From c5f4546593e9911800f0926c1090959b58bc5c93 Mon Sep 17 00:00:00 2001 From: Seth Jennings Date: Tue, 16 Dec 2014 11:58:18 -0600 Subject: livepatch: kernel: add TAINT_LIVEPATCH This adds a new taint flag to indicate when the kernel or a kernel module has been live patched. This will provide a clean indication in bug reports that live patching was used. Additionally, if the crash occurs in a live patched function, the live patch module will appear beside the patched function in the backtrace. Signed-off-by: Seth Jennings Acked-by: Josh Poimboeuf Reviewed-by: Miroslav Benes Reviewed-by: Petr Mladek Reviewed-by: Masami Hiramatsu Signed-off-by: Jiri Kosina --- include/linux/kernel.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 5449d2f4a1ef..d03e3deee091 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -471,6 +471,7 @@ extern enum system_states { #define TAINT_OOT_MODULE 12 #define TAINT_UNSIGNED_MODULE 13 #define TAINT_SOFTLOCKUP 14 +#define TAINT_LIVEPATCH 15 extern const char hex_asc[]; #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] -- cgit v1.2.3 From 00845eb968ead28007338b2bb852b8beef816583 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 1 Feb 2015 12:23:32 -0800 Subject: sched: don't cause task state changes in nested sleep debugging MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 8eb23b9f35aa ("sched: Debug nested sleeps") added code to report on nested sleep conditions, which we generally want to avoid because the inner sleeping operation can re-set the thread state to TASK_RUNNING, but that will then cause the outer sleep loop not actually sleep when it calls schedule. However, that's actually valid traditional behavior, with the inner sleep being some fairly rare case (like taking a sleeping lock that normally doesn't actually need to sleep). And the debug code would actually change the state of the task to TASK_RUNNING internally, which makes that kind of traditional and working code not work at all, because now the nested sleep doesn't just sometimes cause the outer one to not block, but will cause it to happen every time. In particular, it will cause the cardbus kernel daemon (pccardd) to basically busy-loop doing scheduling, converting a laptop into a heater, as reported by Bruno Prémont. But there may be other legacy uses of that nested sleep model in other drivers that are also likely to never get converted to the new model. This fixes both cases: - don't set TASK_RUNNING when the nested condition happens (note: even if WARN_ONCE() only _warns_ once, the return value isn't whether the warning happened, but whether the condition for the warning was true. So despite the warning only happening once, the "if (WARN_ON(..))" would trigger for every nested sleep. - in the cases where we knowingly disable the warning by using "sched_annotate_sleep()", don't change the task state (that is used for all core scheduling decisions), instead use '->task_state_change' that is used for the debugging decision itself. (Credit for the second part of the fix goes to Oleg Nesterov: "Can't we avoid this subtle change in behaviour DEBUG_ATOMIC_SLEEP adds?" with the suggested change to use 'task_state_change' as part of the test) Reported-and-bisected-by: Bruno Prémont Tested-by: Rafael J Wysocki Acked-by: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner , Cc: Ilya Dryomov , Cc: Mike Galbraith Cc: Ingo Molnar Cc: Peter Hurley , Cc: Davidlohr Bueso , Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 5449d2f4a1ef..64ce58bee6f5 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -176,7 +176,7 @@ extern int _cond_resched(void); */ # define might_sleep() \ do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) -# define sched_annotate_sleep() __set_current_state(TASK_RUNNING) +# define sched_annotate_sleep() (current->task_state_change = 0) #else static inline void ___might_sleep(const char *file, int line, int preempt_offset) { } -- cgit v1.2.3 From 02f1f2170d2831b3233e91091c60a66622f29e82 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Thu, 12 Feb 2015 15:01:31 -0800 Subject: kernel.h: remove ancient __FUNCTION__ hack __FUNCTION__ hasn't been treated as a string literal since gcc 3.4, so this only helps people who only test-compile using 3.3 (compiler-gcc3.h barks at anything older than that). Besides, there are almost no occurrences of __FUNCTION__ left in the tree. [akpm@linux-foundation.org: convert remaining __FUNCTION__ references] Signed-off-by: Rasmus Villemoes Cc: Michal Nazarewicz Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index e42e7dc34c68..d6d630d31ef3 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -800,9 +800,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } const typeof( ((type *)0)->member ) *__mptr = (ptr); \ (type *)( (char *)__mptr - offsetof(type,member) );}) -/* Trap pasters of __FUNCTION__ at compile-time */ -#define __FUNCTION__ (__func__) - /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ #ifdef CONFIG_FTRACE_MCOUNT_RECORD # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD -- cgit v1.2.3