Merge branch 'akpm' (patches from Andrew)

Merge fourth patch-bomb from Andrew Morton:

 - sys_membarier syscall

 - seq_file interface changes

 - a few misc fixups

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  revert "ocfs2/dlm: use list_for_each_entry instead of list_for_each"
  mm/early_ioremap: add explicit #include of asm/early_ioremap.h
  fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void
  selftests: enhance membarrier syscall test
  selftests: add membarrier syscall test
  sys_membarrier(): system-wide memory barrier (generic, x86)
  MODSIGN: fix a compilation warning in extract-cert
This commit is contained in:
Linus Torvalds 2015-09-11 19:34:09 -07:00
commit 01b0c014ee
22 changed files with 336 additions and 54 deletions

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@ -6789,6 +6789,14 @@ W: http://www.mellanox.com
Q: http://patchwork.ozlabs.org/project/netdev/list/
F: drivers/net/ethernet/mellanox/mlxsw/
MEMBARRIER SUPPORT
M: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
M: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
L: linux-kernel@vger.kernel.org
S: Supported
F: kernel/membarrier.c
F: include/uapi/linux/membarrier.h
MEMORY MANAGEMENT
L: linux-mm@kvack.org
W: http://www.linux-mm.org

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@ -381,3 +381,4 @@
372 i386 recvmsg sys_recvmsg compat_sys_recvmsg
373 i386 shutdown sys_shutdown
374 i386 userfaultfd sys_userfaultfd
375 i386 membarrier sys_membarrier

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@ -330,6 +330,7 @@
321 common bpf sys_bpf
322 64 execveat stub_execveat
323 common userfaultfd sys_userfaultfd
324 common membarrier sys_membarrier
#
# x32-specific system call numbers start at 512 to avoid cache impact

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@ -135,8 +135,9 @@ __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
struct seq_file *s)
{
return seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
(cr->cam & MMU_CAM_P) ? 1 : 0);
return 0;
}
static size_t omap_dump_tlb_entries(struct omap_iommu *obj, struct seq_file *s)

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@ -142,7 +142,8 @@ static int nsfs_show_path(struct seq_file *seq, struct dentry *dentry)
struct inode *inode = d_inode(dentry);
const struct proc_ns_operations *ns_ops = dentry->d_fsdata;
return seq_printf(seq, "%s:[%lu]", ns_ops->name, inode->i_ino);
seq_printf(seq, "%s:[%lu]", ns_ops->name, inode->i_ino);
return 0;
}
static const struct super_operations nsfs_ops = {

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@ -1776,7 +1776,7 @@ static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
struct dlm_migratable_lockres *mres)
{
struct dlm_migratable_lock *ml;
struct list_head *queue;
struct list_head *queue, *iter;
struct list_head *tmpq = NULL;
struct dlm_lock *newlock = NULL;
struct dlm_lockstatus *lksb = NULL;
@ -1821,7 +1821,9 @@ static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
spin_lock(&res->spinlock);
for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
tmpq = dlm_list_idx_to_ptr(res, j);
list_for_each_entry(lock, tmpq, list) {
list_for_each(iter, tmpq) {
lock = list_entry(iter,
struct dlm_lock, list);
if (lock->ml.cookie == ml->cookie)
break;
lock = NULL;

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@ -372,10 +372,10 @@ EXPORT_SYMBOL(seq_release);
* @esc: set of characters that need escaping
*
* Puts string into buffer, replacing each occurrence of character from
* @esc with usual octal escape. Returns 0 in case of success, -1 - in
* case of overflow.
* @esc with usual octal escape.
* Use seq_has_overflowed() to check for errors.
*/
int seq_escape(struct seq_file *m, const char *s, const char *esc)
void seq_escape(struct seq_file *m, const char *s, const char *esc)
{
char *end = m->buf + m->size;
char *p;
@ -394,14 +394,13 @@ int seq_escape(struct seq_file *m, const char *s, const char *esc)
continue;
}
seq_set_overflow(m);
return -1;
return;
}
m->count = p - m->buf;
return 0;
}
EXPORT_SYMBOL(seq_escape);
int seq_vprintf(struct seq_file *m, const char *f, va_list args)
void seq_vprintf(struct seq_file *m, const char *f, va_list args)
{
int len;
@ -409,24 +408,20 @@ int seq_vprintf(struct seq_file *m, const char *f, va_list args)
len = vsnprintf(m->buf + m->count, m->size - m->count, f, args);
if (m->count + len < m->size) {
m->count += len;
return 0;
return;
}
}
seq_set_overflow(m);
return -1;
}
EXPORT_SYMBOL(seq_vprintf);
int seq_printf(struct seq_file *m, const char *f, ...)
void seq_printf(struct seq_file *m, const char *f, ...)
{
int ret;
va_list args;
va_start(args, f);
ret = seq_vprintf(m, f, args);
seq_vprintf(m, f, args);
va_end(args);
return ret;
}
EXPORT_SYMBOL(seq_printf);
@ -664,26 +659,25 @@ int seq_open_private(struct file *filp, const struct seq_operations *ops,
}
EXPORT_SYMBOL(seq_open_private);
int seq_putc(struct seq_file *m, char c)
void seq_putc(struct seq_file *m, char c)
{
if (m->count < m->size) {
if (m->count >= m->size)
return;
m->buf[m->count++] = c;
return 0;
}
return -1;
}
EXPORT_SYMBOL(seq_putc);
int seq_puts(struct seq_file *m, const char *s)
void seq_puts(struct seq_file *m, const char *s)
{
int len = strlen(s);
if (m->count + len < m->size) {
if (m->count + len >= m->size) {
seq_set_overflow(m);
return;
}
memcpy(m->buf + m->count, s, len);
m->count += len;
return 0;
}
seq_set_overflow(m);
return -1;
}
EXPORT_SYMBOL(seq_puts);
@ -694,7 +688,7 @@ EXPORT_SYMBOL(seq_puts);
* This routine is very quick when you show lots of numbers.
* In usual cases, it will be better to use seq_printf(). It's easier to read.
*/
int seq_put_decimal_ull(struct seq_file *m, char delimiter,
void seq_put_decimal_ull(struct seq_file *m, char delimiter,
unsigned long long num)
{
int len;
@ -707,35 +701,33 @@ int seq_put_decimal_ull(struct seq_file *m, char delimiter,
if (num < 10) {
m->buf[m->count++] = num + '0';
return 0;
return;
}
len = num_to_str(m->buf + m->count, m->size - m->count, num);
if (!len)
goto overflow;
m->count += len;
return 0;
return;
overflow:
seq_set_overflow(m);
return -1;
}
EXPORT_SYMBOL(seq_put_decimal_ull);
int seq_put_decimal_ll(struct seq_file *m, char delimiter,
long long num)
void seq_put_decimal_ll(struct seq_file *m, char delimiter, long long num)
{
if (num < 0) {
if (m->count + 3 >= m->size) {
seq_set_overflow(m);
return -1;
return;
}
if (delimiter)
m->buf[m->count++] = delimiter;
num = -num;
delimiter = '-';
}
return seq_put_decimal_ull(m, delimiter, num);
seq_put_decimal_ull(m, delimiter, num);
}
EXPORT_SYMBOL(seq_put_decimal_ll);

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@ -114,13 +114,18 @@ int seq_open(struct file *, const struct seq_operations *);
ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
loff_t seq_lseek(struct file *, loff_t, int);
int seq_release(struct inode *, struct file *);
int seq_escape(struct seq_file *, const char *, const char *);
int seq_putc(struct seq_file *m, char c);
int seq_puts(struct seq_file *m, const char *s);
int seq_write(struct seq_file *seq, const void *data, size_t len);
__printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);
__printf(2, 0) int seq_vprintf(struct seq_file *, const char *, va_list args);
__printf(2, 0)
void seq_vprintf(struct seq_file *m, const char *fmt, va_list args);
__printf(2, 3)
void seq_printf(struct seq_file *m, const char *fmt, ...);
void seq_putc(struct seq_file *m, char c);
void seq_puts(struct seq_file *m, const char *s);
void seq_put_decimal_ull(struct seq_file *m, char delimiter,
unsigned long long num);
void seq_put_decimal_ll(struct seq_file *m, char delimiter, long long num);
void seq_escape(struct seq_file *m, const char *s, const char *esc);
void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
int rowsize, int groupsize, const void *buf, size_t len,
@ -138,10 +143,6 @@ int single_release(struct inode *, struct file *);
void *__seq_open_private(struct file *, const struct seq_operations *, int);
int seq_open_private(struct file *, const struct seq_operations *, int);
int seq_release_private(struct inode *, struct file *);
int seq_put_decimal_ull(struct seq_file *m, char delimiter,
unsigned long long num);
int seq_put_decimal_ll(struct seq_file *m, char delimiter,
long long num);
static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
{

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@ -885,4 +885,6 @@ asmlinkage long sys_execveat(int dfd, const char __user *filename,
const char __user *const __user *argv,
const char __user *const __user *envp, int flags);
asmlinkage long sys_membarrier(int cmd, int flags);
#endif

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@ -709,9 +709,11 @@ __SYSCALL(__NR_memfd_create, sys_memfd_create)
__SYSCALL(__NR_bpf, sys_bpf)
#define __NR_execveat 281
__SC_COMP(__NR_execveat, sys_execveat, compat_sys_execveat)
#define __NR_membarrier 282
__SYSCALL(__NR_membarrier, sys_membarrier)
#undef __NR_syscalls
#define __NR_syscalls 282
#define __NR_syscalls 283
/*
* All syscalls below here should go away really,

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@ -252,6 +252,7 @@ header-y += mdio.h
header-y += media.h
header-y += media-bus-format.h
header-y += mei.h
header-y += membarrier.h
header-y += memfd.h
header-y += mempolicy.h
header-y += meye.h

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@ -0,0 +1,53 @@
#ifndef _UAPI_LINUX_MEMBARRIER_H
#define _UAPI_LINUX_MEMBARRIER_H
/*
* linux/membarrier.h
*
* membarrier system call API
*
* Copyright (c) 2010, 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/**
* enum membarrier_cmd - membarrier system call command
* @MEMBARRIER_CMD_QUERY: Query the set of supported commands. It returns
* a bitmask of valid commands.
* @MEMBARRIER_CMD_SHARED: Execute a memory barrier on all running threads.
* Upon return from system call, the caller thread
* is ensured that all running threads have passed
* through a state where all memory accesses to
* user-space addresses match program order between
* entry to and return from the system call
* (non-running threads are de facto in such a
* state). This covers threads from all processes
* running on the system. This command returns 0.
*
* Command to be passed to the membarrier system call. The commands need to
* be a single bit each, except for MEMBARRIER_CMD_QUERY which is assigned to
* the value 0.
*/
enum membarrier_cmd {
MEMBARRIER_CMD_QUERY = 0,
MEMBARRIER_CMD_SHARED = (1 << 0),
};
#endif /* _UAPI_LINUX_MEMBARRIER_H */

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@ -1602,6 +1602,18 @@ config PCI_QUIRKS
bugs/quirks. Disable this only if your target machine is
unaffected by PCI quirks.
config MEMBARRIER
bool "Enable membarrier() system call" if EXPERT
default y
help
Enable the membarrier() system call that allows issuing memory
barriers across all running threads, which can be used to distribute
the cost of user-space memory barriers asymmetrically by transforming
pairs of memory barriers into pairs consisting of membarrier() and a
compiler barrier.
If unsure, say Y.
config EMBEDDED
bool "Embedded system"
option allnoconfig_y

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@ -100,6 +100,7 @@ obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o
obj-$(CONFIG_TORTURE_TEST) += torture.o
obj-$(CONFIG_MEMBARRIER) += membarrier.o
obj-$(CONFIG_HAS_IOMEM) += memremap.o

66
kernel/membarrier.c Normal file
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@ -0,0 +1,66 @@
/*
* Copyright (C) 2010, 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* membarrier system call
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/syscalls.h>
#include <linux/membarrier.h>
/*
* Bitmask made from a "or" of all commands within enum membarrier_cmd,
* except MEMBARRIER_CMD_QUERY.
*/
#define MEMBARRIER_CMD_BITMASK (MEMBARRIER_CMD_SHARED)
/**
* sys_membarrier - issue memory barriers on a set of threads
* @cmd: Takes command values defined in enum membarrier_cmd.
* @flags: Currently needs to be 0. For future extensions.
*
* If this system call is not implemented, -ENOSYS is returned. If the
* command specified does not exist, or if the command argument is invalid,
* this system call returns -EINVAL. For a given command, with flags argument
* set to 0, this system call is guaranteed to always return the same value
* until reboot.
*
* All memory accesses performed in program order from each targeted thread
* is guaranteed to be ordered with respect to sys_membarrier(). If we use
* the semantic "barrier()" to represent a compiler barrier forcing memory
* accesses to be performed in program order across the barrier, and
* smp_mb() to represent explicit memory barriers forcing full memory
* ordering across the barrier, we have the following ordering table for
* each pair of barrier(), sys_membarrier() and smp_mb():
*
* The pair ordering is detailed as (O: ordered, X: not ordered):
*
* barrier() smp_mb() sys_membarrier()
* barrier() X X O
* smp_mb() X O O
* sys_membarrier() O O O
*/
SYSCALL_DEFINE2(membarrier, int, cmd, int, flags)
{
if (unlikely(flags))
return -EINVAL;
switch (cmd) {
case MEMBARRIER_CMD_QUERY:
return MEMBARRIER_CMD_BITMASK;
case MEMBARRIER_CMD_SHARED:
if (num_online_cpus() > 1)
synchronize_sched();
return 0;
default:
return -EINVAL;
}
}

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@ -245,3 +245,6 @@ cond_syscall(sys_bpf);
/* execveat */
cond_syscall(sys_execveat);
/* membarrier */
cond_syscall(sys_membarrier);

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@ -15,6 +15,7 @@
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <asm/fixmap.h>
#include <asm/early_ioremap.h>
#ifdef CONFIG_MMU
static int early_ioremap_debug __initdata;

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@ -86,7 +86,7 @@ static void write_cert(X509 *x509)
ERR(!wb, "%s", cert_dst);
}
X509_NAME_oneline(X509_get_subject_name(x509), buf, sizeof(buf));
ERR(!i2d_X509_bio(wb, x509), cert_dst);
ERR(!i2d_X509_bio(wb, x509), "%s", cert_dst);
if (kbuild_verbose)
fprintf(stderr, "Extracted cert: %s\n", buf);
}

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@ -6,6 +6,7 @@ TARGETS += firmware
TARGETS += ftrace
TARGETS += futex
TARGETS += kcmp
TARGETS += membarrier
TARGETS += memfd
TARGETS += memory-hotplug
TARGETS += mount

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@ -0,0 +1 @@
membarrier_test

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@ -0,0 +1,11 @@
CFLAGS += -g -I../../../../usr/include/
all:
$(CC) $(CFLAGS) membarrier_test.c -o membarrier_test
TEST_PROGS := membarrier_test
include ../lib.mk
clean:
$(RM) membarrier_test

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@ -0,0 +1,121 @@
#define _GNU_SOURCE
#define __EXPORTED_HEADERS__
#include <linux/membarrier.h>
#include <asm-generic/unistd.h>
#include <sys/syscall.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include "../kselftest.h"
enum test_membarrier_status {
TEST_MEMBARRIER_PASS = 0,
TEST_MEMBARRIER_FAIL,
TEST_MEMBARRIER_SKIP,
};
static int sys_membarrier(int cmd, int flags)
{
return syscall(__NR_membarrier, cmd, flags);
}
static enum test_membarrier_status test_membarrier_cmd_fail(void)
{
int cmd = -1, flags = 0;
if (sys_membarrier(cmd, flags) != -1) {
printf("membarrier: Wrong command should fail but passed.\n");
return TEST_MEMBARRIER_FAIL;
}
return TEST_MEMBARRIER_PASS;
}
static enum test_membarrier_status test_membarrier_flags_fail(void)
{
int cmd = MEMBARRIER_CMD_QUERY, flags = 1;
if (sys_membarrier(cmd, flags) != -1) {
printf("membarrier: Wrong flags should fail but passed.\n");
return TEST_MEMBARRIER_FAIL;
}
return TEST_MEMBARRIER_PASS;
}
static enum test_membarrier_status test_membarrier_success(void)
{
int cmd = MEMBARRIER_CMD_SHARED, flags = 0;
if (sys_membarrier(cmd, flags) != 0) {
printf("membarrier: Executing MEMBARRIER_CMD_SHARED failed. %s.\n",
strerror(errno));
return TEST_MEMBARRIER_FAIL;
}
printf("membarrier: MEMBARRIER_CMD_SHARED success.\n");
return TEST_MEMBARRIER_PASS;
}
static enum test_membarrier_status test_membarrier(void)
{
enum test_membarrier_status status;
status = test_membarrier_cmd_fail();
if (status)
return status;
status = test_membarrier_flags_fail();
if (status)
return status;
status = test_membarrier_success();
if (status)
return status;
return TEST_MEMBARRIER_PASS;
}
static enum test_membarrier_status test_membarrier_query(void)
{
int flags = 0, ret;
printf("membarrier MEMBARRIER_CMD_QUERY ");
ret = sys_membarrier(MEMBARRIER_CMD_QUERY, flags);
if (ret < 0) {
printf("failed. %s.\n", strerror(errno));
switch (errno) {
case ENOSYS:
/*
* It is valid to build a kernel with
* CONFIG_MEMBARRIER=n. However, this skips the tests.
*/
return TEST_MEMBARRIER_SKIP;
case EINVAL:
default:
return TEST_MEMBARRIER_FAIL;
}
}
if (!(ret & MEMBARRIER_CMD_SHARED)) {
printf("command MEMBARRIER_CMD_SHARED is not supported.\n");
return TEST_MEMBARRIER_FAIL;
}
printf("syscall available.\n");
return TEST_MEMBARRIER_PASS;
}
int main(int argc, char **argv)
{
switch (test_membarrier_query()) {
case TEST_MEMBARRIER_FAIL:
return ksft_exit_fail();
case TEST_MEMBARRIER_SKIP:
return ksft_exit_skip();
}
switch (test_membarrier()) {
case TEST_MEMBARRIER_FAIL:
return ksft_exit_fail();
case TEST_MEMBARRIER_SKIP:
return ksft_exit_skip();
}
printf("membarrier: tests done!\n");
return ksft_exit_pass();
}