From f45d85ff1f3f13d5b67fecb291edc6a771db0c53 Mon Sep 17 00:00:00 2001 From: HATAYAMA Daisuke Date: Tue, 30 Jun 2015 14:57:43 -0700 Subject: kernel/panic: call the 2nd crash_kexec() only if crash_kexec_post_notifiers is enabled For compatibility with the behaviour before the commit f06e5153f4ae2e ("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers"), the 2nd crash_kexec() should be called only if crash_kexec_post_notifiers is enabled. Note that crash_kexec() returns immediately if kdump crash kernel is not loaded, so in this case, this patch makes no functionality change, but the point is to make it explicit, from the caller panic() side, that the 2nd crash_kexec() does nothing. Signed-off-by: HATAYAMA Daisuke Suggested-by: Ingo Molnar Cc: "Eric W. Biederman" Cc: Vivek Goyal Cc: Masami Hiramatsu Cc: Hidehiro Kawai Cc: Baoquan He Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/panic.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/panic.c b/kernel/panic.c index 8136ad76e5fd..774614f72cbd 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -142,7 +142,8 @@ void panic(const char *fmt, ...) * Note: since some panic_notifiers can make crashed kernel * more unstable, it can increase risks of the kdump failure too. */ - crash_kexec(NULL); + if (crash_kexec_post_notifiers) + crash_kexec(NULL); bust_spinlocks(0); -- cgit v1.2.3 From 5375b708f2547f70cd2bee2fd8663ab7035f9551 Mon Sep 17 00:00:00 2001 From: HATAYAMA Daisuke Date: Tue, 30 Jun 2015 14:57:46 -0700 Subject: kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path Commit f06e5153f4ae2e ("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers") introduced "crash_kexec_post_notifiers" kernel boot option, which toggles wheather panic() calls crash_kexec() before panic_notifiers and dump kmsg or after. The problem is that the commit overlooks panic_on_oops kernel boot option. If it is enabled, crash_kexec() is called directly without going through panic() in oops path. To fix this issue, this patch adds a check to "crash_kexec_post_notifiers" in the condition of kexec_should_crash(). Also, put a comment in kexec_should_crash() to explain not obvious things on this patch. Signed-off-by: HATAYAMA Daisuke Acked-by: Baoquan He Tested-by: Hidehiro Kawai Reviewed-by: Masami Hiramatsu Cc: Vivek Goyal Cc: Ingo Molnar Cc: Hidehiro Kawai Cc: Baoquan He Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 3 +++ kernel/kexec.c | 11 +++++++++++ kernel/panic.c | 2 +- 3 files changed, 15 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 5acf5b70866d..0dfa4e31563d 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -439,6 +439,9 @@ extern int panic_on_unrecovered_nmi; extern int panic_on_io_nmi; extern int panic_on_warn; extern int sysctl_panic_on_stackoverflow; + +extern bool crash_kexec_post_notifiers; + /* * Only to be used by arch init code. If the user over-wrote the default * CONFIG_PANIC_TIMEOUT, honor it. diff --git a/kernel/kexec.c b/kernel/kexec.c index 7a36fdcca5bf..a785c1015e25 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -84,6 +84,17 @@ struct resource crashk_low_res = { int kexec_should_crash(struct task_struct *p) { + /* + * If crash_kexec_post_notifiers is enabled, don't run + * crash_kexec() here yet, which must be run after panic + * notifiers in panic(). + */ + if (crash_kexec_post_notifiers) + return 0; + /* + * There are 4 panic() calls in do_exit() path, each of which + * corresponds to each of these 4 conditions. + */ if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) return 1; return 0; diff --git a/kernel/panic.c b/kernel/panic.c index 774614f72cbd..04e91ff7560b 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -32,7 +32,7 @@ static unsigned long tainted_mask; static int pause_on_oops; static int pause_on_oops_flag; static DEFINE_SPINLOCK(pause_on_oops_lock); -static bool crash_kexec_post_notifiers; +bool crash_kexec_post_notifiers; int panic_on_warn __read_mostly; int panic_timeout = CONFIG_PANIC_TIMEOUT; -- cgit v1.2.3 From 3e44c471a2dab210f7e9b1e5f7d4d54d52df59eb Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes Date: Tue, 30 Jun 2015 14:57:49 -0700 Subject: gcov: add support for GCC 5.1 Fix kernel gcov support for GCC 5.1. Similar to commit a992bf836f9 ("gcov: add support for GCC 4.9"), this patch takes into account the existence of a new gcov counter (see gcc's gcc/gcov-counter.def.) Firstly, it increments GCOV_COUNTERS (to 10), which makes the data structure struct gcov_info compatible with GCC 5.1. Secondly, a corresponding counter function __gcov_merge_icall_topn (Top N value tracking for indirect calls) is included in base.c with the other gcov counters unused for kernel profiling. Signed-off-by: Lorenzo Stoakes Cc: Andrey Ryabinin Cc: Yuan Pengfei Tested-by: Peter Oberparleiter Reviewed-by: Peter Oberparleiter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/gcov/base.c | 6 ++++++ kernel/gcov/gcc_4_7.c | 4 +++- 2 files changed, 9 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/gcov/base.c b/kernel/gcov/base.c index a744098e4eb7..7080ae1eb6c1 100644 --- a/kernel/gcov/base.c +++ b/kernel/gcov/base.c @@ -92,6 +92,12 @@ void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters) } EXPORT_SYMBOL(__gcov_merge_time_profile); +void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters) +{ + /* Unused. */ +} +EXPORT_SYMBOL(__gcov_merge_icall_topn); + /** * gcov_enable_events - enable event reporting through gcov_event() * diff --git a/kernel/gcov/gcc_4_7.c b/kernel/gcov/gcc_4_7.c index 826ba9fb5e32..e25e92fb44fa 100644 --- a/kernel/gcov/gcc_4_7.c +++ b/kernel/gcov/gcc_4_7.c @@ -18,7 +18,9 @@ #include #include "gcov.h" -#if __GNUC__ == 4 && __GNUC_MINOR__ >= 9 +#if __GNUC__ == 5 && __GNUC_MINOR__ >= 1 +#define GCOV_COUNTERS 10 +#elif __GNUC__ == 4 && __GNUC_MINOR__ >= 9 #define GCOV_COUNTERS 9 #else #define GCOV_COUNTERS 8 -- cgit v1.2.3 From b389645f041a9fc650819b1c1ce7abbef7f4912d Mon Sep 17 00:00:00 2001 From: Antonio Ospite Date: Tue, 30 Jun 2015 14:59:03 -0700 Subject: printk: improve the description of /dev/kmsg line format The comment about /dev/kmsg does not mention the additional values which may actually be exported, fix that. Also move up the part of the comment instructing the users to ignore these additional values, this way the reading is more fluent and logically compact. Signed-off-by: Antonio Ospite Cc: Joe Perches Cc: Jonathan Corbet Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/printk/printk.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index de553849f3ac..cf8c24203368 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -207,14 +207,14 @@ static int console_may_schedule; * need to be changed in the future, when the requirements change. * * /dev/kmsg exports the structured data in the following line format: - * ",,,;\n" + * ",,,[,additional_values, ... ];\n" + * + * Users of the export format should ignore possible additional values + * separated by ',', and find the message after the ';' character. * * The optional key/value pairs are attached as continuation lines starting * with a space character and terminated by a newline. All possible * non-prinatable characters are escaped in the "\xff" notation. - * - * Users of the export format should ignore possible additional values - * separated by ',', and find the message after the ';' character. */ enum log_flags { -- cgit v1.2.3 From 200f1ce3656b8f466f74756677cea1b5e2aa851a Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Tue, 30 Jun 2015 14:59:06 -0700 Subject: kernel/relay.c: use kvfree() in relay_free_page_array() Use kvfree() instead of open-coding it. Signed-off-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/relay.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/relay.c b/kernel/relay.c index e9dbaeb8fd65..0b4570cfacae 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -81,10 +81,7 @@ static struct page **relay_alloc_page_array(unsigned int n_pages) */ static void relay_free_page_array(struct page **array) { - if (is_vmalloc_addr(array)) - vfree(array); - else - kfree(array); + kvfree(array); } /** -- cgit v1.2.3