On Mon, 27 Mar 2017 13:28:29 +0530
Ravi Bangoria <ravi.bango...@linux.vnet.ibm.com> wrote:
> 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.
Looks good to me.
Acked-by: Masami Hiramatsu <mhira...@kernel.org>
BTW, using regex to parse this short string is a good idea!
Thanks,
>
> Signed-off-by: Ravi Bangoria <ravi.bango...@linux.vnet.ibm.com>
> ---
> tools/perf/arch/powerpc/util/perf_regs.c | 111
> +++++++++++++++++++++++++++++++
> 1 file changed, 111 insertions(+)
>
> diff --git a/tools/perf/arch/powerpc/util/perf_regs.c
> b/tools/perf/arch/powerpc/util/perf_regs.c
> index a3c3e1c..4268f77 100644
> --- a/tools/perf/arch/powerpc/util/perf_regs.c
> +++ b/tools/perf/arch/powerpc/util/perf_regs.c
> @@ -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;
> +}
> --
> 2.9.3
>
--
Masami Hiramatsu <mhira...@kernel.org>
