Messages in this thread Patch in this message |  | | Date | Tue, 29 Dec 2020 21:06:54 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v1 03/19] x86/insn: Add an insn_decode() API |
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On Mon, Dec 28, 2020 at 10:15:10AM +0900, Masami Hiramatsu wrote: > BTW, insn_decode() can return -EINVAL if !insn_complete(), is that OK?
It does with this change. Or are you asking whether it returning -EINVAL in that case is ok?
I don't see why not - this way callers can differentiate where it failed - at fetching bytes with -ENODATA or it wasn't decoded completely - -EINVAL.
> I think tools clone code must not use INSN_MODE_KERN because the tools may > not use kernel Kconfig. > > Hmm, this may be better to make a different patch to introduce a NOSYNC tag > for sync checker in the tools. Something like;
I'd actually prefer this:
diff --git a/tools/arch/x86/include/asm/insn.h b/tools/arch/x86/include/asm/insn.h index f8772b371452..545320c67855 100644 --- a/tools/arch/x86/include/asm/insn.h +++ b/tools/arch/x86/include/asm/insn.h @@ -98,8 +98,6 @@ extern int insn_get_length(struct insn *insn); enum insn_mode { INSN_MODE_32, INSN_MODE_64, - /* Mode is determined by the current kernel build. */ - INSN_MODE_KERN, INSN_NUM_MODES, }; so that when a tool does use INSN_MODE_KERN, it would fail building:
In file included from util/intel-pt-decoder/intel-pt-insn-decoder.c:15: util/intel-pt-decoder/../../../arch/x86/lib/insn.c: In function ‘insn_decode’: util/intel-pt-decoder/../../../arch/x86/lib/insn.c:751:11: error: ‘INSN_MODE_KERN’ undeclared (first use in this function); did you mean ‘INSN_MODE_64’? 751 | if (m == INSN_MODE_KERN) | ^~~~~~~~~~~~~~ | INSN_MODE_64 util/intel-pt-decoder/../../../arch/x86/lib/insn.c:751:11: note: each undeclared identifier is reported only once for each function it appears in LD arch/perf-in.o util/intel-pt-decoder/intel-pt-insn-decoder.c: In function ‘intel_pt_get_insn’: util/intel-pt-decoder/intel-pt-insn-decoder.c:163:37: error: ‘INSN_MODE_KERN’ undeclared (first use in this function); did you mean ‘INSN_MODE_64’? 163 | ret = insn_decode(&insn, buf, len, INSN_MODE_KERN); | ^~~~~~~~~~~~~~ | INSN_MODE_64 Thx.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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