From 4c281074d2e7beb8179d81c3d2c2a53ae47dfa1c Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Tue, 3 Apr 2018 10:31:47 -0400 Subject: lockdep: Add print_irqtrace_events() to __warn Running a test on a x86_32 kernel I triggered a bug that an interrupt disable/enable isn't being catched by lockdep. At least knowing where the last one was found would be helpful, but the warnings that are produced do not show this information. Even without debugging lockdep, having the WARN() display the last place hard and soft irqs were enabled or disabled is valuable. Signed-off-by: Steven Rostedt (VMware) --- 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 2cfef408fec9..fa8d4cc4956a 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -554,6 +554,8 @@ void __warn(const char *file, int line, void *caller, unsigned taint, else dump_stack(); + print_irqtrace_events(current); + print_oops_end_marker(); /* Just a warning, don't kill lockdep. */ -- cgit v1.3-14-g43fede From 47d4b263a2f7324fb3cb641ca00b2725dd12dea0 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 10 Apr 2018 16:32:26 -0700 Subject: taint: convert to indexed initialization This converts to using indexed initializers instead of comments, adds a comment on why the taint flags can't be an enum, and make sure that no one forgets to update the taint_flags when adding new bits. Link: http://lkml.kernel.org/r/1519084390-43867-2-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook Reviewed-by: Andrew Morton Cc: Al Viro Cc: Alexey Dobriyan Cc: Jonathan Corbet Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 1 + kernel/panic.c | 36 +++++++++++++++++++----------------- 2 files changed, 20 insertions(+), 17 deletions(-) (limited to 'kernel/panic.c') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 98273343bd45..086e8e80f765 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -544,6 +544,7 @@ extern enum system_states { SYSTEM_RESTART, } system_state; +/* This cannot be an enum because some may be used in assembly source. */ #define TAINT_PROPRIETARY_MODULE 0 #define TAINT_FORCED_MODULE 1 #define TAINT_CPU_OUT_OF_SPEC 2 diff --git a/kernel/panic.c b/kernel/panic.c index 6c3b08cd1139..af4cfa8eda22 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -308,23 +308,23 @@ EXPORT_SYMBOL(panic); * is being removed anyway. */ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { - { 'P', 'G', true }, /* TAINT_PROPRIETARY_MODULE */ - { 'F', ' ', true }, /* TAINT_FORCED_MODULE */ - { 'S', ' ', false }, /* TAINT_CPU_OUT_OF_SPEC */ - { 'R', ' ', false }, /* TAINT_FORCED_RMMOD */ - { 'M', ' ', false }, /* TAINT_MACHINE_CHECK */ - { 'B', ' ', false }, /* TAINT_BAD_PAGE */ - { 'U', ' ', false }, /* TAINT_USER */ - { 'D', ' ', false }, /* TAINT_DIE */ - { 'A', ' ', false }, /* TAINT_OVERRIDDEN_ACPI_TABLE */ - { 'W', ' ', false }, /* TAINT_WARN */ - { 'C', ' ', true }, /* TAINT_CRAP */ - { 'I', ' ', false }, /* TAINT_FIRMWARE_WORKAROUND */ - { 'O', ' ', true }, /* TAINT_OOT_MODULE */ - { 'E', ' ', true }, /* TAINT_UNSIGNED_MODULE */ - { 'L', ' ', false }, /* TAINT_SOFTLOCKUP */ - { 'K', ' ', true }, /* TAINT_LIVEPATCH */ - { 'X', ' ', true }, /* TAINT_AUX */ + [ TAINT_PROPRIETARY_MODULE ] = { 'P', 'G', true }, + [ TAINT_FORCED_MODULE ] = { 'F', ' ', true }, + [ TAINT_CPU_OUT_OF_SPEC ] = { 'S', ' ', false }, + [ TAINT_FORCED_RMMOD ] = { 'R', ' ', false }, + [ TAINT_MACHINE_CHECK ] = { 'M', ' ', false }, + [ TAINT_BAD_PAGE ] = { 'B', ' ', false }, + [ TAINT_USER ] = { 'U', ' ', false }, + [ TAINT_DIE ] = { 'D', ' ', false }, + [ TAINT_OVERRIDDEN_ACPI_TABLE ] = { 'A', ' ', false }, + [ TAINT_WARN ] = { 'W', ' ', false }, + [ TAINT_CRAP ] = { 'C', ' ', true }, + [ TAINT_FIRMWARE_WORKAROUND ] = { 'I', ' ', false }, + [ TAINT_OOT_MODULE ] = { 'O', ' ', true }, + [ TAINT_UNSIGNED_MODULE ] = { 'E', ' ', true }, + [ TAINT_SOFTLOCKUP ] = { 'L', ' ', false }, + [ TAINT_LIVEPATCH ] = { 'K', ' ', true }, + [ TAINT_AUX ] = { 'X', ' ', true }, }; /** @@ -354,6 +354,8 @@ const char *print_tainted(void) { static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")]; + BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT); + if (tainted_mask) { char *s; int i; -- cgit v1.3-14-g43fede From 9c4560e5bbd8c839c8986f79ef536aa07bd77ec7 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 10 Apr 2018 16:32:29 -0700 Subject: taint: consolidate documentation This consolidates the taint bit documentation into a single place with both numeric and letter values. Additionally adds the missing TAINT_AUX documentation. Link: http://lkml.kernel.org/r/1519084390-43867-3-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook Reviewed-by: Andrew Morton Cc: Al Viro Cc: Alexey Dobriyan Cc: Jonathan Corbet Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/sysctl/kernel.txt | 53 +++++++++++++++++++++-------------------- kernel/panic.c | 23 ++++-------------- 2 files changed, 31 insertions(+), 45 deletions(-) (limited to 'kernel/panic.c') diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 412314eebda6..4a890c7fb6c3 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -964,32 +964,33 @@ detect a hard lockup condition. tainted: -Non-zero if the kernel has been tainted. Numeric values, which -can be ORed together: - - 1 - A module with a non-GPL license has been loaded, this - includes modules with no license. - Set by modutils >= 2.4.9 and module-init-tools. - 2 - A module was force loaded by insmod -f. - Set by modutils >= 2.4.9 and module-init-tools. - 4 - Unsafe SMP processors: SMP with CPUs not designed for SMP. - 8 - A module was forcibly unloaded from the system by rmmod -f. - 16 - A hardware machine check error occurred on the system. - 32 - A bad page was discovered on the system. - 64 - The user has asked that the system be marked "tainted". This - could be because they are running software that directly modifies - the hardware, or for other reasons. - 128 - The system has died. - 256 - The ACPI DSDT has been overridden with one supplied by the user - instead of using the one provided by the hardware. - 512 - A kernel warning has occurred. -1024 - A module from drivers/staging was loaded. -2048 - The system is working around a severe firmware bug. -4096 - An out-of-tree module has been loaded. -8192 - An unsigned module has been loaded in a kernel supporting module - signature. -16384 - A soft lockup has previously occurred on the system. -32768 - The kernel has been live patched. +Non-zero if the kernel has been tainted. Numeric values, which can be +ORed together. The letters are seen in "Tainted" line of Oops reports. + + 1 (P): A module with a non-GPL license has been loaded, this + includes modules with no license. + Set by modutils >= 2.4.9 and module-init-tools. + 2 (F): A module was force loaded by insmod -f. + Set by modutils >= 2.4.9 and module-init-tools. + 4 (S): Unsafe SMP processors: SMP with CPUs not designed for SMP. + 8 (R): A module was forcibly unloaded from the system by rmmod -f. + 16 (M): A hardware machine check error occurred on the system. + 32 (B): A bad page was discovered on the system. + 64 (U): The user has asked that the system be marked "tainted". This + could be because they are running software that directly modifies + the hardware, or for other reasons. + 128 (D): The system has died. + 256 (A): The ACPI DSDT has been overridden with one supplied by the user + instead of using the one provided by the hardware. + 512 (W): A kernel warning has occurred. + 1024 (C): A module from drivers/staging was loaded. + 2048 (I): The system is working around a severe firmware bug. + 4096 (O): An out-of-tree module has been loaded. + 8192 (E): An unsigned module has been loaded in a kernel supporting module + signature. + 16384 (L): A soft lockup has previously occurred on the system. + 32768 (K): The kernel has been live patched. + 65536 (X): Auxiliary taint, defined and used by for distros. ============================================================== diff --git a/kernel/panic.c b/kernel/panic.c index af4cfa8eda22..5ceb9cbec4a2 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -328,27 +328,12 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { }; /** - * print_tainted - return a string to represent the kernel taint state. + * print_tainted - return a string to represent the kernel taint state. * - * 'P' - Proprietary module has been loaded. - * 'F' - Module has been forcibly loaded. - * 'S' - SMP with CPUs not designed for SMP. - * 'R' - User forced a module unload. - * 'M' - System experienced a machine check exception. - * 'B' - System has hit bad_page. - * 'U' - Userspace-defined naughtiness. - * 'D' - Kernel has oopsed before - * 'A' - ACPI table overridden. - * 'W' - Taint on warning. - * 'C' - modules from drivers/staging are loaded. - * 'I' - Working around severe firmware bug. - * 'O' - Out-of-tree module has been loaded. - * 'E' - Unsigned module has been loaded. - * 'L' - A soft lockup has previously occurred. - * 'K' - Kernel has been live patched. - * 'X' - Auxiliary taint, for distros' use. + * For individual taint flag meanings, see Documentation/sysctl/kernel.txt * - * The string is overwritten by the next call to print_tainted(). + * The string is overwritten by the next call to print_tainted(), + * but is always NULL terminated. */ const char *print_tainted(void) { -- cgit v1.3-14-g43fede From bc4f2f5469ac2a52affadc4c00c1276d76151a39 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 10 Apr 2018 16:32:33 -0700 Subject: taint: add taint for randstruct Since the randstruct plugin can intentionally produce extremely unusual kernel structure layouts (even performance pathological ones), some maintainers want to be able to trivially determine if an Oops is coming from a randstruct-built kernel, so as to keep their sanity when debugging. This adds the new flag and initializes taint_mask immediately when built with randstruct. Link: http://lkml.kernel.org/r/1519084390-43867-4-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook Reviewed-by: Andrew Morton Cc: Al Viro Cc: Alexey Dobriyan Cc: Jonathan Corbet Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/sysctl/kernel.txt | 1 + include/linux/kernel.h | 3 ++- kernel/panic.c | 4 +++- 3 files changed, 6 insertions(+), 2 deletions(-) (limited to 'kernel/panic.c') diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 4a890c7fb6c3..eded671d55eb 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -991,6 +991,7 @@ ORed together. The letters are seen in "Tainted" line of Oops reports. 16384 (L): A soft lockup has previously occurred on the system. 32768 (K): The kernel has been live patched. 65536 (X): Auxiliary taint, defined and used by for distros. +131072 (T): The kernel was built with the struct randomization plugin. ============================================================== diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 086e8e80f765..6a1eb0b0aad9 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -562,7 +562,8 @@ extern enum system_states { #define TAINT_SOFTLOCKUP 14 #define TAINT_LIVEPATCH 15 #define TAINT_AUX 16 -#define TAINT_FLAGS_COUNT 17 +#define TAINT_RANDSTRUCT 17 +#define TAINT_FLAGS_COUNT 18 struct taint_flag { char c_true; /* character printed when tainted */ diff --git a/kernel/panic.c b/kernel/panic.c index 5ceb9cbec4a2..42e487488554 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -34,7 +34,8 @@ #define PANIC_BLINK_SPD 18 int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE; -static unsigned long tainted_mask; +static unsigned long tainted_mask = + IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0; static int pause_on_oops; static int pause_on_oops_flag; static DEFINE_SPINLOCK(pause_on_oops_lock); @@ -325,6 +326,7 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { [ TAINT_SOFTLOCKUP ] = { 'L', ' ', false }, [ TAINT_LIVEPATCH ] = { 'K', ' ', true }, [ TAINT_AUX ] = { 'X', ' ', true }, + [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, }; /** -- cgit v1.3-14-g43fede