Re: [PATCH] objtool: continue if find_insn() fails in decode_instructions()
On 09/01/23 22:23, Ingo Molnar wrote:
* Sathvika Vasireddy wrote:
Hi Ingo, Happy New Year!
Happy New Year to you too! :-)
On 07/01/23 15:51, Ingo Molnar wrote:
* Sathvika Vasireddy wrote:
Currently, decode_instructions() is failing if it is not able to find
instruction, and this is happening since commit dbcdbdfdf137b4
("objtool: Rework instruction -> symbol mapping") because it is
expecting instruction for STT_NOTYPE symbols.
Due to this, the following objtool warnings are seen:
[1] arch/powerpc/kernel/optprobes_head.o: warning: objtool:
optprobe_template_end(): can't find starting instruction
[2] arch/powerpc/kernel/kvm_emul.o: warning: objtool: kvm_template_end():
can't find starting instruction
[3] arch/powerpc/kernel/head_64.o: warning: objtool: end_first_256B(): can't
find starting instruction
The warnings are thrown because find_insn() is failing for symbols that
are at the end of the file, or at the end of the section. Given how
STT_NOTYPE symbols are currently handled in decode_instructions(),
continue if the instruction is not found, instead of throwing warning
and returning.
Signed-off-by: Naveen N. Rao
Signed-off-by: Sathvika Vasireddy
The SOB chain doesn't look valid: is Naveen N. Rao, the first SOB line, the
author of the patch? If yes then a matching From: line is needed.
Or if two people developed the patch, then Co-developed-by should be used:
Co-developed-by: First Co-Author
Signed-off-by: First Co-Author
Co-developed-by: Second Co-Author
Signed-off-by: Second Co-Author
[ In this SOB sequence "Second Co-Author" is the one who submits the patch. ]
[ Please only use Co-developed-by if actual lines of code were written by
the co-author that created copyrightable material - it's not a courtesy
tag. Reviewed-by/Acked-by/Tested-by can be used to credit non-code
contributions. ]
Thank you for the clarification, and for bringing these points to my
attention. I'll keep these things in mind. In this case, since both Naveen
N. Rao and I developed the patch, the below tags
are applicable.
Co-developed-by: First Co-Author
Signed-off-by: First Co-Author
Co-developed-by: Second Co-Author
Signed-off-by: Second Co-Author
... while filling in your real names & email addresses I suppose. ;-)
Indeed :-)
However, I would be dropping this particular patch, since I think Nick's
patch [1] is better to fix the objtool issue.
[1] -
https://lore.kernel.org/linuxppc-dev/20221220101323.3119939-1-npig...@gmail.com/
Ok, I'll pick up Nick's fix, with these tags added for the PowerPC
regression aspect and your review:
Reported-by: Naveen N. Rao
Reported-by: Sathvika Vasireddy
Acked-by: Sathvika Vasireddy
To document & credit the efforts of your patch.
Sure, thank you!
- Sathvika
Re: [PATCH] objtool: continue if find_insn() fails in decode_instructions()
* Sathvika Vasireddy wrote:
> Hi Ingo, Happy New Year!
Happy New Year to you too! :-)
> On 07/01/23 15:51, Ingo Molnar wrote:
> > * Sathvika Vasireddy wrote:
> >
> > > Currently, decode_instructions() is failing if it is not able to find
> > > instruction, and this is happening since commit dbcdbdfdf137b4
> > > ("objtool: Rework instruction -> symbol mapping") because it is
> > > expecting instruction for STT_NOTYPE symbols.
> > >
> > > Due to this, the following objtool warnings are seen:
> > > [1] arch/powerpc/kernel/optprobes_head.o: warning: objtool:
> > > optprobe_template_end(): can't find starting instruction
> > > [2] arch/powerpc/kernel/kvm_emul.o: warning: objtool:
> > > kvm_template_end(): can't find starting instruction
> > > [3] arch/powerpc/kernel/head_64.o: warning: objtool: end_first_256B():
> > > can't find starting instruction
> > >
> > > The warnings are thrown because find_insn() is failing for symbols that
> > > are at the end of the file, or at the end of the section. Given how
> > > STT_NOTYPE symbols are currently handled in decode_instructions(),
> > > continue if the instruction is not found, instead of throwing warning
> > > and returning.
> > >
> > > Signed-off-by: Naveen N. Rao
> > > Signed-off-by: Sathvika Vasireddy
> > The SOB chain doesn't look valid: is Naveen N. Rao, the first SOB line, the
> > author of the patch? If yes then a matching From: line is needed.
> >
> > Or if two people developed the patch, then Co-developed-by should be used:
> >
> > Co-developed-by: First Co-Author
> > Signed-off-by: First Co-Author
> > Co-developed-by: Second Co-Author
> > Signed-off-by: Second Co-Author
> >
> > [ In this SOB sequence "Second Co-Author" is the one who submits the patch.
> > ]
> >
> > [ Please only use Co-developed-by if actual lines of code were written by
> >the co-author that created copyrightable material - it's not a courtesy
> >tag. Reviewed-by/Acked-by/Tested-by can be used to credit non-code
> >contributions. ]
> Thank you for the clarification, and for bringing these points to my
> attention. I'll keep these things in mind. In this case, since both Naveen
> N. Rao and I developed the patch, the below tags
> are applicable.
>
> Co-developed-by: First Co-Author
> Signed-off-by: First Co-Author
> Co-developed-by: Second Co-Author
> Signed-off-by: Second Co-Author
... while filling in your real names & email addresses I suppose. ;-)
>
> However, I would be dropping this particular patch, since I think Nick's
> patch [1] is better to fix the objtool issue.
>
> [1] -
> https://lore.kernel.org/linuxppc-dev/20221220101323.3119939-1-npig...@gmail.com/
Ok, I'll pick up Nick's fix, with these tags added for the PowerPC
regression aspect and your review:
Reported-by: Naveen N. Rao
Reported-by: Sathvika Vasireddy
Acked-by: Sathvika Vasireddy
To document & credit the efforts of your patch.
Thanks,
Ingo
Re: [PATCH] objtool: continue if find_insn() fails in decode_instructions()
Hi Ingo, Happy New Year!
On 07/01/23 15:51, Ingo Molnar wrote:
* Sathvika Vasireddy wrote:
Currently, decode_instructions() is failing if it is not able to find
instruction, and this is happening since commit dbcdbdfdf137b4
("objtool: Rework instruction -> symbol mapping") because it is
expecting instruction for STT_NOTYPE symbols.
Due to this, the following objtool warnings are seen:
[1] arch/powerpc/kernel/optprobes_head.o: warning: objtool:
optprobe_template_end(): can't find starting instruction
[2] arch/powerpc/kernel/kvm_emul.o: warning: objtool: kvm_template_end():
can't find starting instruction
[3] arch/powerpc/kernel/head_64.o: warning: objtool: end_first_256B(): can't
find starting instruction
The warnings are thrown because find_insn() is failing for symbols that
are at the end of the file, or at the end of the section. Given how
STT_NOTYPE symbols are currently handled in decode_instructions(),
continue if the instruction is not found, instead of throwing warning
and returning.
Signed-off-by: Naveen N. Rao
Signed-off-by: Sathvika Vasireddy
The SOB chain doesn't look valid: is Naveen N. Rao, the first SOB line, the
author of the patch? If yes then a matching From: line is needed.
Or if two people developed the patch, then Co-developed-by should be used:
Co-developed-by: First Co-Author
Signed-off-by: First Co-Author
Co-developed-by: Second Co-Author
Signed-off-by: Second Co-Author
[ In this SOB sequence "Second Co-Author" is the one who submits the patch. ]
[ Please only use Co-developed-by if actual lines of code were written by
the co-author that created copyrightable material - it's not a courtesy
tag. Reviewed-by/Acked-by/Tested-by can be used to credit non-code
contributions. ]
Thank you for the clarification, and for bringing these points to my
attention. I'll keep these things in mind. In this case, since both
Naveen N. Rao and I developed the patch, the below tags
are applicable.
Co-developed-by: First Co-Author
Signed-off-by: First Co-Author
Co-developed-by: Second Co-Author
Signed-off-by: Second Co-Author
However, I would be dropping this particular patch, since I think Nick's
patch [1] is better to fix the objtool issue.
[1] -
https://lore.kernel.org/linuxppc-dev/20221220101323.3119939-1-npig...@gmail.com/
Thanks for reviewing!
- Sathvika
Re: [PATCH] objtool: continue if find_insn() fails in decode_instructions()
* Sathvika Vasireddy wrote:
> Currently, decode_instructions() is failing if it is not able to find
> instruction, and this is happening since commit dbcdbdfdf137b4
> ("objtool: Rework instruction -> symbol mapping") because it is
> expecting instruction for STT_NOTYPE symbols.
>
> Due to this, the following objtool warnings are seen:
> [1] arch/powerpc/kernel/optprobes_head.o: warning: objtool:
> optprobe_template_end(): can't find starting instruction
> [2] arch/powerpc/kernel/kvm_emul.o: warning: objtool: kvm_template_end():
> can't find starting instruction
> [3] arch/powerpc/kernel/head_64.o: warning: objtool: end_first_256B(): can't
> find starting instruction
>
> The warnings are thrown because find_insn() is failing for symbols that
> are at the end of the file, or at the end of the section. Given how
> STT_NOTYPE symbols are currently handled in decode_instructions(),
> continue if the instruction is not found, instead of throwing warning
> and returning.
>
> Signed-off-by: Naveen N. Rao
> Signed-off-by: Sathvika Vasireddy
The SOB chain doesn't look valid: is Naveen N. Rao, the first SOB line, the
author of the patch? If yes then a matching From: line is needed.
Or if two people developed the patch, then Co-developed-by should be used:
Co-developed-by: First Co-Author
Signed-off-by: First Co-Author
Co-developed-by: Second Co-Author
Signed-off-by: Second Co-Author
[ In this SOB sequence "Second Co-Author" is the one who submits the patch. ]
[ Please only use Co-developed-by if actual lines of code were written by
the co-author that created copyrightable material - it's not a courtesy
tag. Reviewed-by/Acked-by/Tested-by can be used to credit non-code
contributions. ]
Thanks,
Ingo
[PATCH] objtool: continue if find_insn() fails in decode_instructions()
Currently, decode_instructions() is failing if it is not able to find
instruction, and this is happening since commit dbcdbdfdf137b4
("objtool: Rework instruction -> symbol mapping") because it is
expecting instruction for STT_NOTYPE symbols.
Due to this, the following objtool warnings are seen:
[1] arch/powerpc/kernel/optprobes_head.o: warning: objtool:
optprobe_template_end(): can't find starting instruction
[2] arch/powerpc/kernel/kvm_emul.o: warning: objtool: kvm_template_end():
can't find starting instruction
[3] arch/powerpc/kernel/head_64.o: warning: objtool: end_first_256B(): can't
find starting instruction
The warnings are thrown because find_insn() is failing for symbols that
are at the end of the file, or at the end of the section. Given how
STT_NOTYPE symbols are currently handled in decode_instructions(),
continue if the instruction is not found, instead of throwing warning
and returning.
Signed-off-by: Naveen N. Rao
Signed-off-by: Sathvika Vasireddy
---
tools/objtool/check.c | 7 ++-
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 4350be739f4f..bce2be5ebf36 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -430,11 +430,8 @@ static int decode_instructions(struct objtool_file *file)
if (func->return_thunk || func->alias != func)
continue;
- if (!find_insn(file, sec, func->offset)) {
- WARN("%s(): can't find starting instruction",
-func->name);
- return -1;
- }
+ if (!find_insn(file, sec, func->offset))
+ continue;
sym_for_each_insn(file, func, insn) {
insn->sym = func;
--
2.31.1
