diff options
author | Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> | 2010-12-17 22:12:18 +0900 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2010-12-21 19:24:57 -0200 |
commit | 3b4694de3596edac0159524b15a4a06945875421 (patch) | |
tree | 479f76d879f9512ada46f495ef7e602d460c74d8 /tools/perf | |
parent | ea187cfbb9a3de73e7bd7b7125ae345d92d4384b (diff) |
perf probe: Fix to support libdwfl older than 0.148
Since the libdwfl library before 0.148 fails to analyze live kernel debuginfo,
'perf probe --list' compiled with those old libdwfl sometimes crashes.
To avoid that bug, perf probe does not use libdwfl's live kernel analysis
routine when it is compiled with older libdwfl.
Side effect: perf with older libdwfl doesn't support listing probe in modules
with source code line. Those could be shown by symbol+offset.
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20101217131218.24123.62424.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r-- | tools/perf/util/probe-finder.c | 85 |
1 files changed, 55 insertions, 30 deletions
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 3991d73d1cff..ddf4d4556321 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -117,28 +117,6 @@ static void line_list__free(struct list_head *head) } /* Dwarf FL wrappers */ - -static int __linux_kernel_find_elf(Dwfl_Module *mod, - void **userdata, - const char *module_name, - Dwarf_Addr base, - char **file_name, Elf **elfp) -{ - int fd; - const char *path = kernel_get_module_path(module_name); - - if (path) { - fd = open(path, O_RDONLY); - if (fd >= 0) { - *file_name = strdup(path); - return fd; - } - } - /* If failed, try to call standard method */ - return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base, - file_name, elfp); -} - static char *debuginfo_path; /* Currently dummy */ static const Dwfl_Callbacks offline_callbacks = { @@ -151,14 +129,6 @@ static const Dwfl_Callbacks offline_callbacks = { .find_elf = dwfl_build_id_find_elf, }; -static const Dwfl_Callbacks kernel_callbacks = { - .find_debuginfo = dwfl_standard_find_debuginfo, - .debuginfo_path = &debuginfo_path, - - .find_elf = __linux_kernel_find_elf, - .section_address = dwfl_linux_kernel_module_section_address, -}; - /* Get a Dwarf from offline image */ static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias) { @@ -185,6 +155,38 @@ error: return dbg; } +#if _ELFUTILS_PREREQ(0, 148) +/* This method is buggy if elfutils is older than 0.148 */ +static int __linux_kernel_find_elf(Dwfl_Module *mod, + void **userdata, + const char *module_name, + Dwarf_Addr base, + char **file_name, Elf **elfp) +{ + int fd; + const char *path = kernel_get_module_path(module_name); + + pr_debug2("Use file %s for %s\n", path, module_name); + if (path) { + fd = open(path, O_RDONLY); + if (fd >= 0) { + *file_name = strdup(path); + return fd; + } + } + /* If failed, try to call standard method */ + return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base, + file_name, elfp); +} + +static const Dwfl_Callbacks kernel_callbacks = { + .find_debuginfo = dwfl_standard_find_debuginfo, + .debuginfo_path = &debuginfo_path, + + .find_elf = __linux_kernel_find_elf, + .section_address = dwfl_linux_kernel_module_section_address, +}; + /* Get a Dwarf from live kernel image */ static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp, Dwarf_Addr *bias) @@ -205,11 +207,34 @@ static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp, dbg = dwfl_addrdwarf(*dwflp, addr, bias); /* Here, check whether we could get a real dwarf */ if (!dbg) { + pr_debug("Failed to find kernel dwarf at %lx\n", + (unsigned long)addr); dwfl_end(*dwflp); *dwflp = NULL; } return dbg; } +#else +/* With older elfutils, this just support kernel module... */ +static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr __used, Dwfl **dwflp, + Dwarf_Addr *bias) +{ + int fd; + const char *path = kernel_get_module_path("kernel"); + + if (!path) { + pr_err("Failed to find vmlinux path\n"); + return NULL; + } + + pr_debug2("Use file %s for debuginfo\n", path); + fd = open(path, O_RDONLY); + if (fd < 0) + return NULL; + + return dwfl_init_offline_dwarf(fd, dwflp, bias); +} +#endif /* Dwarf wrappers */ |