Prefixed instructions will mean there are instructions of different
length. As a result dereferencing a pointer to an instruction will not
necessarily give the desired result. Introduce a function for reading
instructions from memory into the instruction data type.
Signed-off-by: Jordan Niethe <jniet...@gmail.com>
---
v4: New to series
v5: - Rename read_inst() -> probe_kernel_read_inst()
- No longer modify uprobe probe type in this patch
---
arch/powerpc/include/asm/inst.h | 5 +++++
arch/powerpc/kernel/kprobes.c | 11 ++++------
arch/powerpc/kernel/mce_power.c | 2 +-
arch/powerpc/kernel/optprobes.c | 4 ++--
arch/powerpc/kernel/trace/ftrace.c | 33 +++++++++++++++++++-----------
arch/powerpc/lib/code-patching.c | 23 ++++++++++-----------
arch/powerpc/lib/feature-fixups.c | 2 +-
arch/powerpc/xmon/xmon.c | 6 +++---
8 files changed, 48 insertions(+), 38 deletions(-)
diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index a71decf5f871..369b35ce964c 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -27,6 +27,11 @@ static inline struct ppc_inst ppc_inst_swab(struct ppc_inst
x)
return ppc_inst(swab32(ppc_inst_val(x)));
}
+static inline struct ppc_inst ppc_inst_read(const struct ppc_inst *ptr)
+{
+ return *ptr;
+}
+
static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y)
{
return !memcmp(&x, &y, sizeof(struct ppc_inst));
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 9ed996cb0589..ff53e5ef7e40 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -106,7 +106,7 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name,
unsigned int offset)
int arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
- struct ppc_inst insn = *(struct ppc_inst *)p->addr;
+ struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->addr);
if ((unsigned long)p->addr & 0x03) {
printk("Attempt to register kprobe at an unaligned address\n");
@@ -125,11 +125,8 @@ int arch_prepare_kprobe(struct kprobe *p)
}
if (!ret) {
- memcpy(p->ainsn.insn, p->addr,
- MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
- p->opcode = *p->addr;
- flush_icache_range((unsigned long)p->ainsn.insn,
- (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t));
+ patch_instruction((struct ppc_inst *)p->ainsn.insn, insn);
+ p->opcode = ppc_inst_val(insn);
}
p->ainsn.boostable = 0;
@@ -217,7 +214,7 @@ NOKPROBE_SYMBOL(arch_prepare_kretprobe);
static int try_to_emulate(struct kprobe *p, struct pt_regs *regs)
{
int ret;
- struct ppc_inst insn = *(struct ppc_inst *)p->ainsn.insn;
+ struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->ainsn.insn);
/* regs->nip is also adjusted if emulate_step returns 1 */
ret = emulate_step(regs, insn);
diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
index 7118b46a6543..859b602fa270 100644
--- a/arch/powerpc/kernel/mce_power.c
+++ b/arch/powerpc/kernel/mce_power.c
@@ -374,7 +374,7 @@ static int mce_find_instr_ea_and_phys(struct pt_regs *regs,
uint64_t *addr,
pfn = addr_to_pfn(regs, regs->nip);
if (pfn != ULONG_MAX) {
instr_addr = (pfn << PAGE_SHIFT) + (regs->nip & ~PAGE_MASK);
- instr = *(struct ppc_inst *)(instr_addr);
+ instr = ppc_inst_read((struct ppc_inst *)instr_addr);
if (!analyse_instr(&op, &tmp, instr)) {
pfn = addr_to_pfn(regs, op.ea);
*addr = op.ea;
diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c
index b61bbcee84f4..684640b8fa2e 100644
--- a/arch/powerpc/kernel/optprobes.c
+++ b/arch/powerpc/kernel/optprobes.c
@@ -100,8 +100,8 @@ static unsigned long can_optimize(struct kprobe *p)
* Ensure that the instruction is not a conditional branch,
* and that can be emulated.
*/
- if (!is_conditional_branch(*(struct ppc_inst *)p->ainsn.insn) &&
- analyse_instr(&op, ®s, *(struct ppc_inst
*)p->ainsn.insn) == 1) {
+ if (!is_conditional_branch(ppc_inst_read((struct ppc_inst
*)p->ainsn.insn)) &&
+ analyse_instr(&op, ®s, ppc_inst_read((struct
ppc_inst *)p->ainsn.insn)) == 1) {
emulate_update_regs(®s, &op);
nip = regs.nip;
}
diff --git a/arch/powerpc/kernel/trace/ftrace.c
b/arch/powerpc/kernel/trace/ftrace.c
index 442c62fb68ff..e78742613b36 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -41,6 +41,12 @@
#define NUM_FTRACE_TRAMPS 8
static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS];
+static long
+probe_kernel_read_inst(struct ppc_inst *inst, const void *src)
+{
+ return probe_kernel_read((void *)inst, src, MCOUNT_INSN_SIZE);
+}
+
static struct ppc_inst
ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
{
@@ -68,7 +74,7 @@ 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 +136,7 @@ __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 +170,7 @@ __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;
}
@@ -196,7 +202,7 @@ __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;
}
@@ -348,7 +354,7 @@ 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;
}
@@ -398,7 +404,7 @@ 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;
}
@@ -524,7 +530,10 @@ __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])) {
@@ -587,7 +596,7 @@ __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 */
@@ -643,7 +652,7 @@ 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;
}
@@ -721,7 +730,7 @@ __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;
}
@@ -846,7 +855,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
struct ppc_inst old, new;
int ret;
- old = *(struct ppc_inst *)&ftrace_call;
+ old = ppc_inst_read((struct ppc_inst *)&ftrace_call);
new = ftrace_call_replace(ip, (unsigned long)func, 1);
ret = ftrace_modify_code(ip, old, new);
@@ -854,7 +863,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
/* Also update the regs callback function */
if (!ret) {
ip = (unsigned long)(&ftrace_regs_call);
- old = *(struct ppc_inst *)&ftrace_regs_call;
+ old = ppc_inst_read((struct ppc_inst *)&ftrace_regs_call);
new = ftrace_call_replace(ip, (unsigned long)func, 1);
ret = ftrace_modify_code(ip, old, new);
}
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 91be4a0b51cb..ba08f3815d00 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -349,9 +349,9 @@ static unsigned long branch_bform_target(const struct
ppc_inst *instr)
unsigned long branch_target(const struct ppc_inst *instr)
{
- if (instr_is_branch_iform(*instr))
+ if (instr_is_branch_iform(ppc_inst_read(instr)))
return branch_iform_target(instr);
- else if (instr_is_branch_bform(*instr))
+ else if (instr_is_branch_bform(ppc_inst_read(instr)))
return branch_bform_target(instr);
return 0;
@@ -359,7 +359,7 @@ unsigned long branch_target(const struct ppc_inst *instr)
int instr_is_branch_to_addr(const struct ppc_inst *instr, unsigned long addr)
{
- if (instr_is_branch_iform(*instr) || instr_is_branch_bform(*instr))
+ if (instr_is_branch_iform(ppc_inst_read(instr)) ||
instr_is_branch_bform(ppc_inst_read(instr)))
return branch_target(instr) == addr;
return 0;
@@ -368,13 +368,12 @@ int instr_is_branch_to_addr(const struct ppc_inst *instr,
unsigned long addr)
int translate_branch(struct ppc_inst *instr, const struct ppc_inst *dest,
const struct ppc_inst *src)
{
unsigned long target;
-
target = branch_target(src);
- if (instr_is_branch_iform(*src))
- return create_branch(instr, dest, target, ppc_inst_val(*src));
- else if (instr_is_branch_bform(*src))
- return create_cond_branch(instr, dest, target,
ppc_inst_val(*src));
+ if (instr_is_branch_iform(ppc_inst_read(src)))
+ return create_branch(instr, dest, target,
ppc_inst_val(ppc_inst_read(src)));
+ else if (instr_is_branch_bform(ppc_inst_read(src)))
+ return create_cond_branch(instr, dest, target,
ppc_inst_val(ppc_inst_read(src)));
return 1;
}
@@ -598,7 +597,7 @@ static void __init test_translate_branch(void)
patch_instruction(q, instr);
check(instr_is_branch_to_addr(p, addr));
check(instr_is_branch_to_addr(q, addr));
- check(ppc_inst_equal(*q, ppc_inst(0x4a000000)));
+ check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x4a000000)));
/* Maximum positive case, move x to x - 32 MB + 4 */
p = buf + 0x2000000;
@@ -609,7 +608,7 @@ static void __init test_translate_branch(void)
patch_instruction(q, instr);
check(instr_is_branch_to_addr(p, addr));
check(instr_is_branch_to_addr(q, addr));
- check(ppc_inst_equal(*q, ppc_inst(0x49fffffc)));
+ check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x49fffffc)));
/* Jump to x + 16 MB moved to x + 20 MB */
p = buf;
@@ -655,7 +654,7 @@ static void __init test_translate_branch(void)
patch_instruction(q, instr);
check(instr_is_branch_to_addr(p, addr));
check(instr_is_branch_to_addr(q, addr));
- check(ppc_inst_equal(*q, ppc_inst(0x43ff8000)));
+ check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff8000)));
/* Maximum positive case, move x to x - 32 KB + 4 */
p = buf + 0x8000;
@@ -667,7 +666,7 @@ static void __init test_translate_branch(void)
patch_instruction(q, instr);
check(instr_is_branch_to_addr(p, addr));
check(instr_is_branch_to_addr(q, addr));
- check(ppc_inst_equal(*q, ppc_inst(0x43ff7ffc)));
+ check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff7ffc)));
/* Jump to x + 12 KB moved to x + 20 KB */
p = buf;
diff --git a/arch/powerpc/lib/feature-fixups.c
b/arch/powerpc/lib/feature-fixups.c
index 8c5d0db77013..f00dd13b1c3c 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -48,7 +48,7 @@ static int patch_alt_instruction(struct ppc_inst *src, struct
ppc_inst *dest,
int err;
struct ppc_inst instr;
- instr = *src;
+ instr = ppc_inst_read(src);
if (instr_is_relative_branch(*src)) {
struct ppc_inst *target = (struct ppc_inst *)branch_target(src);
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index e3d8e1b8ce01..5e3949322a6c 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -705,13 +705,13 @@ static int xmon_core(struct pt_regs *regs, int fromipi)
if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) == (MSR_IR|MSR_64BIT)) {
bp = at_breakpoint(regs->nip);
if (bp != NULL) {
- int stepped = emulate_step(regs, bp->instr[0]);
+ int stepped = emulate_step(regs,
ppc_inst_read(bp->instr));
if (stepped == 0) {
regs->nip = (unsigned long) &bp->instr[0];
atomic_inc(&bp->ref_count);
} else if (stepped < 0) {
printf("Couldn't single-step %s instruction\n",
- (IS_RFID(bp->instr[0])? "rfid": "mtmsrd"));
+ IS_RFID(ppc_inst_read(bp->instr))? "rfid":
"mtmsrd");
}
}
}
@@ -952,7 +952,7 @@ static void remove_bpts(void)
if (mread(bp->address, &instr, 4) == 4
&& ppc_inst_equal(instr, ppc_inst(bpinstr))
&& patch_instruction(
- (struct ppc_inst *)bp->address, bp->instr[0]) != 0)
+ (struct ppc_inst *)bp->address,
ppc_inst_read(bp->instr)) != 0)
printf("Couldn't remove breakpoint at %lx\n",
bp->address);
}
--
2.17.1
