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ftrace: Keep address offset in ftrace_lookup_symbols 

We want to store the resolved address on the same index as
the symbol string, because that's the user (bpf kprobe link)
code assumption.

Also making sure we don't store duplicates that might be
present in kallsyms.

Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fixes: bed0d9a50d ("ftrace: Add ftrace_lookup_symbols function")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220615112118.497303-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jiri Olsa 2022-06-15 13:21:16 +02:00 committed by Alexei Starovoitov
parent ad8848535e
commit eb1b2985fe
1 changed files with 11 additions and 2 deletions
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13
kernel/trace/ftrace.c
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@ -8029,15 +8029,23 @@ static int kallsyms_callback(void *data, const char *name,
struct module *mod, unsigned long addr)
{
struct kallsyms_data *args = data;
const char **sym;
int idx;
if (!bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp))
sym = bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp);
if (!sym)
return 0;
idx = sym - args->syms;
if (args->addrs[idx])
return 0;
addr = ftrace_location(addr);
if (!addr)
return 0;
args->addrs[args->found++] = addr;
args->addrs[idx] = addr;
args->found++;
return args->found == args->cnt ? 1 : 0;
}
@ -8062,6 +8070,7 @@ int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *a
struct kallsyms_data args;
int err;
memset(addrs, 0, sizeof(*addrs) * cnt);
args.addrs = addrs;
args.syms = sorted_syms;
args.cnt = cnt;