From 59fcf6c3ec651d043266c4b898390656bd97e4c0 Mon Sep 17 00:00:00 2001 From: Andreas Tobler Date: Sat, 4 Nov 2017 20:40:23 +0100 Subject: re PR libgcc/82635 (std::thread's join broken on FreeBSD with all GCCs >= 5) 2017-11-04 Andreas Tobler 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. From-SVN: r254411 --- libgcc/ChangeLog | 8 +++++++ libgcc/config/i386/freebsd-unwind.h | 43 +++++++++++++++++++++++++++++++++++-- 2 files changed, 49 insertions(+), 2 deletions(-) (limited to 'libgcc') diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index a99d6186ca5..a49078117aa 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,3 +1,11 @@ +2017-11-04 Andreas Tobler + + 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. + 2017-11-03 Cupertino Miranda Vineet Gupta 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 #include +#include +#include #include +#include #include #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. 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. */ -- cgit v1.2.3