mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 18:30:06 +00:00
![Arnd Bergmann](/assets/img/avatar_default.png)
There are no remaining callers of set_fs(), so CONFIG_SET_FS can be removed globally, along with the thread_info field and any references to it. This turns access_ok() into a cheaper check against TASK_SIZE_MAX. As CONFIG_SET_FS is now gone, drop all remaining references to set_fs()/get_fs(), mm_segment_t, user_addr_max() and uaccess_kernel(). Acked-by: Sam Ravnborg <sam@ravnborg.org> # for sparc32 changes Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Tested-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com> # for arc changes Acked-by: Stafford Horne <shorne@gmail.com> # [openrisc, asm-generic] Acked-by: Dinh Nguyen <dinguyen@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
253 lines
5.6 KiB
C
253 lines
5.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Performance events callchain code, extracted from core.c:
|
|
*
|
|
* Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
|
|
* Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
|
|
* Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
|
|
* Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
|
|
*/
|
|
|
|
#include <linux/perf_event.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/sched/task_stack.h>
|
|
|
|
#include "internal.h"
|
|
|
|
struct callchain_cpus_entries {
|
|
struct rcu_head rcu_head;
|
|
struct perf_callchain_entry *cpu_entries[];
|
|
};
|
|
|
|
int sysctl_perf_event_max_stack __read_mostly = PERF_MAX_STACK_DEPTH;
|
|
int sysctl_perf_event_max_contexts_per_stack __read_mostly = PERF_MAX_CONTEXTS_PER_STACK;
|
|
|
|
static inline size_t perf_callchain_entry__sizeof(void)
|
|
{
|
|
return (sizeof(struct perf_callchain_entry) +
|
|
sizeof(__u64) * (sysctl_perf_event_max_stack +
|
|
sysctl_perf_event_max_contexts_per_stack));
|
|
}
|
|
|
|
static DEFINE_PER_CPU(int, callchain_recursion[PERF_NR_CONTEXTS]);
|
|
static atomic_t nr_callchain_events;
|
|
static DEFINE_MUTEX(callchain_mutex);
|
|
static struct callchain_cpus_entries *callchain_cpus_entries;
|
|
|
|
|
|
__weak void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
|
|
struct pt_regs *regs)
|
|
{
|
|
}
|
|
|
|
__weak void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
|
|
struct pt_regs *regs)
|
|
{
|
|
}
|
|
|
|
static void release_callchain_buffers_rcu(struct rcu_head *head)
|
|
{
|
|
struct callchain_cpus_entries *entries;
|
|
int cpu;
|
|
|
|
entries = container_of(head, struct callchain_cpus_entries, rcu_head);
|
|
|
|
for_each_possible_cpu(cpu)
|
|
kfree(entries->cpu_entries[cpu]);
|
|
|
|
kfree(entries);
|
|
}
|
|
|
|
static void release_callchain_buffers(void)
|
|
{
|
|
struct callchain_cpus_entries *entries;
|
|
|
|
entries = callchain_cpus_entries;
|
|
RCU_INIT_POINTER(callchain_cpus_entries, NULL);
|
|
call_rcu(&entries->rcu_head, release_callchain_buffers_rcu);
|
|
}
|
|
|
|
static int alloc_callchain_buffers(void)
|
|
{
|
|
int cpu;
|
|
int size;
|
|
struct callchain_cpus_entries *entries;
|
|
|
|
/*
|
|
* We can't use the percpu allocation API for data that can be
|
|
* accessed from NMI. Use a temporary manual per cpu allocation
|
|
* until that gets sorted out.
|
|
*/
|
|
size = offsetof(struct callchain_cpus_entries, cpu_entries[nr_cpu_ids]);
|
|
|
|
entries = kzalloc(size, GFP_KERNEL);
|
|
if (!entries)
|
|
return -ENOMEM;
|
|
|
|
size = perf_callchain_entry__sizeof() * PERF_NR_CONTEXTS;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
entries->cpu_entries[cpu] = kmalloc_node(size, GFP_KERNEL,
|
|
cpu_to_node(cpu));
|
|
if (!entries->cpu_entries[cpu])
|
|
goto fail;
|
|
}
|
|
|
|
rcu_assign_pointer(callchain_cpus_entries, entries);
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
for_each_possible_cpu(cpu)
|
|
kfree(entries->cpu_entries[cpu]);
|
|
kfree(entries);
|
|
|
|
return -ENOMEM;
|
|
}
|
|
|
|
int get_callchain_buffers(int event_max_stack)
|
|
{
|
|
int err = 0;
|
|
int count;
|
|
|
|
mutex_lock(&callchain_mutex);
|
|
|
|
count = atomic_inc_return(&nr_callchain_events);
|
|
if (WARN_ON_ONCE(count < 1)) {
|
|
err = -EINVAL;
|
|
goto exit;
|
|
}
|
|
|
|
/*
|
|
* If requesting per event more than the global cap,
|
|
* return a different error to help userspace figure
|
|
* this out.
|
|
*
|
|
* And also do it here so that we have &callchain_mutex held.
|
|
*/
|
|
if (event_max_stack > sysctl_perf_event_max_stack) {
|
|
err = -EOVERFLOW;
|
|
goto exit;
|
|
}
|
|
|
|
if (count == 1)
|
|
err = alloc_callchain_buffers();
|
|
exit:
|
|
if (err)
|
|
atomic_dec(&nr_callchain_events);
|
|
|
|
mutex_unlock(&callchain_mutex);
|
|
|
|
return err;
|
|
}
|
|
|
|
void put_callchain_buffers(void)
|
|
{
|
|
if (atomic_dec_and_mutex_lock(&nr_callchain_events, &callchain_mutex)) {
|
|
release_callchain_buffers();
|
|
mutex_unlock(&callchain_mutex);
|
|
}
|
|
}
|
|
|
|
struct perf_callchain_entry *get_callchain_entry(int *rctx)
|
|
{
|
|
int cpu;
|
|
struct callchain_cpus_entries *entries;
|
|
|
|
*rctx = get_recursion_context(this_cpu_ptr(callchain_recursion));
|
|
if (*rctx == -1)
|
|
return NULL;
|
|
|
|
entries = rcu_dereference(callchain_cpus_entries);
|
|
if (!entries) {
|
|
put_recursion_context(this_cpu_ptr(callchain_recursion), *rctx);
|
|
return NULL;
|
|
}
|
|
|
|
cpu = smp_processor_id();
|
|
|
|
return (((void *)entries->cpu_entries[cpu]) +
|
|
(*rctx * perf_callchain_entry__sizeof()));
|
|
}
|
|
|
|
void
|
|
put_callchain_entry(int rctx)
|
|
{
|
|
put_recursion_context(this_cpu_ptr(callchain_recursion), rctx);
|
|
}
|
|
|
|
struct perf_callchain_entry *
|
|
get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
|
|
u32 max_stack, bool crosstask, bool add_mark)
|
|
{
|
|
struct perf_callchain_entry *entry;
|
|
struct perf_callchain_entry_ctx ctx;
|
|
int rctx;
|
|
|
|
entry = get_callchain_entry(&rctx);
|
|
if (!entry)
|
|
return NULL;
|
|
|
|
ctx.entry = entry;
|
|
ctx.max_stack = max_stack;
|
|
ctx.nr = entry->nr = init_nr;
|
|
ctx.contexts = 0;
|
|
ctx.contexts_maxed = false;
|
|
|
|
if (kernel && !user_mode(regs)) {
|
|
if (add_mark)
|
|
perf_callchain_store_context(&ctx, PERF_CONTEXT_KERNEL);
|
|
perf_callchain_kernel(&ctx, regs);
|
|
}
|
|
|
|
if (user) {
|
|
if (!user_mode(regs)) {
|
|
if (current->mm)
|
|
regs = task_pt_regs(current);
|
|
else
|
|
regs = NULL;
|
|
}
|
|
|
|
if (regs) {
|
|
if (crosstask)
|
|
goto exit_put;
|
|
|
|
if (add_mark)
|
|
perf_callchain_store_context(&ctx, PERF_CONTEXT_USER);
|
|
|
|
perf_callchain_user(&ctx, regs);
|
|
}
|
|
}
|
|
|
|
exit_put:
|
|
put_callchain_entry(rctx);
|
|
|
|
return entry;
|
|
}
|
|
|
|
/*
|
|
* Used for sysctl_perf_event_max_stack and
|
|
* sysctl_perf_event_max_contexts_per_stack.
|
|
*/
|
|
int perf_event_max_stack_handler(struct ctl_table *table, int write,
|
|
void *buffer, size_t *lenp, loff_t *ppos)
|
|
{
|
|
int *value = table->data;
|
|
int new_value = *value, ret;
|
|
struct ctl_table new_table = *table;
|
|
|
|
new_table.data = &new_value;
|
|
ret = proc_dointvec_minmax(&new_table, write, buffer, lenp, ppos);
|
|
if (ret || !write)
|
|
return ret;
|
|
|
|
mutex_lock(&callchain_mutex);
|
|
if (atomic_read(&nr_callchain_events))
|
|
ret = -EBUSY;
|
|
else
|
|
*value = new_value;
|
|
|
|
mutex_unlock(&callchain_mutex);
|
|
|
|
return ret;
|
|
}
|