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Diffstat (limited to 'arch/arm/kernel/ftrace.c')
-rw-r--r--arch/arm/kernel/ftrace.c61
1 files changed, 4 insertions, 57 deletions
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index 5c9cecfaeb21..df0bf0c8cb79 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -19,6 +19,8 @@
19#include <asm/opcodes.h> 19#include <asm/opcodes.h>
20#include <asm/ftrace.h> 20#include <asm/ftrace.h>
21 21
22#include "insn.h"
23
22#ifdef CONFIG_THUMB2_KERNEL 24#ifdef CONFIG_THUMB2_KERNEL
23#define NOP 0xf85deb04 /* pop.w {lr} */ 25#define NOP 0xf85deb04 /* pop.w {lr} */
24#else 26#else
@@ -61,64 +63,9 @@ static unsigned long adjust_address(struct dyn_ftrace *rec, unsigned long addr)
61} 63}
62#endif 64#endif
63 65
64#ifdef CONFIG_THUMB2_KERNEL
65static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr,
66 bool link)
67{
68 unsigned long s, j1, j2, i1, i2, imm10, imm11;
69 unsigned long first, second;
70 long offset;
71
72 offset = (long)addr - (long)(pc + 4);
73 if (offset < -16777216 || offset > 16777214) {
74 WARN_ON_ONCE(1);
75 return 0;
76 }
77
78 s = (offset >> 24) & 0x1;
79 i1 = (offset >> 23) & 0x1;
80 i2 = (offset >> 22) & 0x1;
81 imm10 = (offset >> 12) & 0x3ff;
82 imm11 = (offset >> 1) & 0x7ff;
83
84 j1 = (!i1) ^ s;
85 j2 = (!i2) ^ s;
86
87 first = 0xf000 | (s << 10) | imm10;
88 second = 0x9000 | (j1 << 13) | (j2 << 11) | imm11;
89 if (link)
90 second |= 1 << 14;
91
92 return __opcode_thumb32_compose(first, second);
93}
94#else
95static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr,
96 bool link)
97{
98 unsigned long opcode = 0xea000000;
99 long offset;
100
101 if (link)
102 opcode |= 1 << 24;
103
104 offset = (long)addr - (long)(pc + 8);
105 if (unlikely(offset < -33554432 || offset > 33554428)) {
106 /* Can't generate branches that far (from ARM ARM). Ftrace
107 * doesn't generate branches outside of kernel text.
108 */
109 WARN_ON_ONCE(1);
110 return 0;
111 }
112
113 offset = (offset >> 2) & 0x00ffffff;
114
115 return opcode | offset;
116}
117#endif
118
119static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr) 66static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
120{ 67{
121 return ftrace_gen_branch(pc, addr, true); 68 return arm_gen_branch_link(pc, addr);
122} 69}
123 70
124static int ftrace_modify_code(unsigned long pc, unsigned long old, 71static int ftrace_modify_code(unsigned long pc, unsigned long old,
@@ -258,7 +205,7 @@ static int __ftrace_modify_caller(unsigned long *callsite,
258{ 205{
259 unsigned long caller_fn = (unsigned long) func; 206 unsigned long caller_fn = (unsigned long) func;
260 unsigned long pc = (unsigned long) callsite; 207 unsigned long pc = (unsigned long) callsite;
261 unsigned long branch = ftrace_gen_branch(pc, caller_fn, false); 208 unsigned long branch = arm_gen_branch(pc, caller_fn);
262 unsigned long nop = 0xe1a00000; /* mov r0, r0 */ 209 unsigned long nop = 0xe1a00000; /* mov r0, r0 */
263 unsigned long old = enable ? nop : branch; 210 unsigned long old = enable ? nop : branch;
264 unsigned long new = enable ? branch : nop; 211 unsigned long new = enable ? branch : nop;