From 31073a53d8ff1e8bac53e34cb626dae5aa6ce69c Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 8 May 2017 11:22:20 -0300 Subject: powerpc: Fix signal handling in backtrace Now with read consolidation which uses SYSCALL_CANCEL macro, a frame pointer is created in the syscall code and this makes the powerpc backtrace obtain a bogus entry for the signal handling patch. It is because it does not setup the correct frame pointer register (r1) based on the saved value from the kernel sigreturn. It was not failing because the syscall frame pointer register was the same one for the next frame (the function that actually called the syscall). This patch fixes it by setup the next stack frame using the saved one by the kernel sigreturn. It fixes tst-backtrace{5,6} from the read consolidation patch. Checked on powerpc-linux-gnu and powerpc64le-linux-gnu. * sysdeps/powerpc/powerpc32/backtrace.c (is_sigtramp_address): Use void* for argument type and use VDSO_SYMBOL macro. (is_sigtramp_address_rt): Likewise. (__backtrace): Setup expected frame pointer address for signal handling. * sysdeps/powerpc/powerpc64/backtrace.c (is_sigtramp_address): Use void* for argumetn type and use VSDO_SYMBOL macro. (__backtrace): Setup expected frame pointer address for signal handling. --- sysdeps/powerpc/powerpc32/backtrace.c | 17 ++++++++++------- sysdeps/powerpc/powerpc64/backtrace.c | 17 ++++++++++------- 2 files changed, 20 insertions(+), 14 deletions(-) (limited to 'sysdeps') diff --git a/sysdeps/powerpc/powerpc32/backtrace.c b/sysdeps/powerpc/powerpc32/backtrace.c index b60ac329fd..394062136c 100644 --- a/sysdeps/powerpc/powerpc32/backtrace.c +++ b/sysdeps/powerpc/powerpc32/backtrace.c @@ -52,10 +52,10 @@ struct signal_frame_32 { }; static inline int -is_sigtramp_address (unsigned int nip) +is_sigtramp_address (void *nip) { #ifdef SHARED - if (nip == (unsigned int)__vdso_sigtramp32) + if (nip == VDSO_SYMBOL (sigtramp32)) return 1; #endif return 0; @@ -69,10 +69,10 @@ struct rt_signal_frame_32 { }; static inline int -is_sigtramp_address_rt (unsigned int nip) +is_sigtramp_address_rt (void * nip) { #ifdef SHARED - if (nip == (unsigned int)__vdso_sigtramp_rt32) + if (nip == VDSO_SYMBOL (sigtramp_rt32)) return 1; #endif return 0; @@ -100,20 +100,23 @@ __backtrace (void **array, int size) /* Check if the symbol is the signal trampoline and get the interrupted * symbol address from the trampoline saved area. */ - if (is_sigtramp_address ((unsigned int)current->return_address)) + if (is_sigtramp_address (current->return_address)) { struct signal_frame_32 *sigframe = (struct signal_frame_32*) current; gregset = &sigframe->mctx.gregs; } - else if (is_sigtramp_address_rt ((unsigned int)current->return_address)) + else if (is_sigtramp_address_rt (current->return_address)) { struct rt_signal_frame_32 *sigframe = (struct rt_signal_frame_32*) current; gregset = &sigframe->uc.uc_mcontext.uc_regs->gregs; } if (gregset) - array[++count] = (void*)((*gregset)[PT_NIP]); + { + array[++count] = (void*)((*gregset)[PT_NIP]); + current = (void*)((*gregset)[PT_R1]); + } } /* It's possible the second-last stack frame can't return diff --git a/sysdeps/powerpc/powerpc64/backtrace.c b/sysdeps/powerpc/powerpc64/backtrace.c index 83b963e930..723948d78f 100644 --- a/sysdeps/powerpc/powerpc64/backtrace.c +++ b/sysdeps/powerpc/powerpc64/backtrace.c @@ -16,10 +16,12 @@ License along with the GNU C Library; see the file COPYING.LIB. If not, see . */ -#include #include #include #include +#include + +#include #include /* This is the stack layout we see with every stack frame. @@ -37,7 +39,7 @@ struct layout { struct layout *next; - long condition_register; + long int condition_register; void *return_address; }; @@ -47,16 +49,16 @@ struct layout dummy frame to make it look like it has a caller. */ struct signal_frame_64 { #define SIGNAL_FRAMESIZE 128 - char dummy[SIGNAL_FRAMESIZE]; + char dummy[SIGNAL_FRAMESIZE]; struct ucontext uc; /* We don't care about the rest, since the IP value is at 'uc' field. */ }; static inline int -is_sigtramp_address (unsigned long nip) +is_sigtramp_address (void *nip) { #ifdef SHARED - if (nip == (unsigned long)__vdso_sigtramp_rt64) + if (nip == VDSO_SYMBOL (sigtramp_rt64)) return 1; #endif return 0; @@ -82,10 +84,11 @@ __backtrace (void **array, int size) /* Check if the symbol is the signal trampoline and get the interrupted * symbol address from the trampoline saved area. */ - if (is_sigtramp_address ((unsigned long)current->return_address)) + if (is_sigtramp_address (current->return_address)) { struct signal_frame_64 *sigframe = (struct signal_frame_64*) current; - array[++count] = (void*)sigframe->uc.uc_mcontext.gp_regs[PT_NIP]; + array[++count] = (void*) sigframe->uc.uc_mcontext.gp_regs[PT_NIP]; + current = (void*) sigframe->uc.uc_mcontext.gp_regs[PT_R1]; } } -- cgit 1.4.1