diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-11-18 20:48:39 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-11-24 14:42:08 +0100 |
| commit | 6e799cb69a70eedbb41561b750f7180c12cff280 (patch) | |
| tree | ee6b2c78fb94daef46d0da949e4bad4f2efdd070 | |
| parent | 13c8da5db43ad6d9b8637295ff50ddb66a0af05f (diff) | |
| download | linux-6e799cb69a70eedbb41561b750f7180c12cff280.tar.bz2 | |
mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL
CONFIG_KMAP_LOCAL can be enabled by x86/32bit even if CONFIG_HIGHMEM is not
enabled for temporary MMIO space mappings.
Provide it as a seperate config option which depends on CONFIG_KMAP_LOCAL
and let CONFIG_DEBUG_HIGHMEM select it.
This won't increase the debug coverage of this significantly but it paves
the way to do so.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20201118204006.869487226@linutronix.de
| -rw-r--r-- | include/asm-generic/kmap_size.h | 2 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 8 | ||||
| -rw-r--r-- | mm/highmem.c | 4 |
3 files changed, 11 insertions, 3 deletions
diff --git a/include/asm-generic/kmap_size.h b/include/asm-generic/kmap_size.h index 9d6c7786a645..6e36b2443ece 100644 --- a/include/asm-generic/kmap_size.h +++ b/include/asm-generic/kmap_size.h @@ -3,7 +3,7 @@ #define _ASM_GENERIC_KMAP_SIZE_H /* For debug this provides guard pages between the maps */ -#ifdef CONFIG_DEBUG_HIGHMEM +#ifdef CONFIG_DEBUG_KMAP_LOCAL # define KM_MAX_IDX 33 #else # define KM_MAX_IDX 16 diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c789b39ed527..f24fa158f9db 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -849,9 +849,17 @@ config DEBUG_PER_CPU_MAPS Say N if unsure. +config DEBUG_KMAP_LOCAL + bool "Debug kmap_local temporary mappings" + depends on DEBUG_KERNEL && KMAP_LOCAL + help + This option enables additional error checking for the kmap_local + infrastructure. Disable for production use. + config DEBUG_HIGHMEM bool "Highmem debugging" depends on DEBUG_KERNEL && HIGHMEM + select DEBUG_KMAP_LOCAL help This option enables additional error checking for high memory systems. Disable for production systems. diff --git a/mm/highmem.c b/mm/highmem.c index 78c481a30c9a..fab128de97de 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -368,10 +368,10 @@ EXPORT_SYMBOL(kunmap_high); static DEFINE_PER_CPU(int, __kmap_local_idx); /* - * With DEBUG_HIGHMEM the stack depth is doubled and every second + * With DEBUG_KMAP_LOCAL the stack depth is doubled and every second * slot is unused which acts as a guard page */ -#ifdef CONFIG_DEBUG_HIGHMEM +#ifdef CONFIG_DEBUG_KMAP_LOCAL # define KM_INCR 2 #else # define KM_INCR 1 |