Re: [PATCH 1/5] perf beauty: Introduce scrape script for various fs syscalls 'flags' arguments

From: Ian Rogers
Date: Wed Mar 20 2024 - 21:47:54 EST


On Wed, Mar 20, 2024 at 12:31 PM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
>
> It was using the first variation on producing a string representation
> for a binary flag, one that used the system's fcntl.h and preprocessor
> tricks that had to be updated everytime a new flag was introduced.
>
> Use the more recent scrape script + strarray + strarray__scnprintf_flags() combo.
>
> $ tools/perf/trace/beauty/fs_at_flags.sh
> static const char *fs_at_flags[] = {
> [ilog2(0x100) + 1] = "SYMLINK_NOFOLLOW",
> [ilog2(0x200) + 1] = "REMOVEDIR",
> [ilog2(0x400) + 1] = "SYMLINK_FOLLOW",
> [ilog2(0x800) + 1] = "NO_AUTOMOUNT",
> [ilog2(0x1000) + 1] = "EMPTY_PATH",
> [ilog2(0x0000) + 1] = "STATX_SYNC_AS_STAT",
> [ilog2(0x2000) + 1] = "STATX_FORCE_SYNC",
> [ilog2(0x4000) + 1] = "STATX_DONT_SYNC",
> [ilog2(0x8000) + 1] = "RECURSIVE",
> [ilog2(0x80000000) + 1] = "GETATTR_NOSEC",
> };
> $
>
> Now we need a copy of uapi/linux/fcntl.h from tools/include/ in the
> scrape only directory tools/perf/trace/beauty/include and will use that
> fs_at_flags array for other fs syscalls.
>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: Ian Rogers <irogers@xxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian

> ---
> tools/perf/Makefile.perf | 7 +
> tools/perf/builtin-trace.c | 2 +-
> tools/perf/check-headers.sh | 1 +
> tools/perf/trace/beauty/Build | 1 +
> tools/perf/trace/beauty/beauty.h | 4 +-
> tools/perf/trace/beauty/fs_at_flags.c | 26 ++++
> tools/perf/trace/beauty/fs_at_flags.sh | 21 +++
> .../trace/beauty/include/uapi/linux/fcntl.h | 123 ++++++++++++++++++
> tools/perf/trace/beauty/statx.c | 31 -----
> 9 files changed, 182 insertions(+), 34 deletions(-)
> create mode 100644 tools/perf/trace/beauty/fs_at_flags.c
> create mode 100755 tools/perf/trace/beauty/fs_at_flags.sh
> create mode 100644 tools/perf/trace/beauty/include/uapi/linux/fcntl.h
>
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index ccd2dcbc64f720d2..73d5603450b0a547 100644
> --- a/tools/perf/Makefile.perf
> +++ b/tools/perf/Makefile.perf
> @@ -489,6 +489,12 @@ beauty_ioctl_outdir := $(beauty_outdir)/ioctl
> # Create output directory if not already present
> $(shell [ -d '$(beauty_ioctl_outdir)' ] || mkdir -p '$(beauty_ioctl_outdir)')
>
> +fs_at_flags_array := $(beauty_outdir)/fs_at_flags_array.c
> +fs_at_flags_tbl := $(srctree)/tools/perf/trace/beauty/fs_at_flags.sh
> +
> +$(fs_at_flags_array): $(beauty_uapi_linux_dir)/fcntl.h $(fs_at_flags_tbl)
> + $(Q)$(SHELL) '$(fs_at_flags_tbl)' $(beauty_uapi_linux_dir) > $@
> +

I wonder if rather than update Makefile.perf, we could push more of
the logic into tools/perf/trace/beauty/Build. It would also be nice to
add there the shellcheck logic:
https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/perf/tests/Build?h=perf-tools-next#n81

> clone_flags_array := $(beauty_outdir)/clone_flags_array.c
> clone_flags_tbl := $(srctree)/tools/perf/trace/beauty/clone.sh
>
> @@ -772,6 +778,7 @@ build-dir = $(or $(__build-dir),.)
>
> prepare: $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)common-cmds.h archheaders \
> arm64-sysreg-defs \
> + $(fs_at_flags_array) \
> $(clone_flags_array) \
> $(drm_ioctl_array) \
> $(fadvise_advice_array) \
> diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> index 8fb032caeaf53288..8417387aafa8295d 100644
> --- a/tools/perf/builtin-trace.c
> +++ b/tools/perf/builtin-trace.c
> @@ -1144,7 +1144,7 @@ static const struct syscall_fmt syscall_fmts[] = {
> { .name = "stat", .alias = "newstat", },
> { .name = "statx",
> .arg = { [0] = { .scnprintf = SCA_FDAT, /* fdat */ },
> - [2] = { .scnprintf = SCA_STATX_FLAGS, /* flags */ } ,
> + [2] = { .scnprintf = SCA_FS_AT_FLAGS, /* flags */ } ,
> [3] = { .scnprintf = SCA_STATX_MASK, /* mask */ }, }, },
> { .name = "swapoff",
> .arg = { [0] = { .scnprintf = SCA_FILENAME, /* specialfile */ }, }, },
> diff --git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh
> index 413c9b747216020f..d23a84fdf3efef78 100755
> --- a/tools/perf/check-headers.sh
> +++ b/tools/perf/check-headers.sh
> @@ -89,6 +89,7 @@ BEAUTY_FILES=(
> "arch/x86/include/asm/irq_vectors.h"
> "arch/x86/include/uapi/asm/prctl.h"
> "include/linux/socket.h"
> + "include/uapi/linux/fcntl.h"
> "include/uapi/linux/fs.h"
> "include/uapi/linux/mount.h"
> "include/uapi/linux/prctl.h"
> diff --git a/tools/perf/trace/beauty/Build b/tools/perf/trace/beauty/Build
> index d11ce256f5114034..d8ce1b6989832134 100644
> --- a/tools/perf/trace/beauty/Build
> +++ b/tools/perf/trace/beauty/Build
> @@ -1,6 +1,7 @@
> perf-y += clone.o
> perf-y += fcntl.o
> perf-y += flock.o
> +perf-y += fs_at_flags.o
> perf-y += fsmount.o
> perf-y += fspick.o
> ifeq ($(SRCARCH),$(filter $(SRCARCH),x86))
> diff --git a/tools/perf/trace/beauty/beauty.h b/tools/perf/trace/beauty/beauty.h
> index 9feb794f5c6e15f4..c94ae8701bc65a2f 100644
> --- a/tools/perf/trace/beauty/beauty.h
> +++ b/tools/perf/trace/beauty/beauty.h
> @@ -234,8 +234,8 @@ size_t syscall_arg__scnprintf_socket_protocol(char *bf, size_t size, struct sysc
> size_t syscall_arg__scnprintf_socket_level(char *bf, size_t size, struct syscall_arg *arg);
> #define SCA_SK_LEVEL syscall_arg__scnprintf_socket_level
>
> -size_t syscall_arg__scnprintf_statx_flags(char *bf, size_t size, struct syscall_arg *arg);
> -#define SCA_STATX_FLAGS syscall_arg__scnprintf_statx_flags
> +size_t syscall_arg__scnprintf_fs_at_flags(char *bf, size_t size, struct syscall_arg *arg);
> +#define SCA_FS_AT_FLAGS syscall_arg__scnprintf_fs_at_flags
>
> size_t syscall_arg__scnprintf_statx_mask(char *bf, size_t size, struct syscall_arg *arg);
> #define SCA_STATX_MASK syscall_arg__scnprintf_statx_mask
> diff --git a/tools/perf/trace/beauty/fs_at_flags.c b/tools/perf/trace/beauty/fs_at_flags.c
> new file mode 100644
> index 0000000000000000..2a099953d9935782
> --- /dev/null
> +++ b/tools/perf/trace/beauty/fs_at_flags.c
> @@ -0,0 +1,26 @@
> +// SPDX-License-Identifier: LGPL-2.1
> +/*
> + * trace/beauty/fs_at_flags.c
> + *
> + * Copyright (C) 2017, Red Hat Inc, Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> + */
> +
> +#include "trace/beauty/beauty.h"
> +#include <sys/types.h>
> +#include <linux/log2.h>
> +
> +#include "trace/beauty/generated/fs_at_flags_array.c"
> +static DEFINE_STRARRAY(fs_at_flags, "AT_");
> +
> +static size_t fs_at__scnprintf_flags(unsigned long flags, char *bf, size_t size, bool show_prefix)
> +{
> + return strarray__scnprintf_flags(&strarray__fs_at_flags, bf, size, show_prefix, flags);
> +}
> +
> +size_t syscall_arg__scnprintf_fs_at_flags(char *bf, size_t size, struct syscall_arg *arg)
> +{
> + bool show_prefix = arg->show_string_prefix;
> + int flags = arg->val;
> +
> + return fs_at__scnprintf_flags(flags, bf, size, show_prefix);
> +}
> diff --git a/tools/perf/trace/beauty/fs_at_flags.sh b/tools/perf/trace/beauty/fs_at_flags.sh
> new file mode 100755
> index 0000000000000000..456f59addf741062
> --- /dev/null
> +++ b/tools/perf/trace/beauty/fs_at_flags.sh
> @@ -0,0 +1,21 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: LGPL-2.1
> +
> +if [ $# -ne 1 ] ; then
> + beauty_uapi_linux_dir=tools/perf/trace/beauty/include/uapi/linux/
> +else
> + beauty_uapi_linux_dir=$1
> +fi
> +
> +linux_fcntl=${beauty_uapi_linux_dir}/fcntl.h
> +
> +printf "static const char *fs_at_flags[] = {\n"
> +regex='^[[:space:]]*#[[:space:]]*define[[:space:]]+AT_([^_]+[[:alnum:]_]+)[[:space:]]+(0x[[:xdigit:]]+)[[:space:]]*.*'
> +# AT_EACCESS is only meaningful to faccessat, so we will special case it there...
> +# AT_STATX_SYNC_TYPE is not a bit, its a mask of AT_STATX_SYNC_AS_STAT, AT_STATX_FORCE_SYNC and AT_STATX_DONT_SYNC
> +grep -E $regex ${linux_fcntl} | \
> + grep -v AT_EACCESS | \
> + grep -v AT_STATX_SYNC_TYPE | \
> + sed -r "s/$regex/\2 \1/g" | \
> + xargs printf "\t[ilog2(%s) + 1] = \"%s\",\n"
> +printf "};\n"
> diff --git a/tools/perf/trace/beauty/include/uapi/linux/fcntl.h b/tools/perf/trace/beauty/include/uapi/linux/fcntl.h
> new file mode 100644
> index 0000000000000000..282e90aeb163c028
> --- /dev/null
> +++ b/tools/perf/trace/beauty/include/uapi/linux/fcntl.h
> @@ -0,0 +1,123 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +#ifndef _UAPI_LINUX_FCNTL_H
> +#define _UAPI_LINUX_FCNTL_H
> +
> +#include <asm/fcntl.h>
> +#include <linux/openat2.h>
> +
> +#define F_SETLEASE (F_LINUX_SPECIFIC_BASE + 0)
> +#define F_GETLEASE (F_LINUX_SPECIFIC_BASE + 1)
> +
> +/*
> + * Cancel a blocking posix lock; internal use only until we expose an
> + * asynchronous lock api to userspace:
> + */
> +#define F_CANCELLK (F_LINUX_SPECIFIC_BASE + 5)
> +
> +/* Create a file descriptor with FD_CLOEXEC set. */
> +#define F_DUPFD_CLOEXEC (F_LINUX_SPECIFIC_BASE + 6)
> +
> +/*
> + * Request nofications on a directory.
> + * See below for events that may be notified.
> + */
> +#define F_NOTIFY (F_LINUX_SPECIFIC_BASE+2)
> +
> +/*
> + * Set and get of pipe page size array
> + */
> +#define F_SETPIPE_SZ (F_LINUX_SPECIFIC_BASE + 7)
> +#define F_GETPIPE_SZ (F_LINUX_SPECIFIC_BASE + 8)
> +
> +/*
> + * Set/Get seals
> + */
> +#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9)
> +#define F_GET_SEALS (F_LINUX_SPECIFIC_BASE + 10)
> +
> +/*
> + * Types of seals
> + */
> +#define F_SEAL_SEAL 0x0001 /* prevent further seals from being set */
> +#define F_SEAL_SHRINK 0x0002 /* prevent file from shrinking */
> +#define F_SEAL_GROW 0x0004 /* prevent file from growing */
> +#define F_SEAL_WRITE 0x0008 /* prevent writes */
> +#define F_SEAL_FUTURE_WRITE 0x0010 /* prevent future writes while mapped */
> +#define F_SEAL_EXEC 0x0020 /* prevent chmod modifying exec bits */
> +/* (1U << 31) is reserved for signed error codes */
> +
> +/*
> + * Set/Get write life time hints. {GET,SET}_RW_HINT operate on the
> + * underlying inode, while {GET,SET}_FILE_RW_HINT operate only on
> + * the specific file.
> + */
> +#define F_GET_RW_HINT (F_LINUX_SPECIFIC_BASE + 11)
> +#define F_SET_RW_HINT (F_LINUX_SPECIFIC_BASE + 12)
> +#define F_GET_FILE_RW_HINT (F_LINUX_SPECIFIC_BASE + 13)
> +#define F_SET_FILE_RW_HINT (F_LINUX_SPECIFIC_BASE + 14)
> +
> +/*
> + * Valid hint values for F_{GET,SET}_RW_HINT. 0 is "not set", or can be
> + * used to clear any hints previously set.
> + */
> +#define RWH_WRITE_LIFE_NOT_SET 0
> +#define RWH_WRITE_LIFE_NONE 1
> +#define RWH_WRITE_LIFE_SHORT 2
> +#define RWH_WRITE_LIFE_MEDIUM 3
> +#define RWH_WRITE_LIFE_LONG 4
> +#define RWH_WRITE_LIFE_EXTREME 5
> +
> +/*
> + * The originally introduced spelling is remained from the first
> + * versions of the patch set that introduced the feature, see commit
> + * v4.13-rc1~212^2~51.
> + */
> +#define RWF_WRITE_LIFE_NOT_SET RWH_WRITE_LIFE_NOT_SET
> +
> +/*
> + * Types of directory notifications that may be requested.
> + */
> +#define DN_ACCESS 0x00000001 /* File accessed */
> +#define DN_MODIFY 0x00000002 /* File modified */
> +#define DN_CREATE 0x00000004 /* File created */
> +#define DN_DELETE 0x00000008 /* File removed */
> +#define DN_RENAME 0x00000010 /* File renamed */
> +#define DN_ATTRIB 0x00000020 /* File changed attibutes */
> +#define DN_MULTISHOT 0x80000000 /* Don't remove notifier */
> +
> +/*
> + * The constants AT_REMOVEDIR and AT_EACCESS have the same value. AT_EACCESS is
> + * meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to
> + * unlinkat. The two functions do completely different things and therefore,
> + * the flags can be allowed to overlap. For example, passing AT_REMOVEDIR to
> + * faccessat would be undefined behavior and thus treating it equivalent to
> + * AT_EACCESS is valid undefined behavior.
> + */
> +#define AT_FDCWD -100 /* Special value used to indicate
> + openat should use the current
> + working directory. */
> +#define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links. */
> +#define AT_EACCESS 0x200 /* Test access permitted for
> + effective IDs, not real IDs. */
> +#define AT_REMOVEDIR 0x200 /* Remove directory instead of
> + unlinking file. */
> +#define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */
> +#define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount traversal */
> +#define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname */
> +
> +#define AT_STATX_SYNC_TYPE 0x6000 /* Type of synchronisation required from statx() */
> +#define AT_STATX_SYNC_AS_STAT 0x0000 /* - Do whatever stat() does */
> +#define AT_STATX_FORCE_SYNC 0x2000 /* - Force the attributes to be sync'd with the server */
> +#define AT_STATX_DONT_SYNC 0x4000 /* - Don't sync attributes with the server */
> +
> +#define AT_RECURSIVE 0x8000 /* Apply to the entire subtree */
> +
> +/* Flags for name_to_handle_at(2). We reuse AT_ flag space to save bits.. */
> +#define AT_HANDLE_FID AT_REMOVEDIR /* file handle is needed to
> + compare object identity and may not
> + be usable to open_by_handle_at(2) */
> +#if defined(__KERNEL__)
> +#define AT_GETATTR_NOSEC 0x80000000
> +#endif
> +
> +#endif /* _UAPI_LINUX_FCNTL_H */
> diff --git a/tools/perf/trace/beauty/statx.c b/tools/perf/trace/beauty/statx.c
> index 1f7e34ed4e02be86..4e0059fd02118f9c 100644
> --- a/tools/perf/trace/beauty/statx.c
> +++ b/tools/perf/trace/beauty/statx.c
> @@ -8,7 +8,6 @@
> #include "trace/beauty/beauty.h"
> #include <linux/kernel.h>
> #include <sys/types.h>
> -#include <linux/fcntl.h>
> #include <linux/stat.h>
>
> #ifndef STATX_MNT_ID
> @@ -21,36 +20,6 @@
> #define STATX_MNT_ID_UNIQUE 0x00004000U
> #endif
>
> -size_t syscall_arg__scnprintf_statx_flags(char *bf, size_t size, struct syscall_arg *arg)
> -{
> - bool show_prefix = arg->show_string_prefix;
> - const char *prefix = "AT_";
> - int printed = 0, flags = arg->val;
> -
> - if (flags == 0)
> - return scnprintf(bf, size, "%s%s", show_prefix ? "AT_STATX_" : "", "SYNC_AS_STAT");
> -#define P_FLAG(n) \
> - if (flags & AT_##n) { \
> - printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "|" : "", show_prefix ? prefix : "", #n); \
> - flags &= ~AT_##n; \
> - }
> -
> - P_FLAG(SYMLINK_NOFOLLOW);
> - P_FLAG(REMOVEDIR);
> - P_FLAG(SYMLINK_FOLLOW);
> - P_FLAG(NO_AUTOMOUNT);
> - P_FLAG(EMPTY_PATH);
> - P_FLAG(STATX_FORCE_SYNC);
> - P_FLAG(STATX_DONT_SYNC);
> -
> -#undef P_FLAG
> -
> - if (flags)
> - printed += scnprintf(bf + printed, size - printed, "%s%#x", printed ? "|" : "", flags);
> -
> - return printed;
> -}
> -
> size_t syscall_arg__scnprintf_statx_mask(char *bf, size_t size, struct syscall_arg *arg)
> {
> bool show_prefix = arg->show_string_prefix;
> --
> 2.44.0
>