diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-11-18 20:48:41 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-11-24 14:42:09 +0100 |
| commit | 14df32670291588036a498051a54cd8462d7f611 (patch) | |
| tree | b3285fcdb143e581c262a49f4e021c38ac362ceb /arch/x86/include/asm/pgtable_64_types.h | |
| parent | 0e91a0c6984c837a7c6760e3f28e8e1c532abf87 (diff) | |
x86: Support kmap_local() forced debugging
kmap_local() and related interfaces are NOOPs on 64bit and only create
temporary fixmaps for highmem pages on 32bit. That means the test coverage
for this code is pretty small.
CONFIG_KMAP_LOCAL can be enabled independent from CONFIG_HIGHMEM, which
allows to provide support for enforced kmap_local() debugging even on
64bit.
For 32bit the support is unconditional, for 64bit it's only supported when
CONFIG_NR_CPUS <= 4096 as supporting it for 8192 CPUs would require to set
up yet another fixmap PGT.
If CONFIG_KMAP_LOCAL_FORCE_DEBUG is enabled then kmap_local()/kmap_atomic()
will use the temporary fixmap mapping path.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20201118204007.169209557@linutronix.de
Diffstat (limited to 'arch/x86/include/asm/pgtable_64_types.h')
| -rw-r--r-- | arch/x86/include/asm/pgtable_64_types.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index 52e5f5f2240d..91ac10654570 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -143,7 +143,11 @@ extern unsigned int ptrs_per_p4d; #define MODULES_VADDR (__START_KERNEL_map + KERNEL_IMAGE_SIZE) /* The module sections ends with the start of the fixmap */ -#define MODULES_END _AC(0xffffffffff000000, UL) +#ifndef CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP +# define MODULES_END _AC(0xffffffffff000000, UL) +#else +# define MODULES_END _AC(0xfffffffffe000000, UL) +#endif #define MODULES_LEN (MODULES_END - MODULES_VADDR) #define ESPFIX_PGD_ENTRY _AC(-2, UL) |