Messages in this thread | | | Date | Sun, 2 Jan 2005 08:41:12 +0100 | From | Herbert Poetzl <> | Subject | Re: kswapd0 oops -> debug information |
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On Sat, Nov 27, 2004 at 05:21:21PM +0000, Nick Warne wrote: > On Saturday 27 November 2004 17:01, Randy.Dunlap wrote: > > > kernel version? > > Heh. My great debug attempt, eh? > > kernel 2.6.9 > > > .config file? > > full oops message, with stack backtrace? > > The stack backtrace could tell us who a bad caller is. > > It can just be a caller's problem, not a bug in (this) > > one isolated function. > > http://linicks.net/kdebug/ > > > Did you read/check linux/REPORTING-BUGS ? > > Yes, but wanted to try and learn myself on what was going on, rather than push > the onus onto other people. > > The book I have re the make /dir/file.s states that it will produce assembler > with _line_ numbers to corresponding C code. That is where I got lost, as it > doesn't.
hmm, sorry for the late reply, but better late than not at all ...
if you do make fs/file.s V=1
you'll see what make actually does to compile the source code into assembler code ...
make -f scripts/Makefile.build obj=scripts/basic make -f scripts/Makefile.build obj=scripts make -f scripts/Makefile.build obj=fs fs/file.s gcc -Wp,-MD,fs/.file.s.d -nostdinc -iwithprefix include -D__KERNEL__ -Iinclude -Wall -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -O2 -fomit-frame-pointer -g -pipe -msoft-float -mpreferred-stack-boundary=2 -march=i586 -Iinclude/asm-i386/mach-default -DKBUILD_BASENAME=file -DKBUILD_MODNAME=file -S -o fs/file.s fs/file.c
and if that final gcc command does include a -g (which can be controlled by CONFIG_DEBUG_INFO, or simply added by hand), then the output will contain lines like this:
.loc 1 45 0 .loc 1 46 0
which reference the file and line number in the source code. files are 'declared' with lines:
.file "file.c" .file 1 "fs/file.c" .file 2 "include/linux/posix_types.h"
so you can pretty easy find the code in the source. a different, but sometimes easier approach is to use 'addr2line' on the kernel binary (if it was compiled with CONFIG_DEBUG_INFO) to get the source line from a kernel address ...
addr2line -e vmlinux c0123456
HTH, Herbert
> Thanks, > > Nick. > > -- > "When you're chewing on life's gristle, > Don't grumble, Give a whistle..." > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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