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// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <string.h>
#include <regex.h>
#include "../../perf.h"
#include "../../util/util.h"
#include "../../util/perf_regs.h"
#include "../../util/debug.h"
const struct sample_reg sample_reg_masks[] = {
SMPL_REG(AX, PERF_REG_X86_AX),
SMPL_REG(BX, PERF_REG_X86_BX),
SMPL_REG(CX, PERF_REG_X86_CX),
SMPL_REG(DX, PERF_REG_X86_DX),
SMPL_REG(SI, PERF_REG_X86_SI),
SMPL_REG(DI, PERF_REG_X86_DI),
SMPL_REG(BP, PERF_REG_X86_BP),
SMPL_REG(SP, PERF_REG_X86_SP),
SMPL_REG(IP, PERF_REG_X86_IP),
SMPL_REG(FLAGS, PERF_REG_X86_FLAGS),
SMPL_REG(CS, PERF_REG_X86_CS),
SMPL_REG(SS, PERF_REG_X86_SS),
#ifdef HAVE_ARCH_X86_64_SUPPORT
SMPL_REG(R8, PERF_REG_X86_R8),
SMPL_REG(R9, PERF_REG_X86_R9),
SMPL_REG(R10, PERF_REG_X86_R10),
SMPL_REG(R11, PERF_REG_X86_R11),
SMPL_REG(R12, PERF_REG_X86_R12),
SMPL_REG(R13, PERF_REG_X86_R13),
SMPL_REG(R14, PERF_REG_X86_R14),
SMPL_REG(R15, PERF_REG_X86_R15),
#endif
SMPL_REG_END
};
struct sdt_name_reg {
const char *sdt_name;
const char *uprobe_name;
};
#define SDT_NAME_REG(n, m) {.sdt_name = "%" #n, .uprobe_name = "%" #m}
#define SDT_NAME_REG_END {.sdt_name = NULL, .uprobe_name = NULL}
static const struct sdt_name_reg sdt_reg_tbl[] = {
SDT_NAME_REG(eax, ax),
SDT_NAME_REG(rax, ax),
SDT_NAME_REG(al, ax),
SDT_NAME_REG(ah, ax),
SDT_NAME_REG(ebx, bx),
SDT_NAME_REG(rbx, bx),
SDT_NAME_REG(bl, bx),
SDT_NAME_REG(bh, bx),
SDT_NAME_REG(ecx, cx),
SDT_NAME_REG(rcx, cx),
SDT_NAME_REG(cl, cx),
SDT_NAME_REG(ch, cx),
SDT_NAME_REG(edx, dx),
SDT_NAME_REG(rdx, dx),
SDT_NAME_REG(dl, dx),
SDT_NAME_REG(dh, dx),
SDT_NAME_REG(esi, si),
SDT_NAME_REG(rsi, si),
SDT_NAME_REG(sil, si),
SDT_NAME_REG(edi, di),
SDT_NAME_REG(rdi, di),
SDT_NAME_REG(dil, di),
SDT_NAME_REG(ebp, bp),
SDT_NAME_REG(rbp, bp),
SDT_NAME_REG(bpl, bp),
SDT_NAME_REG(rsp, sp),
SDT_NAME_REG(esp, sp),
SDT_NAME_REG(spl, sp),
/* rNN registers */
SDT_NAME_REG(r8b, r8),
SDT_NAME_REG(r8w, r8),
SDT_NAME_REG(r8d, r8),
SDT_NAME_REG(r9b, r9),
SDT_NAME_REG(r9w, r9),
SDT_NAME_REG(r9d, r9),
SDT_NAME_REG(r10b, r10),
SDT_NAME_REG(r10w, r10),
SDT_NAME_REG(r10d, r10),
SDT_NAME_REG(r11b, r11),
SDT_NAME_REG(r11w, r11),
SDT_NAME_REG(r11d, r11),
SDT_NAME_REG(r12b, r12),
SDT_NAME_REG(r12w, r12),
SDT_NAME_REG(r12d, r12),
SDT_NAME_REG(r13b, r13),
SDT_NAME_REG(r13w, r13),
SDT_NAME_REG(r13d, r13),
SDT_NAME_REG(r14b, r14),
SDT_NAME_REG(r14w, r14),
SDT_NAME_REG(r14d, r14),
SDT_NAME_REG(r15b, r15),
SDT_NAME_REG(r15w, r15),
SDT_NAME_REG(r15d, r15),
SDT_NAME_REG_END,
};
/*
* Perf only supports OP which is in +/-NUM(REG) form.
* Here plus-minus sign, NUM and parenthesis are optional,
* only REG is mandatory.
*
* SDT events also supports indirect addressing mode with a
* symbol as offset, scaled mode and constants in OP. But
* perf does not support them yet. Below are few examples.
*
* OP with scaled mode:
* (%rax,%rsi,8)
* 10(%ras,%rsi,8)
*
* OP with indirect addressing mode:
* check_action(%rip)
* mp_+52(%rip)
* 44+mp_(%rip)
*
* OP with constant values:
* $0
* $123
* $-1
*/
#define SDT_OP_REGEX "^([+\\-]?)([0-9]*)(\\(?)(%[a-z][a-z0-9]+)(\\)?)$"
static regex_t sdt_op_regex;
static int sdt_init_op_regex(void)
{
static int initialized;
int ret = 0;
if (initialized)
return 0;
ret = regcomp(&sdt_op_regex, SDT_OP_REGEX, REG_EXTENDED);
if (ret < 0) {
pr_debug4("Regex compilation error.\n");
return ret;
}
initialized = 1;
return 0;
}
/*
* Max x86 register name length is 5(ex: %r15d). So, 6th char
* should always contain NULL. This helps to find register name
* length using strlen, insted of maintaing one more variable.
*/
#define SDT_REG_NAME_SIZE 6
/*
* The uprobe parser does not support all gas register names;
* so, we have to replace them (ex. for x86_64: %rax -> %ax).
* Note: If register does not require renaming, just copy
* paste as it is, but don't leave it empty.
*/
static void sdt_rename_register(char *sdt_reg, int sdt_len, char *uprobe_reg)
{
int i = 0;
for (i = 0; sdt_reg_tbl[i].sdt_name != NULL; i++) {
if (!strncmp(sdt_reg_tbl[i].sdt_name, sdt_reg, sdt_len)) {
strcpy(uprobe_reg, sdt_reg_tbl[i].uprobe_name);
return;
}
}
strncpy(uprobe_reg, sdt_reg, sdt_len);
}
int arch_sdt_arg_parse_op(char *old_op, char **new_op)
{
char new_reg[SDT_REG_NAME_SIZE] = {0};
int new_len = 0, ret;
/*
* rm[0]: +/-NUM(REG)
* rm[1]: +/-
* rm[2]: NUM
* rm[3]: (
* rm[4]: REG
* rm[5]: )
*/
regmatch_t rm[6];
/*
* Max prefix length is 2 as it may contains sign(+/-)
* and displacement 0 (Both sign and displacement 0 are
* optional so it may be empty). Use one more character
* to hold last NULL so that strlen can be used to find
* prefix length, instead of maintaing one more variable.
*/
char prefix[3] = {0};
ret = sdt_init_op_regex();
if (ret < 0)
return ret;
/*
* If unsupported OR does not match with regex OR
* register name too long, skip it.
*/
if (strchr(old_op, ',') || strchr(old_op, '$') ||
regexec(&sdt_op_regex, old_op, 6, rm, 0) ||
rm[4].rm_eo - rm[4].rm_so > SDT_REG_NAME_SIZE) {
pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);
return SDT_ARG_SKIP;
}
/*
* Prepare prefix.
* If SDT OP has parenthesis but does not provide
* displacement, add 0 for displacement.
* SDT Uprobe Prefix
* -----------------------------
* +24(%rdi) +24(%di) +
* 24(%rdi) +24(%di) +
* %rdi %di
* (%rdi) +0(%di) +0
* -80(%rbx) -80(%bx) -
*/
if (rm[3].rm_so != rm[3].rm_eo) {
if (rm[1].rm_so != rm[1].rm_eo)
prefix[0] = *(old_op + rm[1].rm_so);
else if (rm[2].rm_so != rm[2].rm_eo)
prefix[0] = '+';
else
strncpy(prefix, "+0", 2);
}
/* Rename register */
sdt_rename_register(old_op + rm[4].rm_so, rm[4].rm_eo - rm[4].rm_so,
new_reg);
/* Prepare final OP which should be valid for uprobe_events */
new_len = strlen(prefix) +
(rm[2].rm_eo - rm[2].rm_so) +
(rm[3].rm_eo - rm[3].rm_so) +
strlen(new_reg) +
(rm[5].rm_eo - rm[5].rm_so) +
1; /* NULL */
*new_op = zalloc(new_len);
if (!*new_op)
return -ENOMEM;
scnprintf(*new_op, new_len, "%.*s%.*s%.*s%.*s%.*s",
strlen(prefix), prefix,
(int)(rm[2].rm_eo - rm[2].rm_so), old_op + rm[2].rm_so,
(int)(rm[3].rm_eo - rm[3].rm_so), old_op + rm[3].rm_so,
strlen(new_reg), new_reg,
(int)(rm[5].rm_eo - rm[5].rm_so), old_op + rm[5].rm_so);
return SDT_ARG_VALID;
}
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