Now the two OP formats are used for SDT marker argument in Arm64 ELF, one format is general register xNUM (e.g. x1, x2, etc), another is for using stack pointer to access local variables (e.g. [sp], [sp, 8]). This patch adds support SDT marker argument for Arm64, it parses OP and converts to uprobe compatible format.
Unified · Split
| @@ -1,4 +1,12 @@ | ||
| 1 | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | +#include <errno.h> | |
| 3 | +#include <regex.h> | |
| 4 | +#include <string.h> | |
| 5 | +#include <linux/kernel.h> | |
| 6 | +#include <linux/zalloc.h> | |
| 7 | + | |
| 8 | +#include "../../../util/debug.h" | |
| 9 | +#include "../../../util/event.h" | |
| 2 | 10 | #include "../../../util/perf_regs.h" |
| 3 | 11 | |
| 4 | 12 | const struct sample_reg sample_reg_masks[] = { |
| @@ -37,3 +45,89 @@ const struct sample_reg sample_reg_masks[] = { · 32 unmodified lines | ||
| 37 | 45 | SMPL_REG(pc, PERF_REG_ARM64_PC), |
| 38 | 46 | SMPL_REG_END |
| 39 | 47 | }; |
| 48 | + | |
| 49 | +/* %xNUM */ | |
| 50 | +#define SDT_OP_REGEX1 "^(x[1-2]?[0-9]|3[0-1])$" | |
| 51 | + | |
| 52 | +/* [sp], [sp, NUM] */ | |
| 53 | +#define SDT_OP_REGEX2 "^\\[sp(, )?([0-9]+)?\\]$" | |
| 54 | + | |
| 55 | +static regex_t sdt_op_regex1, sdt_op_regex2; | |
| 56 | + | |
| 57 | +static int sdt_init_op_regex(void) | |
| 58 | +{ | |
| 59 | + static int initialized; | |
| 60 | + int ret = 0; | |
| 61 | + | |
| 62 | + if (initialized) | |
| 63 | + return 0; | |
| 64 | + | |
| 65 | + ret = regcomp(&sdt_op_regex1, SDT_OP_REGEX1, REG_EXTENDED); | |
| 66 | + if (ret) | |
| 67 | + goto error; | |
| 68 | + | |
| 69 | + ret = regcomp(&sdt_op_regex2, SDT_OP_REGEX2, REG_EXTENDED); | |
| 70 | + if (ret) | |
| 71 | + goto free_regex1; | |
| 72 | + | |
| 73 | + initialized = 1; | |
| 74 | + return 0; | |
| 75 | + | |
| 76 | +free_regex1: | |
| 77 | + regfree(&sdt_op_regex1); | |
| 78 | +error: | |
| 79 | + pr_debug4("Regex compilation error.\n"); | |
| 80 | + return ret; | |
| 81 | +} | |
| 82 | + | |
| 83 | +/* | |
| 84 | + * SDT marker arguments on Arm64 uses %xREG or [sp, NUM], currently | |
| 85 | + * support these two formats. | |
| 86 | + */ | |
| 87 | +int arch_sdt_arg_parse_op(char *old_op, char **new_op) | |
| 88 | +{ | |
| 89 | + int ret, new_len; | |
| 90 | + regmatch_t rm[5]; | |
| 91 | + | |
| 92 | + ret = sdt_init_op_regex(); | |
| 93 | + if (ret < 0) | |
| 94 | + return ret; | |
| 95 | + | |
| 96 | + if (!regexec(&sdt_op_regex1, old_op, 3, rm, 0)) { | |
| 97 | + /* Extract xNUM */ | |
| 98 | + new_len = 2; /* % NULL */ | |
| 99 | + new_len += (int)(rm[1].rm_eo - rm[1].rm_so); | |
| 100 | + | |
| 101 | + *new_op = zalloc(new_len); | |
| 102 | + if (!*new_op) | |
| 103 | + return -ENOMEM; | |
| 104 | + | |
| 105 | + scnprintf(*new_op, new_len, "%%%.*s", | |
| 106 | + (int)(rm[1].rm_eo - rm[1].rm_so), old_op + rm[1].rm_so); | |
| 107 | + } else if (!regexec(&sdt_op_regex2, old_op, 5, rm, 0)) { | |
| 108 | + /* [sp], [sp, NUM] or [sp,NUM] */ | |
| 109 | + new_len = 7; /* + ( % s p ) NULL */ | |
| 110 | + | |
| 111 | + /* If the arugment is [sp], need to fill offset '0' */ | |
| 112 | + if (rm[2].rm_so == -1) | |
| 113 | + new_len += 1; | |
| 114 | + else | |
| 115 | + new_len += (int)(rm[2].rm_eo - rm[2].rm_so); | |
| 116 | + | |
| 117 | + *new_op = zalloc(new_len); | |
| 118 | + if (!*new_op) | |
| 119 | + return -ENOMEM; | |
| 120 | + | |
| 121 | + if (rm[2].rm_so == -1) | |
| 122 | + scnprintf(*new_op, new_len, "+0(%%sp)"); | |
| 123 | + else | |
| 124 | + scnprintf(*new_op, new_len, "+%.*s(%%sp)", | |
| 125 | + (int)(rm[2].rm_eo - rm[2].rm_so), | |
| 126 | + old_op + rm[2].rm_so); | |
| 127 | + } else { | |
| 128 | + pr_debug4("Skipping unsupported SDT argument: %s\n", old_op); | |
| 129 | + return SDT_ARG_SKIP; | |
| 130 | + } | |
| 131 | + | |
| 132 | + return SDT_ARG_VALID; | |
| 133 | +} | |