From 8be9253344a1d8cd91b22655e55de41e3288aaf9 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Tue, 10 May 2022 14:26:14 +0200 Subject: [PATCH] fprobe: Resolve symbols with ftrace_lookup_symbols Using ftrace_lookup_symbols to speed up symbols lookup in register_fprobe_syms API. Acked-by: Masami Hiramatsu Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20220510122616.2652285-4-jolsa@kernel.org Signed-off-by: Alexei Starovoitov --- kernel/trace/fprobe.c | 32 ++++++++++++-------------------- 1 file changed, 12 insertions(+), 20 deletions(-) diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index 89d9f994ebb0..aac63ca9c3d1 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -85,39 +85,31 @@ static void fprobe_exit_handler(struct rethook_node *rh, void *data, } NOKPROBE_SYMBOL(fprobe_exit_handler); +static int symbols_cmp(const void *a, const void *b) +{ + const char **str_a = (const char **) a; + const char **str_b = (const char **) b; + + return strcmp(*str_a, *str_b); +} + /* Convert ftrace location address from symbols */ static unsigned long *get_ftrace_locations(const char **syms, int num) { - unsigned long addr, size; unsigned long *addrs; - int i; /* Convert symbols to symbol address */ addrs = kcalloc(num, sizeof(*addrs), GFP_KERNEL); if (!addrs) return ERR_PTR(-ENOMEM); - for (i = 0; i < num; i++) { - addr = kallsyms_lookup_name(syms[i]); - if (!addr) /* Maybe wrong symbol */ - goto error; + /* ftrace_lookup_symbols expects sorted symbols */ + sort(syms, num, sizeof(*syms), symbols_cmp, NULL); - /* Convert symbol address to ftrace location. */ - if (!kallsyms_lookup_size_offset(addr, &size, NULL) || !size) - goto error; + if (!ftrace_lookup_symbols(syms, num, addrs)) + return addrs; - addr = ftrace_location_range(addr, addr + size - 1); - if (!addr) /* No dynamic ftrace there. */ - goto error; - - addrs[i] = addr; - } - - return addrs; - -error: kfree(addrs); - return ERR_PTR(-ENOENT); }