On 06/29/15 13:23, Steve Capper wrote:
Hi David, Some comments below.On 15 June 2015 at 20:07, David Long <dave.l...@linaro.org> wrote:From: "David A. Long" <dave.l...@linaro.org> Certain instructions are hard to execute correctly out-of-line (as in kprobes). Test functions are added to insn.[hc] to identify these. The instructions include any that use PC-relative addressing, change the PC, or change interrupt masking. For efficiency and simplicity test functions are also added for small collections of related instructions. Signed-off-by: David A. Long <dave.l...@linaro.org> --- arch/arm64/include/asm/insn.h | 18 ++++++++++++++++++ arch/arm64/kernel/insn.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index f81b328..1fdd237 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -223,8 +223,13 @@ static __always_inline bool aarch64_insn_is_##abbr(u32 code) \ static __always_inline u32 aarch64_insn_get_##abbr##_value(void) \ { return (val); } +__AARCH64_INSN_FUNCS(adr_adrp, 0x1F000000, 0x10000000) +__AARCH64_INSN_FUNCS(prfm_lit, 0xFF000000, 0xD8000000) __AARCH64_INSN_FUNCS(str_reg, 0x3FE0EC00, 0x38206800) __AARCH64_INSN_FUNCS(ldr_reg, 0x3FE0EC00, 0x38606800) +__AARCH64_INSN_FUNCS(ldr_lit, 0xBF000000, 0x18000000) +__AARCH64_INSN_FUNCS(ldrsw_lit, 0xFF000000, 0x98000000) +__AARCH64_INSN_FUNCS(exclusive, 0x3F000000, 0x08000000)Going one step back, if we're worried about the exclusive monitors then we'll be worried about instructions in-between the monitor pairs too?
Yes, but I don't see anything we can reasonably do about that.
__AARCH64_INSN_FUNCS(stp_post, 0x7FC00000, 0x28800000) __AARCH64_INSN_FUNCS(ldp_post, 0x7FC00000, 0x28C00000) __AARCH64_INSN_FUNCS(stp_pre, 0x7FC00000, 0x29800000) @@ -264,19 +269,29 @@ __AARCH64_INSN_FUNCS(ands, 0x7F200000, 0x6A000000) __AARCH64_INSN_FUNCS(bics, 0x7F200000, 0x6A200000) __AARCH64_INSN_FUNCS(b, 0xFC000000, 0x14000000) __AARCH64_INSN_FUNCS(bl, 0xFC000000, 0x94000000) +__AARCH64_INSN_FUNCS(b_bl, 0x7C000000, 0x14000000) +__AARCH64_INSN_FUNCS(cb, 0x7E000000, 0x34000000) __AARCH64_INSN_FUNCS(cbz, 0x7F000000, 0x34000000) __AARCH64_INSN_FUNCS(cbnz, 0x7F000000, 0x35000000) +__AARCH64_INSN_FUNCS(tb, 0x7E000000, 0x36000000) __AARCH64_INSN_FUNCS(tbz, 0x7F000000, 0x36000000) __AARCH64_INSN_FUNCS(tbnz, 0x7F000000, 0x37000000) +__AARCH64_INSN_FUNCS(b_bl_cb_tb, 0x5C000000, 0x14000000) __AARCH64_INSN_FUNCS(bcond, 0xFF000010, 0x54000000) __AARCH64_INSN_FUNCS(svc, 0xFFE0001F, 0xD4000001) __AARCH64_INSN_FUNCS(hvc, 0xFFE0001F, 0xD4000002) __AARCH64_INSN_FUNCS(smc, 0xFFE0001F, 0xD4000003) __AARCH64_INSN_FUNCS(brk, 0xFFE0001F, 0xD4200000) +__AARCH64_INSN_FUNCS(exception, 0xFF000000, 0xD4000000) __AARCH64_INSN_FUNCS(hint, 0xFFFFF01F, 0xD503201F) __AARCH64_INSN_FUNCS(br, 0xFFFFFC1F, 0xD61F0000) __AARCH64_INSN_FUNCS(blr, 0xFFFFFC1F, 0xD63F0000) +__AARCH64_INSN_FUNCS(br_blr, 0xFFDFFC1F, 0xD61F0000) __AARCH64_INSN_FUNCS(ret, 0xFFFFFC1F, 0xD65F0000) +__AARCH64_INSN_FUNCS(msr_imm, 0xFFF8F000, 0xD5004000)Should this not be: __AARCH64_INSN_FUNCS(msr_imm, 0xFFF8F01F, 0xD500401F) As the lower 5 bits of an MSR (immediate) are all 1?
Yeah, that does look more correct.
+__AARCH64_INSN_FUNCS(msr_reg, 0xFFF00000, 0xD5100000) +__AARCH64_INSN_FUNCS(set_clr_daif, 0xFFFFF0DF, 0xD50340DF)Looks good, just an MSR immediate with either DAIFSet or DAIFClr.+__AARCH64_INSN_FUNCS(rd_wr_daif, 0xFFDFFFE0, 0xD51B4220)Looks good, either MRS or MSR (register) where systemreg = DAIF.#undef __AARCH64_INSN_FUNCS @@ -285,6 +300,9 @@ bool aarch64_insn_is_nop(u32 insn); int aarch64_insn_read(void *addr, u32 *insnp); int aarch64_insn_write(void *addr, u32 insn); enum aarch64_insn_encoding_class aarch64_get_insn_class(u32 insn); +bool aarch64_insn_uses_literal(u32 insn); +bool aarch64_insn_is_branch(u32 insn); +bool aarch64_insn_is_daif_access(u32 insn); u64 aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type, u32 insn); u32 aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type, u32 insn, u64 imm); diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index 9249020..ecd8882 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -155,6 +155,34 @@ static bool __kprobes __aarch64_insn_hotpatch_safe(u32 insn) aarch64_insn_is_nop(insn); } +bool __kprobes aarch64_insn_uses_literal(u32 insn) +{ + /* ldr/ldrsw (literal), prfm */ + + return aarch64_insn_is_ldr_lit(insn) || + aarch64_insn_is_ldrsw_lit(insn) || + aarch64_insn_is_adr_adrp(insn) || + aarch64_insn_is_prfm_lit(insn); +} + +bool __kprobes aarch64_insn_is_branch(u32 insn) +{ + /* b, bl, cb*, tb*, b.cond, br, blr */ + + return aarch64_insn_is_b_bl_cb_tb(insn) || + aarch64_insn_is_br_blr(insn) || + aarch64_insn_is_ret(insn) || + aarch64_insn_is_bcond(insn); +} + +bool __kprobes aarch64_insn_is_daif_access(u32 insn) +{ + /* msr daif, mrs daif, msr daifset, msr daifclr */ + + return aarch64_insn_is_rd_wr_daif(insn) || + aarch64_insn_is_set_clr_daif(insn); +} + /* * ARM Architecture Reference Manual for ARMv8 Profile-A, Issue A.a * Section B2.6.5 "Concurrent modification and execution of instructions": -- 1.8.1.2
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