From 027e32bd42314e17095ba39df82ef293f4a72c09 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sat, 16 Nov 2013 06:34:39 +1000 Subject: [PATCH] alpha: Fix signal thunk unwind info --- ports/ChangeLog.alpha | 5 +++++ ports/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S | 18 ++++++++++++++---- 2 files changed, 19 insertions(+), 4 deletions(-) diff --git a/ports/ChangeLog.alpha b/ports/ChangeLog.alpha index 07f5dfb47e..8f97951dec 100644 --- a/ports/ChangeLog.alpha +++ b/ports/ChangeLog.alpha @@ -1,3 +1,8 @@ +2013-11-16 Richard Henderson + + * sysdeps/unix/sysv/linux/alpha/rt_sigaction.S: Include a nop + before each signal thunk. + 2013-10-30 Mike Frysinger * sysdeps/alpha/configure.in: Moved to ... diff --git a/ports/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S b/ports/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S index 3d291fd0b4..6efa7386d5 100644 --- a/ports/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S +++ b/ports/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S @@ -83,14 +83,21 @@ PSEUDO_END(__syscall_rt_sigaction) cfi_offset (64, \base + 2 * 8) .endm - .align 4 - cfi_startproc cfi_return_column (64) .cfi_signal_frame SIGCONTEXT_REGS -648 - cfi_def_cfa_offset (648) + + /* While this frame is marked as a signal frame, that only applies + to how this return address is handled for the outer frame. + The return address that arrived here, from the inner frame, is + not marked as a signal frame and so the unwinder still tries to + subtract 1 to examine the presumed call insn. Thus we must + extend the unwind info to a nop before the start. */ + nop + .align 4 + __syscall_sigreturn: mov sp, a0 ldi v0, __NR_sigreturn @@ -98,8 +105,11 @@ __syscall_sigreturn: .size __syscall_sigreturn, .-__syscall_sigreturn .type __syscall_sigreturn, @function - .align 4 + /* See above wrt including the nop. */ cfi_def_cfa_offset (176 + 648) + nop + .align 4 + __syscall_rt_sigreturn: mov sp,a0 ldi v0,__NR_rt_sigreturn -- 2.11.4.GIT