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| author | Mark Brown <broonie@kernel.org> | 2020-05-12 13:39:50 +0200 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-05-12 19:45:17 +0200 |
| commit | e4e9f6dfeedc86afef2c3fa4102d274862fe2cf9 (patch) | |
| tree | 8e36a28fbfb4f94a42f32168baedf6f3bf117361 | |
| parent | arm64: kconfig: Update and comment GCC version check for kernel BTI (diff) | |
| download | linux-e4e9f6dfeedc86afef2c3fa4102d274862fe2cf9.tar.xz linux-e4e9f6dfeedc86afef2c3fa4102d274862fe2cf9.zip | |
arm64: bti: Fix support for userspace only BTI
When setting PTE_MAYBE_GP we check system_supports_bti() but this is
true for systems where only CONFIG_BTI is set causing us to enable BTI
on some kernel text. Add an extra check for the kernel mode option,
using an ifdef due to line length.
Fixes: c8027285e366 ("arm64: Set GP bit in kernel page tables to enable BTI for the kernel")
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200512113950.29996-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/include/asm/pgtable-prot.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index 310690332896..2e7e0f452301 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -32,7 +32,15 @@ extern bool arm64_use_ng_mappings; #define PTE_MAYBE_NG (arm64_use_ng_mappings ? PTE_NG : 0) #define PMD_MAYBE_NG (arm64_use_ng_mappings ? PMD_SECT_NG : 0) +/* + * If we have userspace only BTI we don't want to mark kernel pages + * guarded even if the system does support BTI. + */ +#ifdef CONFIG_ARM64_BTI_KERNEL #define PTE_MAYBE_GP (system_supports_bti() ? PTE_GP : 0) +#else +#define PTE_MAYBE_GP 0 +#endif #define PROT_DEFAULT (_PROT_DEFAULT | PTE_MAYBE_NG) #define PROT_SECT_DEFAULT (_PROT_SECT_DEFAULT | PMD_MAYBE_NG) |