From 2b356e689c334ca4765a9ffd95a76cf715447200 Mon Sep 17 00:00:00 2001 From: Samuel Thibault Date: Mon, 21 Dec 2020 15:36:30 +0100 Subject: [PATCH] hurd: libgcc unwinding over signal trampolines with SIGINFO When the application sets SA_SIGINFO, the signal trampoline parameters are different to follow POSIX. libgcc/ * config/i386/gnu-unwind.h (x86_gnu_fallback_frame_state): Add the posix siginfo case to struct handler_args. Detect between legacy and siginfo from the second parameter, which is a small sigcode in the legacy case, and a pointer in the siginfo case. --- libgcc/config/i386/gnu-unwind.h | 60 ++++++++++++++++++++++++++++++++--------- 1 file changed, 47 insertions(+), 13 deletions(-) diff --git a/libgcc/config/i386/gnu-unwind.h b/libgcc/config/i386/gnu-unwind.h index d69d07c..0632348 100644 --- a/libgcc/config/i386/gnu-unwind.h +++ b/libgcc/config/i386/gnu-unwind.h @@ -38,10 +38,21 @@ x86_gnu_fallback_frame_state { struct handler_args { int signo; - int sigcode; - struct sigcontext *scp; + union + { + struct + { + long int sigcode; + struct sigcontext *scp; + } legacy; + struct + { + siginfo_t *siginfop; + ucontext_t *uctxp; + } posix; + }; } *handler_args; - struct sigcontext *scp; + long int sigcode; unsigned long usp; /* @@ -75,29 +86,52 @@ x86_gnu_fallback_frame_state return _URC_END_OF_STACK; handler_args = context->cfa; - scp = handler_args->scp; - usp = scp->sc_uesp; + sigcode = handler_args->legacy.sigcode; + if (sigcode >= -16 && sigcode < 4096) + { + /* This cannot be a SIGINFO pointer, assume legacy. */ + struct sigcontext *scp = handler_args->legacy.scp; + usp = scp->sc_uesp; + + fs->regs.reg[0].loc.offset = (unsigned long)&scp->sc_eax - usp; + fs->regs.reg[1].loc.offset = (unsigned long)&scp->sc_ecx - usp; + fs->regs.reg[2].loc.offset = (unsigned long)&scp->sc_edx - usp; + fs->regs.reg[3].loc.offset = (unsigned long)&scp->sc_ebx - usp; + fs->regs.reg[5].loc.offset = (unsigned long)&scp->sc_ebp - usp; + fs->regs.reg[6].loc.offset = (unsigned long)&scp->sc_esi - usp; + fs->regs.reg[7].loc.offset = (unsigned long)&scp->sc_edi - usp; + fs->regs.reg[8].loc.offset = (unsigned long)&scp->sc_eip - usp; + } + else + { + /* This is not a valid sigcode, assume SIGINFO. */ + ucontext_t *uctxp = handler_args->posix.uctxp; + gregset_t *gregset = &uctxp->uc_mcontext.gregs; + usp = (*gregset)[REG_UESP]; + + fs->regs.reg[0].loc.offset = (unsigned long)&(*gregset)[REG_EAX] - usp; + fs->regs.reg[1].loc.offset = (unsigned long)&(*gregset)[REG_ECX] - usp; + fs->regs.reg[2].loc.offset = (unsigned long)&(*gregset)[REG_EDX] - usp; + fs->regs.reg[3].loc.offset = (unsigned long)&(*gregset)[REG_EBX] - usp; + fs->regs.reg[5].loc.offset = (unsigned long)&(*gregset)[REG_EBP] - usp; + fs->regs.reg[6].loc.offset = (unsigned long)&(*gregset)[REG_ESI] - usp; + fs->regs.reg[7].loc.offset = (unsigned long)&(*gregset)[REG_EDI] - usp; + fs->regs.reg[8].loc.offset = (unsigned long)&(*gregset)[REG_EIP] - usp; + } fs->regs.cfa_how = CFA_REG_OFFSET; fs->regs.cfa_reg = 4; fs->regs.cfa_offset = usp - (unsigned long) context->cfa; fs->regs.reg[0].how = REG_SAVED_OFFSET; - fs->regs.reg[0].loc.offset = (unsigned long)&scp->sc_eax - usp; fs->regs.reg[1].how = REG_SAVED_OFFSET; - fs->regs.reg[1].loc.offset = (unsigned long)&scp->sc_ecx - usp; fs->regs.reg[2].how = REG_SAVED_OFFSET; - fs->regs.reg[2].loc.offset = (unsigned long)&scp->sc_edx - usp; fs->regs.reg[3].how = REG_SAVED_OFFSET; - fs->regs.reg[3].loc.offset = (unsigned long)&scp->sc_ebx - usp; fs->regs.reg[5].how = REG_SAVED_OFFSET; - fs->regs.reg[5].loc.offset = (unsigned long)&scp->sc_ebp - usp; fs->regs.reg[6].how = REG_SAVED_OFFSET; - fs->regs.reg[6].loc.offset = (unsigned long)&scp->sc_esi - usp; fs->regs.reg[7].how = REG_SAVED_OFFSET; - fs->regs.reg[7].loc.offset = (unsigned long)&scp->sc_edi - usp; fs->regs.reg[8].how = REG_SAVED_OFFSET; - fs->regs.reg[8].loc.offset = (unsigned long)&scp->sc_eip - usp; + fs->retaddr_column = 8; fs->signal_frame = 1; -- 2.7.4