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author | David A. Long <dave.long@linaro.org> | 2016-07-08 16:35:47 (GMT) |
---|---|---|
committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-07-19 14:03:19 (GMT) |
commit | 2af3ec08b414ceb9c32fad2bb0f87252f3f18de8 (patch) | |
tree | ff2603ec647205a23d00ae652b994a29f703be28 /arch | |
parent | d59bee887231191c80f2ee674d7ec19179eb40ec (diff) | |
download | linux-2af3ec08b414ceb9c32fad2bb0f87252f3f18de8.tar.xz |
arm64: add conditional instruction simulation support
Cease using the arm32 arm_check_condition() function and replace it with
a local version for use in deprecated instruction support on arm64. Also
make the function table used by this available for future use by kprobes
and/or uprobes.
This function is derived from code written by Sandeepa Prabhu.
Signed-off-by: Sandeepa Prabhu <sandeepa.s.prabhu@gmail.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm64/include/asm/insn.h | 3 | ||||
-rw-r--r-- | arch/arm64/kernel/Makefile | 3 | ||||
-rw-r--r-- | arch/arm64/kernel/armv8_deprecated.c | 19 | ||||
-rw-r--r-- | arch/arm64/kernel/insn.c | 98 |
4 files changed, 119 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index 497f7a2..a44abbd 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -406,6 +406,9 @@ u32 aarch64_insn_extract_system_reg(u32 insn); u32 aarch32_insn_extract_reg_num(u32 insn, int offset); u32 aarch32_insn_mcr_extract_opc2(u32 insn); u32 aarch32_insn_mcr_extract_crm(u32 insn); + +typedef bool (pstate_check_t)(unsigned long); +extern pstate_check_t * const aarch32_opcode_cond_checks[16]; #endif /* __ASSEMBLY__ */ #endif /* __ASM_INSN_H */ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 2173149..4653aca 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -26,8 +26,7 @@ $(obj)/%.stub.o: $(obj)/%.o FORCE $(call if_changed,objcopy) arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \ - sys_compat.o entry32.o \ - ../../arm/kernel/opcodes.o + sys_compat.o entry32.o arm64-obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o arm64-obj-$(CONFIG_MODULES) += arm64ksyms.o module.o arm64-obj-$(CONFIG_ARM64_MODULE_PLTS) += module-plts.o diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c index c37202c..2934894 100644 --- a/arch/arm64/kernel/armv8_deprecated.c +++ b/arch/arm64/kernel/armv8_deprecated.c @@ -366,6 +366,21 @@ static int emulate_swpX(unsigned int address, unsigned int *data, return res; } +#define ARM_OPCODE_CONDITION_UNCOND 0xf + +static unsigned int __kprobes aarch32_check_condition(u32 opcode, u32 psr) +{ + u32 cc_bits = opcode >> 28; + + if (cc_bits != ARM_OPCODE_CONDITION_UNCOND) { + if ((*aarch32_opcode_cond_checks[cc_bits])(psr)) + return ARM_OPCODE_CONDTEST_PASS; + else + return ARM_OPCODE_CONDTEST_FAIL; + } + return ARM_OPCODE_CONDTEST_UNCOND; +} + /* * swp_handler logs the id of calling process, dissects the instruction, sanity * checks the memory location, calls emulate_swpX for the actual operation and @@ -380,7 +395,7 @@ static int swp_handler(struct pt_regs *regs, u32 instr) type = instr & TYPE_SWPB; - switch (arm_check_condition(instr, regs->pstate)) { + switch (aarch32_check_condition(instr, regs->pstate)) { case ARM_OPCODE_CONDTEST_PASS: break; case ARM_OPCODE_CONDTEST_FAIL: @@ -461,7 +476,7 @@ static int cp15barrier_handler(struct pt_regs *regs, u32 instr) { perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc); - switch (arm_check_condition(instr, regs->pstate)) { + switch (aarch32_check_condition(instr, regs->pstate)) { case ARM_OPCODE_CONDTEST_PASS: break; case ARM_OPCODE_CONDTEST_FAIL: diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index 28c6110f..5cb2f3d 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -1234,3 +1234,101 @@ u32 aarch32_insn_mcr_extract_crm(u32 insn) { return insn & CRM_MASK; } + +static bool __kprobes __check_eq(unsigned long pstate) +{ + return (pstate & PSR_Z_BIT) != 0; +} + +static bool __kprobes __check_ne(unsigned long pstate) +{ + return (pstate & PSR_Z_BIT) == 0; +} + +static bool __kprobes __check_cs(unsigned long pstate) +{ + return (pstate & PSR_C_BIT) != 0; +} + +static bool __kprobes __check_cc(unsigned long pstate) +{ + return (pstate & PSR_C_BIT) == 0; +} + +static bool __kprobes __check_mi(unsigned long pstate) +{ + return (pstate & PSR_N_BIT) != 0; +} + +static bool __kprobes __check_pl(unsigned long pstate) +{ + return (pstate & PSR_N_BIT) == 0; +} + +static bool __kprobes __check_vs(unsigned long pstate) +{ + return (pstate & PSR_V_BIT) != 0; +} + +static bool __kprobes __check_vc(unsigned long pstate) +{ + return (pstate & PSR_V_BIT) == 0; +} + +static bool __kprobes __check_hi(unsigned long pstate) +{ + pstate &= ~(pstate >> 1); /* PSR_C_BIT &= ~PSR_Z_BIT */ + return (pstate & PSR_C_BIT) != 0; +} + +static bool __kprobes __check_ls(unsigned long pstate) +{ + pstate &= ~(pstate >> 1); /* PSR_C_BIT &= ~PSR_Z_BIT */ + return (pstate & PSR_C_BIT) == 0; +} + +static bool __kprobes __check_ge(unsigned long pstate) +{ + pstate ^= (pstate << 3); /* PSR_N_BIT ^= PSR_V_BIT */ + return (pstate & PSR_N_BIT) == 0; +} + +static bool __kprobes __check_lt(unsigned long pstate) +{ + pstate ^= (pstate << 3); /* PSR_N_BIT ^= PSR_V_BIT */ + return (pstate & PSR_N_BIT) != 0; +} + +static bool __kprobes __check_gt(unsigned long pstate) +{ + /*PSR_N_BIT ^= PSR_V_BIT */ + unsigned long temp = pstate ^ (pstate << 3); + + temp |= (pstate << 1); /*PSR_N_BIT |= PSR_Z_BIT */ + return (temp & PSR_N_BIT) == 0; +} + +static bool __kprobes __check_le(unsigned long pstate) +{ + /*PSR_N_BIT ^= PSR_V_BIT */ + unsigned long temp = pstate ^ (pstate << 3); + + temp |= (pstate << 1); /*PSR_N_BIT |= PSR_Z_BIT */ + return (temp & PSR_N_BIT) != 0; +} + +static bool __kprobes __check_al(unsigned long pstate) +{ + return true; +} + +/* + * Note that the ARMv8 ARM calls condition code 0b1111 "nv", but states that + * it behaves identically to 0b1110 ("al"). + */ +pstate_check_t * const aarch32_opcode_cond_checks[16] = { + __check_eq, __check_ne, __check_cs, __check_cc, + __check_mi, __check_pl, __check_vs, __check_vc, + __check_hi, __check_ls, __check_ge, __check_lt, + __check_gt, __check_le, __check_al, __check_al +}; |