commit 961f830af0658ef5ef8a7708786d634a6115f16b
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri Aug 7 09:36:21 2020 +0200
Linux 4.19.138
Tested-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit aa0962310814356b10a973c578cfe595d89a3e39
Author: Jiang Ying <jiangying8582@126.com>
Date: Wed Aug 5 15:57:21 2020 +0800
ext4: fix direct I/O read error
This patch is used to fix ext4 direct I/O read error when
the read size is not aligned with block size.
Then, I will use a test to explain the error.
(1) Make a file that is not aligned with block size:
$dd if=/dev/zero of=./test.jar bs=1000 count=3
(2) I wrote a source file named "direct_io_read_file.c" as following:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/file.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#define BUF_SIZE 1024
int main()
{
int fd;
int ret;
unsigned char *buf;
ret = posix_memalign((void **)&buf, 512, BUF_SIZE);
if (ret) {
perror("posix_memalign failed");
exit(1);
}
fd = open("./test.jar", O_RDONLY | O_DIRECT, 0755);
if (fd < 0){
perror("open ./test.jar failed");
exit(1);
}
do {
ret = read(fd, buf, BUF_SIZE);
printf("ret=%d\n",ret);
if (ret < 0) {
perror("write test.jar failed");
}
} while (ret > 0);
free(buf);
close(fd);
}
(3) Compile the source file:
$gcc direct_io_read_file.c -D_GNU_SOURCE
(4) Run the test program:
$./a.out
The result is as following:
ret=1024
ret=1024
ret=952
ret=-1
write test.jar failed: Invalid argument.
I have tested this program on XFS filesystem, XFS does not have
this problem, because XFS use iomap_dio_rw() to do direct I/O
read. And the comparing between read offset and file size is done
in iomap_dio_rw(), the code is as following:
if (pos < size) {
retval = filemap_write_and_wait_range(mapping, pos,
pos + iov_length(iov, nr_segs) - 1);
if (!retval) {
retval = mapping->a_ops->direct_IO(READ, iocb,
iov, pos, nr_segs);
}
...
}
...only when "pos < size", direct I/O can be done, or 0 will be return.
I have tested the fix patch on Ext4, it is up to the mustard of
EINVAL in man2(read) as following:
#include <unistd.h>
ssize_t read(int fd, void *buf, size_t count);
EINVAL
fd is attached to an object which is unsuitable for reading;
or the file was opened with the O_DIRECT flag, and either the
address specified in buf, the value specified in count, or the
current file offset is not suitably aligned.
So I think this patch can be applied to fix ext4 direct I/O error.
However Ext4 introduces direct I/O read using iomap infrastructure
on kernel 5.5, the patch is commit <b1b4705d54ab>
("ext4: introduce direct I/O read using iomap infrastructure"),
then Ext4 will be the same as XFS, they all use iomap_dio_rw() to do direct
I/O read. So this problem does not exist on kernel 5.5 for Ext4.
>From above description, we can see this problem exists on all the kernel
versions between kernel 3.14 and kernel 5.4. It will cause the Applications
to fail to read. For example, when the search service downloads a new full
index file, the search engine is loading the previous index file and is
processing the search request, it can not use buffer io that may squeeze
the previous index file in use from pagecache, so the serch service must
use direct I/O read.
Please apply this patch on these kernel versions, or please use the method
on kernel 5.5 to fix this problem.
Fixes: 9fe55eea7e4b ("Fix race when checking i_size on direct i/o read")
Reviewed-by: Jan Kara <jack@suse.cz>
Co-developed-by: Wang Long <wanglong19@meituan.com>
Signed-off-by: Wang Long <wanglong19@meituan.com>
Signed-off-by: Jiang Ying <jiangying8582@126.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit df9a9ac7a4614afa59fae8f7ad56b93fbab45d46
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri Jul 31 07:51:14 2020 +0200
random32: move the pseudo-random 32-bit definitions to prandom.h
commit c0842fbc1b18c7a044e6ff3e8fa78bfa822c7d1a upstream.
The addition of percpu.h to the list of includes in random.h revealed
some circular dependencies on arm64 and possibly other platforms. This
include was added solely for the pseudo-random definitions, which have
nothing to do with the rest of the definitions in this file but are
still there for legacy reasons.
This patch moves the pseudo-random parts to linux/prandom.h and the
percpu.h include with it, which is now guarded by _LINUX_PRANDOM_H and
protected against recursive inclusion.
A further cleanup step would be to remove this from <linux/random.h>
entirely, and make people who use the prandom infrastructure include
just the new header file. That's a bit of a churn patch, but grepping
for "prandom_" and "next_pseudo_random32" "struct rnd_state" should
catch most users.
But it turns out that that nice cleanup step is fairly painful, because
a _lot_ of code currently seems to depend on the implicit include of
<linux/random.h>, which can currently come in a lot of ways, including
such fairly core headfers as <linux/net.h>.
So the "nice cleanup" part may or may never happen.
Fixes: 1c9df907da83 ("random: fix circular include dependency on arm64 after addition of percpu.h")
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e6b7c5f7a420578b1004dad4842b1210c580724e
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Wed Jul 29 19:11:00 2020 -0700
random32: remove net_rand_state from the latent entropy gcc plugin
commit 83bdc7275e6206f560d247be856bceba3e1ed8f2 upstream.
It turns out that the plugin right now ends up being really unhappy
about the change from 'static' to 'extern' storage that happened in
commit f227e3ec3b5c ("random32: update the net random state on interrupt
and activity").
This is probably a trivial fix for the latent_entropy plugin, but for
now, just remove net_rand_state from the list of things the plugin
worries about.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6f697da3eb85610aae888623ca2885b347e86864
Author: Willy Tarreau <w@1wt.eu>
Date: Thu Jul 30 07:59:24 2020 +0200
random: fix circular include dependency on arm64 after addition of percpu.h
commit 1c9df907da83812e4f33b59d3d142c864d9da57f upstream.
Daniel Díaz and Kees Cook independently reported that commit
f227e3ec3b5c ("random32: update the net random state on interrupt and
activity") broke arm64 due to a circular dependency on include files
since the addition of percpu.h in random.h.
The correct fix would definitely be to move all the prandom32 stuff out
of random.h but for backporting, a smaller solution is preferred.
This one replaces linux/percpu.h with asm/percpu.h, and this fixes the
problem on x86_64, arm64, arm, and mips. Note that moving percpu.h
around didn't change anything and that removing it entirely broke
differently. When backporting, such options might still be considered
if this patch fails to help.
[ It turns out that an alternate fix seems to be to just remove the
troublesome <asm/pointer_auth.h> remove from the arm64 <asm/smp.h>
that causes the circular dependency.
But we might as well do the whole belt-and-suspenders thing, and
minimize inclusion in <linux/random.h> too. Either will fix the
problem, and both are good changes. - Linus ]
Reported-by: Daniel Díaz <daniel.diaz@linaro.org>
Reported-by: Kees Cook <keescook@chromium.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Fixes: f227e3ec3b5c
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 546271c2c8d3a4f2d5fd07d43faf49d0b4423dde
Author: Grygorii Strashko <grygorii.strashko@ti.com>
Date: Thu Jul 30 22:05:01 2020 +0300
ARM: percpu.h: fix build error
commit aa54ea903abb02303bf55855fb51e3fcee135d70 upstream.
Fix build error for the case:
defined(CONFIG_SMP) && !defined(CONFIG_CPU_V6)
config: keystone_defconfig
CC arch/arm/kernel/signal.o
In file included from ../include/linux/random.h:14,
from ../arch/arm/kernel/signal.c:8:
../arch/arm/include/asm/percpu.h: In function ‘__my_cpu_offset’:
../arch/arm/include/asm/percpu.h:29:34: error: ‘current_stack_pointer’ undeclared (first use in this function); did you mean ‘user_stack_pointer’?
: "Q" (*(const unsigned long *)current_stack_pointer));
^~~~~~~~~~~~~~~~~~~~~
user_stack_pointer
Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 29204c846894d73108f87e78aea4757a8ec52c74
Author: Willy Tarreau <w@1wt.eu>
Date: Fri Jul 10 15:23:19 2020 +0200
random32: update the net random state on interrupt and activity
commit f227e3ec3b5cad859ad15666874405e8c1bbc1d4 upstream.
This modifies the first 32 bits out of the 128 bits of a random CPU's
net_rand_state on interrupt or CPU activity to complicate remote
observations that could lead to guessing the network RNG's internal
state.
Note that depending on some network devices' interrupt rate moderation
or binding, this re-seeding might happen on every packet or even almost
never.
In addition, with NOHZ some CPUs might not even get timer interrupts,
leaving their local state rarely updated, while they are running
networked processes making use of the random state. For this reason, we
also perform this update in update_process_times() in order to at least
update the state when there is user or system activity, since it's the
only case we care about.
Reported-by: Amit Klein <aksecurity@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>