diff options
Diffstat (limited to 'arch/arm64/mm')
| -rw-r--r-- | arch/arm64/mm/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm64/mm/gcs.c | 42 |
2 files changed, 43 insertions, 0 deletions
diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile index 2fc8c6dd0407..fc92170a8f37 100644 --- a/arch/arm64/mm/Makefile +++ b/arch/arm64/mm/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_TRANS_TABLE) += trans_pgd.o obj-$(CONFIG_TRANS_TABLE) += trans_pgd-asm.o obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o obj-$(CONFIG_ARM64_MTE) += mteswap.o +obj-$(CONFIG_ARM64_GCS) += gcs.o KASAN_SANITIZE_physaddr.o += n obj-$(CONFIG_KASAN) += kasan_init.o diff --git a/arch/arm64/mm/gcs.c b/arch/arm64/mm/gcs.c new file mode 100644 index 000000000000..f8f4f984a247 --- /dev/null +++ b/arch/arm64/mm/gcs.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/syscalls.h> +#include <linux/types.h> + +#include <asm/cpufeature.h> +#include <asm/page.h> + +/* + * Apply the GCS mode configured for the specified task to the + * hardware. + */ +void gcs_set_el0_mode(struct task_struct *task) +{ + u64 gcscre0_el1 = GCSCRE0_EL1_nTR; + + if (task->thread.gcs_el0_mode & PR_SHADOW_STACK_ENABLE) + gcscre0_el1 |= GCSCRE0_EL1_RVCHKEN | GCSCRE0_EL1_PCRSEL; + + if (task->thread.gcs_el0_mode & PR_SHADOW_STACK_WRITE) + gcscre0_el1 |= GCSCRE0_EL1_STREn; + + if (task->thread.gcs_el0_mode & PR_SHADOW_STACK_PUSH) + gcscre0_el1 |= GCSCRE0_EL1_PUSHMEn; + + write_sysreg_s(gcscre0_el1, SYS_GCSCRE0_EL1); +} + +void gcs_free(struct task_struct *task) +{ + if (!system_supports_gcs()) + return; + + if (task->thread.gcs_base) + vm_munmap(task->thread.gcs_base, task->thread.gcs_size); + + task->thread.gcspr_el0 = 0; + task->thread.gcs_base = 0; + task->thread.gcs_size = 0; +} |