diff options
| author | Mark Brown <broonie@kernel.org> | 2024-10-01 23:58:54 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2024-10-04 12:04:36 +0100 |
| commit | 6497b66ba6945f142902c7e8fce86e47016ead1c (patch) | |
| tree | 2cad92c241d5309be6787a006d81c0781a15c389 /arch/arm64/mm | |
| parent | ae80e1629aeaf5be726a9ea94eb7345b1a44b00d (diff) | |
arm64/mm: Map pages for guarded control stack
Map pages flagged as being part of a GCS as such rather than using the
full set of generic VM flags.
This is done using a conditional rather than extending the size of
protection_map since that would make for a very sparse array.
Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-15-222b78d87eee@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm')
| -rw-r--r-- | arch/arm64/mm/mmap.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index 7e3ad97e27d8..07aeab8a7606 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -83,8 +83,15 @@ arch_initcall(adjust_protection_map); pgprot_t vm_get_page_prot(unsigned long vm_flags) { - pteval_t prot = pgprot_val(protection_map[vm_flags & + pteval_t prot; + + /* Short circuit GCS to avoid bloating the table. */ + if (system_supports_gcs() && (vm_flags & VM_SHADOW_STACK)) { + prot = _PAGE_GCS_RO; + } else { + prot = pgprot_val(protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]); + } if (vm_flags & VM_ARM64_BTI) prot |= PTE_GP; |