diff options
| -rw-r--r-- | arch/powerpc/kernel/ftrace.c | 54 |
1 files changed, 12 insertions, 42 deletions
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index a4640e4f117..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; @@ -151,12 +136,6 @@ 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, @@ -402,7 +381,6 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { unsigned int op[2]; unsigned long ip = rec->ip; - unsigned long offset; /* read where this goes */ if (probe_kernel_read(op, (void *)ip, MCOUNT_INSN_SIZE * 2)) @@ -424,17 +402,14 @@ __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; @@ -453,7 +428,6 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { unsigned int op; unsigned long ip = rec->ip; - unsigned long offset; /* read where this goes */ if (probe_kernel_read(&op, (void *)ip, MCOUNT_INSN_SIZE)) @@ -471,18 +445,14 @@ __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 = branch_offset(offset); - DEBUGP("write to %lx\n", rec->ip); if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE)) |