android/android_kernel_samsung_sm8650
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Revert "tracing: Introduce pipe_cpumask to avoid race on trace_pipes"

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This reverts commit 10f358cd4b which is
commit c2489bb7e6be2e8cdced12c16c42fa128403ac03 upstream.

It breaks the Android ABI and is not needed for Android systems at this
point in time.  If needed in the future, it can come back in an abi-safe
way.

Bug: 161946584
Change-Id: I821cce9935fbf264a40b9c089e5591efdf145bcf
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman 2023-10-12 14:01:08 +00:00
parent 8d71a1ef6a
commit cb6717439c
2 changed files with 7 additions and 50 deletions
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55
kernel/trace/trace.c
View File

@ -6617,36 +6617,10 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf,
#endif
static int open_pipe_on_cpu(struct trace_array *tr, int cpu)
{
if (cpu == RING_BUFFER_ALL_CPUS) {
if (cpumask_empty(tr->pipe_cpumask)) {
cpumask_setall(tr->pipe_cpumask);
return 0;
}
} else if (!cpumask_test_cpu(cpu, tr->pipe_cpumask)) {
cpumask_set_cpu(cpu, tr->pipe_cpumask);
return 0;
}
return -EBUSY;
}
static void close_pipe_on_cpu(struct trace_array *tr, int cpu)
{
if (cpu == RING_BUFFER_ALL_CPUS) {
WARN_ON(!cpumask_full(tr->pipe_cpumask));
cpumask_clear(tr->pipe_cpumask);
} else {
WARN_ON(!cpumask_test_cpu(cpu, tr->pipe_cpumask));
cpumask_clear_cpu(cpu, tr->pipe_cpumask);
}
}
static int tracing_open_pipe(struct inode *inode, struct file *filp)
{
struct trace_array *tr = inode->i_private;
struct trace_iterator *iter;
int cpu;
int ret;
ret = tracing_check_open_get_tr(tr);
@ -6654,16 +6628,13 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
return ret;
mutex_lock(&trace_types_lock);
cpu = tracing_get_cpu(inode);
ret = open_pipe_on_cpu(tr, cpu);
if (ret)
goto fail_pipe_on_cpu;
/* create a buffer to store the information to pass to userspace */
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
if (!iter) {
ret = -ENOMEM;
goto fail_alloc_iter;
__trace_array_put(tr);
goto out;
}
trace_seq_init(&iter->seq);
@ -6686,7 +6657,7 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
iter->tr = tr;
iter->array_buffer = &tr->array_buffer;
iter->cpu_file = cpu;
iter->cpu_file = tracing_get_cpu(inode);
mutex_init(&iter->mutex);
filp->private_data = iter;
@ -6696,15 +6667,12 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
nonseekable_open(inode, filp);
tr->trace_ref++;
out:
mutex_unlock(&trace_types_lock);
return ret;
fail:
kfree(iter);
fail_alloc_iter:
close_pipe_on_cpu(tr, cpu);
fail_pipe_on_cpu:
__trace_array_put(tr);
mutex_unlock(&trace_types_lock);
return ret;
@ -6721,7 +6689,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
if (iter->trace->pipe_close)
iter->trace->pipe_close(iter);
close_pipe_on_cpu(tr, iter->cpu_file);
mutex_unlock(&trace_types_lock);
free_cpumask_var(iter->started);
@ -9396,9 +9364,6 @@ static struct trace_array *trace_array_create(const char *name)
if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL))
goto out_free_tr;
if (!alloc_cpumask_var(&tr->pipe_cpumask, GFP_KERNEL))
goto out_free_tr;
tr->trace_flags = global_trace.trace_flags & ~ZEROED_TRACE_FLAGS;
cpumask_copy(tr->tracing_cpumask, cpu_all_mask);
@ -9440,7 +9405,6 @@ static struct trace_array *trace_array_create(const char *name)
out_free_tr:
ftrace_free_ftrace_ops(tr);
free_trace_buffers(tr);
free_cpumask_var(tr->pipe_cpumask);
free_cpumask_var(tr->tracing_cpumask);
kfree(tr->name);
kfree(tr);
@ -9543,7 +9507,6 @@ static int __remove_instance(struct trace_array *tr)
}
kfree(tr->topts);
free_cpumask_var(tr->pipe_cpumask);
free_cpumask_var(tr->tracing_cpumask);
kfree(tr->name);
kfree(tr);
@ -10300,14 +10263,12 @@ __init static int tracer_alloc_buffers(void)
if (trace_create_savedcmd() < 0)
goto out_free_temp_buffer;
if (!alloc_cpumask_var(&global_trace.pipe_cpumask, GFP_KERNEL))
goto out_free_savedcmd;
/* TODO: make the number of buffers hot pluggable with CPUS */
if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {
MEM_FAIL(1, "tracer: failed to allocate ring buffer!\n");
goto out_free_pipe_cpumask;
goto out_free_savedcmd;
}
if (global_trace.buffer_disabled)
tracing_off();
@ -10360,8 +10321,6 @@ __init static int tracer_alloc_buffers(void)
return 0;
out_free_pipe_cpumask:
free_cpumask_var(global_trace.pipe_cpumask);
out_free_savedcmd:
free_saved_cmdlines_buffer(savedcmd);
out_free_temp_buffer:

2
kernel/trace/trace.h
View File

@ -366,8 +366,6 @@ struct trace_array {
struct list_head events;
struct trace_event_file *trace_marker_file;
cpumask_var_t tracing_cpumask; /* only trace on set CPUs */
/* one per_cpu trace_pipe can be opened by only one user */
cpumask_var_t pipe_cpumask;
int ref;
int trace_ref;
#ifdef CONFIG_FUNCTION_TRACER