From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv2 6/8] perf tools powerpc: Fix PPC64 ELF ABIv2 symbol decoding
Date: Thu, 12 Mar 2015 17:35:00 -0300 [thread overview]
Message-ID: <20150312203500.GH3550@kernel.org> (raw)
In-Reply-To: <c81364f6bd46c9ab9074fcb107fccf7de63cc56e.1418654436.git.naveen.n.rao@linux.vnet.ibm.com>
Em Mon, Dec 15, 2014 at 08:20:36PM +0530, Naveen N. Rao escreveu:
> PPC64 ELF ABIv2 has a Global Entry Point (GEP) and a Local Entry Point
> (LEP). For purposes of probing, we need the LEP. Offset to the LEP is
> encoded in st_other.
>
> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> ---
> Changes from previous patchset:
> Simplified logic by adding dependancy on HAVE_ARCH_SYMBOL_HANDLING. Also
> generalized arch_elf_sym_decode() to be suitable for other architectures in
> future.
>
> tools/perf/arch/powerpc/util/sym-handling.c | 10 ++++++++++
> tools/perf/util/symbol-elf.c | 2 ++
> tools/perf/util/symbol.h | 6 ++++++
> 3 files changed, 18 insertions(+)
>
> diff --git a/tools/perf/arch/powerpc/util/sym-handling.c b/tools/perf/arch/powerpc/util/sym-handling.c
> index 0a77825..a27bfaf 100644
> --- a/tools/perf/arch/powerpc/util/sym-handling.c
> +++ b/tools/perf/arch/powerpc/util/sym-handling.c
> @@ -1,8 +1,10 @@
> /*
> * Special symbol handling for PowerPC:
> * - Handle dot symbols on ABIv1
> + * - Decode offset from Global entry point to Local entry point on ABIv2
> *
> * Copyright (C) 2014 Naveen N Rao, IBM Corporation.
> + * Copyright (C) 2014 Ananth N Mavinakayanahalli, IBM Corporation.
> *
> * This program is free software; you can redistribute it and/or
> * modify it under the terms of the GNU General Public License
> @@ -26,3 +28,11 @@ int probe_function_filter(struct map *map __maybe_unused, struct symbol *sym)
> }
> return 1;
> }
> +
> +inline void arch_elf_sym_decode(GElf_Sym *sym __maybe_unused)
> +{
> +#if defined(_CALL_ELF) && _CALL_ELF == 2
> + if (sym && sym->st_other)
> + sym->st_value += PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
> +#endif
> +}
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index 7ac4e4c..557b63b 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -902,6 +902,8 @@ int dso__load_sym(struct dso *dso, struct map *map,
> (sym.st_value & 1))
> --sym.st_value;
>
> + arch_elf_sym_decode(&sym);
> +
arch_elf_sym_adjust()?
But this is done the right way, i.e. provide a way for arches to do
adjustments specific to their ABIs, thanks!
- Arnaldo
> if (dso->kernel || kmodule) {
> char dso_name[PATH_MAX];
>
> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> index 9d602e9..9e03cdf 100644
> --- a/tools/perf/util/symbol.h
> +++ b/tools/perf/util/symbol.h
> @@ -294,4 +294,10 @@ int compare_proc_modules(const char *from, const char *to);
> int setup_list(struct strlist **list, const char *list_str,
> const char *list_name);
>
> +#ifdef HAVE_ARCH_SYMBOL_HANDLING
> +extern void arch_elf_sym_decode(GElf_Sym *sym __maybe_unused);
> +#else
> +static inline void arch_elf_sym_decode(GElf_Sym *sym __maybe_unused) { }
> +#endif
> +
> #endif /* __PERF_SYMBOL */
> --
> 2.1.3
next prev parent reply other threads:[~2015-03-12 20:35 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-15 14:50 [PATCHv2 0/8] Fix perf probe issues on powerpc Naveen N. Rao
2014-12-15 14:50 ` [PATCHv2 1/8] kprobes: Fix kallsyms lookup across powerpc ABIv1 and ABIv2 Naveen N. Rao
2014-12-15 14:50 ` [PATCHv2 2/8] perf probe: Improve detection of file/function name in the probe pattern Naveen N. Rao
2015-03-12 20:24 ` Arnaldo Carvalho de Melo
2015-03-12 20:25 ` Arnaldo Carvalho de Melo
2015-03-13 2:03 ` Ananth N Mavinakayanahalli
2015-03-13 11:20 ` Masami Hiramatsu
2015-04-27 5:05 ` Naveen N. Rao
2015-04-27 5:09 ` Naveen N. Rao
2014-12-15 14:50 ` [PATCHv2 3/8] perf probe powerpc: Fix symbol fixup issues due to ELF type Naveen N. Rao
2015-03-12 20:23 ` Arnaldo Carvalho de Melo
2015-04-27 5:06 ` Naveen N. Rao
2014-12-15 14:50 ` [PATCHv2 4/8] perf probe powerpc: Handle powerpc dot symbols Naveen N. Rao
2015-03-12 20:26 ` Arnaldo Carvalho de Melo
2014-12-15 14:50 ` [PATCHv2 5/8] perf probe powerpc: Allow matching against " Naveen N. Rao
2015-03-12 20:30 ` Arnaldo Carvalho de Melo
2015-04-27 5:08 ` Naveen N. Rao
2014-12-15 14:50 ` [PATCHv2 6/8] perf tools powerpc: Fix PPC64 ELF ABIv2 symbol decoding Naveen N. Rao
2015-03-12 20:35 ` Arnaldo Carvalho de Melo [this message]
2014-12-15 14:50 ` [PATCHv2 7/8] perf probe powerpc: Use DWARF info only if necessary Naveen N. Rao
2014-12-15 14:50 ` [PATCHv2 8/8] perf probe powerpc: Fixup function entry if using kallsyms lookup Naveen N. Rao
2015-03-12 20:37 ` Arnaldo Carvalho de Melo
2015-01-28 5:42 ` [PATCHv2 0/8] Fix perf probe issues on powerpc Naveen N. Rao
2015-01-28 6:14 ` Michael Ellerman
2015-01-28 6:43 ` Naveen N. Rao
2015-01-30 2:19 ` Michael Ellerman
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