diff options
| author |   Lecopzer Chen <lecopzer.chen@mediatek.com> | 2021-03-24 12:05:21 +0800 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2021-03-29 12:35:05 +0100 |
| commit | 31d02e7ab00873befd2cfb6e44581490d947c38b (patch) | |
| tree | ea2440bcbb811caabbcd2b51802f70ea160a718c | |
| parent | arm64: Kconfig: support CONFIG_KASAN_VMALLOC (diff) | |
| download | linux-dev-31d02e7ab00873befd2cfb6e44581490d947c38b.tar.xz linux-dev-31d02e7ab00873befd2cfb6e44581490d947c38b.zip | |
arm64: kaslr: support randomized module area with KASAN_VMALLOC
After KASAN_VMALLOC works in arm64, we can randomize module region
into vmalloc area now.
Test:
VMALLOC area ffffffc010000000 fffffffdf0000000
before the patch:
module_alloc_base/end ffffffc008b80000 ffffffc010000000
after the patch:
module_alloc_base/end ffffffdcf4bed000 ffffffc010000000
And the function that insmod some modules is fine.
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Link: https://lore.kernel.org/r/20210324040522.15548-5-lecopzer.chen@mediatek.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/kernel/kaslr.c | 18 | ||||
| -rw-r--r-- | arch/arm64/kernel/module.c | 16 |
2 files changed, 19 insertions, 15 deletions
diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c index 27f8939deb1b..341342b207f6 100644 --- a/arch/arm64/kernel/kaslr.c +++ b/arch/arm64/kernel/kaslr.c @@ -128,15 +128,17 @@ u64 __init kaslr_early_init(void) /* use the top 16 bits to randomize the linear region */ memstart_offset_seed = seed >> 48; - if (IS_ENABLED(CONFIG_KASAN_GENERIC) || - IS_ENABLED(CONFIG_KASAN_SW_TAGS)) + if (!IS_ENABLED(CONFIG_KASAN_VMALLOC) && + (IS_ENABLED(CONFIG_KASAN_GENERIC) || + IS_ENABLED(CONFIG_KASAN_SW_TAGS))) /* - * KASAN does not expect the module region to intersect the - * vmalloc region, since shadow memory is allocated for each - * module at load time, whereas the vmalloc region is shadowed - * by KASAN zero pages. So keep modules out of the vmalloc - * region if KASAN is enabled, and put the kernel well within - * 4 GB of the module region. + * KASAN without KASAN_VMALLOC does not expect the module region + * to intersect the vmalloc region, since shadow memory is + * allocated for each module at load time, whereas the vmalloc + * region is shadowed by KASAN zero pages. So keep modules + * out of the vmalloc region if KASAN is enabled without + * KASAN_VMALLOC, and put the kernel well within 4 GB of the + * module region. */ return offset % SZ_2G; diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c index fe21e0f06492..b5ec010c481f 100644 --- a/arch/arm64/kernel/module.c +++ b/arch/arm64/kernel/module.c @@ -40,14 +40,16 @@ void *module_alloc(unsigned long size) NUMA_NO_NODE, __builtin_return_address(0)); if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) && - !IS_ENABLED(CONFIG_KASAN_GENERIC) && - !IS_ENABLED(CONFIG_KASAN_SW_TAGS)) + (IS_ENABLED(CONFIG_KASAN_VMALLOC) || + (!IS_ENABLED(CONFIG_KASAN_GENERIC) && + !IS_ENABLED(CONFIG_KASAN_SW_TAGS)))) /* - * KASAN can only deal with module allocations being served - * from the reserved module region, since the remainder of - * the vmalloc region is already backed by zero shadow pages, - * and punching holes into it is non-trivial. Since the module - * region is not randomized when KASAN is enabled, it is even + * KASAN without KASAN_VMALLOC can only deal with module + * allocations being served from the reserved module region, + * since the remainder of the vmalloc region is already + * backed by zero shadow pages, and punching holes into it + * is non-trivial. Since the module region is not randomized + * when KASAN is enabled without KASAN_VMALLOC, it is even * less likely that the module region gets exhausted, so we * can simply omit this fallback in that case. */ |