This was reported as uClicb test suite failures of tst-mqueue3, tst-mqueue5
The syscall args were getting clobbered, so use scratch regs which are not used for syscall args
00002690 <mq_timedsend>:
; SINGLE_THREAD_P
2690: sub r1,r25,0x448 <--- clobers r1, r2 2698: ld r2,[r1] 269c: cmp r2,0
26a0: bz mq_timedsend_nocancel
; DOCARGS (saves syscall args but r1, r2 clobbered already)
26a4: st.aw blink,[sp,-4] 26a8: st.aw r0,[sp,-4] 26ac: st.aw r1,[sp,-4] 26b0: st.aw r2,[sp,-4] 26b4: st.aw r3,[sp,-4] 26b8: st.aw r4,[sp,-4] 26bc: bl 1e28 <__librt_enable_asynccancel>
Reported-by: Eugeniy Paltsev paltsev@synopsys.com Cc: Alexey Brodkin abrodkin@synopsys.com Signed-off-by: Vineet Gupta vgupta@synopsys.com --- libpthread/nptl/sysdeps/unix/sysv/linux/arc/sysdep-cancel.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/arc/sysdep-cancel.h b/libpthread/nptl/sysdeps/unix/sysv/linux/arc/sysdep-cancel.h index cddd754a8680..918f61d67548 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/arc/sysdep-cancel.h +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/arc/sysdep-cancel.h @@ -99,9 +99,9 @@ #define UNDOCARGS_7 pop r6` UNDOCARGS_6
# define SINGLE_THREAD_P \ - THREAD_SELF r1 ` \ - ld r2, [r1, MULTIPLE_THREADS_OFFSET]` \ - cmp r2, 0 + THREAD_SELF r9 ` \ + ld r10, [r9, MULTIPLE_THREADS_OFFSET]` \ + cmp r10, 0
/* ld r2, [r1, -TLS_PRE_TCB_SIZE + MULTIPLE_THREADS_OFFSET] */ #else /* !__ASSEMBLER__ */
Despite the prev fix, tst-mqueue3 was still segfaulting. The issue was BLINK register not restored properly for return
00002690 <mq_timedsend>: 2690: sub r9,r25,0x448 2698: ld r10,[r9] 269c: cmp r10,0 26a0: beq -36 26a4: st.aw blink,[sp,-4] 26a8: st.aw r0,[sp,-4] 26ac: st.aw r1,[sp,-4] 26b0: st.aw r2,[sp,-4] 26b4: st.aw r3,[sp,-4] 26b8: st.aw r4,[sp,-4] 26bc: bl 1e28 <__librt_enable_asynccancel> 26c0: mov r9,r0 26c4: ld.ab r4,[sp,4] 26c8: ld.ab r3,[sp,4] 26cc: ld.ab r2,[sp,4] 26d0: ld.ab r1,[sp,4] 26d4: ld.ab r0,[sp,4] 26d8: ld.ab blink,[sp, 4] <---- function return BLINK 26dc: mov r8,182 26e0: trap_s 0 26e2: cmp r0,-1024 26e6: st.aw r0,[sp,-4] 26ea: mov r0,r9 26ee: bl 1e90 <__librt_disable_asynccancel> <-- BLINK clobbered to next PC
26f2: ld.ab r0,[sp,4] <----| loops here until sp is out of bound 26fa: cmp r0,-1024 | 26fe: jls [blink] -----| 2702: b 15d8 2706: nop_s
So the fix was to retain BLINK on stack before function call, and pop it later
- 26d8: ld.ab blink,[sp, 4] + 26d8: ld blink,[sp] <--- restore BLINK, but retain on stack 26dc: mov r8,182 26e0: trap_s 0 26e2: cmp r0,-1024 26e6: st.aw r0,[sp,-4] 26ea: mov r0,r9 26ee: bl 1e90 <__librt_disable_asynccancel> 26f2: ld.ab r0,[sp,4] + 26f6: ld.ab blink,[sp,4] <--- finally pop BLINK 26fa: cmp r0,-1024 26fe: jls [blink]
Reported-by: Eugeniy Paltsev paltsev@synopsys.com Cc: Alexey Brodkin abrodkin@synopsys.com Signed-off-by: Vineet Gupta vgupta@synopsys.com --- libpthread/nptl/sysdeps/unix/sysv/linux/arc/sysdep-cancel.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/arc/sysdep-cancel.h b/libpthread/nptl/sysdeps/unix/sysv/linux/arc/sysdep-cancel.h index 918f61d67548..01fd844d13f7 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/arc/sysdep-cancel.h +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/arc/sysdep-cancel.h @@ -38,6 +38,7 @@ mov r0, r9 /* prep mask for disable_asynccancel */ ` \ CDISABLE ` \ pop r0 /* get syscall ret value back */ ` \ + pop blink /* UNDOCARGS above left blink on stack */ ` \ cmp r0, -1024 ` \ jls [blink] ` \ b __syscall_error@plt ` \ @@ -75,7 +76,9 @@ .endm
#define DOCARGS_0 push blink -#define UNDOCARGS_0 pop blink + +/* don't pop blink at this point */ +#define UNDOCARGS_0 ld blink, [sp]
#define DOCARGS_1 DOCARGS_0` push r0 #define UNDOCARGS_1 pop r0` UNDOCARGS_0
-
Vineet Gupta