Subject: Re: bug#29183: 27.0.50; SIGSEGV on C-g on Windows

From: John Mastro <[email-masked]>
Date: Tue, 7 Nov 2017 10:14:09 -0800

Eli Zaretskii <[email-masked]> wrote:
> Is this again bug#29040?  Did main_thread become mis-aligned again?

I repeated the commands Richard used in that bug report, and I believe
you're right: it's 8-byte aligned rather than 16-byte aligned.
Transcript below.

Thread 1 received signal SIGSEGV, Segmentation fault.
0x00007ff8cb7893a0 in ntdll!RtlCaptureContext ()
   from C:\Windows\SYSTEM32\ntdll.dll
(gdb) frame 0
#0  0x00007ff8cb7893a0 in ntdll!RtlCaptureContext ()
   from C:\Windows\SYSTEM32\ntdll.dll
(gdb) p/x $rax
$1 = 0x4005d1d68
(gdb) up
#1  0x00007ff8cb6f8f27 in ntdll!RtlUnwindEx ()
   from C:\Windows\SYSTEM32\ntdll.dll
(gdb) up
#2  0x00007ff8c91d1f4a in msvcrt!_setjmpex ()
   from C:\Windows\System32\msvcrt.dll
(gdb) up
#3  0x00000004000a93d4 in quit_throw_to_read_char (
    from_signal=from_signal@entry=false) at keyboard.c:10548
10548     sys_longjmp (getcjmp, 1);
(gdb) p &getcjmp
$2 = (sys_jmp_buf *) 0x4005d1d68 <main_thread+224>