From d7b85cab74edef84a9330c476478ba8cd732b6a9 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 17 Mar 2016 14:21:38 -0700 Subject: lib/bug.c: make panic_on_warn available for all architectures Christian Borntraeger reported that panic_on_warn doesn't have any effect on s390. The panic_on_warn feature was introduced with 9e3961a09798 ("kernel: add panic_on_warn"). However it did care only for the case when WANT_WARN_ON_SLOWPATH is defined. This is turn is only the case for architectures which do not have an own __WARN_TAINT defined. Other architectures which do have __WARN_TAINT defined call report_bug() for warnings within lib/bug.c which does not call panic() in case panic_on_warn is set. Let's simply enable the panic_on_warn feature by adding the same code like it was added to warn_slowpath_common() in panic.c. This enables panic_on_warn also for arm64, parisc, powerpc, s390 and sh. Signed-off-by: Heiko Carstens Reported-by: Christian Borntraeger Tested-by: Christian Borntraeger Acked-by: Prarit Bhargava Cc: Catalin Marinas Cc: Will Deacon Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Tested-by: Michael Ellerman (powerpc) Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/bug.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'lib/bug.c') diff --git a/lib/bug.c b/lib/bug.c index cff145f032a5..6cde380f09de 100644 --- a/lib/bug.c +++ b/lib/bug.c @@ -175,6 +175,17 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs) pr_warn("WARNING: at %p [verbose debug info unavailable]\n", (void *)bugaddr); + if (panic_on_warn) { + /* + * This thread may hit another WARN() in the panic path. + * Resetting this prevents additional WARN() from + * panicking the system on this thread. Other threads + * are blocked by the panic_mutex in panic(). + */ + panic_on_warn = 0; + panic("panic_on_warn set ...\n"); + } + print_modules(); show_regs(regs); print_oops_end_marker(); -- cgit From 2553b67a1fbe7bf202e4e8070ab0b00d3d3a06a2 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Thu, 17 Mar 2016 14:23:04 -0700 Subject: lib/bug.c: use common WARN helper The traceoff_on_warning option doesn't have any effect on s390, powerpc, arm64, parisc, and sh because there are two different types of WARN implementations: 1) The above mentioned architectures treat WARN() as a special case of a BUG() exception. They handle warnings in report_bug() in lib/bug.c. 2) All other architectures just call warn_slowpath_*() directly. Their warnings are handled in warn_slowpath_common() in kernel/panic.c. Support traceoff_on_warning on all architectures and prevent any future divergence by using a single common function to emit the warning. Also remove the '()' from '%pS()', because the parentheses look funky: [ 45.607629] WARNING: at /root/warn_mod/warn_mod.c:17 .init_dummy+0x20/0x40 [warn_mod]() Reported-by: Chunyu Hu Signed-off-by: Josh Poimboeuf Acked-by: Heiko Carstens Tested-by: Prarit Bhargava Acked-by: Prarit Bhargava Acked-by: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/bug.c | 26 ++------------------------ 1 file changed, 2 insertions(+), 24 deletions(-) (limited to 'lib/bug.c') diff --git a/lib/bug.c b/lib/bug.c index 6cde380f09de..bc3656e944d2 100644 --- a/lib/bug.c +++ b/lib/bug.c @@ -167,30 +167,8 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs) if (warning) { /* this is a WARN_ON rather than BUG/BUG_ON */ - pr_warn("------------[ cut here ]------------\n"); - - if (file) - pr_warn("WARNING: at %s:%u\n", file, line); - else - pr_warn("WARNING: at %p [verbose debug info unavailable]\n", - (void *)bugaddr); - - if (panic_on_warn) { - /* - * This thread may hit another WARN() in the panic path. - * Resetting this prevents additional WARN() from - * panicking the system on this thread. Other threads - * are blocked by the panic_mutex in panic(). - */ - panic_on_warn = 0; - panic("panic_on_warn set ...\n"); - } - - print_modules(); - show_regs(regs); - print_oops_end_marker(); - /* Just a warning, don't kill lockdep. */ - add_taint(BUG_GET_TAINT(bug), LOCKDEP_STILL_OK); + __warn(file, line, (void *)bugaddr, BUG_GET_TAINT(bug), regs, + NULL); return BUG_TRAP_TYPE_WARN; } -- cgit