diff options
| author | Benjamin Gray <bgray@linux.ibm.com> | 2022-11-09 15:51:05 +1100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-11-30 21:46:48 +1100 |
| commit | 071c95c1acbd96e76bab8b25b5cad0d71a011f37 (patch) | |
| tree | ba49701bb0bb0f32c37250a8e535f7141c1df247 | |
| parent | 3671f4ebe3eb12e7222e4d7b0f94e85cfe34253a (diff) | |
powerpc/code-patching: Use WARN_ON and fix check in poking_init
BUG_ON() when failing to initialise the code patching window is
unnecessary, and use of BUG_ON is discouraged. We don't set
poking_init_done in this case, so failure to init the boot CPU will
result in a strict RWX error when a following patch_instruction uses
raw_patch_instruction. If it only fails for later CPUs, they won't be
onlined in the first place.
The return value of cpuhp_setup_state() is also >= 0 on success,
so check for < 0.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221109045112.187069-3-bgray@linux.ibm.com
| -rw-r--r-- | arch/powerpc/lib/code-patching.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index ad0cf3108dd0..3055eef7dcdc 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -81,16 +81,17 @@ static int text_area_cpu_down(unsigned int cpu) static __ro_after_init DEFINE_STATIC_KEY_FALSE(poking_init_done); -/* - * Although BUG_ON() is rude, in this case it should only happen if ENOMEM, and - * we judge it as being preferable to a kernel that will crash later when - * someone tries to use patch_instruction(). - */ void __init poking_init(void) { - BUG_ON(!cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, - "powerpc/text_poke:online", text_area_cpu_up, - text_area_cpu_down)); + int ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, + "powerpc/text_poke:online", + text_area_cpu_up, + text_area_cpu_down); + + /* cpuhp_setup_state returns >= 0 on success */ + if (WARN_ON(ret < 0)) + return; + static_branch_enable(&poking_init_done); } |