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| author | Marco Elver <elver@google.com> | 2020-07-29 13:09:16 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-07-31 12:12:03 +0200 |
| commit | 92c209ac6d3d35783c16c8a717547183e6e11162 (patch) | |
| tree | bf34202bebc219dac144f09230b4ba6ce7d7327b /kernel/kcsan/kcsan.h | |
| parent | 0584df9c12f449124d0bfef9899e5365604ee7a9 (diff) | |
| download | lwn-92c209ac6d3d35783c16c8a717547183e6e11162.tar.gz lwn-92c209ac6d3d35783c16c8a717547183e6e11162.zip | |
kcsan: Improve IRQ state trace reporting
To improve the general usefulness of the IRQ state trace events with
KCSAN enabled, save and restore the trace information when entering and
exiting the KCSAN runtime as well as when generating a KCSAN report.
Without this, reporting the IRQ trace events (whether via a KCSAN report
or outside of KCSAN via a lockdep report) is rather useless due to
continuously being touched by KCSAN. This is because if KCSAN is
enabled, every instrumented memory access causes changes to IRQ trace
events (either by KCSAN disabling/enabling interrupts or taking
report_lock when generating a report).
Before "lockdep: Prepare for NMI IRQ state tracking", KCSAN avoided
touching the IRQ trace events via raw_local_irq_save/restore() and
lockdep_off/on().
Fixes: 248591f5d257 ("kcsan: Make KCSAN compatible with new IRQ state tracking")
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200729110916.3920464-2-elver@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/kcsan/kcsan.h')
| -rw-r--r-- | kernel/kcsan/kcsan.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/kcsan/kcsan.h b/kernel/kcsan/kcsan.h index 763d6d08d94b..29480010dc30 100644 --- a/kernel/kcsan/kcsan.h +++ b/kernel/kcsan/kcsan.h @@ -9,6 +9,7 @@ #define _KERNEL_KCSAN_KCSAN_H #include <linux/kcsan.h> +#include <linux/sched.h> /* The number of adjacent watchpoints to check. */ #define KCSAN_CHECK_ADJACENT 1 @@ -23,6 +24,12 @@ extern unsigned int kcsan_udelay_interrupt; extern bool kcsan_enabled; /* + * Save/restore IRQ flags state trace dirtied by KCSAN. + */ +void kcsan_save_irqtrace(struct task_struct *task); +void kcsan_restore_irqtrace(struct task_struct *task); + +/* * Initialize debugfs file. */ void kcsan_debugfs_init(void); |