This is a next version to RFC patch:
https://lkml.org/lkml/2018/5/16/36
kbuild test robot reported the following build failure with RFC.
error: unused variable 'type' [-Werror=unused-variable]
int type;
^~~~
I've fixed it along with following changes.
1st patch introduces a new macro to simplify code a bit.
2nd patch fixes the kernel crash when VSX is not supported
or disabled.
3rd patch fixes emulate_step() tests
Ravi Bangoria (3):
powerpc/sstep: Introduce GETTYPE macro
powerpc/sstep: Fix kernel crash if VSX is not present
powerpc/sstep: Fix emulate_step test if VSX not present
arch/powerpc/include/asm/sstep.h | 2 ++
arch/powerpc/kernel/align.c | 2 +-
arch/powerpc/lib/sstep.c | 15 ++++++++++++---
arch/powerpc/lib/test_emulate_step.c | 21 +++++++++++++++------
4 files changed, 30 insertions(+), 10 deletions(-)
--
2.16.2
Replace 'op->type & INSTR_TYPE_MASK' expression with GETTYPE(op->type)
macro.
Signed-off-by: Ravi Bangoria <[email protected]>
---
arch/powerpc/include/asm/sstep.h | 2 ++
arch/powerpc/kernel/align.c | 2 +-
arch/powerpc/lib/sstep.c | 6 +++---
3 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h
index ab9d849644d0..9a2dfee26f9f 100644
--- a/arch/powerpc/include/asm/sstep.h
+++ b/arch/powerpc/include/asm/sstep.h
@@ -97,6 +97,8 @@ enum instruction_type {
#define SIZE(n) ((n) << 12)
#define GETSIZE(w) ((w) >> 12)
+#define GETTYPE(t) ((t) & INSTR_TYPE_MASK)
+
#define MKOP(t, f, s) ((t) | (f) | SIZE(s))
struct instruction_op {
diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c
index 3e6c0744c174..11550a3d1ac2 100644
--- a/arch/powerpc/kernel/align.c
+++ b/arch/powerpc/kernel/align.c
@@ -339,7 +339,7 @@ int fix_alignment(struct pt_regs *regs)
if (r < 0)
return -EINVAL;
- type = op.type & INSTR_TYPE_MASK;
+ type = GETTYPE(op.type);
if (!OP_IS_LOAD_STORE(type)) {
if (op.type != CACHEOP + DCBZ)
return -EINVAL;
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 34d68f1b1b40..db6bba259d91 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -2641,7 +2641,7 @@ void emulate_update_regs(struct pt_regs *regs, struct instruction_op *op)
unsigned long next_pc;
next_pc = truncate_if_32bit(regs->msr, regs->nip + 4);
- switch (op->type & INSTR_TYPE_MASK) {
+ switch (GETTYPE(op->type)) {
case COMPUTE:
if (op->type & SETREG)
regs->gpr[op->reg] = op->val;
@@ -2739,7 +2739,7 @@ int emulate_loadstore(struct pt_regs *regs, struct instruction_op *op)
err = 0;
size = GETSIZE(op->type);
- type = op->type & INSTR_TYPE_MASK;
+ type = GETTYPE(op->type);
cross_endian = (regs->msr & MSR_LE) != (MSR_KERNEL & MSR_LE);
ea = truncate_if_32bit(regs->msr, op->ea);
@@ -3001,7 +3001,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
}
err = 0;
- type = op.type & INSTR_TYPE_MASK;
+ type = GETTYPE(op.type);
if (OP_IS_LOAD_STORE(type)) {
err = emulate_loadstore(regs, &op);
--
2.16.2
emulate_step() tests are failing if VSX is not supported or disabled.
emulate_step_test: lxvd2x : FAIL
emulate_step_test: stxvd2x : FAIL
If !CPU_FTR_VSX, emulate_step() failure is expected and testcase should
PASS with a valid justification. After patch:
emulate_step_test: lxvd2x : PASS (!CPU_FTR_VSX)
emulate_step_test: stxvd2x : PASS (!CPU_FTR_VSX)
Signed-off-by: Ravi Bangoria <[email protected]>
---
arch/powerpc/lib/test_emulate_step.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/lib/test_emulate_step.c b/arch/powerpc/lib/test_emulate_step.c
index 2534c1447554..6c47daa61614 100644
--- a/arch/powerpc/lib/test_emulate_step.c
+++ b/arch/powerpc/lib/test_emulate_step.c
@@ -387,10 +387,14 @@ static void __init test_lxvd2x_stxvd2x(void)
/* lxvd2x vsr39, r3, r4 */
stepped = emulate_step(®s, TEST_LXVD2X(39, 3, 4));
- if (stepped == 1)
+ if (stepped == 1 && cpu_has_feature(CPU_FTR_VSX)) {
show_result("lxvd2x", "PASS");
- else
- show_result("lxvd2x", "FAIL");
+ } else {
+ if (!cpu_has_feature(CPU_FTR_VSX))
+ show_result("lxvd2x", "PASS (!CPU_FTR_VSX)");
+ else
+ show_result("lxvd2x", "FAIL");
+ }
/*** stxvd2x ***/
@@ -404,10 +408,15 @@ static void __init test_lxvd2x_stxvd2x(void)
stepped = emulate_step(®s, TEST_STXVD2X(39, 3, 4));
if (stepped == 1 && cached_b[0] == c.b[0] && cached_b[1] == c.b[1] &&
- cached_b[2] == c.b[2] && cached_b[3] == c.b[3])
+ cached_b[2] == c.b[2] && cached_b[3] == c.b[3] &&
+ cpu_has_feature(CPU_FTR_VSX)) {
show_result("stxvd2x", "PASS");
- else
- show_result("stxvd2x", "FAIL");
+ } else {
+ if (!cpu_has_feature(CPU_FTR_VSX))
+ show_result("stxvd2x", "PASS (!CPU_FTR_VSX)");
+ else
+ show_result("stxvd2x", "FAIL");
+ }
}
#else
static void __init test_lxvd2x_stxvd2x(void)
--
2.16.2
emulate_step() is not checking runtime VSX feature flag before
emulating an instruction. This is causing kernel crash when kernel
is compiled with CONFIG_VSX=y but running on a machine where VSX
is not supported or disabled. Ex, while running emulate_step tests
on P6 machine:
Oops: Exception in kernel mode, sig: 4 [#1]
NIP [c000000000095c24] .load_vsrn+0x28/0x54
LR [c000000000094bdc] .emulate_loadstore+0x167c/0x17b0
Call Trace:
0x40fe240c7ae147ae (unreliable)
.emulate_loadstore+0x167c/0x17b0
.emulate_step+0x25c/0x5bc
.test_lxvd2x_stxvd2x+0x64/0x154
.test_emulate_step+0x38/0x4c
.do_one_initcall+0x5c/0x2c0
.kernel_init_freeable+0x314/0x4cc
.kernel_init+0x24/0x160
.ret_from_kernel_thread+0x58/0xb4
With fix:
emulate_step_test: lxvd2x : FAIL
emulate_step_test: stxvd2x : FAIL
Fixes: https://github.com/linuxppc/linux/issues/148
Reported-by: Michael Ellerman <[email protected]>
Signed-off-by: Ravi Bangoria <[email protected]>
---
arch/powerpc/lib/sstep.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index db6bba259d91..23b7ddf04521 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -2544,6 +2544,15 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
#endif /* __powerpc64__ */
}
+
+#ifdef CONFIG_VSX
+ if ((GETTYPE(op->type) == LOAD_VSX ||
+ GETTYPE(op->type) == STORE_VSX) &&
+ !cpu_has_feature(CPU_FTR_VSX)) {
+ return -1;
+ }
+#endif /* CONFIG_VSX */
+
return 0;
logical_done:
--
2.16.2
On Mon, 2018-05-21 at 04:21:06 UTC, Ravi Bangoria wrote:
> Replace 'op->type & INSTR_TYPE_MASK' expression with GETTYPE(op->type)
> macro.
>
> Signed-off-by: Ravi Bangoria <[email protected]>
Series applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/e6684d07e4308430b9b6497265781a
cheers