user/sven/linux.git/include, branch v3.16.50

perf: Avoid horrible stack usage

2017-11-11T13:34:02Z

commit 86038c5ea81b519a8a1fcfcd5e4599aab0cdd119 upstream. Both Linus (most recent) and Steve (a while ago) reported that perf related callbacks have massive stack bloat. The problem is that software events need a pt_regs in order to properly report the event location and unwind stack. And because we could not assume one was present we allocated one on stack and filled it with minimal bits required for operation. Now, pt_regs is quite large, so this is undesirable. Furthermore it turns out that most sites actually have a pt_regs pointer available, making this even more onerous, as the stack space is pointless waste. This patch addresses the problem by observing that software events have well defined nesting semantics, therefore we can use static per-cpu storage instead of on-stack. Linus made the further observation that all but the scheduler callers of perf_sw_event() have a pt_regs available, so we change the regular perf_sw_event() to require a valid pt_regs (where it used to be optional) and add perf_sw_event_sched() for the scheduler. We have a scheduler specific call instead of a more generic _noregs() like construct because we can assume non-recursion from the scheduler and thereby simplify the code further (_noregs would have to put the recursion context call inline in order to assertain which __perf_regs element to use). One last note on the implementation of perf_trace_buf_prepare(); we allow .regs = NULL for those cases where we already have a pt_regs pointer available and do not need another. Reported-by: Linus Torvalds Reported-by: Steven Rostedt Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Javi Merino Cc: Linus Torvalds Cc: Mathieu Desnoyers Cc: Oleg Nesterov Cc: Paul Mackerras Cc: Petr Mladek Cc: Steven Rostedt Cc: Tom Zanussi Cc: Vaibhav Nagarnaik Link: http://lkml.kernel.org/r/20141216115041.GW3337@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar Signed-off-by: Arnd Bergmann Signed-off-by: Ben Hutchings

mtd: cfi: reduce stack size

2017-11-11T13:34:01Z

commit d09957fbb4d0b059b3176b510540df69048ad170 upstream. The cfi_staa_write_buffers function uses a large amount of kernel stack whenever CONFIG_MTD_MAP_BANK_WIDTH_32 is set, and that results in a warning on ARM allmodconfig builds: drivers/mtd/chips/cfi_cmdset_0020.c: In function 'cfi_staa_write_buffers': drivers/mtd/chips/cfi_cmdset_0020.c:651:1: warning: the frame size of 1208 bytes is larger than 1024 bytes [-Wframe-larger-than=] It turns out that this is largely a result of a suboptimal implementation of map_word_andequal(). Replacing this function with a straightforward one reduces the stack size in this function by exactly 200 bytes, shrinks the .text segment for this file from 27648 bytes to 26608 bytes, and makes the warning go away. Signed-off-by: Arnd Bergmann Signed-off-by: Brian Norris Signed-off-by: Arnd Bergmann Signed-off-by: Ben Hutchings

gpio: drop retval check enforcing from gpiochip_remove()

2017-11-11T13:33:45Z

commit 14c8a620ba436511b1347c592633befa49535176 upstream. As we start to decomission the return value from gpiochip_remove() the compilers emit warnings due to the function being tagged __must_check. So drop this until we remove the return value altogether. Cc: Abdoulaye Berthe Suggested-by: Stephen Rothwell Signed-off-by: Linus Walleij Signed-off-by: Arnd Bergmann Signed-off-by: Ben Hutchings

cpumask_set_cpu_local_first => cpumask_local_spread, lament

2017-11-11T13:33:43Z

commit f36963c9d3f6f415732710da3acdd8608a9fa0e upstream. da91309e0a7e (cpumask: Utility function to set n'th cpu...) created a genuinely weird function. I never saw it before, it went through DaveM. (He only does this to make us other maintainers feel better about our own mistakes.) cpumask_set_cpu_local_first's purpose is say "I need to spread things across N online cpus, choose the ones on this numa node first"; you call it in a loop. It can fail. One of the two callers ignores this, the other aborts and fails the device open. It can fail in two ways: allocating the off-stack cpumask, or through a convoluted codepath which AFAICT can only occur if cpu_online_mask changes. Which shouldn't happen, because if cpu_online_mask can change while you call this, it could return a now-offline cpu anyway. It contains a nonsensical test "!cpumask_of_node(numa_node)". This was drawn to my attention by Geert, who said this causes a warning on Sparc. It sets a single bit in a cpumask instead of returning a cpu number, because that's what the callers want. It could be made more efficient by passing the previous cpu rather than an index, but that would be more invasive to the callers. Fixes: da91309e0a7e8966d916a74cce42ed170fde06bf Signed-off-by: Rusty Russell (then rebased) Tested-by: Amir Vadai Acked-by: Amir Vadai Acked-by: David S. Miller Signed-off-by: Arnd Bergmann Signed-off-by: Ben Hutchings

module: fix types of device tables aliases

2017-11-11T13:33:43Z

commit 6301939d97d079f0d3dbe71e750f4daf5d39fc33 upstream. MODULE_DEVICE_TABLE() macro used to create aliases to device tables. Normally alias should have the same type as aliased symbol. Device tables are arrays, so they have 'struct type##_device_id[x]' types. Alias created by MODULE_DEVICE_TABLE() will have non-array type - 'struct type##_device_id'. This inconsistency confuses compiler, it could make a wrong assumption about variable's size which leads KASan to produce a false positive report about out of bounds access. For every global variable compiler calls __asan_register_globals() passing information about global variable (address, size, size with redzone, name ...) __asan_register_globals() poison symbols redzone to detect possible out of bounds accesses. When symbol has an alias __asan_register_globals() will be called as for symbol so for alias. Compiler determines size of variable by size of variable's type. Alias and symbol have the same address, so if alias have the wrong size part of memory that actually belongs to the symbol could be poisoned as redzone of alias symbol. By fixing type of alias symbol we will fix size of it, so __asan_register_globals() will not poison valid memory. Signed-off-by: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Konstantin Serebryany Cc: Dmitry Chernenkov Signed-off-by: Andrey Konovalov Cc: Yuri Gribov Cc: Konstantin Khlebnikov Cc: Sasha Levin Cc: Christoph Lameter Cc: Joonsoo Kim Cc: Dave Hansen Cc: Andi Kleen Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman Signed-off-by: Arnd Bergmann Signed-off-by: Ben Hutchings

USB: fix out-of-bounds in usb_set_configuration

2017-11-11T13:33:39Z

commit bd7a3fe770ebd8391d1c7d072ff88e9e76d063eb upstream. Andrey Konovalov reported a possible out-of-bounds problem for a USB interface association descriptor. He writes: It seems there's no proper size check of a USB_DT_INTERFACE_ASSOCIATION descriptor. It's only checked that the size is >= 2 in usb_parse_configuration(), so find_iad() might do out-of-bounds access to intf_assoc->bInterfaceCount. And he's right, we don't check for crazy descriptors of this type very well, so resolve this problem. Yet another issue found by syzkaller... Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings

cpumask: fix spurious cpumask_of_node() on non-NUMA multi-node configs

2017-11-11T13:33:32Z

commit b339752d054fb32863418452dff350a1086885b1 upstream. When !NUMA, cpumask_of_node(@node) equals cpu_online_mask regardless of @node. The assumption seems that if !NUMA, there shouldn't be more than one node and thus reporting cpu_online_mask regardless of @node is correct. However, that assumption was broken years ago to support DISCONTIGMEM and whether a system has multiple nodes or not is separately controlled by NEED_MULTIPLE_NODES. This means that, on a system with !NUMA && NEED_MULTIPLE_NODES, cpumask_of_node() will report cpu_online_mask for all possible nodes, indicating that the CPUs are associated with multiple nodes which is an impossible configuration. This bug has been around forever but doesn't look like it has caused any noticeable symptoms. However, it triggers a WARN recently added to workqueue to verify NUMA affinity configuration. Fix it by reporting empty cpumask on non-zero nodes if !NUMA. Signed-off-by: Tejun Heo Reported-and-tested-by: Geert Uytterhoeven Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

ipv6: fix sparse warning on rt6i_node

2017-11-11T13:33:32Z

commit 4e587ea71bf924f7dac621f1351653bd41e446cb upstream. Commit c5cff8561d2d adds rcu grace period before freeing fib6_node. This generates a new sparse warning on rt->rt6i_node related code: net/ipv6/route.c:1394:30: error: incompatible types in comparison expression (different address spaces) ./include/net/ip6_fib.h:187:14: error: incompatible types in comparison expression (different address spaces) This commit adds "__rcu" tag for rt6i_node and makes sure corresponding rcu API is used for it. After this fix, sparse no longer generates the above warning. Fixes: c5cff8561d2d ("ipv6: add rcu grace period before freeing fib6_node") Signed-off-by: Wei Wang Acked-by: Eric Dumazet Acked-by: Martin KaFai Lau Signed-off-by: David S. Miller [bwh: Backported to 3.16: drop changes in rt6_cache_allowed_for_pmtu()] Signed-off-by: Ben Hutchings

dm: fix printk() rate limiting code

2017-11-11T13:33:30Z

commit 604407890ecf624c2fb41013c82b22aade59b455 upstream. Using the same rate limiting state for different kinds of messages is wrong because this can cause a high frequency message to suppress a report of a low frequency message. Hence use a unique rate limiting state per message type. Fixes: 71a16736a15e ("dm: use local printk ratelimit") Signed-off-by: Bart Van Assche Signed-off-by: Mike Snitzer Signed-off-by: Ben Hutchings

dm: convert DM printk macros to pr_ macros

2017-11-11T13:33:30Z

commit d2c3c8dcb5987b8352e82089c79a41b6e17e28d2 upstream. Using pr_ is the more common logging style. Standardize style and use new macro DM_FMT. Use no_printk in DMDEBUG macros when CONFIG_DM_DEBUG is not #defined. Signed-off-by: Joe Perches Signed-off-by: Mike Snitzer Signed-off-by: Ben Hutchings