From 2c16e9c888985761511bd1905b00fb271169c3c0 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 10 Jul 2006 04:45:42 -0700 Subject: [PATCH] lockdep: disable lock debugging when kernel state becomes untrusted Disable lockdep debugging in two situations where the integrity of the kernel no longer is guaranteed: when oopsing and when hitting a tainting-condition. The goal is to not get weird lockdep traces that don't make sense or are otherwise undebuggable, to not waste time. Lockdep assumes that the previous state it knows about is valid to operate, which is why lockdep turns itself off after the first violation it reports, after that point it can no longer make that assumption. A kernel oops means that the integrity of the kernel compromised; in addition anything lockdep would report is of lesser importance than the oops. All the tainting conditions are of similar integrity-violating nature and also make debugging/diagnosing more difficult. Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/panic.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index ab13f0f668b5..d8a0bca21233 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -172,6 +172,7 @@ const char *print_tainted(void) void add_taint(unsigned flag) { + debug_locks_off(); /* can't trust the integrity of the kernel anymore */ tainted |= flag; } EXPORT_SYMBOL(add_taint); @@ -256,6 +257,7 @@ int oops_may_print(void) */ void oops_enter(void) { + debug_locks_off(); /* can't trust the integrity of the kernel anymore */ do_oops_enter_exit(); } -- cgit v1.2.3 From 657b3010d8f8a72195dfcbe63040127d596f0b14 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Sun, 13 Aug 2006 23:24:19 -0700 Subject: [PATCH] panic.c build fix kernel/panic.c: In function 'add_taint': kernel/panic.c:176: warning: implicit declaration of function 'debug_locks_off' Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- kernel/panic.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index d8a0bca21233..9b8dcfd1ca93 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -18,6 +18,7 @@ #include #include #include +#include int panic_on_oops; int tainted; -- cgit v1.2.3 From 068c4579fe5c21e84c7cb2ba89db80899e25104e Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 6 Sep 2006 00:03:44 -0700 Subject: [PATCH] lockdep: do not touch console state when tainting the kernel Remove an unintended console_verbose() side-effect from add_taint(). Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/panic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index 9b8dcfd1ca93..8010b9b17aca 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -173,7 +173,7 @@ const char *print_tainted(void) void add_taint(unsigned flag) { - debug_locks_off(); /* can't trust the integrity of the kernel anymore */ + debug_locks = 0; /* can't trust the integrity of the kernel anymore */ tainted |= flag; } EXPORT_SYMBOL(add_taint); -- cgit v1.2.3