From aaf5dcfb223617ac2d16113e4b500199c65689de Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 17 Nov 2017 15:27:06 -0800 Subject: kernel debug: support resetting WARN_ONCE for all architectures Some architectures store the WARN_ONCE state in the flags field of the bug_entry. Clear that one too when resetting once state through /sys/kernel/debug/clear_warn_once Pointed out by Michael Ellerman Improves the earlier patch that add clear_warn_once. [ak@linux.intel.com: add a missing ifdef CONFIG_MODULES] Link: http://lkml.kernel.org/r/20171020170633.9593-1-andi@firstfloor.org [akpm@linux-foundation.org: fix unused var warning] [akpm@linux-foundation.org: Use 0200 for clear_warn_once file, per mpe] [akpm@linux-foundation.org: clear BUGFLAG_DONE in clear_once_table(), per mpe] Link: http://lkml.kernel.org/r/20171019204642.7404-1-andi@firstfloor.org Signed-off-by: Andi Kleen Tested-by: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/bug.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'lib/bug.c') diff --git a/lib/bug.c b/lib/bug.c index 1e094408c893..f66be6bf6206 100644 --- a/lib/bug.c +++ b/lib/bug.c @@ -196,3 +196,26 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs) return BUG_TRAP_TYPE_BUG; } + +static void clear_once_table(struct bug_entry *start, struct bug_entry *end) +{ + struct bug_entry *bug; + + for (bug = start; bug < end; bug++) + bug->flags &= ~BUGFLAG_DONE; +} + +void generic_bug_clear_once(void) +{ +#ifdef CONFIG_MODULES + struct module *mod; + + rcu_read_lock_sched(); + list_for_each_entry_rcu(mod, &module_bug_list, bug_list) + clear_once_table(mod->bug_table, + mod->bug_table + mod->num_bugs); + rcu_read_unlock_sched(); +#endif + + clear_once_table(__start___bug_table, __stop___bug_table); +} -- cgit v1.2.3 From 2a8358d8a339540f00ec596526690e8eeca931a3 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 17 Nov 2017 15:27:21 -0800 Subject: bug: define the "cut here" string in a single place The "cut here" string is used in a few paths. Define it in a single place. Link: http://lkml.kernel.org/r/1510100869-73751-3-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook Cc: Arnd Bergmann Cc: Fengguang Wu Cc: Ingo Molnar Cc: Josh Poimboeuf Cc: Peter Zijlstra (Intel) Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/mn10300/mm/fault.c | 2 +- include/asm-generic/bug.h | 2 ++ kernel/panic.c | 2 +- lib/bug.c | 2 +- 4 files changed, 5 insertions(+), 3 deletions(-) (limited to 'lib/bug.c') diff --git a/arch/mn10300/mm/fault.c b/arch/mn10300/mm/fault.c index f23781d6bbb3..f0bfa1448744 100644 --- a/arch/mn10300/mm/fault.c +++ b/arch/mn10300/mm/fault.c @@ -60,7 +60,7 @@ void bust_spinlocks(int yes) void do_BUG(const char *file, int line) { bust_spinlocks(1); - printk(KERN_EMERG "------------[ cut here ]------------\n"); + printk(KERN_EMERG CUT_HERE); printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line); } diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 7844b0df88cd..1283473f234e 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -4,6 +4,8 @@ #include +#define CUT_HERE "------------[ cut here ]------------\n" + #ifdef CONFIG_GENERIC_BUG #define BUGFLAG_WARNING (1 << 0) #define BUGFLAG_ONCE (1 << 1) diff --git a/kernel/panic.c b/kernel/panic.c index 67cebf2a3b67..89df5fa2f798 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -520,7 +520,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint, { disable_trace_on_warning(); - pr_warn("------------[ cut here ]------------\n"); + pr_warn(CUT_HERE); if (file) pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n", diff --git a/lib/bug.c b/lib/bug.c index f66be6bf6206..c1b0fad31b10 100644 --- a/lib/bug.c +++ b/lib/bug.c @@ -186,7 +186,7 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs) return BUG_TRAP_TYPE_WARN; } - printk(KERN_DEFAULT "------------[ cut here ]------------\n"); + printk(KERN_DEFAULT CUT_HERE); if (file) pr_crit("kernel BUG at %s:%u!\n", file, line); -- cgit v1.2.3