diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2018-03-19 13:18:57 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-03-20 08:57:17 +0100 |
| commit | 578ae447e7e5d78c90ac40a06406c1741f79ba96 (patch) | |
| tree | e91e9feb3f19beba63e715c8f4fc058ecd8b58a0 | |
| parent | 45dbac0e288350f9a4226a5b4b651ed434dd9f85 (diff) | |
jump_label: Disable jump labels in __exit code
With the following commit:
333522447063 ("jump_label: Explicitly disable jump labels in __init code")
... we explicitly disabled jump labels in __init code, so they could be
detected and not warned about in the following commit:
dc1dd184c2f0 ("jump_label: Warn on failed jump_label patching attempt")
In-kernel __exit code has the same issue. It's never used, so it's
freed along with the rest of initmem. But jump label entries in __exit
code aren't explicitly disabled, so we get the following warning when
enabling pr_debug() in __exit code:
can't patch jump_label at dmi_sysfs_exit+0x0/0x2d
WARNING: CPU: 0 PID: 22572 at kernel/jump_label.c:376 __jump_label_update+0x9d/0xb0
Fix the warning by disabling all jump labels in initmem (which includes
both __init and __exit code).
Reported-and-tested-by: Li Wang <liwang@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dc1dd184c2f0 ("jump_label: Warn on failed jump_label patching attempt")
Link: http://lkml.kernel.org/r/7121e6e595374f06616c505b6e690e275c0054d1.1521483452.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | include/linux/jump_label.h | 4 | ||||
| -rw-r--r-- | init/main.c | 2 | ||||
| -rw-r--r-- | kernel/jump_label.c | 7 |
3 files changed, 7 insertions, 6 deletions
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 2168cc6b8b30..b46b541c67c4 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -151,7 +151,7 @@ extern struct jump_entry __start___jump_table[]; extern struct jump_entry __stop___jump_table[]; extern void jump_label_init(void); -extern void jump_label_invalidate_init(void); +extern void jump_label_invalidate_initmem(void); extern void jump_label_lock(void); extern void jump_label_unlock(void); extern void arch_jump_label_transform(struct jump_entry *entry, @@ -199,7 +199,7 @@ static __always_inline void jump_label_init(void) static_key_initialized = true; } -static inline void jump_label_invalidate_init(void) {} +static inline void jump_label_invalidate_initmem(void) {} static __always_inline bool static_key_false(struct static_key *key) { diff --git a/init/main.c b/init/main.c index 969eaf140ef0..21efbf6ace93 100644 --- a/init/main.c +++ b/init/main.c @@ -1001,7 +1001,7 @@ static int __ref kernel_init(void *unused) /* need to finish all async __init code before freeing the memory */ async_synchronize_full(); ftrace_free_init_mem(); - jump_label_invalidate_init(); + jump_label_invalidate_initmem(); free_initmem(); mark_readonly(); system_state = SYSTEM_RUNNING; diff --git a/kernel/jump_label.c b/kernel/jump_label.c index e7214093dcd1..01ebdf1f9f40 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -16,6 +16,7 @@ #include <linux/jump_label_ratelimit.h> #include <linux/bug.h> #include <linux/cpu.h> +#include <asm/sections.h> #ifdef HAVE_JUMP_LABEL @@ -421,15 +422,15 @@ void __init jump_label_init(void) cpus_read_unlock(); } -/* Disable any jump label entries in __init code */ -void __init jump_label_invalidate_init(void) +/* Disable any jump label entries in __init/__exit code */ +void __init jump_label_invalidate_initmem(void) { struct jump_entry *iter_start = __start___jump_table; struct jump_entry *iter_stop = __stop___jump_table; struct jump_entry *iter; for (iter = iter_start; iter < iter_stop; iter++) { - if (init_kernel_text(iter->code)) + if (init_section_contains((void *)(unsigned long)iter->code, 1)) iter->code = 0; } } |