Introduce a probe_kernel_read_inst() function to use in cases where
probe_kernel_read() is used for getting an instruction. This will be
more useful for prefixed instructions.
Reviewed-by: Alistair Popple <alist...@popple.id.au>
Signed-off-by: Jordan Niethe <jniet...@gmail.com>
---
v6: - This was previously just in ftrace.c
---
arch/powerpc/include/asm/inst.h | 2 ++
arch/powerpc/kernel/trace/ftrace.c | 23 +++++++++++++----------
arch/powerpc/lib/inst.c | 11 +++++++++++
3 files changed, 26 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index 3e9a58420151..0d581b332c20 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -39,5 +39,7 @@ static inline bool ppc_inst_equal(struct ppc_inst x, struct
ppc_inst y)
int probe_user_read_inst(struct ppc_inst *inst,
struct ppc_inst *nip);
+int probe_kernel_read_inst(struct ppc_inst *inst,
+ struct ppc_inst *src);
#endif /* _ASM_INST_H */
diff --git a/arch/powerpc/kernel/trace/ftrace.c
b/arch/powerpc/kernel/trace/ftrace.c
index acd5b889815f..5e399628f51a 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -68,7 +68,7 @@ ftrace_modify_code(unsigned long ip, struct ppc_inst old,
struct ppc_inst new)
*/
/* read the text we want to modify */
- if (probe_kernel_read(&replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ if (probe_kernel_read_inst(&replaced, (void *)ip))
return -EFAULT;
/* Make sure it is what we expect it to be */
@@ -130,7 +130,7 @@ __ftrace_make_nop(struct module *mod,
struct ppc_inst op, pop;
/* read where this goes */
- if (probe_kernel_read(&op, (void *)ip, sizeof(int))) {
+ if (probe_kernel_read_inst(&op, (void *)ip)) {
pr_err("Fetching opcode failed.\n");
return -EFAULT;
}
@@ -164,7 +164,7 @@ __ftrace_make_nop(struct module *mod,
/* When using -mkernel_profile there is no load to jump over */
pop = ppc_inst(PPC_INST_NOP);
- if (probe_kernel_read(&op, (void *)(ip - 4), 4)) {
+ if (probe_kernel_read_inst(&op, (void *)(ip - 4))) {
pr_err("Fetching instruction at %lx failed.\n", ip - 4);
return -EFAULT;
}
@@ -197,7 +197,7 @@ __ftrace_make_nop(struct module *mod,
* Check what is in the next instruction. We can see ld r2,40(r1), but
* on first pass after boot we will see mflr r0.
*/
- if (probe_kernel_read(&op, (void *)(ip+4), MCOUNT_INSN_SIZE)) {
+ if (probe_kernel_read_inst(&op, (void *)(ip + 4))) {
pr_err("Fetching op failed.\n");
return -EFAULT;
}
@@ -349,7 +349,7 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
return -1;
/* New trampoline -- read where this goes */
- if (probe_kernel_read(&op, (void *)tramp, sizeof(int))) {
+ if (probe_kernel_read_inst(&op, (void *)tramp)) {
pr_debug("Fetching opcode failed.\n");
return -1;
}
@@ -399,7 +399,7 @@ static int __ftrace_make_nop_kernel(struct dyn_ftrace *rec,
unsigned long addr)
struct ppc_inst op;
/* Read where this goes */
- if (probe_kernel_read(&op, (void *)ip, sizeof(int))) {
+ if (probe_kernel_read_inst(&op, (void *)ip)) {
pr_err("Fetching opcode failed.\n");
return -EFAULT;
}
@@ -526,7 +526,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long
addr)
struct module *mod = rec->arch.mod;
/* read where this goes */
- if (probe_kernel_read(op, ip, sizeof(op)))
+ if (probe_kernel_read_inst(op, ip))
+ return -EFAULT;
+
+ if (probe_kernel_read_inst(op + 1, ip + 4))
return -EFAULT;
if (!expected_nop_sequence(ip, op[0], op[1])) {
@@ -589,7 +592,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long
addr)
unsigned long ip = rec->ip;
/* read where this goes */
- if (probe_kernel_read(&op, (void *)ip, MCOUNT_INSN_SIZE))
+ if (probe_kernel_read_inst(&op, (void *)ip))
return -EFAULT;
/* It should be pointing to a nop */
@@ -645,7 +648,7 @@ static int __ftrace_make_call_kernel(struct dyn_ftrace
*rec, unsigned long addr)
}
/* Make sure we have a nop */
- if (probe_kernel_read(&op, ip, sizeof(op))) {
+ if (probe_kernel_read_inst(&op, ip)) {
pr_err("Unable to read ftrace location %p\n", ip);
return -EFAULT;
}
@@ -723,7 +726,7 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long
old_addr,
}
/* read where this goes */
- if (probe_kernel_read(&op, (void *)ip, sizeof(int))) {
+ if (probe_kernel_read_inst(&op, (void *)ip)) {
pr_err("Fetching opcode failed.\n");
return -EFAULT;
}
diff --git a/arch/powerpc/lib/inst.c b/arch/powerpc/lib/inst.c
index eaf786afad2b..08dedd927268 100644
--- a/arch/powerpc/lib/inst.c
+++ b/arch/powerpc/lib/inst.c
@@ -16,3 +16,14 @@ int probe_user_read_inst(struct ppc_inst *inst,
*inst = ppc_inst(val);
return err;
}
+
+int probe_kernel_read_inst(struct ppc_inst *inst,
+ struct ppc_inst *src)
+{
+ unsigned int val;
+ int err;
+
+ err = probe_kernel_read(&val, src, sizeof(val));
+ *inst = ppc_inst(val);
+ return err;
+}
--
2.17.1
