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Diffstat (limited to 'arch/powerpc/kernel/ftrace.c')
-rw-r--r--arch/powerpc/kernel/ftrace.c182
1 files changed, 85 insertions, 97 deletions
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index 3271cd698e4..5355244c99f 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -114,19 +114,9 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
*/
static int test_24bit_addr(unsigned long ip, unsigned long addr)
{
- long diff;
- /*
- * Can we get to addr from ip in 24 bits?
- * (26 really, since we mulitply by 4 for 4 byte alignment)
- */
- diff = addr - ip;
-
- /*
- * Return true if diff is less than 1 << 25
- * and greater than -1 << 26.
- */
- return (diff < (1 << 25)) && (diff > (-1 << 26));
+ /* use the create_branch to verify that this offset can be branched */
+ return create_branch((unsigned int *)ip, addr, 0);
}
static int is_bl_op(unsigned int op)
@@ -134,11 +124,6 @@ static int is_bl_op(unsigned int op)
return (op & 0xfc000003) == 0x48000001;
}
-static int test_offset(unsigned long offset)
-{
- return (offset + 0x2000000 > 0x3ffffff) || ((offset & 3) != 0);
-}
-
static unsigned long find_bl_target(unsigned long ip, unsigned int op)
{
static int offset;
@@ -151,37 +136,30 @@ static unsigned long find_bl_target(unsigned long ip, unsigned int op)
return ip + (long)offset;
}
-static unsigned int branch_offset(unsigned long offset)
-{
- /* return "bl ip+offset" */
- return 0x48000001 | (offset & 0x03fffffc);
-}
-
#ifdef CONFIG_PPC64
static int
__ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr)
{
- unsigned char replaced[MCOUNT_INSN_SIZE * 2];
- unsigned int *op = (unsigned *)&replaced;
- unsigned char jmp[8];
- unsigned long *ptr = (unsigned long *)&jmp;
+ unsigned int op;
+ unsigned int jmp[5];
+ unsigned long ptr;
unsigned long ip = rec->ip;
unsigned long tramp;
int offset;
/* read where this goes */
- if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ if (probe_kernel_read(&op, (void *)ip, sizeof(int)))
return -EFAULT;
/* Make sure that that this is still a 24bit jump */
- if (!is_bl_op(*op)) {
- printk(KERN_ERR "Not expected bl: opcode is %x\n", *op);
+ if (!is_bl_op(op)) {
+ printk(KERN_ERR "Not expected bl: opcode is %x\n", op);
return -EINVAL;
}
/* lets find where the pointer goes */
- tramp = find_bl_target(ip, *op);
+ tramp = find_bl_target(ip, op);
/*
* On PPC64 the trampoline looks like:
@@ -200,19 +178,25 @@ __ftrace_make_nop(struct module *mod,
DEBUGP("ip:%lx jumps to %lx r2: %lx", ip, tramp, mod->arch.toc);
/* Find where the trampoline jumps to */
- if (probe_kernel_read(jmp, (void *)tramp, 8)) {
+ if (probe_kernel_read(jmp, (void *)tramp, sizeof(jmp))) {
printk(KERN_ERR "Failed to read %lx\n", tramp);
return -EFAULT;
}
- DEBUGP(" %08x %08x",
- (unsigned)(*ptr >> 32),
- (unsigned)*ptr);
+ DEBUGP(" %08x %08x", jmp[0], jmp[1]);
+
+ /* verify that this is what we expect it to be */
+ if (((jmp[0] & 0xffff0000) != 0x3d820000) ||
+ ((jmp[1] & 0xffff0000) != 0x398c0000) ||
+ (jmp[2] != 0xf8410028) ||
+ (jmp[3] != 0xe96c0020) ||
+ (jmp[4] != 0xe84c0028)) {
+ printk(KERN_ERR "Not a trampoline\n");
+ return -EINVAL;
+ }
- offset = (unsigned)jmp[2] << 24 |
- (unsigned)jmp[3] << 16 |
- (unsigned)jmp[6] << 8 |
- (unsigned)jmp[7];
+ offset = (unsigned)((unsigned short)jmp[0]) << 16 |
+ (unsigned)((unsigned short)jmp[1]);
DEBUGP(" %x ", offset);
@@ -225,13 +209,13 @@ __ftrace_make_nop(struct module *mod,
return -EFAULT;
}
- DEBUGP(" %08x %08x\n",
- (unsigned)(*ptr >> 32),
- (unsigned)*ptr);
+ DEBUGP(" %08x %08x\n", jmp[0], jmp[1]);
+
+ ptr = ((unsigned long)jmp[0] << 32) + jmp[1];
/* This should match what was called */
- if (*ptr != GET_ADDR(addr)) {
- printk(KERN_ERR "addr does not match %lx\n", *ptr);
+ if (ptr != GET_ADDR(addr)) {
+ printk(KERN_ERR "addr does not match %lx\n", ptr);
return -EINVAL;
}
@@ -240,11 +224,11 @@ __ftrace_make_nop(struct module *mod,
* 0xe8, 0x41, 0x00, 0x28 ld r2,40(r1)
* This needs to be turned to a nop too.
*/
- if (probe_kernel_read(replaced, (void *)(ip+4), MCOUNT_INSN_SIZE))
+ if (probe_kernel_read(&op, (void *)(ip+4), MCOUNT_INSN_SIZE))
return -EFAULT;
- if (*op != 0xe8410028) {
- printk(KERN_ERR "Next line is not ld! (%08x)\n", *op);
+ if (op != 0xe8410028) {
+ printk(KERN_ERR "Next line is not ld! (%08x)\n", op);
return -EINVAL;
}
@@ -261,11 +245,14 @@ __ftrace_make_nop(struct module *mod,
* ld r2,40(r1)
* 1:
*/
- op[0] = 0x48000008; /* b +8 */
+ op = 0x48000008; /* b +8 */
- if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE))
+ if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE))
return -EPERM;
+
+ flush_icache_range(ip, ip + 8);
+
return 0;
}
@@ -274,46 +261,52 @@ static int
__ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr)
{
- unsigned char replaced[MCOUNT_INSN_SIZE];
- unsigned int *op = (unsigned *)&replaced;
- unsigned char jmp[8];
- unsigned int *ptr = (unsigned int *)&jmp;
+ unsigned int op;
+ unsigned int jmp[4];
unsigned long ip = rec->ip;
unsigned long tramp;
- int offset;
- if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ if (probe_kernel_read(&op, (void *)ip, MCOUNT_INSN_SIZE))
return -EFAULT;
/* Make sure that that this is still a 24bit jump */
- if (!is_bl_op(*op)) {
- printk(KERN_ERR "Not expected bl: opcode is %x\n", *op);
+ if (!is_bl_op(op)) {
+ printk(KERN_ERR "Not expected bl: opcode is %x\n", op);
return -EINVAL;
}
/* lets find where the pointer goes */
- tramp = find_bl_target(ip, *op);
+ tramp = find_bl_target(ip, op);
/*
* On PPC32 the trampoline looks like:
- * lis r11,sym@ha
- * addi r11,r11,sym@l
- * mtctr r11
- * bctr
+ * 0x3d, 0x60, 0x00, 0x00 lis r11,sym@ha
+ * 0x39, 0x6b, 0x00, 0x00 addi r11,r11,sym@l
+ * 0x7d, 0x69, 0x03, 0xa6 mtctr r11
+ * 0x4e, 0x80, 0x04, 0x20 bctr
*/
DEBUGP("ip:%lx jumps to %lx", ip, tramp);
/* Find where the trampoline jumps to */
- if (probe_kernel_read(jmp, (void *)tramp, 8)) {
+ if (probe_kernel_read(jmp, (void *)tramp, sizeof(jmp))) {
printk(KERN_ERR "Failed to read %lx\n", tramp);
return -EFAULT;
}
- DEBUGP(" %08x %08x ", ptr[0], ptr[1]);
+ DEBUGP(" %08x %08x ", jmp[0], jmp[1]);
+
+ /* verify that this is what we expect it to be */
+ if (((jmp[0] & 0xffff0000) != 0x3d600000) ||
+ ((jmp[1] & 0xffff0000) != 0x396b0000) ||
+ (jmp[2] != 0x7d6903a6) ||
+ (jmp[3] != 0x4e800420)) {
+ printk(KERN_ERR "Not a trampoline\n");
+ return -EINVAL;
+ }
- tramp = (ptr[1] & 0xffff) |
- ((ptr[0] & 0xffff) << 16);
+ tramp = (jmp[1] & 0xffff) |
+ ((jmp[0] & 0xffff) << 16);
if (tramp & 0x8000)
tramp -= 0x10000;
@@ -326,11 +319,13 @@ __ftrace_make_nop(struct module *mod,
return -EINVAL;
}
- op[0] = PPC_NOP_INSTR;
+ op = PPC_NOP_INSTR;
- if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE))
+ if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE))
return -EPERM;
+ flush_icache_range(ip, ip + 8);
+
return 0;
}
#endif /* PPC64 */
@@ -384,13 +379,11 @@ int ftrace_make_nop(struct module *mod,
static int
__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
- unsigned char replaced[MCOUNT_INSN_SIZE * 2];
- unsigned int *op = (unsigned *)&replaced;
+ unsigned int op[2];
unsigned long ip = rec->ip;
- unsigned long offset;
/* read where this goes */
- if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE * 2))
+ if (probe_kernel_read(op, (void *)ip, MCOUNT_INSN_SIZE * 2))
return -EFAULT;
/*
@@ -409,43 +402,40 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
return -EINVAL;
}
- /* now calculate a jump to the ftrace caller trampoline */
- offset = rec->arch.mod->arch.tramp - ip;
-
- if (test_offset(offset)) {
- printk(KERN_ERR "REL24 %li out of range!\n",
- (long int)offset);
+ /* create the branch to the trampoline */
+ op[0] = create_branch((unsigned int *)ip,
+ rec->arch.mod->arch.tramp, BRANCH_SET_LINK);
+ if (!op[0]) {
+ printk(KERN_ERR "REL24 out of range!\n");
return -EINVAL;
}
- /* Set to "bl addr" */
- op[0] = branch_offset(offset);
/* ld r2,40(r1) */
op[1] = 0xe8410028;
DEBUGP("write to %lx\n", rec->ip);
- if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE * 2))
+ if (probe_kernel_write((void *)ip, op, MCOUNT_INSN_SIZE * 2))
return -EPERM;
+ flush_icache_range(ip, ip + 8);
+
return 0;
}
#else
static int
__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
- unsigned char replaced[MCOUNT_INSN_SIZE];
- unsigned int *op = (unsigned *)&replaced;
+ unsigned int op;
unsigned long ip = rec->ip;
- unsigned long offset;
/* read where this goes */
- if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ if (probe_kernel_read(&op, (void *)ip, MCOUNT_INSN_SIZE))
return -EFAULT;
/* It should be pointing to a nop */
- if (op[0] != PPC_NOP_INSTR) {
- printk(KERN_ERR "Expected NOP but have %x\n", op[0]);
+ if (op != PPC_NOP_INSTR) {
+ printk(KERN_ERR "Expected NOP but have %x\n", op);
return -EINVAL;
}
@@ -455,23 +445,21 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
return -EINVAL;
}
- /* now calculate a jump to the ftrace caller trampoline */
- offset = rec->arch.mod->arch.tramp - ip;
-
- if (test_offset(offset)) {
- printk(KERN_ERR "REL24 %li out of range!\n",
- (long int)offset);
+ /* create the branch to the trampoline */
+ op = create_branch((unsigned int *)ip,
+ rec->arch.mod->arch.tramp, BRANCH_SET_LINK);
+ if (!op) {
+ printk(KERN_ERR "REL24 out of range!\n");
return -EINVAL;
}
- /* Set to "bl addr" */
- op[0] = branch_offset(offset);
-
DEBUGP("write to %lx\n", rec->ip);
- if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE))
+ if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE))
return -EPERM;
+ flush_icache_range(ip, ip + 8);
+
return 0;
}
#endif /* CONFIG_PPC64 */
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-13 13:09:14 +0000