| Message ID | 20221208072813.25799-1-sv@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | objtool: continue if find_insn() fails in decode_instructions() | expand |
* Sathvika Vasireddy <sv@linux.ibm.com> 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 <naveen.n.rao@linux.vnet.ibm.com> > Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> 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 <first@coauthor.example.org> Signed-off-by: First Co-Author <first@coauthor.example.org> Co-developed-by: Second Co-Author <second@coauthor.example.org> Signed-off-by: Second Co-Author <second@coauthor.example.org> [ 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
Hi Ingo, Happy New Year! On 07/01/23 15:51, Ingo Molnar wrote: > * Sathvika Vasireddy <sv@linux.ibm.com> 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 <naveen.n.rao@linux.vnet.ibm.com> >> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> > 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 <first@coauthor.example.org> > Signed-off-by: First Co-Author <first@coauthor.example.org> > Co-developed-by: Second Co-Author <second@coauthor.example.org> > Signed-off-by: Second Co-Author <second@coauthor.example.org> > > [ 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 <first@coauthor.example.org> Signed-off-by: First Co-Author <first@coauthor.example.org> Co-developed-by: Second Co-Author <second@coauthor.example.org> Signed-off-by: Second Co-Author <second@coauthor.example.org> 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-npiggin@gmail.com/ Thanks for reviewing! - Sathvika
* Sathvika Vasireddy <sv@linux.ibm.com> wrote: > Hi Ingo, Happy New Year! Happy New Year to you too! :-) > On 07/01/23 15:51, Ingo Molnar wrote: > > * Sathvika Vasireddy <sv@linux.ibm.com> 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 <naveen.n.rao@linux.vnet.ibm.com> > > > Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> > > 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 <first@coauthor.example.org> > > Signed-off-by: First Co-Author <first@coauthor.example.org> > > Co-developed-by: Second Co-Author <second@coauthor.example.org> > > Signed-off-by: Second Co-Author <second@coauthor.example.org> > > > > [ 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 <first@coauthor.example.org> > Signed-off-by: First Co-Author <first@coauthor.example.org> > Co-developed-by: Second Co-Author <second@coauthor.example.org> > Signed-off-by: Second Co-Author <second@coauthor.example.org> ... 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-npiggin@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 <naveen.n.rao@linux.vnet.ibm.com> Reported-by: Sathvika Vasireddy <sv@linux.ibm.com> Acked-by: Sathvika Vasireddy <sv@linux.ibm.com> To document & credit the efforts of your patch. Thanks, Ingo
On 09/01/23 22:23, Ingo Molnar wrote: > * Sathvika Vasireddy <sv@linux.ibm.com> wrote: > >> Hi Ingo, Happy New Year! > Happy New Year to you too! :-) > >> On 07/01/23 15:51, Ingo Molnar wrote: >>> * Sathvika Vasireddy <sv@linux.ibm.com> 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 <naveen.n.rao@linux.vnet.ibm.com> >>>> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> >>> 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 <first@coauthor.example.org> >>> Signed-off-by: First Co-Author <first@coauthor.example.org> >>> Co-developed-by: Second Co-Author <second@coauthor.example.org> >>> Signed-off-by: Second Co-Author <second@coauthor.example.org> >>> >>> [ 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 <first@coauthor.example.org> >> Signed-off-by: First Co-Author <first@coauthor.example.org> >> Co-developed-by: Second Co-Author <second@coauthor.example.org> >> Signed-off-by: Second Co-Author <second@coauthor.example.org> > ... 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-npiggin@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 <naveen.n.rao@linux.vnet.ibm.com> > Reported-by: Sathvika Vasireddy <sv@linux.ibm.com> > Acked-by: Sathvika Vasireddy <sv@linux.ibm.com> > > To document & credit the efforts of your patch. Sure, thank you! - Sathvika
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;
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 <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> --- tools/objtool/check.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)