user/sven/linux.git/include/linux/kernel.h, branch v4.9.328

hex2bin: make the function hex_to_bin constant-time

2022-05-12T10:14:54Z

commit e5be15767e7e284351853cbaba80cde8620341fb upstream. The function hex2bin is used to load cryptographic keys into device mapper targets dm-crypt and dm-integrity. It should take constant time independent on the processed data, so that concurrently running unprivileged code can't infer any information about the keys via microarchitectural convert channels. This patch changes the function hex_to_bin so that it contains no branches and no memory accesses. Note that this shouldn't cause performance degradation because the size of the new function is the same as the size of the old function (on x86-64) - and the new function causes no branch misprediction penalties. I compile-tested this function with gcc on aarch64 alpha arm hppa hppa64 i386 ia64 m68k mips32 mips64 powerpc powerpc64 riscv sh4 s390x sparc32 sparc64 x86_64 and with clang on aarch64 arm hexagon i386 mips32 mips64 powerpc powerpc64 s390x sparc32 sparc64 x86_64 to verify that there are no branches in the generated code. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

linux/kernel.h: Use parentheses around argument in u64_to_user_ptr()

2019-05-10T15:52:09Z

[ Upstream commit a0fe2c6479aab5723239b315ef1b552673f434a3 ] Use parentheses around uses of the argument in u64_to_user_ptr() to ensure that the cast doesn't apply to part of the argument. There are existing uses of the macro of the form u64_to_user_ptr(A + B) which expands to (void __user *)(uintptr_t)A + B (the cast applies to the first operand of the addition, the addition is a pointer addition). This happens to still work as intended, the semantic difference doesn't cause a difference in behavior. But I want to use u64_to_user_ptr() with a ternary operator in the argument, like so: u64_to_user_ptr(A ? B : C) This currently doesn't work as intended. Signed-off-by: Jann Horn Signed-off-by: Borislav Petkov Reviewed-by: Mukesh Ojha Cc: Andrei Vagin Cc: Andrew Morton Cc: Dan Carpenter Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jani Nikula Cc: Kees Cook Cc: Masahiro Yamada Cc: NeilBrown Cc: Peter Zijlstra Cc: Qiaowei Ren Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20190329214652.258477-1-jannh@google.com Signed-off-by: Sasha Levin

libnvdimm, dax: fix 1GB-aligned namespaces vs physical misalignment

2018-02-28T09:18:34Z

commit 41fce90f26333c4fa82e8e43b9ace86c4e8a0120 upstream. The following namespace configuration attempt: # ndctl create-namespace -e namespace0.0 -m devdax -a 1G -f libndctl: ndctl_dax_enable: dax0.1: failed to enable Error: namespace0.0: failed to enable failed to reconfigure namespace: No such device or address ...fails when the backing memory range is not physically aligned to 1G: # cat /proc/iomem | grep Persistent 210000000-30fffffff : Persistent Memory (legacy) In the above example the 4G persistent memory range starts and ends on a 256MB boundary. We handle this case correctly when needing to handle cases that violate section alignment (128MB) collisions against "System RAM", and we simply need to extend that padding/truncation for the 1GB alignment use case. Cc: Fixes: 315c562536c4 ("libnvdimm, pfn: add 'align' attribute...") Reported-and-tested-by: Jane Chu Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

min/max: remove sparse warnings when they're nested

2016-10-08T01:46:30Z

Currently, when min/max are nested within themselves, sparse will warn: warning: symbol '_min1' shadows an earlier one originally declared here warning: symbol '_min1' shadows an earlier one originally declared here warning: symbol '_min2' shadows an earlier one originally declared here This also immediately happens when min3() or max3() are used. Since sparse implements __COUNTER__, we can use __UNIQUE_ID() to generate unique variable names, avoiding this. Link: http://lkml.kernel.org/r/1471519773-29882-1-git-send-email-johannes@sipsolutions.net Signed-off-by: Johannes Berg Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sched/core: Optimize __schedule()

2016-09-22T12:53:45Z

Oleg noted that by making do_exit() use __schedule() for the TASK_DEAD context switch, we can avoid the TASK_DEAD special case currently in __schedule() because that avoids the extra preempt_disable() from schedule(). In order to facilitate this, create a do_task_dead() helper which we place in the scheduler code, such that it can access __schedule(). Also add some __noreturn annotations to the functions, there's no coming back from do_exit(). Suggested-by: Oleg Nesterov Signed-off-by: Peter Zijlstra (Intel) Cc: Cheng Chao Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: akpm@linux-foundation.org Cc: chris@chris-wilson.co.uk Cc: tj@kernel.org Link: http://lkml.kernel.org/r/20160913163729.GB5012@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar

dynamic_debug: only add header when used

2016-08-02T23:35:03Z

kernel.h header doesn't directly use dynamic debug, instead we can include it in module.c (which used it via kernel.h). printk.h only uses it if CONFIG_DYNAMIC_DEBUG is on, changing the inclusion to only happen in that case. Link: http://lkml.kernel.org/r/1468429793-16917-1-git-send-email-luisbg@osg.samsung.com [luisbg@osg.samsung.com: include dynamic_debug.h in drb_int.h] Link: http://lkml.kernel.org/r/1468447828-18558-2-git-send-email-luisbg@osg.samsung.com Signed-off-by: Luis de Bethencourt Cc: Rusty Russell Cc: Hidehiro Kawai Cc: Borislav Petkov Cc: Michal Nazarewicz Cc: Rasmus Villemoes Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rcu: sysctl: Panic on RCU Stall

2016-06-15T23:00:05Z

It is not always easy to determine the cause of an RCU stall just by analysing the RCU stall messages, mainly when the problem is caused by the indirect starvation of rcu threads. For example, when preempt_rcu is not awakened due to the starvation of a timer softirq. We have been hard coding panic() in the RCU stall functions for some time while testing the kernel-rt. But this is not possible in some scenarios, like when supporting customers. This patch implements the sysctl kernel.panic_on_rcu_stall. If set to 1, the system will panic() when an RCU stall takes place, enabling the capture of a vmcore. The vmcore provides a way to analyze all kernel/tasks states, helping out to point to the culprit and the solution for the stall. The kernel.panic_on_rcu_stall sysctl is disabled by default. Changes from v1: - Fixed a typo in the git log - The if(sysctl_panic_on_rcu_stall) panic() is in a static function - Fixed the CONFIG_TINY_RCU compilation issue - The var sysctl_panic_on_rcu_stall is now __read_mostly Cc: Jonathan Corbet Cc: "Paul E. McKenney" Cc: Josh Triplett Cc: Steven Rostedt Cc: Mathieu Desnoyers Cc: Lai Jiangshan Acked-by: Christian Borntraeger Reviewed-by: Josh Triplett Reviewed-by: Arnaldo Carvalho de Melo Tested-by: "Luis Claudio R. Goncalves" Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Paul E. McKenney

Merge tag 'staging-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

2016-05-21T05:20:48Z

Pull staging and IIO driver updates from Greg KH: "Here's the big staging and iio driver update for 4.7-rc1. I think we almost broke even with this release, only adding a few more lines than we removed, which isn't bad overall given that there's a bunch of new iio drivers added. The Lustre developers seem to have woken up from their sleep and have been doing a great job in cleaning up the code and pruning unused or old cruft, the filesystem is almost readable :) Other than that, just a lot of basic coding style cleanups in the churn. All have been in linux-next for a while with no reported issues" * tag 'staging-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (938 commits) Staging: emxx_udc: emxx_udc: fixed coding style issue staging/gdm724x: fix "alignment should match open parenthesis" issues staging/gdm724x: Fix avoid CamelCase staging: unisys: rename misleading var ii with frag staging: unisys: visorhba: switch success handling to error handling staging: unisys: visorhba: main path needs to flow down the left margin staging: unisys: visorinput: handle_locking_key() simplifications staging: unisys: visorhba: fail gracefully for thread creation failures staging: unisys: visornic: comment restructuring and removing bad diction staging: unisys: fix format string %Lx to %llx for u64 staging: unisys: remove unused struct members staging: unisys: visorchannel: correct variable misspelling staging: unisys: visorhba: replace functionlike macro with function staging: dgnc: Need to check for NULL of ch staging: dgnc: remove redundant condition check staging: dgnc: fix 'line over 80 characters' staging: dgnc: clean up the dgnc_get_modem_info() staging: lustre: lnet: enable configuration per NI interface staging: lustre: o2iblnd: properly set ibr_why staging: lustre: o2iblnd: remove last of kiblnd_tunables_fini ...

include/linux: apply __malloc attribute

2016-05-20T02:12:14Z

Attach the malloc attribute to a few allocation functions. This helps gcc generate better code by telling it that the return value doesn't alias any existing pointers (which is even more valuable given the pessimizations implied by -fno-strict-aliasing). A simple example of what this allows gcc to do can be seen by looking at the last part of drm_atomic_helper_plane_reset: plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL); if (plane->state) { plane->state->plane = plane; plane->state->rotation = BIT(DRM_ROTATE_0); } which compiles to e8 99 bf d6 ff callq ffffffff8116d540 48 85 c0 test %rax,%rax 48 89 83 40 02 00 00 mov %rax,0x240(%rbx) 74 11 je ffffffff814015c4 48 89 18 mov %rbx,(%rax) 48 8b 83 40 02 00 00 mov 0x240(%rbx),%rax [*] c7 40 40 01 00 00 00 movl $0x1,0x40(%rax) With this patch applied, the instruction at [*] is elided, since the store to plane->state->plane is known to not alter the value of plane->state. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Rasmus Villemoes Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel.h: add u64_to_user_ptr()

2016-04-30T00:03:49Z

This function had copies in 3 different files. Unify them in kernel.h. Cc: Joe Perches Cc: Andrew Morton Cc: David Airlie Cc: Daniel Vetter Cc: Rob Clark Signed-off-by: Gustavo Padovan Acked-by: Daniel Vetter [drm/i915/] Acked-by: Rob Clark [drm/msm/] Acked-by: Lucas Stach [drm/etinav/] Acked-by: Maarten Lankhorst Signed-off-by: Greg Kroah-Hartman