diff options
| author | Jeremy Linton <jeremy.linton@arm.com> | 2025-08-24 22:34:15 -0500 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2025-09-16 20:31:44 +0100 |
| commit | 47687aa4d9c91a9d9b1dbae40c242cd291030bd9 (patch) | |
| tree | 39da0226af8aaa9cd3941c0cb1cb8dc1bfc4e92a | |
| parent | 8f5ae30d69d7543eee0d70083daf4de8fe15d585 (diff) | |
arm64: probes: Break ret out from bl/blr
Prepare for GCS by breaking RET out into its own function, where
it makes more sense to encapsulate the new behavior independent
from the branch instructions.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/kernel/probes/decode-insn.c | 7 | ||||
| -rw-r--r-- | arch/arm64/kernel/probes/simulate-insn.c | 10 | ||||
| -rw-r--r-- | arch/arm64/kernel/probes/simulate-insn.h | 3 |
3 files changed, 15 insertions, 5 deletions
diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c index 6438bf62e753..4137cc5ef031 100644 --- a/arch/arm64/kernel/probes/decode-insn.c +++ b/arch/arm64/kernel/probes/decode-insn.c @@ -108,9 +108,10 @@ arm_probe_decode_insn(u32 insn, struct arch_probe_insn *api) aarch64_insn_is_bl(insn)) { api->handler = simulate_b_bl; } else if (aarch64_insn_is_br(insn) || - aarch64_insn_is_blr(insn) || - aarch64_insn_is_ret(insn)) { - api->handler = simulate_br_blr_ret; + aarch64_insn_is_blr(insn)) { + api->handler = simulate_br_blr; + } else if (aarch64_insn_is_ret(insn)) { + api->handler = simulate_ret; } else { /* * Instruction cannot be stepped out-of-line and we don't diff --git a/arch/arm64/kernel/probes/simulate-insn.c b/arch/arm64/kernel/probes/simulate-insn.c index 4c6d2d712fbd..09a0b36122d0 100644 --- a/arch/arm64/kernel/probes/simulate-insn.c +++ b/arch/arm64/kernel/probes/simulate-insn.c @@ -126,7 +126,7 @@ simulate_b_cond(u32 opcode, long addr, struct pt_regs *regs) } void __kprobes -simulate_br_blr_ret(u32 opcode, long addr, struct pt_regs *regs) +simulate_br_blr(u32 opcode, long addr, struct pt_regs *regs) { int xn = (opcode >> 5) & 0x1f; @@ -139,6 +139,14 @@ simulate_br_blr_ret(u32 opcode, long addr, struct pt_regs *regs) } void __kprobes +simulate_ret(u32 opcode, long addr, struct pt_regs *regs) +{ + int xn = (opcode >> 5) & 0x1f; + + instruction_pointer_set(regs, get_x_reg(regs, xn)); +} + +void __kprobes simulate_cbz_cbnz(u32 opcode, long addr, struct pt_regs *regs) { int disp = 4; diff --git a/arch/arm64/kernel/probes/simulate-insn.h b/arch/arm64/kernel/probes/simulate-insn.h index efb2803ec943..9e772a292d56 100644 --- a/arch/arm64/kernel/probes/simulate-insn.h +++ b/arch/arm64/kernel/probes/simulate-insn.h @@ -11,7 +11,8 @@ void simulate_adr_adrp(u32 opcode, long addr, struct pt_regs *regs); void simulate_b_bl(u32 opcode, long addr, struct pt_regs *regs); void simulate_b_cond(u32 opcode, long addr, struct pt_regs *regs); -void simulate_br_blr_ret(u32 opcode, long addr, struct pt_regs *regs); +void simulate_br_blr(u32 opcode, long addr, struct pt_regs *regs); +void simulate_ret(u32 opcode, long addr, struct pt_regs *regs); void simulate_cbz_cbnz(u32 opcode, long addr, struct pt_regs *regs); void simulate_tbz_tbnz(u32 opcode, long addr, struct pt_regs *regs); void simulate_ldr_literal(u32 opcode, long addr, struct pt_regs *regs); |