user/sven/linux.git, branch v4.19.138

Linux 4.19.138

2020-08-07T07:36:21Z

Tested-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman

ext4: fix direct I/O read error

2020-08-07T07:36:21Z

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 #include #include #include #include #include #include #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 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 ("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 Co-developed-by: Wang Long Signed-off-by: Wang Long Signed-off-by: Jiang Ying Signed-off-by: Greg Kroah-Hartman

random32: move the pseudo-random 32-bit definitions to prandom.h

2020-08-07T07:36:21Z

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 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 , which can currently come in a lot of ways, including such fairly core headfers as . 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 Acked-by: Willy Tarreau Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

random32: remove net_rand_state from the latent entropy gcc plugin

2020-08-07T07:36:20Z

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 Cc: Emese Revfy Cc: Kees Cook Cc: Willy Tarreau Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

random: fix circular include dependency on arm64 after addition of percpu.h

2020-08-07T07:36:20Z

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 remove from the arm64 that causes the circular dependency. But we might as well do the whole belt-and-suspenders thing, and minimize inclusion in too. Either will fix the problem, and both are good changes. - Linus ] Reported-by: Daniel Díaz Reported-by: Kees Cook Tested-by: Marc Zyngier Fixes: f227e3ec3b5c Cc: Stephen Rothwell Signed-off-by: Willy Tarreau Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ARM: percpu.h: fix build error

2020-08-07T07:36:20Z

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 Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

random32: update the net random state on interrupt and activity

2020-08-07T07:36:20Z

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 Suggested-by: Linus Torvalds Cc: Eric Dumazet Cc: "Jason A. Donenfeld" Cc: Andy Lutomirski Cc: Kees Cook Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Signed-off-by: Willy Tarreau Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Linux 4.19.137

2020-08-05T08:06:06Z

Tested-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman

x86/i8259: Use printk_deferred() to prevent deadlock

2020-08-05T08:06:06Z

commit bdd65589593edd79b6a12ce86b3b7a7c6dae5208 upstream. 0day reported a possible circular locking dependency: Chain exists of: &irq_desc_lock_class --> console_owner --> &port_lock_key Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port_lock_key); lock(console_owner); lock(&port_lock_key); lock(&irq_desc_lock_class); The reason for this is a printk() in the i8259 interrupt chip driver which is invoked with the irq descriptor lock held, which reverses the lock operations vs. printk() from arbitrary contexts. Switch the printk() to printk_deferred() to avoid that. Reported-by: kernel test robot Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87365abt2v.fsf@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman

KVM: LAPIC: Prevent setting the tscdeadline timer if the lapic is hw disabled

2020-08-05T08:06:06Z

commit d2286ba7d574ba3103a421a2f9ec17cb5b0d87a1 upstream. Prevent setting the tscdeadline timer if the lapic is hw disabled. Fixes: bce87cce88 (KVM: x86: consolidate different ways to test for in-kernel LAPIC) Cc: Signed-off-by: Wanpeng Li Message-Id: <1596165141-28874-1-git-send-email-wanpengli@tencent.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman