Sandipan Das <sandi...@linux.ibm.com> writes:
> This enhances the current selftest framework for validating
> the in-kernel instruction emulation infrastructure by adding
> support for compute type instructions i.e. integer ALU-based
> instructions. Originally, this framework was limited to only
> testing load and store instructions.
>
> While most of the GPRs can be validated, support for SPRs is
> limited to LR, CR and XER for now.
>
> When writing the test cases, one must ensure that the Stack
> Pointer (GPR1) or the Thread Pointer (GPR13) are not touched
> by any means as these are vital non-volatile registers.
>
> Signed-off-by: Sandipan Das <sandi...@linux.ibm.com>
> ---
> arch/powerpc/lib/Makefile | 3 +-
> arch/powerpc/lib/test_emulate_step.c | 167 +++++++++++++++++-
> .../lib/test_emulate_step_exec_instr.S | 150 ++++++++++++++++
> 3 files changed, 315 insertions(+), 5 deletions(-)
> create mode 100644 arch/powerpc/lib/test_emulate_step_exec_instr.S
Hi Sandipan,
Thanks for the exceptionally well written asm, I wish all our asm code
was that neat and well commented :)
I'd like to get this merged today so I tweaked it slightly when
applying to use the new patch_site helpers we added recently, see diff
below.
cheers
diff --git a/arch/powerpc/lib/test_emulate_step.c
b/arch/powerpc/lib/test_emulate_step.c
index 1c13b3bebeca..9992c1ea7a1d 100644
--- a/arch/powerpc/lib/test_emulate_step.c
+++ b/arch/powerpc/lib/test_emulate_step.c
@@ -865,14 +865,14 @@ static int __init emulate_compute_instr(struct pt_regs
*regs,
static int __init execute_compute_instr(struct pt_regs *regs,
unsigned int instr)
{
- extern unsigned int exec_instr_execute[];
extern int exec_instr(struct pt_regs *regs);
+ extern s32 patch__exec_instr;
if (!regs || !instr)
return -EINVAL;
/* Patch the NOP with the actual instruction */
- patch_instruction(&exec_instr_execute[0], instr);
+ patch_instruction_site(&patch__exec_instr, instr);
if (exec_instr(regs)) {
pr_info("execution failed, instruction = 0x%08x\n", instr);
return -EFAULT;
diff --git a/arch/powerpc/lib/test_emulate_step_exec_instr.S
b/arch/powerpc/lib/test_emulate_step_exec_instr.S
index 84cef7d78d9d..1580f34f4f4f 100644
--- a/arch/powerpc/lib/test_emulate_step_exec_instr.S
+++ b/arch/powerpc/lib/test_emulate_step_exec_instr.S
@@ -8,6 +8,7 @@
#include <asm/asm-offsets.h>
#include <asm/ppc_asm.h>
+#include <asm/code-patching-asm.h>
#include <linux/errno.h>
/* int exec_instr(struct pt_regs *regs) */
@@ -78,10 +79,9 @@ _GLOBAL(exec_instr)
REST_GPR(12, r31)
REST_NVGPRS(r31)
- .global exec_instr_execute
-exec_instr_execute:
/* Placeholder for the test instruction */
1: nop
+ patch_site 1b patch__exec_instr
/*
* Since GPR3 is overwritten, temporarily restore it back to its
