Subject: Unaligned access in C library
To: NetBSD/Alpha <firstname.lastname@example.org>
From: B. James Phillippe <email@example.com>
Date: 02/16/2002 18:17:20
I am running 1.5.2 on a DEC Alpha, and have bumped into what I believe is
an unaligned access in the C library. At least, I have an application
which blows up with "unaligned access" only when compiled with "-pg" for
profiling. When I run the address through gbd, this is what I get:
% test/unix_util.TEST -r test/input.dump.1 tcp
pid 25891 (unix_util.TEST): unaligned access: va=0x1201aef14 pc=0x1200244d8 ra=0x120016e1c op=ldq
% gdb !:0 (returned 139)
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This GDB was configured as "alpha--netbsd"...
(gdb) l *0x1200244d8
0x1200244d8 is in __setjmp14 (/usr/src/lib/libc/arch/alpha/gen/__setjmp14.S:67).
/usr/src/lib/libc/arch/alpha/gen/__setjmp14.S:62: No such file or directory.
(gdb) p *0x1201aef14
$1 = 0
(gdb) l *0x120016e1c
No source file for address 0x120016e1c.
If I pop open __setjmp14.c, line 67 contains CALL:
/* see what's blocked */
mov zero, a0 /* how (insignificant) */
mov zero, a1 /* set (NULL) */
lda a2, 648(s0) /* point to mask in sc */
Which expands to:
* Function invocation
#define CALL(_name_) \
.loc 1 __LINE__; \
jsr ra,_name_; \
# bryan at darkforest dot org
# Software Engineer