2.5.21: fixdep starts spitting out 'unaligned traps'

alpha:/usr/src/linux-2.5.21# make boot
make[1]: Entering directory `/usr/src/linux-2.5.21/scripts'
  gcc -Wp,-MD,.fixdep.d -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer  -o fixdep fixdep.c
fixdep(12602): unaligned trap at 00000001200018d8: 0000000120001b6a 28 2
  gcc -Wp,-MD,.split-include.d -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer  -o split-include split-include.c
fixdep(12612): unaligned trap at 00000001200018d8: 0000000120001b6a 28 2
make[1]: Leaving directory `/usr/src/linux-2.5.21/scripts'
Splitting include/linux/autoconf.h -> include/config
make[1]: Entering directory `/usr/src/linux-2.5.21/init'
  gcc -Wp,-MD,.main.o.d -D__KERNEL__ -I/usr/src/linux-2.5.21/include -Wall -Wstrict-prototypes -Wno-trigraphs -O2 -fomit-frame-pointe
r -fno-strict-aliasing -fno-common -pipe -mno-fp-regs -ffixed-8 -mcpu=ev56 -Wa,-mev6 -nostdinc -iwithprefix include    -DKBUILD_BASEN
AME=main   -c -o main.o main.c
fixdep(12630): unaligned trap at 00000001200018d8: 0000000120001b6a 28 2
Generating ../include/linux/compile.h (updated)
  gcc -Wp,-MD,.version.o.d -D__KERNEL__ -I/usr/src/linux-2.5.21/include -Wall -Wstrict-prototypes -Wno-trigraphs -O2 -fomit-frame-poi
nter -fno-strict-aliasing -fno-common -pipe -mno-fp-regs -ffixed-8 -mcpu=ev56 -Wa,-mev6 -nostdinc -iwithprefix include    -DKBUILD_BA
SENAME=version   -c -o version.o version.c
fixdep(12661): unaligned trap at 00000001200018d8: 0000000120001b6a 28 2
  gcc -Wp,-MD,.do_mounts.o.d -D__KERNEL__ -I/usr/src/linux-2.5.21/include -Wall -Wstrict-prototypes -Wno-trigraphs -O2 -fomit-frame-p
ointer -fno-strict-aliasing -fno-common -pipe -mno-fp-regs -ffixed-8 -mcpu=ev56 -Wa,-mev6 -nostdinc -iwithprefix include    -DKBUILD_
BASENAME=do_mounts   -c -o do_mounts.o do_mounts.c

and so on - fixdep has changed, and on my alpha, it now has 'unaligned traps'.

Of course, 2.5.21 won't compile at all, but still, this is a regression.

This seems to be caused by line 364 of fixdep.c:

alpha:/usr/src/linux-2.5.21# /home/jurriaan/unalign scripts/fixdep scripts/lxdialog/checklist.o /usr/src/linux-2.5.21 gcc -Wp,-MD,scr
ipts/lsdialog/.checklist.o.d -g -c -o scripts/lxdialog/checklist.o scripts/lxdialog/checklist.c
Extra arguments passed to gdb in file /tmp/file4Hb5gq.
Be sure to delete it when you're done.

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fixdep(15767): unaligned trap at 0000000120001d48: 000000012000210a 28 3

Program received signal SIGBUS, Bus error.
0x120001d48 in traps () at scripts/fixdep.c:364
364 if (*(int *)test != INT_CONF) {
(gdb) bt
#0 0x120001d48 in traps () at scripts/fixdep.c:364
#1 0x120001de8 in main (argc=10, argv=0x11ffffc58) at scripts/fixdep.c:375 (gdb)

I'm not expert enough in C to suggest a solution for this, but I'm willing to test.

Good luck,
Jurriaan

Everybody need to deviate from the norm
   Rush - Vital Signs
Debian GNU/Linux 2.4.19p8 on Alpha 990 bogomips 5 users load:0.04 0.06 0.07

Yeah, makes sense, that's a bug trap to test if we guessed endianness right. Could you try to just comment out the call to traps() in main()?

The rest of the code should be safe. If commenting out fixes the problem, could you try to replace

- char *test = "CONF";
+ static char __attribute__((aligned(8))) test[] = "CONF";

Thanks,

--Kai