From 92c209ac6d3d35783c16c8a717547183e6e11162 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Wed, 29 Jul 2020 13:09:16 +0200 Subject: 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 Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200729110916.3920464-2-elver@google.com Signed-off-by: Ingo Molnar --- kernel/kcsan/kcsan.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'kernel/kcsan/kcsan.h') 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 +#include /* The number of adjacent watchpoints to check. */ #define KCSAN_CHECK_ADJACENT 1 @@ -22,6 +23,12 @@ 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. */ -- cgit v1.2.3