diff options
author | andreast <andreast@138bc75d-0d04-0410-961f-82ee72b054a4> | 2017-11-05 19:30:41 +0000 |
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committer | andreast <andreast@138bc75d-0d04-0410-961f-82ee72b054a4> | 2017-11-05 19:30:41 +0000 |
commit | 64159cb845943ac809fc77863e9cb9838dabcf58 (patch) | |
tree | 974e1d6c42c82c7dea105722539d8030cc407c3e | |
parent | 52d1a1c8da6ac43bd520c7bd6e941fdb3396d4b2 (diff) | |
download | gcc-64159cb845943ac809fc77863e9cb9838dabcf58.tar.gz |
2017-11-05 Andreas Tobler <andreast@gcc.gnu.org>
Backport from mainline
2017-11-04 Andreas Tobler <andreast@gcc.gnu.org>
PR libgcc/82635
* config/i386/freebsd-unwind.h (MD_FALLBACK_FRAME_STATE_FOR): Use a
sysctl to determine whether we're in a trampoline.
Keep the pattern matching method for systems without
KERN_PROC_SIGTRAMP sysctl.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-7-branch@254431 138bc75d-0d04-0410-961f-82ee72b054a4
-rw-r--r-- | libgcc/ChangeLog | 11 | ||||
-rw-r--r-- | libgcc/config/i386/freebsd-unwind.h | 43 |
2 files changed, 52 insertions, 2 deletions
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index 2c08fe306dc..569963ba46e 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,3 +1,14 @@ +2017-11-05 Andreas Tobler <andreast@gcc.gnu.org> + + Backport from mainline + 2017-11-04 Andreas Tobler <andreast@gcc.gnu.org> + + PR libgcc/82635 + * config/i386/freebsd-unwind.h (MD_FALLBACK_FRAME_STATE_FOR): Use a + sysctl to determine whether we're in a trampoline. + Keep the pattern matching method for systems without + KERN_PROC_SIGTRAMP sysctl. + 2017-10-13 Jakub Jelinek <jakub@redhat.com> PR target/82274 diff --git a/libgcc/config/i386/freebsd-unwind.h b/libgcc/config/i386/freebsd-unwind.h index 0eec584a11e..a8e8edb993a 100644 --- a/libgcc/config/i386/freebsd-unwind.h +++ b/libgcc/config/i386/freebsd-unwind.h @@ -28,7 +28,10 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see #include <sys/types.h> #include <signal.h> +#include <unistd.h> +#include <sys/sysctl.h> #include <sys/ucontext.h> +#include <sys/user.h> #include <machine/sigframe.h> #define REG_NAME(reg) sf_uc.uc_mcontext.mc_## reg @@ -36,6 +39,38 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see #ifdef __x86_64__ #define MD_FALLBACK_FRAME_STATE_FOR x86_64_freebsd_fallback_frame_state +#ifdef KERN_PROC_SIGTRAMP +/* FreeBSD past 9.3 provides a kern.proc.sigtramp.<pid> sysctl that + returns the location of the signal trampoline. Use this to find + out whether we're in a trampoline. +*/ +static int +x86_64_outside_sigtramp_range (unsigned char *pc) +{ + static int sigtramp_range_determined = 0; + static unsigned char *sigtramp_start, *sigtramp_end; + + if (sigtramp_range_determined == 0) + { + struct kinfo_sigtramp kst = {0}; + size_t len = sizeof (kst); + int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_SIGTRAMP, getpid() }; + + sigtramp_range_determined = 1; + if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0) + { + sigtramp_range_determined = 2; + sigtramp_start = kst.ksigtramp_start; + sigtramp_end = kst.ksigtramp_end; + } + } + if (sigtramp_range_determined < 2) /* sysctl failed if < 2 */ + return 1; + + return (pc < sigtramp_start || pc >= sigtramp_end); +} +#endif + static _Unwind_Reason_Code x86_64_freebsd_fallback_frame_state (struct _Unwind_Context *context, _Unwind_FrameState *fs) @@ -43,6 +78,7 @@ x86_64_freebsd_fallback_frame_state struct sigframe *sf; long new_cfa; +#ifndef KERN_PROC_SIGTRAMP /* Prior to FreeBSD 9, the signal trampoline was located immediately before the ps_strings. To support non-executable stacks on AMD64, the sigtramp was moved to a shared page for FreeBSD 9. Unfortunately @@ -62,12 +98,15 @@ x86_64_freebsd_fallback_frame_state && *(unsigned int *)(context->ra + 8) == 0x01a1c0c7 && *(unsigned int *)(context->ra + 12) == 0x050f0000 )) return _URC_END_OF_STACK; +#else + if (x86_64_outside_sigtramp_range(context->ra)) + return _URC_END_OF_STACK; +#endif sf = (struct sigframe *) context->cfa; new_cfa = sf->REG_NAME(rsp); fs->regs.cfa_how = CFA_REG_OFFSET; - /* Register 7 is rsp */ - fs->regs.cfa_reg = 7; + fs->regs.cfa_reg = __LIBGCC_STACK_POINTER_REGNUM__; fs->regs.cfa_offset = new_cfa - (long) context->cfa; /* The SVR4 register numbering macros aren't usable in libgcc. */ |