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fprobe: Resolve symbols with ftrace_lookup_symbols

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Using ftrace_lookup_symbols to speed up symbols lookup
in register_fprobe_syms API.

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220510122616.2652285-4-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jiri Olsa 2022-05-10 14:26:14 +02:00 committed by Alexei Starovoitov
parent bed0d9a50d
commit 8be9253344
1 changed files with 12 additions and 20 deletions
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32
kernel/trace/fprobe.c
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@ -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);
}