This is an alternative to NT_PRSTATUS that clobbers ip/r12 on AArch32, x7 on AArch64 when a tracee is stopped in syscall entry or syscall exit traps.
Signed-off-by: Andrei Vagin <[email protected]> --- arch/arm64/kernel/ptrace.c | 39 ++++++++++++++++++++++++++++++++++++++ include/uapi/linux/elf.h | 1 + 2 files changed, 40 insertions(+) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 1863f080cb07..b8e4c2ddf636 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -591,6 +591,15 @@ static int gpr_get(struct task_struct *target, return ret; } +static int gpr_get_full(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs; + + return membuf_write(&to, uregs, sizeof(*uregs)); +} + static int gpr_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) @@ -1088,6 +1097,7 @@ static int tagged_addr_ctrl_set(struct task_struct *target, const struct enum aarch64_regset { REGSET_GPR, + REGSET_GPR_FULL, REGSET_FPR, REGSET_TLS, #ifdef CONFIG_HAVE_HW_BREAKPOINT @@ -1119,6 +1129,14 @@ static const struct user_regset aarch64_regsets[] = { .regset_get = gpr_get, .set = gpr_set }, + [REGSET_GPR_FULL] = { + .core_note_type = NT_ARM_PRSTATUS, + .n = sizeof(struct user_pt_regs) / sizeof(u64), + .size = sizeof(u64), + .align = sizeof(u64), + .regset_get = gpr_get_full, + .set = gpr_set + }, [REGSET_FPR] = { .core_note_type = NT_PRFPREG, .n = sizeof(struct user_fpsimd_state) / sizeof(u32), @@ -1225,6 +1243,7 @@ static const struct user_regset_view user_aarch64_view = { #ifdef CONFIG_COMPAT enum compat_regset { REGSET_COMPAT_GPR, + REGSET_COMPAT_GPR_FULL, REGSET_COMPAT_VFP, }; @@ -1285,6 +1304,18 @@ static int compat_gpr_get(struct task_struct *target, return 0; } +/* compat_gpr_get_full doesn't overwrite x12 like compat_gpr_get. */ +static int compat_gpr_get_full(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + int i = 0; + + while (to.left) + membuf_store(&to, compat_get_user_reg(target, i++)); + return 0; +} + static int compat_gpr_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, @@ -1435,6 +1466,14 @@ static const struct user_regset aarch32_regsets[] = { .regset_get = compat_gpr_get, .set = compat_gpr_set }, + [REGSET_COMPAT_GPR_FULL] = { + .core_note_type = NT_ARM_PRSTATUS, + .n = COMPAT_ELF_NGREG, + .size = sizeof(compat_elf_greg_t), + .align = sizeof(compat_elf_greg_t), + .regset_get = compat_gpr_get_full, + .set = compat_gpr_set + }, [REGSET_COMPAT_VFP] = { .core_note_type = NT_ARM_VFP, .n = VFP_STATE_SIZE / sizeof(compat_ulong_t), diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index 30f68b42eeb5..a2086d19263a 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -426,6 +426,7 @@ typedef struct elf64_shdr { #define NT_ARM_PACA_KEYS 0x407 /* ARM pointer authentication address keys */ #define NT_ARM_PACG_KEYS 0x408 /* ARM pointer authentication generic key */ #define NT_ARM_TAGGED_ADDR_CTRL 0x409 /* arm64 tagged address control (prctl()) */ +#define NT_ARM_PRSTATUS 0x410 /* ARM general-purpose registers */ #define NT_ARC_V2 0x600 /* ARCv2 accumulator/extra registers */ #define NT_VMCOREDD 0x700 /* Vmcore Device Dump Note */ #define NT_MIPS_DSP 0x800 /* MIPS DSP ASE registers */ -- 2.29.2
