From: Shuah K. <sk...@li...> - 2020-11-10 20:26:11
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seqnum_ops api is introduced to be used when a variable is used as a sequence/stat counter and doesn't guard object lifetimes. This clearly differentiates atomic_t usages that guard object lifetimes. seqnum32 variables wrap around to INT_MIN when it overflows and should not be used to guard resource lifetimes, device usage and open counts that control state changes, and pm states. atomic_t variables used for stats are atomic counters. Overflow will wrap around and reset the stats and no change with the conversion. Convert them to use seqnum_ops. Signed-off-by: Shuah Khan <sk...@li...> --- drivers/oprofile/buffer_sync.c | 9 +++++---- drivers/oprofile/event_buffer.c | 3 ++- drivers/oprofile/oprof.c | 3 ++- drivers/oprofile/oprofile_stats.c | 11 ++++++----- drivers/oprofile/oprofile_stats.h | 11 ++++++----- drivers/oprofile/oprofilefs.c | 3 ++- include/linux/oprofile.h | 3 ++- 7 files changed, 25 insertions(+), 18 deletions(-) diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c index cc917865f13a..0503d467429b 100644 --- a/drivers/oprofile/buffer_sync.c +++ b/drivers/oprofile/buffer_sync.c @@ -34,6 +34,7 @@ #include <linux/sched/mm.h> #include <linux/sched/task.h> #include <linux/gfp.h> +#include <linux/seqnum_ops.h> #include "oprofile_stats.h" #include "event_buffer.h" @@ -347,7 +348,7 @@ static void add_data(struct op_entry *entry, struct mm_struct *mm) if (cookie == NO_COOKIE) offset = pc; if (cookie == INVALID_COOKIE) { - atomic_inc(&oprofile_stats.sample_lost_no_mapping); + seqnum32_inc(&oprofile_stats.sample_lost_no_mapping); offset = pc; } if (cookie != last_cookie) { @@ -391,14 +392,14 @@ add_sample(struct mm_struct *mm, struct op_sample *s, int in_kernel) /* add userspace sample */ if (!mm) { - atomic_inc(&oprofile_stats.sample_lost_no_mm); + seqnum32_inc(&oprofile_stats.sample_lost_no_mm); return 0; } cookie = lookup_dcookie(mm, s->eip, &offset); if (cookie == INVALID_COOKIE) { - atomic_inc(&oprofile_stats.sample_lost_no_mapping); + seqnum32_inc(&oprofile_stats.sample_lost_no_mapping); return 0; } @@ -556,7 +557,7 @@ void sync_buffer(int cpu) /* ignore backtraces if failed to add a sample */ if (state == sb_bt_start) { state = sb_bt_ignore; - atomic_inc(&oprofile_stats.bt_lost_no_mapping); + seqnum32_inc(&oprofile_stats.bt_lost_no_mapping); } } release_mm(mm); diff --git a/drivers/oprofile/event_buffer.c b/drivers/oprofile/event_buffer.c index 6c9edc8bbc95..6ec2f1ed8d94 100644 --- a/drivers/oprofile/event_buffer.c +++ b/drivers/oprofile/event_buffer.c @@ -19,6 +19,7 @@ #include <linux/dcookies.h> #include <linux/fs.h> #include <linux/uaccess.h> +#include <linux/seqnum_ops.h> #include "oprof.h" #include "event_buffer.h" @@ -53,7 +54,7 @@ void add_event_entry(unsigned long value) } if (buffer_pos == buffer_size) { - atomic_inc(&oprofile_stats.event_lost_overflow); + seqnum32_inc(&oprofile_stats.event_lost_overflow); return; } diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c index ed2c3ec07024..f3183ef0f607 100644 --- a/drivers/oprofile/oprof.c +++ b/drivers/oprofile/oprof.c @@ -15,6 +15,7 @@ #include <linux/workqueue.h> #include <linux/time.h> #include <linux/mutex.h> +#include <linux/seqnum_ops.h> #include "oprof.h" #include "event_buffer.h" @@ -110,7 +111,7 @@ static void switch_worker(struct work_struct *work) if (oprofile_ops.switch_events()) return; - atomic_inc(&oprofile_stats.multiplex_counter); + seqnum32_inc(&oprofile_stats.multiplex_counter); start_switch_worker(); } diff --git a/drivers/oprofile/oprofile_stats.c b/drivers/oprofile/oprofile_stats.c index 59659cea4582..04e9b2a0d35a 100644 --- a/drivers/oprofile/oprofile_stats.c +++ b/drivers/oprofile/oprofile_stats.c @@ -11,6 +11,7 @@ #include <linux/smp.h> #include <linux/cpumask.h> #include <linux/threads.h> +#include <linux/seqnum_ops.h> #include "oprofile_stats.h" #include "cpu_buffer.h" @@ -30,11 +31,11 @@ void oprofile_reset_stats(void) cpu_buf->sample_invalid_eip = 0; } - atomic_set(&oprofile_stats.sample_lost_no_mm, 0); - atomic_set(&oprofile_stats.sample_lost_no_mapping, 0); - atomic_set(&oprofile_stats.event_lost_overflow, 0); - atomic_set(&oprofile_stats.bt_lost_no_mapping, 0); - atomic_set(&oprofile_stats.multiplex_counter, 0); + seqnum32_set(&oprofile_stats.sample_lost_no_mm, 0); + seqnum32_set(&oprofile_stats.sample_lost_no_mapping, 0); + seqnum32_set(&oprofile_stats.event_lost_overflow, 0); + seqnum32_set(&oprofile_stats.bt_lost_no_mapping, 0); + seqnum32_set(&oprofile_stats.multiplex_counter, 0); } diff --git a/drivers/oprofile/oprofile_stats.h b/drivers/oprofile/oprofile_stats.h index 1fc622bd1834..229bcbb16527 100644 --- a/drivers/oprofile/oprofile_stats.h +++ b/drivers/oprofile/oprofile_stats.h @@ -11,13 +11,14 @@ #define OPROFILE_STATS_H #include <linux/atomic.h> +#include <linux/seqnum_ops.h> struct oprofile_stat_struct { - atomic_t sample_lost_no_mm; - atomic_t sample_lost_no_mapping; - atomic_t bt_lost_no_mapping; - atomic_t event_lost_overflow; - atomic_t multiplex_counter; + struct seqnum32 sample_lost_no_mm; + struct seqnum32 sample_lost_no_mapping; + struct seqnum32 bt_lost_no_mapping; + struct seqnum32 event_lost_overflow; + struct seqnum32 multiplex_counter; }; extern struct oprofile_stat_struct oprofile_stats; diff --git a/drivers/oprofile/oprofilefs.c b/drivers/oprofile/oprofilefs.c index 0875f2f122b3..c5749b9aca11 100644 --- a/drivers/oprofile/oprofilefs.c +++ b/drivers/oprofile/oprofilefs.c @@ -17,6 +17,7 @@ #include <linux/fs_context.h> #include <linux/pagemap.h> #include <linux/uaccess.h> +#include <linux/seqnum_ops.h> #include "oprof.h" @@ -193,7 +194,7 @@ static const struct file_operations atomic_ro_fops = { int oprofilefs_create_ro_atomic(struct dentry *root, - char const *name, atomic_t *val) + char const *name, struct seqnum32 *val) { return __oprofilefs_create_file(root, name, &atomic_ro_fops, 0444, val); diff --git a/include/linux/oprofile.h b/include/linux/oprofile.h index b2a0f15f11fe..f770254a0c8a 100644 --- a/include/linux/oprofile.h +++ b/include/linux/oprofile.h @@ -19,6 +19,7 @@ #include <linux/errno.h> #include <linux/printk.h> #include <linux/atomic.h> +#include <linux/seqnum_ops.h> /* Each escaped entry is prefixed by ESCAPE_CODE * then one of the following codes, then the @@ -140,7 +141,7 @@ int oprofilefs_create_ro_ulong(struct dentry * root, /** Create a file for read-only access to an atomic_t. */ int oprofilefs_create_ro_atomic(struct dentry * root, - char const * name, atomic_t * val); + char const *name, struct seqnum32 *val); /** create a directory */ struct dentry *oprofilefs_mkdir(struct dentry *parent, char const *name); -- 2.27.0 |