From f4b62423383e7a26eb1a6ce0fc52c472ed955d6f Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Fri, 31 May 2024 12:04:54 +0300 Subject: kernel/panic: return early from print_tainted() when not tainted Reduce indent to make follow-up changes slightly easier on the eyes. Link: https://lkml.kernel.org/r/01d6c03de1c9d1b52b59c652a3704a0a9886ed63.1717146197.git.jani.nikula@intel.com Signed-off-by: Jani Nikula Reviewed-by: Greg Kroah-Hartman Signed-off-by: Andrew Morton --- kernel/panic.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index 8bff183d6180..3edad0c6091d 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -507,22 +507,23 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { const char *print_tainted(void) { static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")]; + char *s; + int i; BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT); - if (tainted_mask) { - char *s; - int i; - - s = buf + sprintf(buf, "Tainted: "); - for (i = 0; i < TAINT_FLAGS_COUNT; i++) { - const struct taint_flag *t = &taint_flags[i]; - *s++ = test_bit(i, &tainted_mask) ? - t->c_true : t->c_false; - } - *s = 0; - } else + if (!tainted_mask) { snprintf(buf, sizeof(buf), "Not tainted"); + return buf; + } + + s = buf + sprintf(buf, "Tainted: "); + for (i = 0; i < TAINT_FLAGS_COUNT; i++) { + const struct taint_flag *t = &taint_flags[i]; + *s++ = test_bit(i, &tainted_mask) ? + t->c_true : t->c_false; + } + *s = 0; return buf; } -- cgit v1.2.3 From aff1db0e4eb579a06290d7054871383aa0607015 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Fri, 31 May 2024 12:04:55 +0300 Subject: kernel/panic: convert print_tainted() to use struct seq_buf internally Convert print_tainted() to use struct seq_buf internally in order to be more aware of the buffer constraints as well as make it easier to extend in follow-up work. Link: https://lkml.kernel.org/r/cb6006fa7c0f82a6b6885e8eea2920fcdc4fc9d0.1717146197.git.jani.nikula@intel.com Signed-off-by: Jani Nikula Reviewed-by: Greg Kroah-Hartman Signed-off-by: Andrew Morton --- kernel/panic.c | 38 ++++++++++++++++++++++++-------------- 1 file changed, 24 insertions(+), 14 deletions(-) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index 3edad0c6091d..f7c0fddfd89a 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include @@ -496,6 +497,25 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { [ TAINT_TEST ] = { 'N', ' ', true }, }; +static void print_tainted_seq(struct seq_buf *s) +{ + int i; + + if (!tainted_mask) { + seq_buf_puts(s, "Not tainted"); + return; + } + + seq_buf_printf(s, "Tainted: "); + for (i = 0; i < TAINT_FLAGS_COUNT; i++) { + const struct taint_flag *t = &taint_flags[i]; + bool is_set = test_bit(i, &tainted_mask); + char c = is_set ? t->c_true : t->c_false; + + seq_buf_putc(s, c); + } +} + /** * print_tainted - return a string to represent the kernel taint state. * @@ -507,25 +527,15 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { const char *print_tainted(void) { static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")]; - char *s; - int i; + struct seq_buf s; BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT); - if (!tainted_mask) { - snprintf(buf, sizeof(buf), "Not tainted"); - return buf; - } + seq_buf_init(&s, buf, sizeof(buf)); - s = buf + sprintf(buf, "Tainted: "); - for (i = 0; i < TAINT_FLAGS_COUNT; i++) { - const struct taint_flag *t = &taint_flags[i]; - *s++ = test_bit(i, &tainted_mask) ? - t->c_true : t->c_false; - } - *s = 0; + print_tainted_seq(&s); - return buf; + return seq_buf_str(&s); } int test_taint(unsigned flag) -- cgit v1.2.3 From f36fc96c15bd860776ffc66e53bdeeb791b6f442 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Fri, 31 May 2024 12:04:56 +0300 Subject: kernel/panic: initialize taint_flags[] using a macro Make it easier to extend struct taint_flags in follow-up. Link: https://lkml.kernel.org/r/8a2498285d37953cfad9dce939ed3abef61051bd.1717146197.git.jani.nikula@intel.com Signed-off-by: Jani Nikula Reviewed-by: Greg Kroah-Hartman Signed-off-by: Andrew Morton --- kernel/panic.c | 46 +++++++++++++++++++++++++++------------------- 1 file changed, 27 insertions(+), 19 deletions(-) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index f7c0fddfd89a..21975497bfa4 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -471,32 +471,40 @@ void panic(const char *fmt, ...) EXPORT_SYMBOL(panic); +#define TAINT_FLAG(taint, _c_true, _c_false, _module) \ + [ TAINT_##taint ] = { \ + .c_true = _c_true, .c_false = _c_false, \ + .module = _module, \ + } + /* * TAINT_FORCED_RMMOD could be a per-module flag but the module * is being removed anyway. */ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { - [ 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 }, - [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, - [ TAINT_TEST ] = { 'N', ' ', true }, + TAINT_FLAG(PROPRIETARY_MODULE, 'P', 'G', true), + TAINT_FLAG(FORCED_MODULE, 'F', ' ', true), + TAINT_FLAG(CPU_OUT_OF_SPEC, 'S', ' ', false), + TAINT_FLAG(FORCED_RMMOD, 'R', ' ', false), + TAINT_FLAG(MACHINE_CHECK, 'M', ' ', false), + TAINT_FLAG(BAD_PAGE, 'B', ' ', false), + TAINT_FLAG(USER, 'U', ' ', false), + TAINT_FLAG(DIE, 'D', ' ', false), + TAINT_FLAG(OVERRIDDEN_ACPI_TABLE, 'A', ' ', false), + TAINT_FLAG(WARN, 'W', ' ', false), + TAINT_FLAG(CRAP, 'C', ' ', true), + TAINT_FLAG(FIRMWARE_WORKAROUND, 'I', ' ', false), + TAINT_FLAG(OOT_MODULE, 'O', ' ', true), + TAINT_FLAG(UNSIGNED_MODULE, 'E', ' ', true), + TAINT_FLAG(SOFTLOCKUP, 'L', ' ', false), + TAINT_FLAG(LIVEPATCH, 'K', ' ', true), + TAINT_FLAG(AUX, 'X', ' ', true), + TAINT_FLAG(RANDSTRUCT, 'T', ' ', true), + TAINT_FLAG(TEST, 'N', ' ', true), }; +#undef TAINT_FLAG + static void print_tainted_seq(struct seq_buf *s) { int i; -- cgit v1.2.3 From 2f183c68345a26213e5e7f798399bee68d1c4a97 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Fri, 31 May 2024 12:04:57 +0300 Subject: kernel/panic: add verbose logging of kernel taints in backtraces With nearly 20 taint flags and respective characters, it's getting a bit difficult to remember what each taint flag character means. Add verbose logging of the set taints in the format: Tainted: [P]=PROPRIETARY_MODULE, [W]=WARN in dump_stack_print_info() when there are taints. Note that the "negative flag" G is not included. Link: https://lkml.kernel.org/r/7321e306166cb2ca2807ab8639e665baa2462e9c.1717146197.git.jani.nikula@intel.com Signed-off-by: Jani Nikula Reviewed-by: Greg Kroah-Hartman Signed-off-by: Andrew Morton --- include/linux/panic.h | 8 +++++--- kernel/panic.c | 45 ++++++++++++++++++++++++++++++++++----------- lib/dump_stack.c | 3 +++ 3 files changed, 42 insertions(+), 14 deletions(-) (limited to 'kernel/panic.c') diff --git a/include/linux/panic.h b/include/linux/panic.h index 6717b15e798c..3130e0b5116b 100644 --- a/include/linux/panic.h +++ b/include/linux/panic.h @@ -77,9 +77,10 @@ static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) #define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1) struct taint_flag { - char c_true; /* character printed when tainted */ - char c_false; /* character printed when not tainted */ - bool module; /* also show as a per-module taint flag */ + char c_true; /* character printed when tainted */ + char c_false; /* character printed when not tainted */ + bool module; /* also show as a per-module taint flag */ + const char *desc; /* verbose description of the set taint flag */ }; extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT]; @@ -90,6 +91,7 @@ enum lockdep_ok { }; extern const char *print_tainted(void); +extern const char *print_tainted_verbose(void); extern void add_taint(unsigned flag, enum lockdep_ok); extern int test_taint(unsigned flag); extern unsigned long get_taint(void); diff --git a/kernel/panic.c b/kernel/panic.c index 21975497bfa4..f861bedc1925 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -475,6 +475,7 @@ EXPORT_SYMBOL(panic); [ TAINT_##taint ] = { \ .c_true = _c_true, .c_false = _c_false, \ .module = _module, \ + .desc = #taint, \ } /* @@ -505,8 +506,9 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { #undef TAINT_FLAG -static void print_tainted_seq(struct seq_buf *s) +static void print_tainted_seq(struct seq_buf *s, bool verbose) { + const char *sep = ""; int i; if (!tainted_mask) { @@ -520,10 +522,32 @@ static void print_tainted_seq(struct seq_buf *s) bool is_set = test_bit(i, &tainted_mask); char c = is_set ? t->c_true : t->c_false; - seq_buf_putc(s, c); + if (verbose) { + if (is_set) { + seq_buf_printf(s, "%s[%c]=%s", sep, c, t->desc); + sep = ", "; + } + } else { + seq_buf_putc(s, c); + } } } +static const char *_print_tainted(bool verbose) +{ + /* FIXME: what should the size be? */ + static char buf[sizeof(taint_flags)]; + struct seq_buf s; + + BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT); + + seq_buf_init(&s, buf, sizeof(buf)); + + print_tainted_seq(&s, verbose); + + return seq_buf_str(&s); +} + /** * print_tainted - return a string to represent the kernel taint state. * @@ -534,16 +558,15 @@ static void print_tainted_seq(struct seq_buf *s) */ const char *print_tainted(void) { - static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")]; - struct seq_buf s; - - BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT); - - seq_buf_init(&s, buf, sizeof(buf)); - - print_tainted_seq(&s); + return _print_tainted(false); +} - return seq_buf_str(&s); +/** + * print_tainted_verbose - A more verbose version of print_tainted() + */ +const char *print_tainted_verbose(void) +{ + return _print_tainted(true); } int test_taint(unsigned flag) diff --git a/lib/dump_stack.c b/lib/dump_stack.c index 222c6d6c8281..8b6b70eaf949 100644 --- a/lib/dump_stack.c +++ b/lib/dump_stack.c @@ -62,6 +62,9 @@ void dump_stack_print_info(const char *log_lvl) (int)strcspn(init_utsname()->version, " "), init_utsname()->version, BUILD_ID_VAL); + if (get_taint()) + printk("%s%s\n", log_lvl, print_tainted_verbose()); + if (dump_stack_arch_desc_str[0] != '\0') printk("%sHardware name: %s\n", log_lvl, dump_stack_arch_desc_str); -- cgit v1.2.3