Commit 566e3022 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

perf trace: Beautify 'move_mount' arguments 

Use existing beautifiers for the first 4 args (to/from fds, pathnames)
and wire up the recently introduced move_mount flags table generator.

Now it should be possible to just use:

      perf trace -e move_mount

As root and see all move_mount syscalls with its args beautified, except
for the filenames, that need work in the augmented_raw_syscalls.c eBPF
helper to pass more than one, see comment in the
augmented_raw_syscalls.c source code, the other args should work in all
cases, i.e. all that is needed can be obtained directly from the
raw_syscalls:sys_enter tracepoint args.

Running without the strace "skin" (.perfconfig setting output formatting
switches to look like strace output + BPF to collect strings, as we
still need to support collecting multiple string args for the same
syscall, like with move_mount):

  # cat sys_move_mount.c
  #define _GNU_SOURCE         /* See feature_test_macros(7) */
  #include <unistd.h>
  #include <sys/syscall.h>   /* For SYS_xxx definitions */

  #define __NR_move_mount 429

  #define MOVE_MOUNT_F_SYMLINKS		0x00000001 /* Follow symlinks on from path */
  #define MOVE_MOUNT_F_AUTOMOUNTS		0x00000002 /* Follow automounts on from path */
  #define MOVE_MOUNT_F_EMPTY_PATH		0x00000004 /* Empty from path permitted */
  #define MOVE_MOUNT_T_SYMLINKS		0x00000010 /* Follow symlinks on to path */
  #define MOVE_MOUNT_T_AUTOMOUNTS		0x00000020 /* Follow automounts on to path */
  #define MOVE_MOUNT_T_EMPTY_PATH		0x00000040 /* Empty to path permitted */

  static inline int sys_move_mount(int from_fd, const char *from_pathname,
  				 int to_fd, const char *to_pathname,
  				 int flags)
  {
  	  syscall(__NR_move_mount, from_fd, from_pathname, to_fd, to_pathname, flags);
  }

  int main(int argc, char *argv[])
  {
  	  int flags = 0, from_fd = 0, to_fd = 100;

  	  sys_move_mount(from_fd++, "/foo", to_fd++, "bar", flags);
  	  flags |= MOVE_MOUNT_F_SYMLINKS;
  	  sys_move_mount(from_fd++, "/foo1", to_fd++, "bar1", flags);
          flags |= MOVE_MOUNT_F_AUTOMOUNTS;
  	  sys_move_mount(from_fd++, "/foo2", to_fd++, "bar2", flags);
          flags |= MOVE_MOUNT_F_EMPTY_PATH;
  	  sys_move_mount(from_fd++, "/foo3", to_fd++, "bar3", flags);
          flags |= MOVE_MOUNT_T_SYMLINKS;
  	  sys_move_mount(from_fd++, "/foo4", to_fd++, "bar4", flags);
          flags |= MOVE_MOUNT_T_AUTOMOUNTS;
  	  sys_move_mount(from_fd++, "/foo5", to_fd++, "bar5", flags);
          flags |= MOVE_MOUNT_T_EMPTY_PATH;
  	  return sys_move_mount(from_fd++, "/foo6", to_fd++, "bar6", flags);
  }
  # mv ~/.perfconfig  ~/.perfconfig.OFF
  # perf trace -e move_mount ./sys_move_mount
       0.000 ( 0.009 ms): sys_move_mount/28971 move_mount(from_pathname: 0x402010, to_dfd: 100, to_pathname: 0x402015) = -1 ENOENT (No such file or directory)
       0.011 ( 0.003 ms): sys_move_mount/28971 move_mount(from_dfd: 1, from_pathname: 0x40201e, to_dfd: 101, to_pathname: 0x402019, flags: F_SYMLINKS) = -1 ENOENT (No such file or directory)
       0.016 ( 0.002 ms): sys_move_mount/28971 move_mount(from_dfd: 2, from_pathname: 0x402029, to_dfd: 102, to_pathname: 0x402024, flags: F_SYMLINKS|F_AUTOMOUNTS) = -1 ENOENT (No such file or directory)
       0.020 ( 0.002 ms): sys_move_mount/28971 move_mount(from_dfd: 3, from_pathname: 0x402034, to_dfd: 103, to_pathname: 0x40202f, flags: F_SYMLINKS|F_AUTOMOUNTS|F_EMPTY_PATH) = -1 ENOENT (No such file or directory)
       0.023 ( 0.002 ms): sys_move_mount/28971 move_mount(from_dfd: 4, from_pathname: 0x40203f, to_dfd: 104, to_pathname: 0x40203a, flags: F_SYMLINKS|F_AUTOMOUNTS|F_EMPTY_PATH|T_SYMLINKS) = -1 ENOENT (No such file or directory)
       0.027 ( 0.002 ms): sys_move_mount/28971 move_mount(from_dfd: 5, from_pathname: 0x40204a, to_dfd: 105, to_pathname: 0x402045, flags: F_SYMLINKS|F_AUTOMOUNTS|F_EMPTY_PATH|T_SYMLINKS|T_AUTOMOUNTS) = -1 ENOENT (No such file or directory)
       0.031 ( 0.017 ms): sys_move_mount/28971 move_mount(from_dfd: 6, from_pathname: 0x402055, to_dfd: 106, to_pathname: 0x402050, flags: F_SYMLINKS|F_AUTOMOUNTS|F_EMPTY_PATH|T_SYMLINKS|T_AUTOMOUNTS|T_EMPTY_PATH) = -1 ENOENT (No such file or directory)
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-83rim8g4k0s4gieieh5nnlck@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent eefa09b4

tools/perf/Makefile.perf

+8 −0
Original line number Diff line number Diff line
@@ -493,6 +493,12 @@ mount_flags_tbl := $(srctree)/tools/perf/trace/beauty/mount_flags.sh 
$(mount_flags_array): $(linux_uapi_dir)/fs.h $(mount_flags_tbl)

	$(Q)$(SHELL) '$(mount_flags_tbl)' $(linux_uapi_dir) > $@



move_mount_flags_array := $(beauty_outdir)/move_mount_flags_array.c

move_mount_flags_tbl := $(srctree)/tools/perf/trace/beauty/move_mount_flags.sh



$(move_mount_flags_array): $(linux_uapi_dir)/fs.h $(move_mount_flags_tbl)

	$(Q)$(SHELL) '$(move_mount_flags_tbl)' $(linux_uapi_dir) > $@



prctl_option_array := $(beauty_outdir)/prctl_option_array.c

prctl_hdr_dir := $(srctree)/tools/include/uapi/linux/

prctl_option_tbl := $(srctree)/tools/perf/trace/beauty/prctl_option.sh
@@ -638,6 +644,7 @@ prepare: $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)common-cmds.h archheaders $(drm_ioc 
	$(madvise_behavior_array) \

	$(mmap_flags_array) \

	$(mount_flags_array) \

	$(move_mount_flags_array) \

	$(perf_ioctl_array) \

	$(prctl_option_array) \

	$(usbdevfs_ioctl_array) \
@@ -925,6 +932,7 @@ clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clea 
		$(OUTPUT)$(madvise_behavior_array) \

		$(OUTPUT)$(mmap_flags_array) \

		$(OUTPUT)$(mount_flags_array) \

		$(OUTPUT)$(move_mount_flags_array) \

		$(OUTPUT)$(drm_ioctl_array) \

		$(OUTPUT)$(pkey_alloc_access_rights_array) \

		$(OUTPUT)$(sndrv_ctl_ioctl_array) \

tools/perf/builtin-trace.c

+6 −0
Original line number Diff line number Diff line
@@ -775,6 +775,12 @@ static struct syscall_fmt { 
	  .arg = { [0] = { .scnprintf = SCA_FILENAME, /* dev_name */ },

		   [3] = { .scnprintf = SCA_MOUNT_FLAGS, /* flags */

			   .mask_val  = SCAMV_MOUNT_FLAGS, /* flags */ }, }, },

	{ .name	    = "move_mount",

	  .arg = { [0] = { .scnprintf = SCA_FDAT,	/* from_dfd */ },

		   [1] = { .scnprintf = SCA_FILENAME, /* from_pathname */ },

		   [2] = { .scnprintf = SCA_FDAT,	/* to_dfd */ },

		   [3] = { .scnprintf = SCA_FILENAME, /* to_pathname */ },

		   [4] = { .scnprintf = SCA_MOVE_MOUNT_FLAGS, /* flags */ }, }, },

	{ .name	    = "mprotect",

	  .arg = { [0] = { .scnprintf = SCA_HEX,	/* start */ },

		   [2] = { .scnprintf = SCA_MMAP_PROT,	/* prot */ }, }, },

tools/perf/examples/bpf/augmented_raw_syscalls.c

+11 −0
Original line number Diff line number Diff line
@@ -117,6 +117,7 @@ struct augmented_filename { 
#define SYS_RENAMEAT2          316

#define SYS_EXECVEAT           322

#define SYS_STATX              332

#define SYS_MOVE_MOUNT         429



pid_filter(pids_filtered);
@@ -257,6 +258,16 @@ int sys_enter(struct syscall_enter_args *args) 
	case SYS_LINKAT:

	case SYS_MKDIRAT:

	case SYS_MKNODAT:

	// case SYS_MOVE_MOUNT:

	// For now don't copy move_mount first string arg, as it has two and

	// 'perf trace's syscall_arg__scnprintf_filename() will use the one

	// copied here, the first, for both args, duplicating the first and

	// ignoring the second.

	//

	// We need to copy both here and make syscall_arg__scnprintf_filename

	// skip the first when reading the second, using the size of the first, etc.

	// Shouldn't be difficult, but now its perf/urgent time, lets wait for

	// the next devel window.

	case SYS_MQ_TIMEDSEND:

	case SYS_NAME_TO_HANDLE_AT:

	case SYS_NEWFSTATAT:

tools/perf/trace/beauty/Build

+1 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ perf-y += ioctl.o 
endif

perf-y += kcmp.o

perf-y += mount_flags.o

perf-y += move_mount.o

perf-y += pkey_alloc.o

perf-y += arch_prctl.o

perf-y += prctl.o

tools/perf/trace/beauty/beauty.h

+3 −0
Original line number Diff line number Diff line
@@ -156,6 +156,9 @@ unsigned long syscall_arg__mask_val_mount_flags(struct syscall_arg *arg, unsigne 
size_t syscall_arg__scnprintf_mount_flags(char *bf, size_t size, struct syscall_arg *arg);

#define SCA_MOUNT_FLAGS syscall_arg__scnprintf_mount_flags



size_t syscall_arg__scnprintf_move_mount_flags(char *bf, size_t size, struct syscall_arg *arg);

#define SCA_MOVE_MOUNT_FLAGS syscall_arg__scnprintf_move_mount_flags



size_t syscall_arg__scnprintf_pkey_alloc_access_rights(char *bf, size_t size, struct syscall_arg *arg);

#define SCA_PKEY_ALLOC_ACCESS_RIGHTS syscall_arg__scnprintf_pkey_alloc_access_rights