Re: [PATCH] tools/perf/tests: Update is_ignored_symbol function in vmlinux-kallsyms test

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Wed, Sep 28, 2022 at 10:22:18AM +0530, Athira Rajeev escreveu:
> The testcase “vmlinux-kallsyms.c” fails in powerpc.
> 
> 	vmlinux symtab matches kallsyms: FAILED!

Thanks, applied.

- Arnaldo

 
> This test look at the symbols in the vmlinux DSO
> and check if we find all of them in the kallsyms dso.
> But from the powerpc logs , observed that the failure
> happens for:
> 	ERR : 0xc0000000000fe9c8: .Lmfspr_table not on kallsyms
> 	ERR : 0xc0000000001009c8: .Lmtspr_table not on kallsyms
> 
> These are labels ( with .L) in the source code and
> has to be ignored. Reference code with .Lmtspr_table:
> arch/powerpc/xmon/spr_access.S
> 
> The testcases invokes is_ignored_symbol() function to
> ignore hidden symbols in the dso like local symbols. This
> function is adapted from is_ignored_symbol() kernel
> function in code: scripts/kallsyms.c . The kernel
> function got some updates which is not reflected in
> the testcase function and the new updates also handles
> ignoring "labels".
> 
> Below is the changes that went in the kernel function.
> 
> 	 /* Symbol names that begin with the following are ignored.*/
> 	 static const char * const ignored_prefixes[] = {
> 	 		"$",			/* local symbols for ARM, MIPS, etc. */
> 	-		".LASANPC",		/* s390 kasan local symbols */
> 	+		".L",			/* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */
> 	 		"__crc_",		/* modversions */
> 	 		"__efistub_",		/* arm64 EFI stub namespace */
> 	-		"__kvm_nvhe_",		/* arm64 non-VHE KVM namespace */
> 	+		"__kvm_nvhe_$",		/* arm64 local symbols in non-VHE KVM namespace */
> 	+		"__kvm_nvhe_.L",	/* arm64 local symbols in non-VHE KVM namespace */
> 	 		"__AArch64ADRPThunk_",	/* arm64 lld */
> 	 		"__ARMV5PILongThunk_",	/* arm lld */
> 	 		"__ARMV7PILongThunk_",
> 
> This change is part of below commits and will handle the
> symbols with “.L”
> 
> commit d4c858643263 ("kallsyms: ignore all local labels prefixed
> by '.L'")
> commit 6ccf9cb557bd ("KVM: arm64: Symbolize the nVHE HYP addresses")
> 
> Update the testcase function to include the new
> changes.
> 
> Reported-by: Disha Goel <disgoel@linux.vnet.ibm.com>
> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> ---
>  tools/perf/tests/vmlinux-kallsyms.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/tests/vmlinux-kallsyms.c b/tools/perf/tests/vmlinux-kallsyms.c
> index 4fd8d703ff19..8ab035b55875 100644
> --- a/tools/perf/tests/vmlinux-kallsyms.c
> +++ b/tools/perf/tests/vmlinux-kallsyms.c
> @@ -43,10 +43,11 @@ static bool is_ignored_symbol(const char *name, char type)
>  	/* Symbol names that begin with the following are ignored.*/
>  	static const char * const ignored_prefixes[] = {
>  		"$",			/* local symbols for ARM, MIPS, etc. */
> -		".LASANPC",		/* s390 kasan local symbols */
> +		".L",			/* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */
>  		"__crc_",		/* modversions */
>  		"__efistub_",		/* arm64 EFI stub namespace */
> -		"__kvm_nvhe_",		/* arm64 non-VHE KVM namespace */
> +		"__kvm_nvhe_$",		/* arm64 local symbols in non-VHE KVM namespace */
> +		"__kvm_nvhe_.L",	/* arm64 local symbols in non-VHE KVM namespace */
>  		"__AArch64ADRPThunk_",	/* arm64 lld */
>  		"__ARMV5PILongThunk_",	/* arm lld */
>  		"__ARMV7PILongThunk_",
> -- 
> 2.31.1

-- 

- Arnaldo