* [PATCH v3] scripts: Create objdump-func helper script @ 2022-04-20 17:16 Josh Poimboeuf 2022-04-20 18:35 ` Borislav Petkov 2022-04-21 8:52 ` Peter Zijlstra 0 siblings, 2 replies; 5+ messages in thread From: Josh Poimboeuf @ 2022-04-20 17:16 UTC (permalink / raw) To: Peter Zijlstra; +Cc: linux-kernel, x86, Miroslav Benes, Borislav Petkov Add a simple script which disassembles a single function from an object file. Comes in handy for objtool warnings and kernel stack traces. Originally-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> --- v3: - Add usage - Fix vmlinux scripts/objdump-func | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100755 scripts/objdump-func diff --git a/scripts/objdump-func b/scripts/objdump-func new file mode 100755 index 000000000000..0908f9f616c3 --- /dev/null +++ b/scripts/objdump-func @@ -0,0 +1,25 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Disassemble a single function. +# +# usage: objdump-func <file> <func> + +set -o errexit +set -o nounset + +OBJDUMP="${CROSS_COMPILE:-}objdump" + +command -v gawk >/dev/null 2>&1 || die "gawk isn't installed" + +usage() { + echo "usage: objdump-func <file> <func>" >&2 + exit 1 +} + +[[ $# -ne 2 ]] && usage + +OBJ=$1; shift +FUNC=$1; shift + +${OBJDUMP} -wdr $OBJ | gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f ">:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }' -- 2.34.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v3] scripts: Create objdump-func helper script 2022-04-20 17:16 [PATCH v3] scripts: Create objdump-func helper script Josh Poimboeuf @ 2022-04-20 18:35 ` Borislav Petkov 2022-04-21 8:52 ` Peter Zijlstra 1 sibling, 0 replies; 5+ messages in thread From: Borislav Petkov @ 2022-04-20 18:35 UTC (permalink / raw) To: Josh Poimboeuf; +Cc: Peter Zijlstra, linux-kernel, x86, Miroslav Benes On Wed, Apr 20, 2022 at 10:16:36AM -0700, Josh Poimboeuf wrote: > Add a simple script which disassembles a single function from an object > file. Comes in handy for objtool warnings and kernel stack traces. > > Originally-by: Peter Zijlstra <peterz@infradead.org> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> > --- > v3: > - Add usage Thanks! Acked-by: Borislav Petkov <bp@suse.de> -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v3] scripts: Create objdump-func helper script 2022-04-20 17:16 [PATCH v3] scripts: Create objdump-func helper script Josh Poimboeuf 2022-04-20 18:35 ` Borislav Petkov @ 2022-04-21 8:52 ` Peter Zijlstra 2022-04-21 17:37 ` Josh Poimboeuf 1 sibling, 1 reply; 5+ messages in thread From: Peter Zijlstra @ 2022-04-21 8:52 UTC (permalink / raw) To: Josh Poimboeuf; +Cc: linux-kernel, x86, Miroslav Benes, Borislav Petkov On Wed, Apr 20, 2022 at 10:16:36AM -0700, Josh Poimboeuf wrote: > +${OBJDUMP} -wdr $OBJ | gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f ">:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }' Two noteworthy changes: - $@ went missing, I've occasionally abused that to add extra argument to objdump. - you removed the glob after FUNC, I had that so that .cold and .constprop etc.. variants of the function also show up. I don't suppose either one are super important, but esp. that latter one has been convenient. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v3] scripts: Create objdump-func helper script 2022-04-21 8:52 ` Peter Zijlstra @ 2022-04-21 17:37 ` Josh Poimboeuf 2022-04-21 20:39 ` Peter Zijlstra 0 siblings, 1 reply; 5+ messages in thread From: Josh Poimboeuf @ 2022-04-21 17:37 UTC (permalink / raw) To: Peter Zijlstra; +Cc: linux-kernel, x86, Miroslav Benes, Borislav Petkov On Thu, Apr 21, 2022 at 10:52:44AM +0200, Peter Zijlstra wrote: > On Wed, Apr 20, 2022 at 10:16:36AM -0700, Josh Poimboeuf wrote: > > > +${OBJDUMP} -wdr $OBJ | gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f ">:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }' > > Two noteworthy changes: > > - $@ went missing, I've occasionally abused that to add extra argument > to objdump. Just to clarify, you'd add the extra arg at the end like this, right? objdump-func <file> <func> -Mintel > - you removed the glob after FUNC, I had that so that .cold and > .constprop etc.. variants of the function also show up. Sure, I'll match ".whatever" if there's a period, but not other substring matches, e.g. "put_page" shouldn't match "put_pages_list". {OBJDUMP} -wdr $@ $OBJ | gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f "(\\..*)?>:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }' -- Josh ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v3] scripts: Create objdump-func helper script 2022-04-21 17:37 ` Josh Poimboeuf @ 2022-04-21 20:39 ` Peter Zijlstra 0 siblings, 0 replies; 5+ messages in thread From: Peter Zijlstra @ 2022-04-21 20:39 UTC (permalink / raw) To: Josh Poimboeuf; +Cc: linux-kernel, x86, Miroslav Benes, Borislav Petkov On Thu, Apr 21, 2022 at 10:37:59AM -0700, Josh Poimboeuf wrote: > On Thu, Apr 21, 2022 at 10:52:44AM +0200, Peter Zijlstra wrote: > > On Wed, Apr 20, 2022 at 10:16:36AM -0700, Josh Poimboeuf wrote: > > > > > +${OBJDUMP} -wdr $OBJ | gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f ">:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }' > > > > Two noteworthy changes: > > > > - $@ went missing, I've occasionally abused that to add extra argument > > to objdump. > > Just to clarify, you'd add the extra arg at the end like this, right? > > objdump-func <file> <func> -Mintel Yeah, highly awkward, but it worked ;-) > > - you removed the glob after FUNC, I had that so that .cold and > > .constprop etc.. variants of the function also show up. > > Sure, I'll match ".whatever" if there's a period, but not other > substring matches, e.g. "put_page" shouldn't match "put_pages_list". > > {OBJDUMP} -wdr $@ $OBJ | gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f "(\\..*)?>:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }' Ah, good thinking requiring that '.' in there. I just ignored the extra gunk on the very rare occasion I got it. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-04-21 20:40 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-04-20 17:16 [PATCH v3] scripts: Create objdump-func helper script Josh Poimboeuf 2022-04-20 18:35 ` Borislav Petkov 2022-04-21 8:52 ` Peter Zijlstra 2022-04-21 17:37 ` Josh Poimboeuf 2022-04-21 20:39 ` Peter Zijlstra
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