From 47144eca282189afcf34ef25aee8408c168765d4 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Fri, 10 Jan 2020 19:48:33 +0100 Subject: kcsan: Show full access type in report This commit adds access-type information to KCSAN's reports as follows: "read", "read (marked)", "write", and "write (marked)". Suggested-by: Paul E. McKenney Signed-off-by: Marco Elver Signed-off-by: Paul E. McKenney Signed-off-by: Ingo Molnar --- kernel/kcsan/report.c | 43 ++++++++++++++++++++++++++++--------------- 1 file changed, 28 insertions(+), 15 deletions(-) (limited to 'kernel/kcsan/report.c') diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c index 0eea05a3135b..9f503ca2ff7a 100644 --- a/kernel/kcsan/report.c +++ b/kernel/kcsan/report.c @@ -24,7 +24,7 @@ static struct { const volatile void *ptr; size_t size; - bool is_write; + int access_type; int task_pid; int cpu_id; unsigned long stack_entries[NUM_STACK_ENTRIES]; @@ -41,8 +41,10 @@ static DEFINE_SPINLOCK(report_lock); * Special rules to skip reporting. */ static bool -skip_report(bool is_write, bool value_change, unsigned long top_frame) +skip_report(int access_type, bool value_change, unsigned long top_frame) { + const bool is_write = (access_type & KCSAN_ACCESS_WRITE) != 0; + if (IS_ENABLED(CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY) && is_write && !value_change) { /* @@ -63,9 +65,20 @@ skip_report(bool is_write, bool value_change, unsigned long top_frame) return kcsan_skip_report_debugfs(top_frame); } -static inline const char *get_access_type(bool is_write) +static const char *get_access_type(int type) { - return is_write ? "write" : "read"; + switch (type) { + case 0: + return "read"; + case KCSAN_ACCESS_ATOMIC: + return "read (marked)"; + case KCSAN_ACCESS_WRITE: + return "write"; + case KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC: + return "write (marked)"; + default: + BUG(); + } } /* Return thread description: in task or interrupt. */ @@ -112,7 +125,7 @@ static int sym_strcmp(void *addr1, void *addr2) /* * Returns true if a report was generated, false otherwise. */ -static bool print_report(const volatile void *ptr, size_t size, bool is_write, +static bool print_report(const volatile void *ptr, size_t size, int access_type, bool value_change, int cpu_id, enum kcsan_report_type type) { @@ -124,7 +137,7 @@ static bool print_report(const volatile void *ptr, size_t size, bool is_write, /* * Must check report filter rules before starting to print. */ - if (skip_report(is_write, true, stack_entries[skipnr])) + if (skip_report(access_type, true, stack_entries[skipnr])) return false; if (type == KCSAN_REPORT_RACE_SIGNAL) { @@ -132,7 +145,7 @@ static bool print_report(const volatile void *ptr, size_t size, bool is_write, other_info.num_stack_entries); /* @value_change is only known for the other thread */ - if (skip_report(other_info.is_write, value_change, + if (skip_report(other_info.access_type, value_change, other_info.stack_entries[other_skipnr])) return false; } @@ -170,7 +183,7 @@ static bool print_report(const volatile void *ptr, size_t size, bool is_write, switch (type) { case KCSAN_REPORT_RACE_SIGNAL: pr_err("%s to 0x%px of %zu bytes by %s on cpu %i:\n", - get_access_type(other_info.is_write), other_info.ptr, + get_access_type(other_info.access_type), other_info.ptr, other_info.size, get_thread_desc(other_info.task_pid), other_info.cpu_id); @@ -181,14 +194,14 @@ static bool print_report(const volatile void *ptr, size_t size, bool is_write, pr_err("\n"); pr_err("%s to 0x%px of %zu bytes by %s on cpu %i:\n", - get_access_type(is_write), ptr, size, + get_access_type(access_type), ptr, size, get_thread_desc(in_task() ? task_pid_nr(current) : -1), cpu_id); break; case KCSAN_REPORT_RACE_UNKNOWN_ORIGIN: pr_err("race at unknown origin, with %s to 0x%px of %zu bytes by %s on cpu %i:\n", - get_access_type(is_write), ptr, size, + get_access_type(access_type), ptr, size, get_thread_desc(in_task() ? task_pid_nr(current) : -1), cpu_id); break; @@ -223,7 +236,7 @@ static void release_report(unsigned long *flags, enum kcsan_report_type type) * required for the report type, simply acquires report_lock and returns true. */ static bool prepare_report(unsigned long *flags, const volatile void *ptr, - size_t size, bool is_write, int cpu_id, + size_t size, int access_type, int cpu_id, enum kcsan_report_type type) { if (type != KCSAN_REPORT_CONSUMED_WATCHPOINT && @@ -243,7 +256,7 @@ retry: other_info.ptr = ptr; other_info.size = size; - other_info.is_write = is_write; + other_info.access_type = access_type; other_info.task_pid = in_task() ? task_pid_nr(current) : -1; other_info.cpu_id = cpu_id; other_info.num_stack_entries = stack_trace_save(other_info.stack_entries, NUM_STACK_ENTRIES, 1); @@ -302,14 +315,14 @@ retry: goto retry; } -void kcsan_report(const volatile void *ptr, size_t size, bool is_write, +void kcsan_report(const volatile void *ptr, size_t size, int access_type, bool value_change, int cpu_id, enum kcsan_report_type type) { unsigned long flags = 0; kcsan_disable_current(); - if (prepare_report(&flags, ptr, size, is_write, cpu_id, type)) { - if (print_report(ptr, size, is_write, value_change, cpu_id, type) && panic_on_warn) + if (prepare_report(&flags, ptr, size, access_type, cpu_id, type)) { + if (print_report(ptr, size, access_type, value_change, cpu_id, type) && panic_on_warn) panic("panic_on_warn set ...\n"); release_report(&flags, type); -- cgit v1.2.3