From: Kees Cook <keescook@xxxxxxxxxxxx> 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@xxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/sysctl/kernel.txt | 1 + include/linux/kernel.h | 3 ++- kernel/panic.c | 4 +++- 3 files changed, 6 insertions(+), 2 deletions(-) diff -puN Documentation/sysctl/kernel.txt~taint-add-taint-for-randstruct Documentation/sysctl/kernel.txt --- a/Documentation/sysctl/kernel.txt~taint-add-taint-for-randstruct +++ a/Documentation/sysctl/kernel.txt @@ -991,6 +991,7 @@ ORed together. The letters are seen in " 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 -puN include/linux/kernel.h~taint-add-taint-for-randstruct include/linux/kernel.h --- a/include/linux/kernel.h~taint-add-taint-for-randstruct +++ a/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 -puN kernel/panic.c~taint-add-taint-for-randstruct kernel/panic.c --- a/kernel/panic.c~taint-add-taint-for-randstruct +++ a/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[TAIN [ TAINT_SOFTLOCKUP ] = { 'L', ' ', false }, [ TAINT_LIVEPATCH ] = { 'K', ' ', true }, [ TAINT_AUX ] = { 'X', ' ', true }, + [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, }; /** _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
