perf sdt powerpc: Add argument support

SDT marker argument is in N@OP format. Here OP is arch dependent
component. Add powerpc logic to parse OP and convert it to uprobe
compatible format.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexis Berlemont <alexis.berlemont@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170328094754.3156-4-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ravi Bangoria 2017-03-28 15:17:54 +05:30 committed by Arnaldo Carvalho de Melo
parent fcc309e618
commit f5a70801b7

View file

@ -1,5 +1,10 @@
#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(r0, PERF_REG_POWERPC_R0),
@ -47,3 +52,109 @@ const struct sample_reg sample_reg_masks[] = {
SMPL_REG(dsisr, PERF_REG_POWERPC_DSISR),
SMPL_REG_END
};
/* REG or %rREG */
#define SDT_OP_REGEX1 "^(%r)?([1-2]?[0-9]|3[0-1])$"
/* -NUM(REG) or NUM(REG) or -NUM(%rREG) or NUM(%rREG) */
#define SDT_OP_REGEX2 "^(\\-)?([0-9]+)\\((%r)?([1-2]?[0-9]|3[0-1])\\)$"
static regex_t sdt_op_regex1, sdt_op_regex2;
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;
}
/*
* 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;
}