path: root/tools/perf/util/jitdump.c

// SPDX-License-Identifier: GPL-2.0
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <errno.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <inttypes.h>
#include <byteswap.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <linux/stringify.h>

#include "event.h"
#include "debug.h"
#include "dso.h"
#include "evlist.h"
#include "namespaces.h"
#include "symbol.h"
#include <elf.h>

#include "tsc.h"
#include "session.h"
#include "jit.h"
#include "jitdump.h"
#include "genelf.h"
#include "thread.h"

#include <linux/ctype.h>
#include <linux/zalloc.h>

struct jit_buf_desc {
	struct perf_data *output;
	struct perf_session *session;
	struct machine *machine;
	struct nsinfo  *nsi;
	union jr_entry   *entry;
	void             *buf;
	uint64_t	 sample_type;
	size_t           bufsize;
	FILE             *in;
	bool		 needs_bswap; /* handles cross-endianness */
	bool		 use_arch_timestamp;
	void		 *debug_data;
	void		 *unwinding_data;
	uint64_t	 unwinding_size;
	uint64_t	 unwinding_mapped_size;
	uint64_t         eh_frame_hdr_size;
	size_t		 nr_debug_entries;
	uint32_t         code_load_count;
	u64		 bytes_written;
	struct rb_root   code_root;
	char		 dir[PATH_MAX];
};

struct jit_tool {
	struct perf_tool tool;
	struct perf_data	output;
	struct perf_data	input;
	u64 bytes_written;
};

#define hmax(a, b) ((a) > (b) ? (a) : (b))
#define get_jit_tool(t) (container_of(tool, struct jit_tool, tool))

static int
jit_emit_elf(struct jit_buf_desc *jd,
	     char *filename,
	     const char *sym,
	     uint64_t code_addr,
	     const void *code,
	     int csize,
	     void *debug,
	     int nr_debug_entries,
	     void *unwinding,
	     uint32_t unwinding_header_size,
	     uint32_t unwinding_size)
{
	int ret, fd, saved_errno;
	struct nscookie nsc;

	if (verbose > 0)
		fprintf(stderr, "write ELF image %s\n", filename);

	nsinfo__mountns_enter(jd->nsi, &nsc);
	fd = open(filename, O_CREAT|O_TRUNC|O_WRONLY, 0644);
	saved_errno = errno;
	nsinfo__mountns_exit(&nsc);
	if (fd == -1) {
		pr_warning("cannot create jit ELF %s: %s\n", filename, strerror(saved_errno));
		return -1;
	}

	ret = jit_write_elf(fd, code_addr, sym, (const void *)code, csize, debug, nr_debug_entries,
			    unwinding, unwinding_header_size, unwinding_size);

        close(fd);

	if (ret) {
		nsinfo__mountns_enter(jd->nsi, &nsc);
		unlink(filename);
		nsinfo__mountns_exit(&nsc);
	}

	return ret;
}

static void
jit_close(struct jit_buf_desc *jd)
{
	if (!(jd && jd->in))
		return;
	funlockfile(jd->in);
	fclose(jd->in);
	jd->in = NULL;
}

static int
jit_validate_events(struct perf_session *session)
{
	struct evsel *evsel;

	/*
	 * check that all events use CLOCK_MONOTONIC
	 */
	evlist__for_each_entry(session->evlist, evsel) {
		if (evsel->core.attr.use_clockid == 0 || evsel->core.attr.clockid != CLOCK_MONOTONIC)
			return -1;
	}
	return 0;
}

static int
jit_open(struct jit_buf_desc *jd, const char *name)
{
	struct jitheader header;
	struct nscookie nsc;
	struct jr_prefix *prefix;
	ssize_t bs, bsz = 0;
	void *n, *buf = NULL;
	int ret, retval = -1;

	nsinfo__mountns_enter(jd->nsi, &nsc);
	jd->in = fopen(name, "r");
	nsinfo__mountns_exit(&nsc);
	if (!jd->in)
		return -1;

	bsz = hmax(sizeof(header), sizeof(*prefix));

	buf = malloc(bsz);
	if (!buf)
		goto error;

	/*
	 * protect from writer modifying the file while we are reading it
	 */
	flockfile(jd->in);

	ret = fread(buf, sizeof(header), 1, jd->in);
	if (ret != 1)
		goto error;

	memcpy(&header, buf, sizeof(header));

	if (header.magic != JITHEADER_MAGIC) {
		if (header.magic != <