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
---
arch/powerpc/include/asm/uprobes.h | 4 ++--
arch/powerpc/kernel/kprobes.c | 8 ++++----
arch/powerpc/kernel/mce_power.c | 2 +-
arch/powerpc/kernel/optprobes.c | 6 +++---
arch/powerpc/kernel/trace/ftrace.c | 33 +++++++++++++++++++-----------
arch/powerpc/kernel/uprobes.c | 2 +-
arch/powerpc/lib/code-patching.c | 22 ++++++++++----------
arch/powerpc/lib/feature-fixups.c | 6 +++---
arch/powerpc/xmon/xmon.c | 6 +++---
9 files changed, 49 insertions(+), 40 deletions(-)
diff --git a/arch/powerpc/include/asm/uprobes.h
b/arch/powerpc/include/asm/uprobes.h
index 2bbdf27d09b5..fff3c5fc90b5 100644
--- a/arch/powerpc/include/asm/uprobes.h
+++ b/arch/powerpc/include/asm/uprobes.h
@@ -23,8 +23,8 @@ typedef ppc_opcode_t uprobe_opcode_t;
struct arch_uprobe {
union {
- u32 insn;
- u32 ixol;
+ u8 insn[MAX_UINSN_BYTES];
+ u8 ixol[MAX_UINSN_BYTES];
};
};
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 0c600b6e4ead..f142d11d7b48 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -117,7 +117,7 @@ void *alloc_insn_page(void)
int arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
- kprobe_opcode_t insn = *p->addr;
+ ppc_inst insn = ppc_inst_read(p->addr);
if ((unsigned long)p->addr & 0x03) {
printk("Attempt to register kprobe at an unaligned address\n");
@@ -136,8 +136,8 @@ int arch_prepare_kprobe(struct kprobe *p)
}
if (!ret) {
- patch_instruction(p->ainsn.insn, *p->addr);
- p->opcode = *p->addr;
+ patch_instruction(p->ainsn.insn, insn);
+ p->opcode = ppc_inst_word(insn);
}
p->ainsn.boostable = 0;
@@ -225,7 +225,7 @@ NOKPROBE_SYMBOL(arch_prepare_kretprobe);
static int try_to_emulate(struct kprobe *p, struct pt_regs *regs)
{
int ret;
- ppc_inst insn = *p->ainsn.insn;
+ ppc_inst insn = ppc_inst_read((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 e65616bb3a3e..d1fdb5105d32 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 = *(ppc_inst *)(instr_addr);
+ instr = ppc_inst_read((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 6027425a85f2..5b53c373373b 100644
--- a/arch/powerpc/kernel/optprobes.c
+++ b/arch/powerpc/kernel/optprobes.c
@@ -99,8 +99,8 @@ 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(*p->ainsn.insn) &&
- analyse_instr(&op, ®s, *p->ainsn.insn) == 1) {
+ if (!is_conditional_branch(ppc_inst_read(p->ainsn.insn)) &&
+ analyse_instr(&op, ®s, ppc_inst_read(p->ainsn.insn))
== 1) {
emulate_update_regs(®s, &op);
nip = regs.nip;
}
@@ -268,7 +268,7 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe
*op, struct kprobe *p)
/*
* 3. load instruction to be emulated into relevant register, and
*/
- patch_imm32_load_insns(*p->ainsn.insn, buff + TMPL_INSN_IDX);
+ patch_imm32_load_insns(*(unsigned int *)p->ainsn.insn, buff +
TMPL_INSN_IDX);
/*
* 4. branch back from trampoline
diff --git a/arch/powerpc/kernel/trace/ftrace.c
b/arch/powerpc/kernel/trace/ftrace.c
index 7614a9f537fd..ad451205f268 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
+read_inst(ppc_inst *inst, const void *src)
+{
+ return probe_kernel_read((void *)inst, src, MCOUNT_INSN_SIZE);
+}
+
static ppc_inst
ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
{
@@ -68,7 +74,7 @@ ftrace_modify_code(unsigned long ip, ppc_inst old, ppc_inst
new)
*/
/* read the text we want to modify */
- if (probe_kernel_read(&replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ if (read_inst(&replaced, (void *)ip))
return -EFAULT;
/* Make sure it is what we expect it to be */
@@ -129,7 +135,7 @@ __ftrace_make_nop(struct module *mod,
ppc_inst op, pop;
/* read where this goes */
- if (probe_kernel_read(&op, (void *)ip, sizeof(int))) {
+ if (read_inst(&op, (void *)ip)) {
pr_err("Fetching opcode failed.\n");
return -EFAULT;
}
@@ -163,7 +169,7 @@ __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 (read_inst(&op, (void *)(ip - 4))) {
pr_err("Fetching instruction at %lx failed.\n", ip - 4);
return -EFAULT;
}
@@ -195,7 +201,7 @@ __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 (read_inst(&op, (void *)(ip+4))) {
pr_err("Fetching op failed.\n");
return -EFAULT;
}
@@ -344,7 +350,7 @@ 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 (read_inst(&op, (void *)tramp)) {
pr_debug("Fetching opcode failed.\n");
return -1;
}
@@ -394,7 +400,7 @@ static int __ftrace_make_nop_kernel(struct dyn_ftrace *rec,
unsigned long addr)
ppc_inst op;
/* Read where this goes */
- if (probe_kernel_read(&op, (void *)ip, sizeof(int))) {
+ if (read_inst(&op, (void *)ip)) {
pr_err("Fetching opcode failed.\n");
return -EFAULT;
}
@@ -520,7 +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 (read_inst(op, ip))
+ return -EFAULT;
+
+ if (read_inst(op + 1, ip + 4))
return -EFAULT;
if (!expected_nop_sequence(ip, op[0], op[1])) {
@@ -582,7 +591,7 @@ __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 (read_inst(&op, (void *)ip))
return -EFAULT;
/* It should be pointing to a nop */
@@ -638,7 +647,7 @@ 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 (read_inst(&op, ip)) {
pr_err("Unable to read ftrace location %p\n", ip);
return -EFAULT;
}
@@ -716,7 +725,7 @@ __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 (read_inst(&op, (void *)ip)) {
pr_err("Fetching opcode failed.\n");
return -EFAULT;
}
@@ -842,7 +851,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
ppc_inst old, new;
int ret;
- old = *(unsigned int *)&ftrace_call;
+ old = ppc_inst_read((ppc_inst *)&ftrace_call);
new = ftrace_call_replace(ip, (unsigned long)func, 1);
ret = ftrace_modify_code(ip, old, new);
@@ -850,7 +859,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
/* Also update the regs callback function */
if (!ret) {
ip = (unsigned long)(&ftrace_regs_call);
- old = *(unsigned int *)&ftrace_regs_call;
+ old = ppc_inst_read((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/kernel/uprobes.c b/arch/powerpc/kernel/uprobes.c
index 1cfef0e5fec5..d1dff1dc3a11 100644
--- a/arch/powerpc/kernel/uprobes.c
+++ b/arch/powerpc/kernel/uprobes.c
@@ -173,7 +173,7 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe,
struct pt_regs *regs)
* emulate_step() returns 1 if the insn was successfully emulated.
* For all other cases, we need to single-step in hardware.
*/
- ret = emulate_step(regs, auprobe->insn);
+ ret = emulate_step(regs, ppc_inst_read((ppc_inst *)auprobe->insn));
if (ret > 0)
return true;
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 849eee63df3d..88ee03ff55f1 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -346,9 +346,9 @@ static unsigned long branch_bform_target(const ppc_inst
*instr)
unsigned long branch_target(const 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;
@@ -356,7 +356,7 @@ unsigned long branch_target(const ppc_inst *instr)
int instr_is_branch_to_addr(const 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;
@@ -368,10 +368,10 @@ ppc_inst translate_branch(const ppc_inst *dest, const
ppc_inst *src)
target = branch_target(src);
- if (instr_is_branch_iform(*src))
- return create_branch(dest, target, *src);
- else if (instr_is_branch_bform(*src))
- return create_cond_branch(dest, target, *src);
+ if (instr_is_branch_iform(ppc_inst_read(src)))
+ return create_branch(dest, target,
ppc_inst_word(ppc_inst_read(src)));
+ else if (instr_is_branch_bform(ppc_inst_read(src)))
+ return create_cond_branch(dest, target,
ppc_inst_word(ppc_inst_read(src)));
return PPC_INST(0);
}
@@ -588,7 +588,7 @@ static void __init test_translate_branch(void)
patch_instruction(q, translate_branch(q, p));
check(instr_is_branch_to_addr(p, addr));
check(instr_is_branch_to_addr(q, addr));
- check(*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;
@@ -598,7 +598,7 @@ static void __init test_translate_branch(void)
patch_instruction(q, translate_branch(q, p));
check(instr_is_branch_to_addr(p, addr));
check(instr_is_branch_to_addr(q, addr));
- check(*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;
@@ -638,7 +638,7 @@ static void __init test_translate_branch(void)
patch_instruction(q, translate_branch(q, p));
check(instr_is_branch_to_addr(p, addr));
check(instr_is_branch_to_addr(q, addr));
- check(*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;
@@ -648,7 +648,7 @@ static void __init test_translate_branch(void)
patch_instruction(q, translate_branch(q, p));
check(instr_is_branch_to_addr(p, addr));
check(instr_is_branch_to_addr(q, addr));
- check(*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 fe8ec099aa96..9e322f701e32 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -49,8 +49,8 @@ static int patch_alt_instruction(unsigned int *src, unsigned
int *dest,
instr = *src;
- if (instr_is_relative_branch(*src)) {
- unsigned int *target = (unsigned int *)branch_target(src);
+ if (instr_is_relative_branch(PPC_INST(*src))) {
+ unsigned int *target = (unsigned int *)branch_target((ppc_inst
*)src);
/* Branch within the section doesn't need translating */
if (target < alt_start || target > alt_end) {
@@ -60,7 +60,7 @@ static int patch_alt_instruction(unsigned int *src, unsigned
int *dest,
}
}
- raw_patch_instruction(dest, instr);
+ raw_patch_instruction((ppc_inst *)dest, PPC_INST(instr));
return 0;
}
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index dec522fa8201..ee084411f2f5 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -704,13 +704,13 @@ 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");
}
}
}
@@ -953,7 +953,7 @@ static void remove_bpts(void)
if (mread(bp->address, &instr, 4) == 4
&& ppc_inst_equal(instr, PPC_INST(bpinstr))
&& patch_instruction(
- (ppc_inst *)bp->address, bp->instr[0]) != 0)
+ (ppc_inst *)bp->address, ppc_inst_read(bp->instr)) != 0)
printf("Couldn't remove breakpoint at %lx\n",
bp->address);
}
--
2.17.1
