tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#include <linux/linkage.h>
2
3#define R0 0x00
4#define R1 0x08
5#define R2 0x10
6#define R3 0x18
7#define R4 0x20
8#define R5 0x28
9#define R6 0x30
10#define R7 0x38
11#define R8 0x40
12#define R9 0x48
13#define SL 0x50
14#define FP 0x58
15#define IP 0x60
16#define SP 0x68
17#define LR 0x70
18#define PC 0x78
19
20/*
21 * Implementation of void perf_regs_load(u64 *regs);
22 *
23 * This functions fills in the 'regs' buffer from the actual registers values,
24 * in the way the perf built-in unwinding test expects them:
25 * - the PC at the time at the call to this function. Since this function
26 * is called using a bl instruction, the PC value is taken from LR.
27 * The built-in unwinding test then unwinds the call stack from the dwarf
28 * information in unwind__get_entries.
29 *
30 * Notes:
31 * - the 8 bytes stride in the registers offsets comes from the fact
32 * that the registers are stored in an u64 array (u64 *regs),
33 * - the regs buffer needs to be zeroed before the call to this function,
34 * in this case using a calloc in dwarf-unwind.c.
35 */
36
37.text
38.type perf_regs_load,%function
39ENTRY(perf_regs_load)
40 str r0, [r0, #R0]
41 str r1, [r0, #R1]
42 str r2, [r0, #R2]
43 str r3, [r0, #R3]
44 str r4, [r0, #R4]
45 str r5, [r0, #R5]
46 str r6, [r0, #R6]
47 str r7, [r0, #R7]
48 str r8, [r0, #R8]
49 str r9, [r0, #R9]
50 str sl, [r0, #SL]
51 str fp, [r0, #FP]
52 str ip, [r0, #IP]
53 str sp, [r0, #SP]
54 str lr, [r0, #LR]
55 str lr, [r0, #PC] // store pc as lr in order to skip the call
56 // to this function
57 mov pc, lr
58ENDPROC(perf_regs_load)