X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fcompat%2Fpoll.c;fp=src%2Fcommon%2Fcompat%2Fpoll.c;h=0000000000000000000000000000000000000000;hp=9da2470d08767e4d83bc2e9a3ff0a9fc9faf38d4;hb=740da7d5000ca1ffdcf14bda5096bf7ccfb86bdd;hpb=02c3d2c2e3b27ab0bad1207c70465f84b649c816

diff --git a/src/common/compat/poll.c b/src/common/compat/poll.c
deleted file mode 100644
index 9da2470d0..000000000
--- a/src/common/compat/poll.c
+++ /dev/null
@@ -1,719 +0,0 @@
-/*
- * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
- * Copyright (C) 2019 Yannick Lamarre <ylamarre@efficios.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#define _LGPL_SOURCE
-#include <stdlib.h>
-#include <stdbool.h>
-
-#include <common/defaults.h>
-#include <common/error.h>
-#include <common/macros.h>
-#include <common/utils.h>
-
-#include "poll.h"
-
-#if HAVE_EPOLL
-
-#include <fcntl.h>
-#include <limits.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
-
-/*
- * Maximum number of fd we can monitor.
- *
- * For epoll(7), /proc/sys/fs/epoll/max_user_watches (since Linux 2.6.28) will
- * be used for the maximum size of the poll set. If this interface is not
- * available, according to the manpage, the max_user_watches value is 1/25 (4%)
- * of the available low memory divided by the registration cost in bytes which
- * is 90 bytes on a 32-bit kernel and 160 bytes on a 64-bit kernel.
- *
- */
-static unsigned int poll_max_size;
-
-/*
- * Resize the epoll events structure of the new size.
- *
- * Return 0 on success or else -1 with the current events pointer untouched.
- */
-static int resize_poll_event(struct lttng_poll_event *events,
-		uint32_t new_size)
-{
-	struct epoll_event *ptr;
-
-	LTTNG_ASSERT(events);
-
-	ptr = realloc(events->events, new_size * sizeof(*ptr));
-	if (ptr == NULL) {
-		PERROR("realloc epoll add");
-		goto error;
-	}
-	if (new_size > events->alloc_size) {
-		/* Zero newly allocated memory */
-		memset(ptr + events->alloc_size, 0,
-			(new_size - events->alloc_size) * sizeof(*ptr));
-	}
-	events->events = ptr;
-	events->alloc_size = new_size;
-
-	return 0;
-
-error:
-	return -1;
-}
-
-/*
- * Create epoll set and allocate returned events structure.
- */
-int compat_epoll_create(struct lttng_poll_event *events, int size, int flags)
-{
-	int ret;
-
-	if (events == NULL || size <= 0) {
-		goto error;
-	}
-
-	if (!poll_max_size) {
-		if (lttng_poll_set_max_size()) {
-			goto error;
-		}
-	}
-
-	/* Don't bust the limit here */
-	if (size > poll_max_size) {
-		size = poll_max_size;
-	}
-
-	ret = compat_glibc_epoll_create(size, flags);
-	if (ret < 0) {
-		/* At this point, every error is fatal */
-		PERROR("epoll_create1");
-		goto error;
-	}
-
-	events->epfd = ret;
-
-	/* This *must* be freed by using lttng_poll_free() */
-	events->events = zmalloc(size * sizeof(struct epoll_event));
-	if (events->events == NULL) {
-		PERROR("zmalloc epoll set");
-		goto error_close;
-	}
-
-	events->alloc_size = events->init_size = size;
-	events->nb_fd = 0;
-
-	return 0;
-
-error_close:
-	ret = close(events->epfd);
-	if (ret) {
-		PERROR("close");
-	}
-error:
-	return -1;
-}
-
-/*
- * Add a fd to the epoll set with requesting events.
- */
-int compat_epoll_add(struct lttng_poll_event *events, int fd, uint32_t req_events)
-{
-	int ret;
-	struct epoll_event ev;
-
-	if (events == NULL || events->events == NULL || fd < 0) {
-		ERR("Bad compat epoll add arguments");
-		goto error;
-	}
-
-	/*
-	 * Zero struct epoll_event to ensure all representations of its
-	 * union are zeroed.
-	 */
-	memset(&ev, 0, sizeof(ev));
-	ev.events = req_events;
-	ev.data.fd = fd;
-
-	ret = epoll_ctl(events->epfd, EPOLL_CTL_ADD, fd, &ev);
-	if (ret < 0) {
-		switch (errno) {
-		case EEXIST:
-			/* If exist, it's OK. */
-			goto end;
-		case ENOSPC:
-		case EPERM:
-			/* Print PERROR and goto end not failing. Show must go on. */
-			PERROR("epoll_ctl ADD");
-			goto end;
-		default:
-			PERROR("epoll_ctl ADD fatal");
-			goto error;
-		}
-	}
-
-	events->nb_fd++;
-
-end:
-	return 0;
-
-error:
-	return -1;
-}
-
-/*
- * Remove a fd from the epoll set.
- */
-int compat_epoll_del(struct lttng_poll_event *events, int fd)
-{
-	int ret;
-
-	if (events == NULL || fd < 0 || events->nb_fd == 0) {
-		goto error;
-	}
-
-	ret = epoll_ctl(events->epfd, EPOLL_CTL_DEL, fd, NULL);
-	if (ret < 0) {
-		switch (errno) {
-		case ENOENT:
-		case EPERM:
-			/* Print PERROR and goto end not failing. Show must go on. */
-			PERROR("epoll_ctl DEL");
-			goto end;
-		default:
-			PERROR("epoll_ctl DEL fatal");
-			goto error;
-		}
-	}
-
-	events->nb_fd--;
-
-end:
-	return 0;
-
-error:
-	return -1;
-}
-
-/*
- * Set an fd's events.
- */
-int compat_epoll_mod(struct lttng_poll_event *events, int fd, uint32_t req_events)
-{
-	int ret;
-	struct epoll_event ev;
-
-	if (events == NULL || fd < 0 || events->nb_fd == 0) {
-		goto error;
-	}
-
-	/*
-	 * Zero struct epoll_event to ensure all representations of its
-	 * union are zeroed.
-	 */
-	memset(&ev, 0, sizeof(ev));
-	ev.events = req_events;
-	ev.data.fd = fd;
-
-	ret = epoll_ctl(events->epfd, EPOLL_CTL_MOD, fd, &ev);
-	if (ret < 0) {
-		switch (errno) {
-		case ENOENT:
-		case EPERM:
-			/* Print PERROR and goto end not failing. Show must go on. */
-			PERROR("epoll_ctl MOD");
-			goto end;
-		default:
-			PERROR("epoll_ctl MOD fatal");
-			goto error;
-		}
-	}
-
-end:
-	return 0;
-
-error:
-	return -1;
-}
-
-/*
- * Wait on epoll set. This is a blocking call of timeout value.
- */
-int compat_epoll_wait(struct lttng_poll_event *events, int timeout,
-		bool interruptible)
-{
-	int ret;
-	uint32_t new_size;
-
-	if (events == NULL || events->events == NULL) {
-		ERR("Wrong arguments in compat_epoll_wait");
-		goto error;
-	}
-
-	if (events->nb_fd == 0) {
-		errno = EINVAL;
-		return -1;
-	}
-
-	/*
-	 * Resize if needed before waiting. We could either expand the array or
-	 * shrink it down. It's important to note that after this step, we are
-	 * ensured that the events argument of the epoll_wait call will be large
-	 * enough to hold every possible returned events.
-	 */
-	new_size = 1U << utils_get_count_order_u32(events->nb_fd);
-	if (new_size != events->alloc_size && new_size >= events->init_size) {
-		ret = resize_poll_event(events, new_size);
-		if (ret < 0) {
-			/* ENOMEM problem at this point. */
-			goto error;
-		}
-	}
-
-	do {
-		ret = epoll_wait(events->epfd, events->events, events->nb_fd, timeout);
-	} while (!interruptible && ret == -1 && errno == EINTR);
-	if (ret < 0) {
-		if (errno != EINTR) {
-			PERROR("epoll_wait");
-		}
-		goto error;
-	}
-
-	/*
-	 * Since the returned events are set sequentially in the "events" structure
-	 * we only need to return the epoll_wait value and iterate over it.
-	 */
-	return ret;
-
-error:
-	return -1;
-}
-
-/*
- * Setup poll set maximum size.
- */
-int compat_epoll_set_max_size(void)
-{
-	int ret, fd, retval = 0;
-	ssize_t size_ret;
-	char buf[64];
-
-	fd = open(COMPAT_EPOLL_PROC_PATH, O_RDONLY);
-	if (fd < 0) {
-		/*
-		 * Failing on opening [1] is not an error per see. [1] was
-		 * introduced in Linux 2.6.28 but epoll is available since
-		 * 2.5.44. Hence, goto end and set a default value without
-		 * setting an error return value.
-		 *
-		 * [1] /proc/sys/fs/epoll/max_user_watches
-		 */
-		retval = 0;
-		goto end;
-	}
-
-	size_ret = lttng_read(fd, buf, sizeof(buf));
-	/*
-	 * Allow reading a file smaller than buf, but keep space for
-	 * final \0.
-	 */
-	if (size_ret < 0 || size_ret >= sizeof(buf)) {
-		PERROR("read set max size");
-		retval = -1;
-		goto end_read;
-	}
-	buf[size_ret] = '\0';
-	poll_max_size = atoi(buf);
-end_read:
-	ret = close(fd);
-	if (ret) {
-		PERROR("close");
-	}
-end:
-	if (!poll_max_size) {
-		poll_max_size = DEFAULT_POLL_SIZE;
-	}
-	DBG("epoll set max size is %d", poll_max_size);
-	return retval;
-}
-
-#else /* HAVE_EPOLL */
-
-#include <sys/resource.h>
-#include <sys/time.h>
-
-/*
- * Maximum number of fd we can monitor.
- *
- * For poll(2), the max fds must not exceed RLIMIT_NOFILE given by
- * getrlimit(2).
- */
-static unsigned int poll_max_size;
-
-/*
- * Resize the epoll events structure of the new size.
- *
- * Return 0 on success or else -1 with the current events pointer untouched.
- */
-static int resize_poll_event(struct compat_poll_event_array *array,
-		uint32_t new_size)
-{
-	struct pollfd *ptr;
-
-	LTTNG_ASSERT(array);
-
-	/* Refuse to resize the array more than the max size. */
-	if (new_size > poll_max_size) {
-		goto error;
-	}
-
-	ptr = realloc(array->events, new_size * sizeof(*ptr));
-	if (ptr == NULL) {
-		PERROR("realloc epoll add");
-		goto error;
-	}
-	if (new_size > array->alloc_size) {
-		/* Zero newly allocated memory */
-		memset(ptr + array->alloc_size, 0,
-			(new_size - array->alloc_size) * sizeof(*ptr));
-	}
-	array->events = ptr;
-	array->alloc_size = new_size;
-
-	return 0;
-
-error:
-	return -1;
-}
-
-/*
- * Update events with the current events object.
- */
-static int update_current_events(struct lttng_poll_event *events)
-{
-	int ret;
-	struct compat_poll_event_array *current, *wait;
-
-	LTTNG_ASSERT(events);
-
-	current = &events->current;
-	wait = &events->wait;
-
-	wait->nb_fd = current->nb_fd;
-	if (current->alloc_size != wait->alloc_size) {
-		ret = resize_poll_event(wait, current->alloc_size);
-		if (ret < 0) {
-			goto error;
-		}
-	}
-	memcpy(wait->events, current->events,
-			current->nb_fd * sizeof(*current->events));
-
-	/* Update is done. */
-	events->need_update = 0;
-
-	return 0;
-
-error:
-	return -1;
-}
-
-/*
- * Create pollfd data structure.
- */
-int compat_poll_create(struct lttng_poll_event *events, int size)
-{
-	struct compat_poll_event_array *current, *wait;
-
-	if (events == NULL || size <= 0) {
-		ERR("Wrong arguments for poll create");
-		goto error;
-	}
-
-	if (!poll_max_size) {
-		if (lttng_poll_set_max_size()) {
-			goto error;
-		}
-	}
-
-	/* Don't bust the limit here */
-	if (size > poll_max_size) {
-		size = poll_max_size;
-	}
-
-	/* Reset everything before begining the allocation. */
-	memset(events, 0, sizeof(struct lttng_poll_event));
-
-	current = &events->current;
-	wait = &events->wait;
-
-	/* This *must* be freed by using lttng_poll_free() */
-	wait->events = zmalloc(size * sizeof(struct pollfd));
-	if (wait->events == NULL) {
-		PERROR("zmalloc struct pollfd");
-		goto error;
-	}
-
-	wait->alloc_size = wait->init_size = size;
-
-	current->events = zmalloc(size * sizeof(struct pollfd));
-	if (current->events == NULL) {
-		PERROR("zmalloc struct current pollfd");
-		goto error;
-	}
-
-	current->alloc_size = current->init_size = size;
-
-	return 0;
-
-error:
-	return -1;
-}
-
-/*
- * Add fd to pollfd data structure with requested events.
- */
-int compat_poll_add(struct lttng_poll_event *events, int fd,
-		uint32_t req_events)
-{
-	int new_size, ret, i;
-	struct compat_poll_event_array *current;
-
-	if (events == NULL || events->current.events == NULL || fd < 0) {
-		ERR("Bad compat poll add arguments");
-		goto error;
-	}
-
-	current = &events->current;
-
-	/* Check if fd we are trying to add is already there. */
-	for (i = 0; i < current->nb_fd; i++) {
-		if (current->events[i].fd == fd) {
-			errno = EEXIST;
-			goto error;
-		}
-	}
-
-	/* Resize array if needed. */
-	new_size = 1U << utils_get_count_order_u32(current->nb_fd + 1);
-	if (new_size != current->alloc_size && new_size >= current->init_size) {
-		ret = resize_poll_event(current, new_size);
-		if (ret < 0) {
-			goto error;
-		}
-	}
-
-	current->events[current->nb_fd].fd = fd;
-	current->events[current->nb_fd].events = req_events;
-	current->nb_fd++;
-	events->need_update = 1;
-
-	DBG("fd %d of %d added to pollfd", fd, current->nb_fd);
-
-	return 0;
-
-error:
-	return -1;
-}
-
-/*
- * Modify an fd's events..
- */
-int compat_poll_mod(struct lttng_poll_event *events, int fd,
-		uint32_t req_events)
-{
-	int i;
-	struct compat_poll_event_array *current;
-
-	if (events == NULL || events->current.nb_fd == 0 ||
-			events->current.events == NULL || fd < 0) {
-		ERR("Bad compat poll mod arguments");
-		goto error;
-	}
-
-	current = &events->current;
-
-	for (i = 0; i < current->nb_fd; i++) {
-		if (current->events[i].fd == fd) {
-			current->events[i].events = req_events;
-			events->need_update = 1;
-			break;
-		}
-	}
-
-	/*
-	 * The epoll flavor doesn't flag modifying a non-included FD as an
-	 * error.
-	 */
-
-	return 0;
-
-error:
-	return -1;
-}
-
-/*
- * Remove a fd from the pollfd structure.
- */
-int compat_poll_del(struct lttng_poll_event *events, int fd)
-{
-	int i, count = 0, ret;
-	uint32_t new_size;
-	struct compat_poll_event_array *current;
-
-	if (events == NULL || events->current.nb_fd == 0 ||
-			events->current.events == NULL || fd < 0) {
-		goto error;
-	}
-
-	/* Ease our life a bit. */
-	current = &events->current;
-
-	for (i = 0; i < current->nb_fd; i++) {
-		/* Don't put back the fd we want to delete */
-		if (current->events[i].fd != fd) {
-			current->events[count].fd = current->events[i].fd;
-			current->events[count].events = current->events[i].events;
-			count++;
-		}
-	}
-
-	/* The fd was not in our set, return no error as with epoll. */
-	if (current->nb_fd == count) {
-		goto end;
-	}
-
-	/* No fd duplicate should be ever added into array. */
-	LTTNG_ASSERT(current->nb_fd - 1 == count);
-	current->nb_fd = count;
-
-	/* Resize array if needed. */
-	new_size = 1U << utils_get_count_order_u32(current->nb_fd);
-	if (new_size != current->alloc_size && new_size >= current->init_size
-			&& current->nb_fd != 0) {
-		ret = resize_poll_event(current, new_size);
-		if (ret < 0) {
-			goto error;
-		}
-	}
-
-	events->need_update = 1;
-
-end:
-	return 0;
-
-error:
-	return -1;
-}
-
-/*
- * Wait on poll() with timeout. Blocking call.
- */
-int compat_poll_wait(struct lttng_poll_event *events, int timeout,
-		bool interruptible)
-{
-	int ret, active_fd_count;
-	size_t pos = 0, consecutive_entries = 0, non_idle_pos;
-
-	if (events == NULL || events->current.events == NULL) {
-		ERR("poll wait arguments error");
-		goto error;
-	}
-
-	if (events->current.nb_fd == 0) {
-		/* Return an invalid error to be consistent with epoll. */
-		errno = EINVAL;
-		events->wait.nb_fd = 0;
-		goto error;
-	}
-
-	if (events->need_update) {
-		ret = update_current_events(events);
-		if (ret < 0) {
-			errno = ENOMEM;
-			goto error;
-		}
-	}
-
-	do {
-		ret = poll(events->wait.events, events->wait.nb_fd, timeout);
-	} while (!interruptible && ret == -1 && errno == EINTR);
-	if (ret < 0) {
-		if (errno != EINTR) {
-			PERROR("poll wait");
-		}
-		goto error;
-	}
-
-	active_fd_count = ret;
-
-	/*
-	 * Move all active pollfd structs to the beginning of the
-	 * array to emulate compat-epoll behaviour.
-	 */
-	if (active_fd_count == events->wait.nb_fd) {
-		goto end;
-	}
-
-	while (consecutive_entries != active_fd_count) {
-		struct pollfd *current = &events->wait.events[pos];
-		struct pollfd idle_entry;
-
-		if (current->revents != 0) {
-			consecutive_entries++;
-			pos++;
-			continue;
-		}
-
-		non_idle_pos = pos;
-
-		/* Look for next non-idle entry. */
-		while (events->wait.events[++non_idle_pos].revents == 0);
-
-		/* Swap idle and non-idle entries. */
-		idle_entry = *current;
-		*current = events->wait.events[non_idle_pos];
-		events->wait.events[non_idle_pos] = idle_entry;
-
-		consecutive_entries++;
-		pos++;
-	}
-end:
-	return ret;
-
-error:
-	return -1;
-}
-
-/*
- * Setup poll set maximum size.
- */
-int compat_poll_set_max_size(void)
-{
-	int ret, retval = 0;
-	struct rlimit lim;
-
-	ret = getrlimit(RLIMIT_NOFILE, &lim);
-	if (ret < 0) {
-		PERROR("getrlimit poll RLIMIT_NOFILE");
-		retval = -1;
-		goto end;
-	}
-
-	poll_max_size = lim.rlim_cur;
-end:
-	if (poll_max_size == 0) {
-		poll_max_size = DEFAULT_POLL_SIZE;
-	}
-	DBG("poll set max size set to %u", poll_max_size);
-	return retval;
-}
-
-#endif /* !HAVE_EPOLL */