On 06/03/2016 11:53 PM, Masami Hiramatsu wrote:
On Thu, 2 Jun 2016 23:26:17 -0400
David Long <[email protected]> wrote:
From: "David A. Long" <[email protected]>
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 dervied from code written by Sandeepa Prabhu.
Basically looks good to me. I have some comments;
Signed-off-by: Sandeepa Prabhu <[email protected]>
Signed-off-by: David A. Long <[email protected]>
---
arch/arm64/include/asm/insn.h | 3 ++
arch/arm64/kernel/Makefile | 3 +-
arch/arm64/kernel/armv8_deprecated.c | 19 ++++++-
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 9785d10..98e4edd 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -406,6 +406,9 @@ u32 aarch64_extract_system_register(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 opcode_condition_checks[16];
Are those condition checkers only for aarch32 opcode? or
general for aarch64 too? If it is only for aarch32, we'd better
add aarch32 prefix.
I have this vague recollection there once was a reason for this but I
can't for the life of me remember why. I altered the symbol name to
something that begins with aarch32.
#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..88b9165 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 arm32_check_condition(u32 opcode, u32 psr)
Would you be OK for using arm32 instead of aarch32 prefix?
I think you meant the opposite of that? I guess that would make sense,
and would be simple enough since it's an internal function. I will
change arm32 to aarch32.
+{
+ u32 cc_bits = opcode >> 28;
+
+ if (cc_bits != ARM_OPCODE_CONDITION_UNCOND) {
+ if ((*opcode_condition_checks[cc_bits])(psr))
+ return ARM_OPCODE_CONDTEST_PASS;
+ else
+ return ARM_OPCODE_CONDTEST_FAIL;
+ }
+ return ARM_OPCODE_CONDTEST_UNCOND;
+}
Thank you,
Thanks,
-dl
