diff options
Diffstat (limited to 'tools/lib/api')
| -rw-r--r-- | tools/lib/api/Makefile | 2 | ||||
| -rw-r--r-- | tools/lib/api/fd/array.c | 40 | ||||
| -rw-r--r-- | tools/lib/api/fd/array.h | 18 | ||||
| -rw-r--r-- | tools/lib/api/fs/Build | 1 | ||||
| -rw-r--r-- | tools/lib/api/fs/cgroup.c | 102 | ||||
| -rw-r--r-- | tools/lib/api/fs/fs.c | 17 | ||||
| -rw-r--r-- | tools/lib/api/fs/fs.h | 14 | ||||
| -rw-r--r-- | tools/lib/api/io.h | 115 |
8 files changed, 295 insertions, 14 deletions
diff --git a/tools/lib/api/Makefile b/tools/lib/api/Makefile index a13e9c7f1fc5..e21e1b40b525 100644 --- a/tools/lib/api/Makefile +++ b/tools/lib/api/Makefile @@ -60,7 +60,7 @@ $(LIBFILE): $(API_IN) clean: $(call QUIET_CLEAN, libapi) $(RM) $(LIBFILE); \ - find $(if $(OUTPUT),$(OUTPUT),.) -name \*.o -or -name \*.o.cmd -or -name \*.o.d | xargs $(RM) + find $(or $(OUTPUT),.) -name \*.o -or -name \*.o.cmd -or -name \*.o.d | xargs $(RM) FORCE: diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c index 58d44d5eee31..f0f195207fca 100644 --- a/tools/lib/api/fd/array.c +++ b/tools/lib/api/fd/array.c @@ -8,6 +8,7 @@ #include <poll.h> #include <stdlib.h> #include <unistd.h> +#include <string.h> void fdarray__init(struct fdarray *fda, int nr_autogrow) { @@ -19,7 +20,7 @@ void fdarray__init(struct fdarray *fda, int nr_autogrow) int fdarray__grow(struct fdarray *fda, int nr) { - void *priv; + struct priv *priv; int nr_alloc = fda->nr_alloc + nr; size_t psize = sizeof(fda->priv[0]) * nr_alloc; size_t size = sizeof(struct pollfd) * nr_alloc; @@ -34,6 +35,9 @@ int fdarray__grow(struct fdarray *fda, int nr) return -ENOMEM; } + memset(&entries[fda->nr_alloc], 0, sizeof(struct pollfd) * nr); + memset(&priv[fda->nr_alloc], 0, sizeof(fda->priv[0]) * nr); + fda->nr_alloc = nr_alloc; fda->entries = entries; fda->priv = priv; @@ -69,7 +73,7 @@ void fdarray__delete(struct fdarray *fda) free(fda); } -int fdarray__add(struct fdarray *fda, int fd, short revents) +int fdarray__add(struct fdarray *fda, int fd, short revents, enum fdarray_flags flags) { int pos = fda->nr; @@ -79,10 +83,28 @@ int fdarray__add(struct fdarray *fda, int fd, short revents) fda->entries[fda->nr].fd = fd; fda->entries[fda->nr].events = revents; + fda->priv[fda->nr].flags = flags; fda->nr++; return pos; } +int fdarray__dup_entry_from(struct fdarray *fda, int pos, struct fdarray *from) +{ + struct pollfd *entry; + int npos; + + if (pos >= from->nr) + return -EINVAL; + + entry = &from->entries[pos]; + + npos = fdarray__add(fda, entry->fd, entry->events, from->priv[pos].flags); + if (npos >= 0) + fda->priv[npos] = from->priv[pos]; + + return npos; +} + int fdarray__filter(struct fdarray *fda, short revents, void (*entry_destructor)(struct fdarray *fda, int fd, void *arg), void *arg) @@ -93,22 +115,22 @@ int fdarray__filter(struct fdarray *fda, short revents, return 0; for (fd = 0; fd < fda->nr; ++fd) { + if (!fda->entries[fd].events) + continue; + if (fda->entries[fd].revents & revents) { if (entry_destructor) entry_destructor(fda, fd, arg); + fda->entries[fd].revents = fda->entries[fd].events = 0; continue; } - if (fd != nr) { - fda->entries[nr] = fda->entries[fd]; - fda->priv[nr] = fda->priv[fd]; - } - - ++nr; + if (!(fda->priv[fd].flags & fdarray_flag__nonfilterable)) + ++nr; } - return fda->nr = nr; + return nr; } int fdarray__poll(struct fdarray *fda, int timeout) diff --git a/tools/lib/api/fd/array.h b/tools/lib/api/fd/array.h index b39557d1a88f..5c01f7b05dfb 100644 --- a/tools/lib/api/fd/array.h +++ b/tools/lib/api/fd/array.h @@ -21,19 +21,29 @@ struct fdarray { int nr_alloc; int nr_autogrow; struct pollfd *entries; - union { - int idx; - void *ptr; + struct priv { + union { + int idx; + void *ptr; + }; + unsigned int flags; } *priv; }; +enum fdarray_flags { + fdarray_flag__default = 0x00000000, + fdarray_flag__nonfilterable = 0x00000001, + fdarray_flag__non_perf_event = 0x00000002, +}; + void fdarray__init(struct fdarray *fda, int nr_autogrow); void fdarray__exit(struct fdarray *fda); struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow); void fdarray__delete(struct fdarray *fda); -int fdarray__add(struct fdarray *fda, int fd, short revents); +int fdarray__add(struct fdarray *fda, int fd, short revents, enum fdarray_flags flags); +int fdarray__dup_entry_from(struct fdarray *fda, int pos, struct fdarray *from); int fdarray__poll(struct fdarray *fda, int timeout); int fdarray__filter(struct fdarray *fda, short revents, void (*entry_destructor)(struct fdarray *fda, int fd, void *arg), diff --git a/tools/lib/api/fs/Build b/tools/lib/api/fs/Build index f4ed9629ae85..0f75b28654de 100644 --- a/tools/lib/api/fs/Build +++ b/tools/lib/api/fs/Build @@ -1,2 +1,3 @@ libapi-y += fs.o libapi-y += tracing_path.o +libapi-y += cgroup.o diff --git a/tools/lib/api/fs/cgroup.c b/tools/lib/api/fs/cgroup.c new file mode 100644 index 000000000000..1573dae4259d --- /dev/null +++ b/tools/lib/api/fs/cgroup.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/stringify.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "fs.h" + +struct cgroupfs_cache_entry { + char subsys[32]; + char mountpoint[PATH_MAX]; +}; + +/* just cache last used one */ +static struct cgroupfs_cache_entry cached; + +int cgroupfs_find_mountpoint(char *buf, size_t maxlen, const char *subsys) +{ + FILE *fp; + char *line = NULL; + size_t len = 0; + char *p, *path; + char mountpoint[PATH_MAX]; + + if (!strcmp(cached.subsys, subsys)) { + if (strlen(cached.mountpoint) < maxlen) { + strcpy(buf, cached.mountpoint); + return 0; + } + return -1; + } + + fp = fopen("/proc/mounts", "r"); + if (!fp) + return -1; + + /* + * in order to handle split hierarchy, we need to scan /proc/mounts + * and inspect every cgroupfs mount point to find one that has + * the given subsystem. If we found v1, just use it. If not we can + * use v2 path as a fallback. + */ + mountpoint[0] = '\0'; + + /* + * The /proc/mounts has the follow format: + * + * <devname> <mount point> <fs type> <options> ... + * + */ + while (getline(&line, &len, fp) != -1) { + /* skip devname */ + p = strchr(line, ' '); + if (p == NULL) + continue; + + /* save the mount point */ + path = ++p; + p = strchr(p, ' '); + if (p == NULL) + continue; + + *p++ = '\0'; + + /* check filesystem type */ + if (strncmp(p, "cgroup", 6)) + continue; + + if (p[6] == '2') { + /* save cgroup v2 path */ + strcpy(mountpoint, path); + continue; + } + + /* now we have cgroup v1, check the options for subsystem */ + p += 7; + + p = strstr(p, subsys); + if (p == NULL) + continue; + + /* sanity check: it should be separated by a space or a comma */ + if (!strchr(" ,", p[-1]) || !strchr(" ,", p[strlen(subsys)])) + continue; + + strcpy(mountpoint, path); + break; + } + free(line); + fclose(fp); + + strncpy(cached.subsys, subsys, sizeof(cached.subsys) - 1); + strcpy(cached.mountpoint, mountpoint); + + if (mountpoint[0] && strlen(mountpoint) < maxlen) { + strcpy(buf, mountpoint); + return 0; + } + return -1; +} diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c index 027b18f7ed8c..82f53d81a7a7 100644 --- a/tools/lib/api/fs/fs.c +++ b/tools/lib/api/fs/fs.c @@ -90,6 +90,7 @@ struct fs { const char * const *mounts; char path[PATH_MAX]; bool found; + bool checked; long magic; }; @@ -111,31 +112,37 @@ static struct fs fs__entries[] = { .name = "sysfs", .mounts = sysfs__fs_known_mountpoints, .magic = SYSFS_MAGIC, + .checked = false, }, [FS__PROCFS] = { .name = "proc", .mounts = procfs__known_mountpoints, .magic = PROC_SUPER_MAGIC, + .checked = false, }, [FS__DEBUGFS] = { .name = "debugfs", .mounts = debugfs__known_mountpoints, .magic = DEBUGFS_MAGIC, + .checked = false, }, [FS__TRACEFS] = { .name = "tracefs", .mounts = tracefs__known_mountpoints, .magic = TRACEFS_MAGIC, + .checked = false, }, [FS__HUGETLBFS] = { .name = "hugetlbfs", .mounts = hugetlbfs__known_mountpoints, .magic = HUGETLBFS_MAGIC, + .checked = false, }, [FS__BPF_FS] = { .name = "bpf", .mounts = bpf_fs__known_mountpoints, .magic = BPF_FS_MAGIC, + .checked = false, }, }; @@ -158,6 +165,7 @@ static bool fs__read_mounts(struct fs *fs) } fclose(fp); + fs->checked = true; return fs->found = found; } @@ -220,6 +228,7 @@ static bool fs__env_override(struct fs *fs) return false; fs->found = true; + fs->checked = true; strncpy(fs->path, override_path, sizeof(fs->path) - 1); fs->path[sizeof(fs->path) - 1] = '\0'; return true; @@ -246,6 +255,14 @@ static const char *fs__mountpoint(int idx) if (fs->found) return (const char *)fs->path; + /* the mount point was already checked for the mount point + * but and did not exist, so return NULL to avoid scanning again. + * This makes the found and not found paths cost equivalent + * in case of multiple calls. + */ + if (fs->checked) + return NULL; + return fs__get_mountpoint(fs); } diff --git a/tools/lib/api/fs/fs.h b/tools/lib/api/fs/fs.h index 92d03b8396b1..aa222ca30311 100644 --- a/tools/lib/api/fs/fs.h +++ b/tools/lib/api/fs/fs.h @@ -18,6 +18,18 @@ const char *name##__mount(void); \ bool name##__configured(void); \ +/* + * The xxxx__mountpoint() entry points find the first match mount point for each + * filesystems listed below, where xxxx is the filesystem type. + * + * The interface is as follows: + * + * - If a mount point is found on first call, it is cached and used for all + * subsequent calls. + * + * - If a mount point is not found, NULL is returned on first call and all + * subsequent calls. + */ FS(sysfs) FS(procfs) FS(debugfs) @@ -28,6 +40,8 @@ FS(bpf_fs) #undef FS +int cgroupfs_find_mountpoint(char *buf, size_t maxlen, const char *subsys); + int filename__read_int(const char *filename, int *value); int filename__read_ull(const char *filename, unsigned long long *value); int filename__read_xll(const char *filename, unsigned long long *value); diff --git a/tools/lib/api/io.h b/tools/lib/api/io.h new file mode 100644 index 000000000000..777c20f6b604 --- /dev/null +++ b/tools/lib/api/io.h @@ -0,0 +1,115 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Lightweight buffered reading library. + * + * Copyright 2019 Google LLC. + */ +#ifndef __API_IO__ +#define __API_IO__ + +#include <stdlib.h> +#include <unistd.h> + +struct io { + /* File descriptor being read/ */ + int fd; + /* Size of the read buffer. */ + unsigned int buf_len; + /* Pointer to storage for buffering read. */ + char *buf; + /* End of the storage. */ + char *end; + /* Currently accessed data pointer. */ + char *data; + /* Set true on when the end of file on read error. */ + bool eof; +}; + +static inline void io__init(struct io *io, int fd, + char *buf, unsigned int buf_len) +{ + io->fd = fd; + io->buf_len = buf_len; + io->buf = buf; + io->end = buf; + io->data = buf; + io->eof = false; +} + +/* Reads one character from the "io" file with similar semantics to fgetc. */ +static inline int io__get_char(struct io *io) +{ + char *ptr = io->data; + + if (io->eof) + return -1; + + if (ptr == io->end) { + ssize_t n = read(io->fd, io->buf, io->buf_len); + + if (n <= 0) { + io->eof = true; + return -1; + } + ptr = &io->buf[0]; + io->end = &io->buf[n]; + } + io->data = ptr + 1; + return *ptr; +} + +/* Read a hexadecimal value with no 0x prefix into the out argument hex. If the + * first character isn't hexadecimal returns -2, io->eof returns -1, otherwise + * returns the character after the hexadecimal value which may be -1 for eof. + * If the read value is larger than a u64 the high-order bits will be dropped. + */ +static inline int io__get_hex(struct io *io, __u64 *hex) +{ + bool first_read = true; + + *hex = 0; + while (true) { + int ch = io__get_char(io); + + if (ch < 0) + return ch; + if (ch >= '0' && ch <= '9') + *hex = (*hex << 4) | (ch - '0'); + else if (ch >= 'a' && ch <= 'f') + *hex = (*hex << 4) | (ch - 'a' + 10); + else if (ch >= 'A' && ch <= 'F') + *hex = (*hex << 4) | (ch - 'A' + 10); + else if (first_read) + return -2; + else + return ch; + first_read = false; + } +} + +/* Read a positive decimal value with out argument dec. If the first character + * isn't a decimal returns -2, io->eof returns -1, otherwise returns the + * character after the decimal value which may be -1 for eof. If the read value + * is larger than a u64 the high-order bits will be dropped. + */ +static inline int io__get_dec(struct io *io, __u64 *dec) +{ + bool first_read = true; + + *dec = 0; + while (true) { + int ch = io__get_char(io); + + if (ch < 0) + return ch; + if (ch >= '0' && ch <= '9') + *dec = (*dec * 10) + ch - '0'; + else if (first_read) + return -2; + else + return ch; + first_read = false; + } +} + +#endif /* __API_IO__ */ |