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author | 2021-04-14 13:28:18 +0200 | |
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committer | 2021-05-18 10:58:14 -0700 | |
commit | 793c2579beefa95894fc0afbbdc1a80a4e3bf306 (patch) | |
tree | e31b88824a91ed8dbe2092bfae3c62f3d7e4ff72 /kernel/kcsan/core.c | |
parent | kcsan: Simplify value change detection (diff) | |
download | linux-793c2579beefa95894fc0afbbdc1a80a4e3bf306.tar.gz linux-793c2579beefa95894fc0afbbdc1a80a4e3bf306.tar.bz2 linux-793c2579beefa95894fc0afbbdc1a80a4e3bf306.zip |
kcsan: Distinguish kcsan_report() calls
Currently kcsan_report() is used to handle three distinct cases:
* The caller hit a watchpoint when attempting an access. Some
information regarding the caller and access are recorded, but no
output is produced.
* A caller which previously setup a watchpoint detected that the
watchpoint has been hit, and possibly detected a change to the
location in memory being watched. This may result in output reporting
the interaction between this caller and the caller which hit the
watchpoint.
* A caller detected a change to a modification to a memory location
which wasn't detected by a watchpoint, for which there is no
information on the other thread. This may result in output reporting
the unexpected change.
... depending on the specific case the caller has distinct pieces of
information available, but the prototype of kcsan_report() has to handle
all three cases. This means that in some cases we pass redundant
information, and in others we don't pass all the information we could
pass. This also means that the report code has to demux these three
cases.
So that we can pass some additional information while also simplifying
the callers and report code, add separate kcsan_report_*() functions for
the distinct cases, updating callers accordingly. As the watchpoint_idx
is unused in the case of kcsan_report_unknown_origin(), this passes a
dummy value into kcsan_report(). Subsequent patches will refactor the
report code to avoid this.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[ elver@google.com: try to make kcsan_report_*() names more descriptive ]
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/kcsan/core.c')
-rw-r--r-- | kernel/kcsan/core.c | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c index d360183002d6..6fe1513e1e6a 100644 --- a/kernel/kcsan/core.c +++ b/kernel/kcsan/core.c @@ -380,9 +380,7 @@ static noinline void kcsan_found_watchpoint(const volatile void *ptr, if (consumed) { kcsan_save_irqtrace(current); - kcsan_report(ptr, size, type, KCSAN_VALUE_CHANGE_MAYBE, - KCSAN_REPORT_CONSUMED_WATCHPOINT, - watchpoint - watchpoints); + kcsan_report_set_info(ptr, size, type, watchpoint - watchpoints); kcsan_restore_irqtrace(current); } else { /* @@ -558,8 +556,8 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) if (is_assert && value_change == KCSAN_VALUE_CHANGE_TRUE) atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_ASSERT_FAILURES]); - kcsan_report(ptr, size, type, value_change, KCSAN_REPORT_RACE_SIGNAL, - watchpoint - watchpoints); + kcsan_report_known_origin(ptr, size, type, value_change, + watchpoint - watchpoints); } else if (value_change == KCSAN_VALUE_CHANGE_TRUE) { /* Inferring a race, since the value should not have changed. */ @@ -568,9 +566,7 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_ASSERT_FAILURES]); if (IS_ENABLED(CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN) || is_assert) - kcsan_report(ptr, size, type, KCSAN_VALUE_CHANGE_TRUE, - KCSAN_REPORT_RACE_UNKNOWN_ORIGIN, - watchpoint - watchpoints); + kcsan_report_unknown_origin(ptr, size, type); } /* |