diff options
author | Marco Elver <elver@google.com> | 2020-02-11 17:04:21 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2020-03-21 09:44:03 +0100 |
commit | b738f6169f1260b4ed5bd9f220b1c84d79f3ab8d (patch) | |
tree | b15d523664449bf30e59c034e4517eb5e399744d /kernel/kcsan/report.c | |
parent | b968a08f242d51982e46041c506115b5e11a7570 (diff) | |
download | linux-b738f6169f1260b4ed5bd9f220b1c84d79f3ab8d.tar.bz2 |
kcsan: Introduce kcsan_value_change type
Introduces kcsan_value_change type, which explicitly points out if we
either observed a value-change (TRUE), or we could not observe one but
cannot rule out a value-change happened (MAYBE). The MAYBE state can
either be reported or not, depending on configuration preferences.
A follow-up patch introduces the FALSE state, which should never be
reported.
No functional change intended.
Acked-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/kcsan/report.c')
-rw-r--r-- | kernel/kcsan/report.c | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c index abf6852dff72..d871476dc134 100644 --- a/kernel/kcsan/report.c +++ b/kernel/kcsan/report.c @@ -130,26 +130,27 @@ static bool rate_limit_report(unsigned long frame1, unsigned long frame2) * Special rules to skip reporting. */ static bool -skip_report(bool value_change, unsigned long top_frame) +skip_report(enum kcsan_value_change value_change, unsigned long top_frame) { /* - * The first call to skip_report always has value_change==true, since we + * The first call to skip_report always has value_change==TRUE, since we * cannot know the value written of an instrumented access. For the 2nd * call there are 6 cases with CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY: * - * 1. read watchpoint, conflicting write (value_change==true): report; - * 2. read watchpoint, conflicting write (value_change==false): skip; - * 3. write watchpoint, conflicting write (value_change==true): report; - * 4. write watchpoint, conflicting write (value_change==false): skip; - * 5. write watchpoint, conflicting read (value_change==false): skip; - * 6. write watchpoint, conflicting read (value_change==true): report; + * 1. read watchpoint, conflicting write (value_change==TRUE): report; + * 2. read watchpoint, conflicting write (value_change==MAYBE): skip; + * 3. write watchpoint, conflicting write (value_change==TRUE): report; + * 4. write watchpoint, conflicting write (value_change==MAYBE): skip; + * 5. write watchpoint, conflicting read (value_change==MAYBE): skip; + * 6. write watchpoint, conflicting read (value_change==TRUE): report; * * Cases 1-4 are intuitive and expected; case 5 ensures we do not report * data races where the write may have rewritten the same value; case 6 * is possible either if the size is larger than what we check value * changes for or the access type is KCSAN_ACCESS_ASSERT. */ - if (IS_ENABLED(CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY) && !value_change) { + if (IS_ENABLED(CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY) && + value_change == KCSAN_VALUE_CHANGE_MAYBE) { /* * The access is a write, but the data value did not change. * @@ -245,7 +246,7 @@ 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, int access_type, - bool value_change, int cpu_id, + enum kcsan_value_change value_change, int cpu_id, enum kcsan_report_type type) { unsigned long stack_entries[NUM_STACK_ENTRIES] = { 0 }; @@ -258,7 +259,7 @@ static bool print_report(const volatile void *ptr, size_t size, int access_type, /* * Must check report filter rules before starting to print. */ - if (skip_report(true, stack_entries[skipnr])) + if (skip_report(KCSAN_VALUE_CHANGE_TRUE, stack_entries[skipnr])) return false; if (type == KCSAN_REPORT_RACE_SIGNAL) { @@ -477,7 +478,8 @@ retry: } void kcsan_report(const volatile void *ptr, size_t size, int access_type, - bool value_change, int cpu_id, enum kcsan_report_type type) + enum kcsan_value_change value_change, int cpu_id, + enum kcsan_report_type type) { unsigned long flags = 0; |