[glibc/vineet/upstream-work] hurd: Fix unwinding over interruptible RPC

[glibc/vineet/upstream-work] hurd: Fix unwinding over interruptible RPC

[Vineet Gupta]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=337a7b74faed2c8daf8c91cbb3038dc4984f3207

commit 337a7b74faed2c8daf8c91cbb3038dc4984f3207
Author: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date:   Sun Jun 7 17:51:21 2020 +0000

    hurd: Fix unwinding over interruptible RPC
    
    * sysdeps/mach/hurd/i386/intr-msg.h (INTR_MSG_TRAP): Set CFA register to
    %ecx while %esp is altered.

Diff:
---
 sysdeps/mach/hurd/i386/intr-msg.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sysdeps/mach/hurd/i386/intr-msg.h b/sysdeps/mach/hurd/i386/intr-msg.h
index 54420fed01..70e6cc6592 100644
--- a/sysdeps/mach/hurd/i386/intr-msg.h
+++ b/sysdeps/mach/hurd/i386/intr-msg.h
@@ -37,10 +37,12 @@
        "				movl %6, %%eax\n"		      \
        "				jmp _hurd_intr_rpc_msg_sp_restored\n" \
        "_hurd_intr_rpc_msg_do:		movl %%esp, %%ecx\n"		      \
+       "				.cfi_def_cfa_register %%ecx\n"	      \
        "				leal %4, %%esp\n"		      \
        "_hurd_intr_rpc_msg_cx_sp:	movl $-25, %%eax\n"		      \
        "_hurd_intr_rpc_msg_do_trap:	lcall $7, $0 # status in %0\n"	      \
        "_hurd_intr_rpc_msg_in_trap:	movl %%ecx, %%esp\n"		      \
+       "				.cfi_def_cfa_register %%esp\n"	      \
        "_hurd_intr_rpc_msg_sp_restored:"				      \
        : "=a" (err), "+m" (option), "+m" (timeout), "=m" (*intr_port_p)	      \
        : "m" ((&msg)[-1]), "m" (*cancel_p), "i" (EINTR)			      \