Arnaldo Carvalho de Melo 566e30229e 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: Arnaldo Carvalho de Melo <acme@redhat.com>		2019-05-28 18:37:42 -03:00
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bpf	perf trace: Beautify 'move_mount' arguments	2019-05-28 18:37:42 -03:00