From 4d004365e25251002935fc3843d80934248ad3ed Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Tue, 22 May 2018 13:54:34 +0300 Subject: [PATCH] perf machine: Fix map_groups__split_kallsyms() for entry trampoline symbols When kernel symbols are derived from /proc/kallsyms only (not using vmlinux or /proc/kcore) map_groups__split_kallsyms() is used. However that function makes assumptions that are not true with entry trampoline symbols. For now, remove the entry trampoline symbols at that point, as they are no longer needed at that point. Signed-off-by: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Andy Lutomirski Cc: Dave Hansen Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Joerg Roedel Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1526986485-6562-7-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/map.h | 8 ++++++++ tools/perf/util/symbol.c | 13 +++++++++++++ 2 files changed, 21 insertions(+) diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h index f1afe1ab6ff7..fafcc375ed37 100644 --- a/tools/perf/util/map.h +++ b/tools/perf/util/map.h @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include "rwsem.h" @@ -239,4 +240,11 @@ static inline bool __map__is_kmodule(const struct map *map) bool map__has_symbols(const struct map *map); +#define ENTRY_TRAMPOLINE_NAME "__entry_SYSCALL_64_trampoline" + +static inline bool is_entry_trampoline(const char *name) +{ + return !strcmp(name, ENTRY_TRAMPOLINE_NAME); +} + #endif /* __PERF_MAP_H */ diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 701144094183..929058da6727 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -737,12 +737,15 @@ static int map_groups__split_kallsyms(struct map_groups *kmaps, struct dso *dso, struct rb_root *root = &dso->symbols; struct rb_node *next = rb_first(root); int kernel_range = 0; + bool x86_64; if (!kmaps) return -1; machine = kmaps->machine; + x86_64 = machine__is(machine, "x86_64"); + while (next) { char *module; @@ -790,6 +793,16 @@ static int map_groups__split_kallsyms(struct map_groups *kmaps, struct dso *dso, */ pos->start = curr_map->map_ip(curr_map, pos->start); pos->end = curr_map->map_ip(curr_map, pos->end); + } else if (x86_64 && is_entry_trampoline(pos->name)) { + /* + * These symbols are not needed anymore since the + * trampoline maps refer to the text section and it's + * symbols instead. Avoid having to deal with + * relocations, and the assumption that the first symbol + * is the start of kernel text, by simply removing the + * symbols at this point. + */ + goto discard_symbol; } else if (curr_map != initial_map) { char dso_name[PATH_MAX]; struct dso *ndso; -- 2.30.2