endif +#endif + #ifdef _LIBC extern int __drand48_iterate (unsigned short int xsubi[3], struct drand48_data *buffer) attribute_hidden; -- 2.48.1

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fenv support in arch arm
by hacklife＠126.com 31 Mar '25

31 Mar '25

Hi guys， Hello, I want to ask why the uclibc-ng(test on version 1.0.39) does not support fenv(Symbol: UCLIBC_HAS_FENV) setting in arch arm, but it can be enabled in arch x86.

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[PATCH] spawn.h: fix compiler warning about unused variable
by Marcus Haehnel 27 Mar '25

27 Mar '25

From: Frank Mehnert <frank.mehnert(a)kernkonzept.com> Avoid the warning by marking the unused parameter appropriately. Signed-off-by: Marcus Haehnel <marcus.haehnel(a)kernkonzept.com> --- include/spawn.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/spawn.h b/include/spawn.h index 3de375b41..cf01639c1 100644 --- a/include/spawn.h +++ b/include/spawn.h @@ -103,6 +103,7 @@ int posix_spawnattr_init (posix_spawnattr_t *__attr) static inline int posix_spawnattr_destroy (posix_spawnattr_t *__attr) { + (void)__attr; return 0; } -- 2.47.1

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[RFC][PATCH] stdint.h: don't define __INT64_C / __UINT64_C if already defined
by Marcus Hähnel 27 Mar '25

27 Mar '25

Dear list, we came across a problem that might be very specific to our own setup and how we use the lib. We still wanted to share the patch if there is general interest. Recent Clang versions (Starting from 20) have the __INT64_C and __UINT64_C macros built-in. The compiler does not warn about this normally because <stdint.h> is a system header. In special cases where stdint.h may be included as normal header (which is the case for our system) it does warn however. Avoid re-defining if a definition already exists. The change would not impact users that use stdint.h exclusively as system header. Best regards, - Marcus -- +++++++++++++++++++ Register now for our workshop "Get to know L4Re in 3 days" on April 8-10. Learn to design and deploy secure system architectures for your product with L4Re: https://www.kernkonzept.com/workshop-getting-started-with-l4re/ +++++++++++++++++++ Kernkonzept GmbH Sitz: Dresden HRB 31129 Geschäftsführer: Dr.-Ing. Michael Hohmuth

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[Patch] Use __ehdr_start as known zero link address symbol
by Marcus Hähnel 27 Mar '25

27 Mar '25

Hello devs, The _start symbol does not necessarily have to be on the first page of the application. But the __ehdr_start symbol is always at address zero for PIE binaries. So now we know how it works ;) Best regards, - Marcus -- +++++++++++++++++++ Register now for our workshop "Get to know L4Re in 3 days" on April 8-10. Learn to design and deploy secure system architectures for your product with L4Re: https://www.kernkonzept.com/workshop-getting-started-with-l4re/ +++++++++++++++++++ Kernkonzept GmbH Sitz: Dresden HRB 31129 Geschäftsführer: Dr.-Ing. Michael Hohmuth

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Do not rely on unrelocated GOT entries
by Marcus Hähnel 27 Mar '25

27 Mar '25

Dear uclibc-ng devs, The LLVM linker seems to be quite clever. When resolving relocations, accesses to the GOT are potentially replaced by PC relative addressing to the requested symbol. This breaks the old method of calculating the load address by using an unrelocated GOT entry value. Instead, rely on __ehdr_start having a link address of zero.The LLVM linker seems to be quite clever. When resolving relocations, accesses to the GOT are potentially replaced by PC relative addressing to the requested symbol. This breaks the old method of calculating the load address by using an unrelocated GOT entry value. Instead, rely on __ehdr_start having a link address of zero. The patch is attached. Best regards, - Marcus -- +++++++++++++++++++ Register now for our workshop "Get to know L4Re in 3 days" on April 8-10. Learn to design and deploy secure system architectures for your product with L4Re: https://www.kernkonzept.com/workshop-getting-started-with-l4re/ +++++++++++++++++++ Kernkonzept GmbH Sitz: Dresden HRB 31129 Geschäftsführer: Dr.-Ing. Michael Hohmuth

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