Keeping the resolved 'addr' in kallsyms_callback, instead of taking
ftrace_location value, because we depend on symbol address in the
cookie related code.
With CONFIG_X86_KERNEL_IBT option the ftrace_location value differs
from symbol address, which screwes the symbol address cookies matching.
There are 2 users of this function:
- bpf_kprobe_multi_link_attach
for which this fix is for
- get_ftrace_locations
which is used by register_fprobe_syms
this function needs to get symbols resolved to addresses,
but does not need 'ftrace location addresses' at this point
there's another ftrace location translation in the path done
by ftrace_set_filter_ips call:
register_fprobe_syms
addrs = get_ftrace_locations
register_fprobe_ips(addrs)
...
ftrace_set_filter_ips
...
__ftrace_match_addr
ip = ftrace_location(ip);
...
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
kernel/trace/ftrace.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 439e2ab6905e..447d2e2a8549 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -8265,8 +8265,7 @@ static int kallsyms_callback(void *data, const char *name,
if (args->addrs[idx])
return 0;
- addr = ftrace_location(addr);
- if (!addr)
+ if (!ftrace_location(addr))
return 0;
args->addrs[idx] = addr;
--
2.37.3
