diff options
| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2022-02-15 19:31:23 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-02-16 23:09:47 +1100 |
| commit | df45a55788286c541449d82ee09fef3ac5ff77a1 (patch) | |
| tree | 6cac61e962dd1bf768a0fcbf9a90297720a91efc /arch/powerpc/kernel/trace | |
| parent | 34d8dac807f0ee3dc42ab45bdb284a3caf2b5ed1 (diff) | |
| download | linux-next-df45a55788286c541449d82ee09fef3ac5ff77a1.tar.gz | |
powerpc/ftrace: Add recursion protection in prepare_ftrace_return()
The function_graph_enter() does not provide any recursion protection.
Add a protection in prepare_ftrace_return() in case
function_graph_enter() calls something that gets
function graph traced.
Fixes: 830213786c49 ("powerpc/ftrace: directly call of function graph tracer by ftrace caller")
Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/74edf2ff0a60e66b0d9225a137100a86a0557032.1644949750.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/kernel/trace')
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 74a176e394ef..f21b8fbd418e 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -944,6 +944,7 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp) { unsigned long return_hooker; + int bit; if (unlikely(ftrace_graph_is_dead())) goto out; @@ -951,10 +952,16 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip, if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; + bit = ftrace_test_recursion_trylock(ip, parent); + if (bit < 0) + goto out; + return_hooker = ppc_function_entry(return_to_handler); if (!function_graph_enter(parent, ip, 0, (unsigned long *)sp)) parent = return_hooker; + + ftrace_test_recursion_unlock(bit); out: return parent; } |