Re: [PATCH 2/5] perf beauty: Introduce scrape script for the 'statx' syscall 'mask' argument

From: Ian Rogers
Date: Wed Mar 20 2024 - 21:49:41 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 stat.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/statx_mask.sh
> static const char *statx_mask[] = {
> [ilog2(0x00000001) + 1] = "TYPE",
> [ilog2(0x00000002) + 1] = "MODE",
> [ilog2(0x00000004) + 1] = "NLINK",
> [ilog2(0x00000008) + 1] = "UID",
> [ilog2(0x00000010) + 1] = "GID",
> [ilog2(0x00000020) + 1] = "ATIME",
> [ilog2(0x00000040) + 1] = "MTIME",
> [ilog2(0x00000080) + 1] = "CTIME",
> [ilog2(0x00000100) + 1] = "INO",
> [ilog2(0x00000200) + 1] = "SIZE",
> [ilog2(0x00000400) + 1] = "BLOCKS",
> [ilog2(0x00000800) + 1] = "BTIME",
> [ilog2(0x00001000) + 1] = "MNT_ID",
> [ilog2(0x00002000) + 1] = "DIOALIGN",
> [ilog2(0x00004000) + 1] = "MNT_ID_UNIQUE",
> };
> $
>
> Now we need a copy of uapi/linux/stat.h from tools/include/ in the
> scrape only directory tools/perf/trace/beauty/include.
>
> 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/check-headers.sh | 1 +
> .../trace/beauty/include/uapi/linux/stat.h | 195 ++++++++++++++++++
> tools/perf/trace/beauty/statx.c | 50 +----
> tools/perf/trace/beauty/statx_mask.sh | 23 +++
> 5 files changed, 235 insertions(+), 41 deletions(-)
> create mode 100644 tools/perf/trace/beauty/include/uapi/linux/stat.h
> create mode 100755 tools/perf/trace/beauty/statx_mask.sh
>
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index 73d5603450b0a547..0d2dbdfc44df3019 100644
> --- a/tools/perf/Makefile.perf
> +++ b/tools/perf/Makefile.perf
> @@ -673,6 +673,12 @@ arch_errno_tbl := $(srctree)/tools/perf/trace/beauty/arch_errno_names.sh
> $(arch_errno_name_array): $(arch_errno_tbl)
> $(Q)$(SHELL) '$(arch_errno_tbl)' '$(patsubst -%,,$(CC))' $(arch_errno_hdr_dir) > $@
>
> +statx_mask_array := $(beauty_outdir)/statx_mask_array.c
> +statx_mask_tbl := $(srctree)/tools/perf/trace/beauty/statx_mask.sh
> +
> +$(statx_mask_array): $(beauty_uapi_linux_dir)/stat.h $(statx_mask_tbl)
> + $(Q)$(SHELL) '$(statx_mask_tbl)' $(beauty_uapi_linux_dir) > $@
> +
> sync_file_range_arrays := $(beauty_outdir)/sync_file_range_arrays.c
> sync_file_range_tbls := $(srctree)/tools/perf/trace/beauty/sync_file_range.sh
>
> @@ -807,6 +813,7 @@ prepare: $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)common-cmds.h archheaders \
> $(x86_arch_prctl_code_array) \
> $(rename_flags_array) \
> $(arch_errno_name_array) \
> + $(statx_mask_array) \
> $(sync_file_range_arrays) \
> $(LIBAPI) \
> $(LIBPERF) \
> diff --git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh
> index d23a84fdf3efef78..76726a5a7c789273 100755
> --- a/tools/perf/check-headers.sh
> +++ b/tools/perf/check-headers.sh
> @@ -94,6 +94,7 @@ BEAUTY_FILES=(
> "include/uapi/linux/mount.h"
> "include/uapi/linux/prctl.h"
> "include/uapi/linux/sched.h"
> + "include/uapi/linux/stat.h"
> "include/uapi/linux/usbdevice_fs.h"
> "include/uapi/sound/asound.h"
> )
> diff --git a/tools/perf/trace/beauty/include/uapi/linux/stat.h b/tools/perf/trace/beauty/include/uapi/linux/stat.h
> new file mode 100644
> index 0000000000000000..2f2ee82d55175d05
> --- /dev/null
> +++ b/tools/perf/trace/beauty/include/uapi/linux/stat.h
> @@ -0,0 +1,195 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +#ifndef _UAPI_LINUX_STAT_H
> +#define _UAPI_LINUX_STAT_H
> +
> +#include <linux/types.h>
> +
> +#if defined(__KERNEL__) || !defined(__GLIBC__) || (__GLIBC__ < 2)
> +
> +#define S_IFMT 00170000
> +#define S_IFSOCK 0140000
> +#define S_IFLNK 0120000
> +#define S_IFREG 0100000
> +#define S_IFBLK 0060000
> +#define S_IFDIR 0040000
> +#define S_IFCHR 0020000
> +#define S_IFIFO 0010000
> +#define S_ISUID 0004000
> +#define S_ISGID 0002000
> +#define S_ISVTX 0001000
> +
> +#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
> +#define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
> +#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
> +#define S_ISCHR(m) (((m) & S_IFMT) == S_IFCHR)
> +#define S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK)
> +#define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
> +#define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)
> +
> +#define S_IRWXU 00700
> +#define S_IRUSR 00400
> +#define S_IWUSR 00200
> +#define S_IXUSR 00100
> +
> +#define S_IRWXG 00070
> +#define S_IRGRP 00040
> +#define S_IWGRP 00020
> +#define S_IXGRP 00010
> +
> +#define S_IRWXO 00007
> +#define S_IROTH 00004
> +#define S_IWOTH 00002
> +#define S_IXOTH 00001
> +
> +#endif
> +
> +/*
> + * Timestamp structure for the timestamps in struct statx.
> + *
> + * tv_sec holds the number of seconds before (negative) or after (positive)
> + * 00:00:00 1st January 1970 UTC.
> + *
> + * tv_nsec holds a number of nanoseconds (0..999,999,999) after the tv_sec time.
> + *
> + * __reserved is held in case we need a yet finer resolution.
> + */
> +struct statx_timestamp {
> + __s64 tv_sec;
> + __u32 tv_nsec;
> + __s32 __reserved;
> +};
> +
> +/*
> + * Structures for the extended file attribute retrieval system call
> + * (statx()).
> + *
> + * The caller passes a mask of what they're specifically interested in as a
> + * parameter to statx(). What statx() actually got will be indicated in
> + * st_mask upon return.
> + *
> + * For each bit in the mask argument:
> + *
> + * - if the datum is not supported:
> + *
> + * - the bit will be cleared, and
> + *
> + * - the datum will be set to an appropriate fabricated value if one is
> + * available (eg. CIFS can take a default uid and gid), otherwise
> + *
> + * - the field will be cleared;
> + *
> + * - otherwise, if explicitly requested:
> + *
> + * - the datum will be synchronised to the server if AT_STATX_FORCE_SYNC is
> + * set or if the datum is considered out of date, and
> + *
> + * - the field will be filled in and the bit will be set;
> + *
> + * - otherwise, if not requested, but available in approximate form without any
> + * effort, it will be filled in anyway, and the bit will be set upon return
> + * (it might not be up to date, however, and no attempt will be made to
> + * synchronise the internal state first);
> + *
> + * - otherwise the field and the bit will be cleared before returning.
> + *
> + * Items in STATX_BASIC_STATS may be marked unavailable on return, but they
> + * will have values installed for compatibility purposes so that stat() and
> + * co. can be emulated in userspace.
> + */
> +struct statx {
> + /* 0x00 */
> + __u32 stx_mask; /* What results were written [uncond] */
> + __u32 stx_blksize; /* Preferred general I/O size [uncond] */
> + __u64 stx_attributes; /* Flags conveying information about the file [uncond] */
> + /* 0x10 */
> + __u32 stx_nlink; /* Number of hard links */
> + __u32 stx_uid; /* User ID of owner */
> + __u32 stx_gid; /* Group ID of owner */
> + __u16 stx_mode; /* File mode */
> + __u16 __spare0[1];
> + /* 0x20 */
> + __u64 stx_ino; /* Inode number */
> + __u64 stx_size; /* File size */
> + __u64 stx_blocks; /* Number of 512-byte blocks allocated */
> + __u64 stx_attributes_mask; /* Mask to show what's supported in stx_attributes */
> + /* 0x40 */
> + struct statx_timestamp stx_atime; /* Last access time */
> + struct statx_timestamp stx_btime; /* File creation time */
> + struct statx_timestamp stx_ctime; /* Last attribute change time */
> + struct statx_timestamp stx_mtime; /* Last data modification time */
> + /* 0x80 */
> + __u32 stx_rdev_major; /* Device ID of special file [if bdev/cdev] */
> + __u32 stx_rdev_minor;
> + __u32 stx_dev_major; /* ID of device containing file [uncond] */
> + __u32 stx_dev_minor;
> + /* 0x90 */
> + __u64 stx_mnt_id;
> + __u32 stx_dio_mem_align; /* Memory buffer alignment for direct I/O */
> + __u32 stx_dio_offset_align; /* File offset alignment for direct I/O */
> + /* 0xa0 */
> + __u64 __spare3[12]; /* Spare space for future expansion */
> + /* 0x100 */
> +};
> +
> +/*
> + * Flags to be stx_mask
> + *
> + * Query request/result mask for statx() and struct statx::stx_mask.
> + *
> + * These bits should be set in the mask argument of statx() to request
> + * particular items when calling statx().
> + */
> +#define STATX_TYPE 0x00000001U /* Want/got stx_mode & S_IFMT */
> +#define STATX_MODE 0x00000002U /* Want/got stx_mode & ~S_IFMT */
> +#define STATX_NLINK 0x00000004U /* Want/got stx_nlink */
> +#define STATX_UID 0x00000008U /* Want/got stx_uid */
> +#define STATX_GID 0x00000010U /* Want/got stx_gid */
> +#define STATX_ATIME 0x00000020U /* Want/got stx_atime */
> +#define STATX_MTIME 0x00000040U /* Want/got stx_mtime */
> +#define STATX_CTIME 0x00000080U /* Want/got stx_ctime */
> +#define STATX_INO 0x00000100U /* Want/got stx_ino */
> +#define STATX_SIZE 0x00000200U /* Want/got stx_size */
> +#define STATX_BLOCKS 0x00000400U /* Want/got stx_blocks */
> +#define STATX_BASIC_STATS 0x000007ffU /* The stuff in the normal stat struct */
> +#define STATX_BTIME 0x00000800U /* Want/got stx_btime */
> +#define STATX_MNT_ID 0x00001000U /* Got stx_mnt_id */
> +#define STATX_DIOALIGN 0x00002000U /* Want/got direct I/O alignment info */
> +#define STATX_MNT_ID_UNIQUE 0x00004000U /* Want/got extended stx_mount_id */
> +
> +#define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */
> +
> +#ifndef __KERNEL__
> +/*
> + * This is deprecated, and shall remain the same value in the future. To avoid
> + * confusion please use the equivalent (STATX_BASIC_STATS | STATX_BTIME)
> + * instead.
> + */
> +#define STATX_ALL 0x00000fffU
> +#endif
> +
> +/*
> + * Attributes to be found in stx_attributes and masked in stx_attributes_mask.
> + *
> + * These give information about the features or the state of a file that might
> + * be of use to ordinary userspace programs such as GUIs or ls rather than
> + * specialised tools.
> + *
> + * Note that the flags marked [I] correspond to the FS_IOC_SETFLAGS flags
> + * semantically. Where possible, the numerical value is picked to correspond
> + * also. Note that the DAX attribute indicates that the file is in the CPU
> + * direct access state. It does not correspond to the per-inode flag that
> + * some filesystems support.
> + *
> + */
> +#define STATX_ATTR_COMPRESSED 0x00000004 /* [I] File is compressed by the fs */
> +#define STATX_ATTR_IMMUTABLE 0x00000010 /* [I] File is marked immutable */
> +#define STATX_ATTR_APPEND 0x00000020 /* [I] File is append-only */
> +#define STATX_ATTR_NODUMP 0x00000040 /* [I] File is not to be dumped */
> +#define STATX_ATTR_ENCRYPTED 0x00000800 /* [I] File requires key to decrypt in fs */
> +#define STATX_ATTR_AUTOMOUNT 0x00001000 /* Dir: Automount trigger */
> +#define STATX_ATTR_MOUNT_ROOT 0x00002000 /* Root of a mount */
> +#define STATX_ATTR_VERITY 0x00100000 /* [I] Verity protected file */
> +#define STATX_ATTR_DAX 0x00200000 /* File is currently in DAX state */
> +
> +
> +#endif /* _UAPI_LINUX_STAT_H */
> diff --git a/tools/perf/trace/beauty/statx.c b/tools/perf/trace/beauty/statx.c
> index 4e0059fd02118f9c..24843e614b935f3a 100644
> --- a/tools/perf/trace/beauty/statx.c
> +++ b/tools/perf/trace/beauty/statx.c
> @@ -6,52 +6,20 @@
> */
>
> #include "trace/beauty/beauty.h"
> -#include <linux/kernel.h>
> #include <sys/types.h>
> -#include <linux/stat.h>
> +#include <linux/log2.h>
>
> -#ifndef STATX_MNT_ID
> -#define STATX_MNT_ID 0x00001000U
> -#endif
> -#ifndef STATX_DIOALIGN
> -#define STATX_DIOALIGN 0x00002000U
> -#endif
> -#ifndef STATX_MNT_ID_UNIQUE
> -#define STATX_MNT_ID_UNIQUE 0x00004000U
> -#endif
> +static size_t statx__scnprintf_mask(unsigned long mask, char *bf, size_t size, bool show_prefix)
> +{
> + #include "trace/beauty/generated/statx_mask_array.c"
> + static DEFINE_STRARRAY(statx_mask, "STATX_");
> + return strarray__scnprintf_flags(&strarray__statx_mask, bf, size, show_prefix, mask);
> +}
>
> size_t syscall_arg__scnprintf_statx_mask(char *bf, size_t size, struct syscall_arg *arg)
> {
> bool show_prefix = arg->show_string_prefix;
> - const char *prefix = "STATX_";
> - int printed = 0, flags = arg->val;
> -
> -#define P_FLAG(n) \
> - if (flags & STATX_##n) { \
> - printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "|" : "", show_prefix ? prefix : "", #n); \
> - flags &= ~STATX_##n; \
> - }
> -
> - P_FLAG(TYPE);
> - P_FLAG(MODE);
> - P_FLAG(NLINK);
> - P_FLAG(UID);
> - P_FLAG(GID);
> - P_FLAG(ATIME);
> - P_FLAG(MTIME);
> - P_FLAG(CTIME);
> - P_FLAG(INO);
> - P_FLAG(SIZE);
> - P_FLAG(BLOCKS);
> - P_FLAG(BTIME);
> - P_FLAG(MNT_ID);
> - P_FLAG(DIOALIGN);
> - P_FLAG(MNT_ID_UNIQUE);
> -
> -#undef P_FLAG
> -
> - if (flags)
> - printed += scnprintf(bf + printed, size - printed, "%s%#x", printed ? "|" : "", flags);
> + int mask = arg->val;
>
> - return printed;
> + return statx__scnprintf_mask(mask, bf, size, show_prefix);
> }
> diff --git a/tools/perf/trace/beauty/statx_mask.sh b/tools/perf/trace/beauty/statx_mask.sh
> new file mode 100755
> index 0000000000000000..18c802ed0c71578f
> --- /dev/null
> +++ b/tools/perf/trace/beauty/statx_mask.sh
> @@ -0,0 +1,23 @@
> +#!/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=$1
> +fi
> +
> +linux_stat=${beauty_uapi_linux_dir}/stat.h
> +
> +printf "static const char *statx_mask[] = {\n"
> +regex='^[[:space:]]*#[[:space:]]*define[[:space:]]+STATX_([^_]+[[:alnum:]_]+)[[:space:]]+(0x[[:xdigit:]]+)[[:space:]]*.*'
> +# STATX_BASIC_STATS its a bitmask formed by the mask in the normal stat struct
> +# STATX_ALL is another bitmask and deprecated
> +# STATX_ATTR_*: Attributes to be found in stx_attributes and masked in stx_attributes_mask
> +grep -E $regex ${linux_stat} | \
> + grep -v STATX_ALL | \
> + grep -v STATX_BASIC_STATS | \
> + grep -v '\<STATX_ATTR_' | \
> + sed -r "s/$regex/\2 \1/g" | \
> + xargs printf "\t[ilog2(%s) + 1] = \"%s\",\n"
> +printf "};\n"
> --
> 2.44.0
>