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authorDave Martin <Dave.Martin@arm.com>2020-03-16 16:50:45 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2020-03-16 17:19:48 +0000
commit8ef8f360cf30be12382f89ff48a57fbbd9b31c14 (patch)
tree6060caf0bfe50a4c370c86625b7325f6199b746a /arch/arm64/kernel/ptrace.c
parentELF: Add ELF program property parsing support (diff)
downloadlinux-dev-8ef8f360cf30be12382f89ff48a57fbbd9b31c14.tar.xz
linux-dev-8ef8f360cf30be12382f89ff48a57fbbd9b31c14.zip
arm64: Basic Branch Target Identification support
This patch adds the bare minimum required to expose the ARMv8.5 Branch Target Identification feature to userspace. By itself, this does _not_ automatically enable BTI for any initial executable pages mapped by execve(). This will come later, but for now it should be possible to enable BTI manually on those pages by using mprotect() from within the target process. Other arches already using the generic mman.h are already using 0x10 for arch-specific prot flags, so we use that for PROT_BTI here. For consistency, signal handler entry points in BTI guarded pages are required to be annotated as such, just like any other function. This blocks a relatively minor attack vector, but comforming userspace will have the annotations anyway, so we may as well enforce them. Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/ptrace.c')
-rw-r--r--arch/arm64/kernel/ptrace.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index cd6e5fa48b9c..fd8ac7cf68e7 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1874,7 +1874,7 @@ void syscall_trace_exit(struct pt_regs *regs)
*/
#define SPSR_EL1_AARCH64_RES0_BITS \
(GENMASK_ULL(63, 32) | GENMASK_ULL(27, 25) | GENMASK_ULL(23, 22) | \
- GENMASK_ULL(20, 13) | GENMASK_ULL(11, 10) | GENMASK_ULL(5, 5))
+ GENMASK_ULL(20, 13) | GENMASK_ULL(5, 5))
#define SPSR_EL1_AARCH32_RES0_BITS \
(GENMASK_ULL(63, 32) | GENMASK_ULL(22, 22) | GENMASK_ULL(20, 20))