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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-04-28 13:33:57 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-04-28 13:33:57 -0700 |
commit | 16b3d0cf5bad844daaf436ad2e9061de0fe36e5c (patch) | |
tree | d553a51e6d95fb166df7fa62264e9a27e4c438a4 /fs/debugfs | |
parent | 42dec9a936e7696bea1f27d3c5a0068cd9aa95fd (diff) | |
parent | 2ea46c6fc9452ac100ad907b051d797225847e33 (diff) | |
download | linux-16b3d0cf5bad844daaf436ad2e9061de0fe36e5c.tar.bz2 |
Merge tag 'sched-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Clean up SCHED_DEBUG: move the decades old mess of sysctl, procfs and
debugfs interfaces to a unified debugfs interface.
- Signals: Allow caching one sigqueue object per task, to improve
performance & latencies.
- Improve newidle_balance() irq-off latencies on systems with a large
number of CPU cgroups.
- Improve energy-aware scheduling
- Improve the PELT metrics for certain workloads
- Reintroduce select_idle_smt() to improve load-balancing locality -
but without the previous regressions
- Add 'scheduler latency debugging': warn after long periods of pending
need_resched. This is an opt-in feature that requires the enabling of
the LATENCY_WARN scheduler feature, or the use of the
resched_latency_warn_ms=xx boot parameter.
- CPU hotplug fixes for HP-rollback, and for the 'fail' interface. Fix
remaining balance_push() vs. hotplug holes/races
- PSI fixes, plus allow /proc/pressure/ files to be written by
CAP_SYS_RESOURCE tasks as well
- Fix/improve various load-balancing corner cases vs. capacity margins
- Fix sched topology on systems with NUMA diameter of 3 or above
- Fix PF_KTHREAD vs to_kthread() race
- Minor rseq optimizations
- Misc cleanups, optimizations, fixes and smaller updates
* tag 'sched-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (61 commits)
cpumask/hotplug: Fix cpu_dying() state tracking
kthread: Fix PF_KTHREAD vs to_kthread() race
sched/debug: Fix cgroup_path[] serialization
sched,psi: Handle potential task count underflow bugs more gracefully
sched: Warn on long periods of pending need_resched
sched/fair: Move update_nohz_stats() to the CONFIG_NO_HZ_COMMON block to simplify the code & fix an unused function warning
sched/debug: Rename the sched_debug parameter to sched_verbose
sched,fair: Alternative sched_slice()
sched: Move /proc/sched_debug to debugfs
sched,debug: Convert sysctl sched_domains to debugfs
debugfs: Implement debugfs_create_str()
sched,preempt: Move preempt_dynamic to debug.c
sched: Move SCHED_DEBUG sysctl to debugfs
sched: Don't make LATENCYTOP select SCHED_DEBUG
sched: Remove sched_schedstats sysctl out from under SCHED_DEBUG
sched/numa: Allow runtime enabling/disabling of NUMA balance without SCHED_DEBUG
sched: Use cpu_dying() to fix balance_push vs hotplug-rollback
cpumask: Introduce DYING mask
cpumask: Make cpu_{online,possible,present,active}() inline
rseq: Optimise rseq_get_rseq_cs() and clear_rseq_cs()
...
Diffstat (limited to 'fs/debugfs')
-rw-r--r-- | fs/debugfs/file.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 9979d981e9be..e813acfaa6e8 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -864,6 +864,97 @@ struct dentry *debugfs_create_bool(const char *name, umode_t mode, } EXPORT_SYMBOL_GPL(debugfs_create_bool); +ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct dentry *dentry = F_DENTRY(file); + char *str, *copy = NULL; + int copy_len, len; + ssize_t ret; + + ret = debugfs_file_get(dentry); + if (unlikely(ret)) + return ret; + + str = *(char **)file->private_data; + len = strlen(str) + 1; + copy = kmalloc(len, GFP_KERNEL); + if (!copy) { + debugfs_file_put(dentry); + return -ENOMEM; + } + + copy_len = strscpy(copy, str, len); + debugfs_file_put(dentry); + if (copy_len < 0) { + kfree(copy); + return copy_len; + } + + copy[copy_len] = '\n'; + + ret = simple_read_from_buffer(user_buf, count, ppos, copy, copy_len); + kfree(copy); + + return ret; +} + +static ssize_t debugfs_write_file_str(struct file *file, const char __user *user_buf, + size_t count, loff_t *ppos) +{ + /* This is really only for read-only strings */ + return -EINVAL; +} + +static const struct file_operations fops_str = { + .read = debugfs_read_file_str, + .write = debugfs_write_file_str, + .open = simple_open, + .llseek = default_llseek, +}; + +static const struct file_operations fops_str_ro = { + .read = debugfs_read_file_str, + .open = simple_open, + .llseek = default_llseek, +}; + +static const struct file_operations fops_str_wo = { + .write = debugfs_write_file_str, + .open = simple_open, + .llseek = default_llseek, +}; + +/** + * debugfs_create_str - create a debugfs file that is used to read and write a string value + * @name: a pointer to a string containing the name of the file to create. + * @mode: the permission that the file should have + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this parameter is %NULL, then the + * file will be created in the root of the debugfs filesystem. + * @value: a pointer to the variable that the file should read to and write + * from. + * + * This function creates a file in debugfs with the given name that + * contains the value of the variable @value. If the @mode variable is so + * set, it can be read from, and written to. + * + * This function will return a pointer to a dentry if it succeeds. This + * pointer must be passed to the debugfs_remove() function when the file is + * to be removed (no automatic cleanup happens if your module is unloaded, + * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be + * returned. + * + * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will + * be returned. + */ +void debugfs_create_str(const char *name, umode_t mode, + struct dentry *parent, char **value) +{ + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_str, + &fops_str_ro, &fops_str_wo); +} + static ssize_t read_file_blob(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { |