/*
* Parse OP and convert it into uprobe format, which is, +/-NUM(%gprREG).
* Possible variants of OP are:
* Format Example
* -------------------------
* NUM(REG) 48(18)
* -NUM(REG) -48(18)
* NUM(%rREG) 48(%r18)
* -NUM(%rREG) -48(%r18)
* REG 18
* %rREG %r18
* iNUM i0
* i-NUM i-1
*
* SDT marker arguments on Powerpc uses %rREG form with -mregnames flag
* and REG form with -mno-regnames. Here REG is general purpose register,
* which is in 0 to 31 range.
*/
int arch_sdt_arg_parse_op(char *old_op, char **new_op)
{
int ret, new_len;
regmatch_t rm[5];
char prefix;
/* Constant argument. Uprobe does not support it */
if (old_op[0] == 'i') {
pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);
return SDT_ARG_SKIP;
}
ret = sdt_init_op_regex();
if (ret < 0)
return ret;
if (!regexec(&sdt_op_regex1, old_op, 3, rm, 0)) {
/* REG or %rREG --> %gprREG */
new_len = 5; /* % g p r NULL */
new_len += (int)(rm[2].rm_eo - rm[2].rm_so);
*new_op = zalloc(new_len);
if (!*new_op)
return -ENOMEM;
scnprintf(*new_op, new_len, "%%gpr%.*s",
(int)(rm[2].rm_eo - rm[2].rm_so), old_op + rm[2].rm_so);
} else if (!regexec(&sdt_op_regex2, old_op, 5, rm, 0)) {
/*
* -NUM(REG) or NUM(REG) or -NUM(%rREG) or NUM(%rREG) -->
* +/-NUM(%gprREG)
*/
prefix = (rm[1].rm_so == -1) ? '+' : '-';
new_len = 8; /* +/- ( % g p r ) NULL */
new_len += (int)(rm[2].rm_eo - rm[2].rm_so);
new_len += (int)(rm[4].rm_eo - rm[4].rm_so);
*new_op = zalloc(new_len);
if (!*new_op)
return -ENOMEM;
scnprintf(*new_op, new_len, "%c%.*s(%%gpr%.*s)", prefix,
(int)(rm[2].rm_eo - rm[2].rm_so), old_op + rm[2].rm_so,
(int)(rm[4].rm_eo - rm[4].rm_so), old_op + rm[4].rm_so);
} else {
pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);
return SDT_ARG_SKIP;
}
return SDT_ARG_VALID;
}
static int sdt_init_op_regex(void)
{
static int initialized;
int ret = 0;
if (initialized)
return 0;
ret = regcomp(&sdt_op_regex1, SDT_OP_REGEX1, REG_EXTENDED);
if (ret)
goto error;
ret = regcomp(&sdt_op_regex2, SDT_OP_REGEX2, REG_EXTENDED);
if (ret)
goto free_regex1;
initialized = 1;
return 0;
free_regex1:
regfree(&sdt_op_regex1);
error:
pr_debug4("Regex compilation error.\n");
return ret;
}
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;
}
static struct symbol *symbol__new(u64 start, u64 len, const char *name)
{
size_t namelen = strlen(name) + 1;
struct symbol *self = zalloc(symbol_conf.priv_size +
sizeof(*self) + namelen);
if (self == NULL)
return NULL;
if (symbol_conf.priv_size)
self = ((void *)self) + symbol_conf.priv_size;
self->start = start;
self->end = len ? start + len - 1 : start;
pr_debug4("%s: %s %#Lx-%#Lx\n", __func__, name, start, self->end);
memcpy(self->name, name, namelen);
return self;
}
struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
{
size_t namelen = strlen(name) + 1;
struct symbol *sym = calloc(1, (symbol_conf.priv_size +
sizeof(*sym) + namelen));
if (sym == NULL)
return NULL;
if (symbol_conf.priv_size)
sym = ((void *)sym) + symbol_conf.priv_size;
sym->start = start;
sym->end = len ? start + len - 1 : start;
sym->binding = binding;
sym->namelen = namelen - 1;
pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
__func__, name, start, sym->end);
memcpy(sym->name, name, namelen);
return sym;
}
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
scnprintf(prefix, sizeof(prefix), "+0");
}
/* 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;
}
