From a623f87a72de35096a9eae7cc7764d0c9533c2e9 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 15 Jan 2016 16:58:24 -0800 Subject: printk: do cond_resched() between lines while outputting to consoles commit 8d91f8b15361dfb438ab6eb3b319e2ded43458ff upstream. @console_may_schedule tracks whether console_sem was acquired through lock or trylock. If the former, we're inside a sleepable context and console_conditional_schedule() performs cond_resched(). This allows console drivers which use console_lock for synchronization to yield while performing time-consuming operations such as scrolling. However, the actual console outputting is performed while holding irq-safe logbuf_lock, so console_unlock() clears @console_may_schedule before starting outputting lines. Also, only a few drivers call console_conditional_schedule() to begin with. This means that when a lot of lines need to be output by console_unlock(), for example on a console registration, the task doing console_unlock() may not yield for a long time on a non-preemptible kernel. If this happens with a slow console devices, for example a serial console, the outputting task may occupy the cpu for a very long time. Long enough to trigger softlockup and/or RCU stall warnings, which in turn pile more messages, sometimes enough to trigger the next cycle of warnings incapacitating the system. Fix it by making console_unlock() insert cond_resched() between lines if @console_may_schedule. Signed-off-by: Tejun Heo Reported-by: Calvin Owens Acked-by: Jan Kara Cc: Dave Jones Cc: Kyle McMartin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/console.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/console.h b/include/linux/console.h index bd194343c346..ea731af2451e 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -150,6 +150,7 @@ extern int console_trylock(void); extern void console_unlock(void); extern void console_conditional_schedule(void); extern void console_unblank(void); +extern void console_flush_on_panic(void); extern struct tty_driver *console_device(int *); extern void console_stop(struct console *); extern void console_start(struct console *); -- cgit v1.2.3 From dd0d511548ea1ad8f233e9fa4a4acfb83af9bd29 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 14 Jan 2016 16:54:46 +0000 Subject: hrtimer: Handle remaining time proper for TIME_LOW_RES commit 203cbf77de59fc8f13502dcfd11350c6d4a5c95f upstream. If CONFIG_TIME_LOW_RES is enabled we add a jiffie to the relative timeout to prevent short sleeps, but we do not account for that in interfaces which retrieve the remaining time. Helge observed that timerfd can return a remaining time larger than the relative timeout. That's not expected and breaks userland test programs. Store the information that the timer was armed relative and provide functions to adjust the remaining time. To avoid bloating the hrtimer struct make state a u8, which as a bonus results in better code on x86 at least. Reported-and-tested-by: Helge Deller Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: John Stultz Cc: linux-m68k@lists.linux-m68k.org Cc: dhowells@redhat.com Link: http://lkml.kernel.org/r/20160114164159.273328486@linutronix.de Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- include/linux/hrtimer.h | 34 +++++++++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 76dd4f0da5ca..2ead22dd74a0 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -87,7 +87,8 @@ enum hrtimer_restart { * @function: timer expiry callback function * @base: pointer to the timer base (per cpu and per clock) * @state: state information (See bit values above) - * @start_pid: timer statistics field to store the pid of the task which + * @is_rel: Set if the timer was armed relative + * @start_pid: timer statistics field to store the pid of the task which * started the timer * @start_site: timer statistics field to store the site where the timer * was started @@ -101,7 +102,8 @@ struct hrtimer { ktime_t _softexpires; enum hrtimer_restart (*function)(struct hrtimer *); struct hrtimer_clock_base *base; - unsigned long state; + u8 state; + u8 is_rel; #ifdef CONFIG_TIMER_STATS int start_pid; void *start_site; @@ -321,6 +323,27 @@ static inline void clock_was_set_delayed(void) { } #endif +static inline ktime_t +__hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now) +{ + ktime_t rem = ktime_sub(timer->node.expires, now); + + /* + * Adjust relative timers for the extra we added in + * hrtimer_start_range_ns() to prevent short timeouts. + */ + if (IS_ENABLED(CONFIG_TIME_LOW_RES) && timer->is_rel) + rem.tv64 -= hrtimer_resolution; + return rem; +} + +static inline ktime_t +hrtimer_expires_remaining_adjusted(const struct hrtimer *timer) +{ + return __hrtimer_expires_remaining_adjusted(timer, + timer->base->get_time()); +} + extern void clock_was_set(void); #ifdef CONFIG_TIMERFD extern void timerfd_clock_was_set(void); @@ -390,7 +413,12 @@ static inline void hrtimer_restart(struct hrtimer *timer) } /* Query timers: */ -extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer); +extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust); + +static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer) +{ + return __hrtimer_get_remaining(timer, false); +} extern u64 hrtimer_get_next_event(void); -- cgit v1.2.3 From c35f1234931e2cae81726440ad4df8ef1f313219 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Sat, 9 Jan 2016 21:13:44 -0800 Subject: tty: Wait interruptibly for tty lock on reopen commit 0bfd464d3fdd5bb322f9cace4cc47f1796545cf7 upstream. Allow a signal to interrupt the wait for a tty reopen; eg., if the tty has starting final close and is waiting for the device to drain. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/linux/tty.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/tty.h b/include/linux/tty.h index 5e31f1b99037..6b6e811f4575 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -654,6 +654,7 @@ extern long vt_compat_ioctl(struct tty_struct *tty, /* tty_mutex.c */ /* functions for preparation of BKL removal */ extern void __lockfunc tty_lock(struct tty_struct *tty); +extern int tty_lock_interruptible(struct tty_struct *tty); extern void __lockfunc tty_unlock(struct tty_struct *tty); extern void __lockfunc tty_lock_slave(struct tty_struct *tty); extern void __lockfunc tty_unlock_slave(struct tty_struct *tty); -- cgit v1.2.3 From 1bdf16025dfc5ed335f3d7d8bbe78461583105fc Mon Sep 17 00:00:00 2001 From: "Herton R. Krzesinski" Date: Thu, 14 Jan 2016 17:56:58 -0200 Subject: pty: make sure super_block is still valid in final /dev/tty close commit 1f55c718c290616889c04946864a13ef30f64929 upstream. Considering current pty code and multiple devpts instances, it's possible to umount a devpts file system while a program still has /dev/tty opened pointing to a previosuly closed pty pair in that instance. In the case all ptmx and pts/N files are closed, umount can be done. If the program closes /dev/tty after umount is done, devpts_kill_index will use now an invalid super_block, which was already destroyed in the umount operation after running ->kill_sb. This is another "use after free" type of issue, but now related to the allocated super_block instance. To avoid the problem (warning at ida_remove and potential crashes) for this specific case, I added two functions in devpts which grabs additional references to the super_block, which pty code now uses so it makes sure the super block structure is still valid until pty shutdown is done. I also moved the additional inode references to the same functions, which also covered similar case with inode being freed before /dev/tty final close/shutdown. Signed-off-by: Herton R. Krzesinski Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/linux/devpts_fs.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/devpts_fs.h b/include/linux/devpts_fs.h index 251a2090a554..e0ee0b3000b2 100644 --- a/include/linux/devpts_fs.h +++ b/include/linux/devpts_fs.h @@ -19,6 +19,8 @@ int devpts_new_index(struct inode *ptmx_inode); void devpts_kill_index(struct inode *ptmx_inode, int idx); +void devpts_add_ref(struct inode *ptmx_inode); +void devpts_del_ref(struct inode *ptmx_inode); /* mknod in devpts */ struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index, void *priv); @@ -32,6 +34,8 @@ void devpts_pty_kill(struct inode *inode); /* Dummy stubs in the no-pty case */ static inline int devpts_new_index(struct inode *ptmx_inode) { return -EINVAL; } static inline void devpts_kill_index(struct inode *ptmx_inode, int idx) { } +static inline void devpts_add_ref(struct inode *ptmx_inode) { } +static inline void devpts_del_ref(struct inode *ptmx_inode) { } static inline struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index, void *priv) { -- cgit v1.2.3 From 969624b7c1c8c9784651eb97431e6f2bbb7a024c Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Wed, 20 Jan 2016 15:00:04 -0800 Subject: ptrace: use fsuid, fsgid, effective creds for fs access checks commit caaee6234d05a58c5b4d05e7bf766131b810a657 upstream. By checking the effective credentials instead of the real UID / permitted capabilities, ensure that the calling process actually intended to use its credentials. To ensure that all ptrace checks use the correct caller credentials (e.g. in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS flag), use two new flags and require one of them to be set. The problem was that when a privileged task had temporarily dropped its privileges, e.g. by calling setreuid(0, user_uid), with the intent to perform following syscalls with the credentials of a user, it still passed ptrace access checks that the user would not be able to pass. While an attacker should not be able to convince the privileged task to perform a ptrace() syscall, this is a problem because the ptrace access check is reused for things in procfs. In particular, the following somewhat interesting procfs entries only rely on ptrace access checks: /proc/$pid/stat - uses the check for determining whether pointers should be visible, useful for bypassing ASLR /proc/$pid/maps - also useful for bypassing ASLR /proc/$pid/cwd - useful for gaining access to restricted directories that contain files with lax permissions, e.g. in this scenario: lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar drwx------ root root /root drwxr-xr-x root root /root/foobar -rw-r--r-- root root /root/foobar/secret Therefore, on a system where a root-owned mode 6755 binary changes its effective credentials as described and then dumps a user-specified file, this could be used by an attacker to reveal the memory layout of root's processes or reveal the contents of files he is not allowed to access (through /proc/$pid/cwd). [akpm@linux-foundation.org: fix warning] Signed-off-by: Jann Horn Acked-by: Kees Cook Cc: Casey Schaufler Cc: Oleg Nesterov Cc: Ingo Molnar Cc: James Morris Cc: "Serge E. Hallyn" Cc: Andy Shevchenko Cc: Andy Lutomirski Cc: Al Viro Cc: "Eric W. Biederman" Cc: Willy Tarreau Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/ptrace.h | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 061265f92876..504c98a278d4 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -57,7 +57,29 @@ extern void exit_ptrace(struct task_struct *tracer, struct list_head *dead); #define PTRACE_MODE_READ 0x01 #define PTRACE_MODE_ATTACH 0x02 #define PTRACE_MODE_NOAUDIT 0x04 -/* Returns true on success, false on denial. */ +#define PTRACE_MODE_FSCREDS 0x08 +#define PTRACE_MODE_REALCREDS 0x10 + +/* shorthands for READ/ATTACH and FSCREDS/REALCREDS combinations */ +#define PTRACE_MODE_READ_FSCREDS (PTRACE_MODE_READ | PTRACE_MODE_FSCREDS) +#define PTRACE_MODE_READ_REALCREDS (PTRACE_MODE_READ | PTRACE_MODE_REALCREDS) +#define PTRACE_MODE_ATTACH_FSCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_FSCREDS) +#define PTRACE_MODE_ATTACH_REALCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_REALCREDS) + +/** + * ptrace_may_access - check whether the caller is permitted to access + * a target task. + * @task: target task + * @mode: selects type of access and caller credentials + * + * Returns true on success, false on denial. + * + * One of the flags PTRACE_MODE_FSCREDS and PTRACE_MODE_REALCREDS must + * be set in @mode to specify whether the access was requested through + * a filesystem syscall (should use effective capabilities and fsuid + * of the caller) or through an explicit syscall such as + * process_vm_writev or ptrace (and should use the real credentials). + */ extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); static inline int ptrace_reparented(struct task_struct *child) -- cgit v1.2.3 From 2fa82bbbc73a7d8716e3f7aba6b2b5c84147a2fc Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 12 Feb 2016 22:26:42 +0100 Subject: tracing: Fix freak link error caused by branch tracer commit b33c8ff4431a343561e2319f17c14286f2aa52e2 upstream. In my randconfig tests, I came across a bug that involves several components: * gcc-4.9 through at least 5.3 * CONFIG_GCOV_PROFILE_ALL enabling -fprofile-arcs for all files * CONFIG_PROFILE_ALL_BRANCHES overriding every if() * The optimized implementation of do_div() that tries to replace a library call with an division by multiplication * code in drivers/media/dvb-frontends/zl10353.c doing u32 adc_clock = 450560; /* 45.056 MHz */ if (state->config.adc_clock) adc_clock = state->config.adc_clock; do_div(value, adc_clock); In this case, gcc fails to determine whether the divisor in do_div() is __builtin_constant_p(). In particular, it concludes that __builtin_constant_p(adc_clock) is false, while __builtin_constant_p(!!adc_clock) is true. That in turn throws off the logic in do_div() that also uses __builtin_constant_p(), and instead of picking either the constant- optimized division, and the code in ilog2() that uses __builtin_constant_p() to figure out whether it knows the answer at compile time. The result is a link error from failing to find multiple symbols that should never have been called based on the __builtin_constant_p(): dvb-frontends/zl10353.c:138: undefined reference to `____ilog2_NaN' dvb-frontends/zl10353.c:138: undefined reference to `__aeabi_uldivmod' ERROR: "____ilog2_NaN" [drivers/media/dvb-frontends/zl10353.ko] undefined! ERROR: "__aeabi_uldivmod" [drivers/media/dvb-frontends/zl10353.ko] undefined! This patch avoids the problem by changing __trace_if() to check whether the condition is known at compile-time to be nonzero, rather than checking whether it is actually a constant. I see this one link error in roughly one out of 1600 randconfig builds on ARM, and the patch fixes all known instances. Link: http://lkml.kernel.org/r/1455312410-1058841-1-git-send-email-arnd@arndb.de Acked-by: Nicolas Pitre Fixes: ab3c9c686e22 ("branch tracer, intel-iommu: fix build with CONFIG_BRANCH_TRACER=y") Signed-off-by: Arnd Bergmann Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- include/linux/compiler.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 4dac1036594f..6fc9a6dd5ed2 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -144,7 +144,7 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); */ #define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) ) #define __trace_if(cond) \ - if (__builtin_constant_p((cond)) ? !!(cond) : \ + if (__builtin_constant_p(!!(cond)) ? !!(cond) : \ ({ \ int ______r; \ static struct ftrace_branch_data \ -- cgit v1.2.3 From 152fb02241b60ffb8d406b87c68d1908478a205f Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Mon, 15 Feb 2016 12:36:14 -0500 Subject: tracepoints: Do not trace when cpu is offline commit f37755490fe9bf76f6ba1d8c6591745d3574a6a6 upstream. The tracepoint infrastructure uses RCU sched protection to enable and disable tracepoints safely. There are some instances where tracepoints are used in infrastructure code (like kfree()) that get called after a CPU is going offline, and perhaps when it is coming back online but hasn't been registered yet. This can probuce the following warning: [ INFO: suspicious RCU usage. ] 4.4.0-00006-g0fe53e8-dirty #34 Tainted: G S ------------------------------- include/trace/events/kmem.h:141 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 no locks held by swapper/8/0. stack backtrace: CPU: 8 PID: 0 Comm: swapper/8 Tainted: G S 4.4.0-00006-g0fe53e8-dirty #34 Call Trace: [c0000005b76c78d0] [c0000000008b9540] .dump_stack+0x98/0xd4 (unreliable) [c0000005b76c7950] [c00000000010c898] .lockdep_rcu_suspicious+0x108/0x170 [c0000005b76c79e0] [c00000000029adc0] .kfree+0x390/0x440 [c0000005b76c7a80] [c000000000055f74] .destroy_context+0x44/0x100 [c0000005b76c7b00] [c0000000000934a0] .__mmdrop+0x60/0x150 [c0000005b76c7b90] [c0000000000e3ff0] .idle_task_exit+0x130/0x140 [c0000005b76c7c20] [c000000000075804] .pseries_mach_cpu_die+0x64/0x310 [c0000005b76c7cd0] [c000000000043e7c] .cpu_die+0x3c/0x60 [c0000005b76c7d40] [c0000000000188d8] .arch_cpu_idle_dead+0x28/0x40 [c0000005b76c7db0] [c000000000101e6c] .cpu_startup_entry+0x50c/0x560 [c0000005b76c7ed0] [c000000000043bd8] .start_secondary+0x328/0x360 [c0000005b76c7f90] [c000000000008a6c] start_secondary_prolog+0x10/0x14 This warning is not a false positive either. RCU is not protecting code that is being executed while the CPU is offline. Instead of playing "whack-a-mole(TM)" and adding conditional statements to the tracepoints we find that are used in this instance, simply add a cpu_online() test to the tracepoint code where the tracepoint will be ignored if the CPU is offline. Use of raw_smp_processor_id() is fine, as there should never be a case where the tracepoint code goes from running on a CPU that is online and suddenly gets migrated to a CPU that is offline. Link: http://lkml.kernel.org/r/1455387773-4245-1-git-send-email-kda@linux-powerpc.org Reported-by: Denis Kirjanov Fixes: 97e1c18e8d17b ("tracing: Kernel Tracepoints") Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- include/linux/tracepoint.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 696a339c592c..03c7efb60c91 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -14,8 +14,10 @@ * See the file COPYING for more details. */ +#include #include #include +#include #include #include @@ -146,6 +148,9 @@ extern void syscall_unregfunc(void); void *it_func; \ void *__data; \ \ + if (!cpu_online(raw_smp_processor_id())) \ + return; \ + \ if (!(cond)) \ return; \ prercu; \ -- cgit v1.2.3 From 413aab16bc7b9b58fb1a52010eb3af3d227d7007 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Fri, 5 Feb 2016 15:36:50 -0800 Subject: mm: replace vma_lock_anon_vma with anon_vma_lock_read/write commit 12352d3cae2cebe18805a91fab34b534d7444231 upstream. Sequence vma_lock_anon_vma() - vma_unlock_anon_vma() isn't safe if anon_vma appeared between lock and unlock. We have to check anon_vma first or call anon_vma_prepare() to be sure that it's here. There are only few users of these legacy helpers. Let's get rid of them. This patch fixes anon_vma lock imbalance in validate_mm(). Write lock isn't required here, read lock is enough. And reorders expand_downwards/expand_upwards: security_mmap_addr() and wrapping-around check don't have to be under anon vma lock. Link: https://lkml.kernel.org/r/CACT4Y+Y908EjM2z=706dv4rV6dWtxTLK9nFg9_7DhRMLppBo2g@mail.gmail.com Signed-off-by: Konstantin Khlebnikov Reported-by: Dmitry Vyukov Acked-by: Kirill A. Shutemov Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/rmap.h | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'include/linux') diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 29446aeef36e..ddda2ac3446e 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -108,20 +108,6 @@ static inline void put_anon_vma(struct anon_vma *anon_vma) __put_anon_vma(anon_vma); } -static inline void vma_lock_anon_vma(struct vm_area_struct *vma) -{ - struct anon_vma *anon_vma = vma->anon_vma; - if (anon_vma) - down_write(&anon_vma->root->rwsem); -} - -static inline void vma_unlock_anon_vma(struct vm_area_struct *vma) -{ - struct anon_vma *anon_vma = vma->anon_vma; - if (anon_vma) - up_write(&anon_vma->root->rwsem); -} - static inline void anon_vma_lock_write(struct anon_vma *anon_vma) { down_write(&anon_vma->root->rwsem); -- cgit v1.2.3 From 2231e5748746cd57df389521397e1c7f91882077 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Mon, 15 Feb 2016 12:42:38 +0000 Subject: iommu/vt-d: Clear PPR bit to ensure we get more page request interrupts commit 46924008273ed03bd11dbb32136e3da4cfe056e1 upstream. According to the VT-d specification we need to clear the PPR bit in the Page Request Status register when handling page requests, or the hardware won't generate any more interrupts. This wasn't actually necessary on SKL/KBL (which may well be the subject of a hardware erratum, although it's harmless enough). But other implementations do appear to get it right, and we only ever get one interrupt unless we clear the PPR bit. Reported-by: CQ Tang Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman --- include/linux/intel-iommu.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index 821273ca4873..2d9b650047a5 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -235,6 +235,9 @@ static inline void dmar_writeq(void __iomem *addr, u64 val) /* low 64 bit */ #define dma_frcd_page_addr(d) (d & (((u64)-1) << PAGE_SHIFT)) +/* PRS_REG */ +#define DMA_PRS_PPR ((u32)1) + #define IOMMU_WAIT_OP(iommu, offset, op, cond, sts) \ do { \ cycles_t start_time = get_cycles(); \ -- cgit v1.2.3 From f4595e0081495b677a98c780e9ec1ab68ce89488 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Tue, 2 Feb 2016 16:57:52 -0800 Subject: radix-tree: fix race in gang lookup commit 46437f9a554fbe3e110580ca08ab703b59f2f95a upstream. If the indirect_ptr bit is set on a slot, that indicates we need to redo the lookup. Introduce a new function radix_tree_iter_retry() which forces the loop to retry the lookup by setting 'slot' to NULL and turning the iterator back to point at the problematic entry. This is a pretty rare problem to hit at the moment; the lookup has to race with a grow of the radix tree from a height of 0. The consequences of hitting this race are that gang lookup could return a pointer to a radix_tree_node instead of a pointer to whatever the user had inserted in the tree. Fixes: cebbd29e1c2f ("radix-tree: rewrite gang lookup using iterator") Signed-off-by: Matthew Wilcox Cc: Hugh Dickins Cc: Ohad Ben-Cohen Cc: Konstantin Khlebnikov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/radix-tree.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/linux') diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index 33170dbd9db4..1a2b2276ffb3 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -369,6 +369,22 @@ radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start) void **radix_tree_next_chunk(struct radix_tree_root *root, struct radix_tree_iter *iter, unsigned flags); +/** + * radix_tree_iter_retry - retry this chunk of the iteration + * @iter: iterator state + * + * If we iterate over a tree protected only by the RCU lock, a race + * against deletion or creation may result in seeing a slot for which + * radix_tree_deref_retry() returns true. If so, call this function + * and continue the iteration. + */ +static inline __must_check +void **radix_tree_iter_retry(struct radix_tree_iter *iter) +{ + iter->next_index = iter->index; + return NULL; +} + /** * radix_tree_chunk_size - get current chunk size * -- cgit v1.2.3 From 55e0d9869f1d3a6bbd5d1e864c0e866fe1247f97 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Fri, 5 Feb 2016 15:37:01 -0800 Subject: radix-tree: fix oops after radix_tree_iter_retry commit 732042821cfa106b3c20b9780e4c60fee9d68900 upstream. Helper radix_tree_iter_retry() resets next_index to the current index. In following radix_tree_next_slot current chunk size becomes zero. This isn't checked and it tries to dereference null pointer in slot. Tagged iterator is fine because retry happens only at slot 0 where tag bitmask in iter->tags is filled with single bit. Fixes: 46437f9a554f ("radix-tree: fix race in gang lookup") Signed-off-by: Konstantin Khlebnikov Cc: Matthew Wilcox Cc: Hugh Dickins Cc: Ohad Ben-Cohen Cc: Jeremiah Mahler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/radix-tree.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index 1a2b2276ffb3..5d5174b59802 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -391,7 +391,7 @@ void **radix_tree_iter_retry(struct radix_tree_iter *iter) * @iter: pointer to radix tree iterator * Returns: current chunk size */ -static __always_inline unsigned +static __always_inline long radix_tree_chunk_size(struct radix_tree_iter *iter) { return iter->next_index - iter->index; @@ -425,9 +425,9 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags) return slot + offset + 1; } } else { - unsigned size = radix_tree_chunk_size(iter) - 1; + long size = radix_tree_chunk_size(iter); - while (size--) { + while (--size > 0) { slot++; iter->index++; if (likely(*slot)) -- cgit v1.2.3 From 1bec5f40664ccef7efa54102c5e29ac52c7db634 Mon Sep 17 00:00:00 2001 From: Hans Westgaard Ry Date: Wed, 3 Feb 2016 09:26:57 +0100 Subject: net:Add sysctl_max_skb_frags MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 5f74f82ea34c0da80ea0b49192bb5ea06e063593 ] Devices may have limits on the number of fragments in an skb they support. Current codebase uses a constant as maximum for number of fragments one skb can hold and use. When enabling scatter/gather and running traffic with many small messages the codebase uses the maximum number of fragments and may thereby violate the max for certain devices. The patch introduces a global variable as max number of fragments. Signed-off-by: Hans Westgaard Ry Reviewed-by: Håkon Bugge Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/linux/skbuff.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 9147f9f34cbe..75f136a22a5e 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -219,6 +219,7 @@ struct sk_buff; #else #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1) #endif +extern int sysctl_max_skb_frags; typedef struct skb_frag_struct skb_frag_t; -- cgit v1.2.3 From e7f2a86c9106eb9417f4bc7b97f1dfa63140277a Mon Sep 17 00:00:00 2001 From: Peter Jones Date: Mon, 8 Feb 2016 14:48:11 -0500 Subject: lib/ucs2_string: Add ucs2 -> utf8 helper functions commit 73500267c930baadadb0d02284909731baf151f7 upstream. This adds ucs2_utf8size(), which tells us how big our ucs2 string is in bytes, and ucs2_as_utf8, which translates from ucs2 to utf8.. Signed-off-by: Peter Jones Tested-by: Lee, Chun-Yi Acked-by: Matthew Garrett Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman --- include/linux/ucs2_string.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ucs2_string.h b/include/linux/ucs2_string.h index cbb20afdbc01..bb679b48f408 100644 --- a/include/linux/ucs2_string.h +++ b/include/linux/ucs2_string.h @@ -11,4 +11,8 @@ unsigned long ucs2_strlen(const ucs2_char_t *s); unsigned long ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength); int ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len); +unsigned long ucs2_utf8size(const ucs2_char_t *src); +unsigned long ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, + unsigned long maxlength); + #endif /* _LINUX_UCS2_STRING_H_ */ -- cgit v1.2.3 From 5134c82b53ddd6f95317f159f62827d9cb7843e1 Mon Sep 17 00:00:00 2001 From: Peter Jones Date: Mon, 8 Feb 2016 14:48:14 -0500 Subject: efi: Make our variable validation list include the guid commit 8282f5d9c17fe15a9e658c06e3f343efae1a2a2f upstream. All the variables in this list so far are defined to be in the global namespace in the UEFI spec, so this just further ensures we're validating the variables we think we are. Including the guid for entries will become more important in future patches when we decide whether or not to allow deletion of variables based on presence in this list. Signed-off-by: Peter Jones Tested-by: Lee, Chun-Yi Acked-by: Matthew Garrett Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman --- include/linux/efi.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/efi.h b/include/linux/efi.h index 569b5a866bb1..16ca611aabc8 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1199,7 +1199,8 @@ int efivar_entry_iter(int (*func)(struct efivar_entry *, void *), struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid, struct list_head *head, bool remove); -bool efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len); +bool efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data, + unsigned long data_size); extern struct work_struct efivar_work; void efivar_run_worker(void); -- cgit v1.2.3 From 05913989c8892f6dc1726d03b0d8e680aec3c1a5 Mon Sep 17 00:00:00 2001 From: Peter Jones Date: Mon, 8 Feb 2016 14:48:15 -0500 Subject: efi: Make efivarfs entries immutable by default commit ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879 upstream. "rm -rf" is bricking some peoples' laptops because of variables being used to store non-reinitializable firmware driver data that's required to POST the hardware. These are 100% bugs, and they need to be fixed, but in the mean time it shouldn't be easy to *accidentally* brick machines. We have to have delete working, and picking which variables do and don't work for deletion is quite intractable, so instead make everything immutable by default (except for a whitelist), and make tools that aren't quite so broad-spectrum unset the immutable flag. Signed-off-by: Peter Jones Tested-by: Lee, Chun-Yi Acked-by: Matthew Garrett Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman --- include/linux/efi.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/efi.h b/include/linux/efi.h index 16ca611aabc8..47be3ad7d3e5 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1201,6 +1201,8 @@ struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid, bool efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data, unsigned long data_size); +bool efivar_variable_is_removable(efi_guid_t vendor, const char *name, + size_t len); extern struct work_struct efivar_work; void efivar_run_worker(void); -- cgit v1.2.3 From 2a383bcc68ad1437315eb4298a84cdde070a69bc Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Mon, 14 Dec 2015 16:01:54 -0800 Subject: Drivers: hv: vmbus: Fix a Host signaling bug commit 8599846d73997cdbccf63f23394d871cfad1e5e6 upstream. Currently we have two policies for deciding when to signal the host: One based on the ring buffer state and the other based on what the VMBUS client driver wants to do. Consider the case when the client wants to explicitly control when to signal the host. In this case, if the client were to defer signaling, we will not be able to signal the host subsequently when the client does want to signal since the ring buffer state will prevent the signaling. Implement logic to have only one signaling policy in force for a given channel. Signed-off-by: K. Y. Srinivasan Reviewed-by: Haiyang Zhang Tested-by: Haiyang Zhang Signed-off-by: Greg Kroah-Hartman --- include/linux/hyperv.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/linux') diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 8fdc17b84739..ae6a711dcd1d 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -630,6 +630,11 @@ struct hv_input_signal_event_buffer { struct hv_input_signal_event event; }; +enum hv_signal_policy { + HV_SIGNAL_POLICY_DEFAULT = 0, + HV_SIGNAL_POLICY_EXPLICIT, +}; + struct vmbus_channel { /* Unique channel id */ int id; @@ -757,8 +762,21 @@ struct vmbus_channel { * link up channels based on their CPU affinity. */ struct list_head percpu_list; + /* + * Host signaling policy: The default policy will be + * based on the ring buffer state. We will also support + * a policy where the client driver can have explicit + * signaling control. + */ + enum hv_signal_policy signal_policy; }; +static inline void set_channel_signal_state(struct vmbus_channel *c, + enum hv_signal_policy policy) +{ + c->signal_policy = policy; +} + static inline void set_channel_read_state(struct vmbus_channel *c, bool state) { c->batched_reading = state; -- cgit v1.2.3 From bcb1875a069043c70af27dc9f0f5e075a09d76b1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 22 Jan 2016 18:08:52 -0500 Subject: make sure that freeing shmem fast symlinks is RCU-delayed commit 3ed47db34f480df7caf44436e3e63e555351ae9a upstream. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- include/linux/shmem_fs.h | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index 50777b5b1e4c..92d112aeec68 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -15,10 +15,7 @@ struct shmem_inode_info { unsigned int seals; /* shmem seals */ unsigned long flags; unsigned long alloced; /* data pages alloced to file */ - union { - unsigned long swapped; /* subtotal assigned to swap */ - char *symlink; /* unswappable short symlink */ - }; + unsigned long swapped; /* subtotal assigned to swap */ struct shared_policy policy; /* NUMA memory alloc policy */ struct list_head swaplist; /* chain of maybes on swap */ struct simple_xattrs xattrs; /* list of xattrs */ -- cgit v1.2.3 From 774ac8b7eff69e0786970157de2157e68b22f456 Mon Sep 17 00:00:00 2001 From: Zhang Rui Date: Fri, 30 Oct 2015 16:31:47 +0800 Subject: Thermal: initialize thermal zone device correctly commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 upstream. After thermal zone device registered, as we have not read any temperature before, thus tz->temperature should not be 0, which actually means 0C, and thermal trend is not available. In this case, we need specially handling for the first thermal_zone_device_update(). Both thermal core framework and step_wise governor is enhanced to handle this. And since the step_wise governor is the only one that uses trends, so it's the only thermal governor that needs to be updated. Tested-by: Manuel Krause Tested-by: szegad Tested-by: prash Tested-by: amish Tested-by: Matthias Reviewed-by: Javi Merino Signed-off-by: Zhang Rui Signed-off-by: Chen Yu Signed-off-by: Greg Kroah-Hartman --- include/linux/thermal.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 613c29bd6baf..103fcbe6bdaf 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -43,6 +43,9 @@ /* Default weight of a bound cooling device */ #define THERMAL_WEIGHT_DEFAULT 0 +/* use value, which < 0K, to indicate an invalid/uninitialized temperature */ +#define THERMAL_TEMP_INVALID -274000 + /* Unit conversion macros */ #define DECI_KELVIN_TO_CELSIUS(t) ({ \ long _t = (t); \ -- cgit v1.2.3 From 27f356149d599d1ee55318641f9d3ed69e66174a Mon Sep 17 00:00:00 2001 From: Chen Yu Date: Fri, 30 Oct 2015 16:32:10 +0800 Subject: Thermal: do thermal zone update after a cooling device registered commit 4511f7166a2deb5f7a578cf87fd2fe1ae83527e3 upstream. When a new cooling device is registered, we need to update the thermal zone to set the new registered cooling device to a proper state. This fixes a problem that the system is cool, while the fan devices are left running on full speed after boot, if fan device is registered after thermal zone device. Here is the history of why current patch looks like this: https://patchwork.kernel.org/patch/7273041/ Reference:https://bugzilla.kernel.org/show_bug.cgi?id=92431 Tested-by: Manuel Krause Tested-by: szegad Tested-by: prash Tested-by: amish Reviewed-by: Javi Merino Signed-off-by: Zhang Rui Signed-off-by: Chen Yu Signed-off-by: Greg Kroah-Hartman --- include/linux/thermal.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 103fcbe6bdaf..e13a1ace50e9 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -170,6 +170,7 @@ struct thermal_attr { * @forced_passive: If > 0, temperature at which to switch on all ACPI * processor cooling devices. Currently only used by the * step-wise governor. + * @need_update: if equals 1, thermal_zone_device_update needs to be invoked. * @ops: operations this &thermal_zone_device supports * @tzp: thermal zone parameters * @governor: pointer to the governor for this thermal zone @@ -197,6 +198,7 @@ struct thermal_zone_device { int emul_temperature; int passive; unsigned int forced_passive; + atomic_t need_update; struct thermal_zone_device_ops *ops; struct thermal_zone_params *tzp; struct thermal_governor *governor; -- cgit v1.2.3 From ee834473805f5fd77a3d2625a40552159641029e Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Mon, 28 Dec 2015 13:18:34 +0300 Subject: libceph: fix ceph_msg_revoke() commit 67645d7619738e51c668ca69f097cb90b5470422 upstream. There are a number of problems with revoking a "was sending" message: (1) We never make any attempt to revoke data - only kvecs contibute to con->out_skip. However, once the header (envelope) is written to the socket, our peer learns data_len and sets itself to expect at least data_len bytes to follow front or front+middle. If ceph_msg_revoke() is called while the messenger is sending message's data portion, anything we send after that call is counted by the OSD towards the now revoked message's data portion. The effects vary, the most common one is the eventual hang - higher layers get stuck waiting for the reply to the message that was sent out after ceph_msg_revoke() returned and treated by the OSD as a bunch of data bytes. This is what Matt ran into. (2) Flat out zeroing con->out_kvec_bytes worth of bytes to handle kvecs is wrong. If ceph_msg_revoke() is called before the tag is sent out or while the messenger is sending the header, we will get a connection reset, either due to a bad tag (0 is not a valid tag) or a bad header CRC, which kind of defeats the purpose of revoke. Currently the kernel client refuses to work with header CRCs disabled, but that will likely change in the future, making this even worse. (3) con->out_skip is not reset on connection reset, leading to one or more spurious connection resets if we happen to get a real one between con->out_skip is set in ceph_msg_revoke() and before it's cleared in write_partial_skip(). Fixing (1) and (3) is trivial. The idea behind fixing (2) is to never zero the tag or the header, i.e. send out tag+header regardless of when ceph_msg_revoke() is called. That way the header is always correct, no unnecessary resets are induced and revoke stands ready for disabled CRCs. Since ceph_msg_revoke() rips out con->out_msg, introduce a new "message out temp" and copy the header into it before sending. Reported-by: Matt Conner Signed-off-by: Ilya Dryomov Tested-by: Matt Conner Reviewed-by: Sage Weil Signed-off-by: Greg Kroah-Hartman --- include/linux/ceph/messenger.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h index 71b1d6cdcb5d..8dbd7879fdc6 100644 --- a/include/linux/ceph/messenger.h +++ b/include/linux/ceph/messenger.h @@ -220,6 +220,7 @@ struct ceph_connection { struct ceph_entity_addr actual_peer_addr; /* message out temps */ + struct ceph_msg_header out_hdr; struct ceph_msg *out_msg; /* sending message (== tail of out_sent) */ bool out_msg_done; @@ -229,7 +230,6 @@ struct ceph_connection { int out_kvec_left; /* kvec's left in out_kvec */ int out_skip; /* skip this many bytes */ int out_kvec_bytes; /* total bytes left */ - bool out_kvec_is_msg; /* kvec refers to out_msg */ int out_more; /* there is more data after the kvecs */ __le64 out_temp_ack; /* for writing an ack */ struct ceph_timespec out_temp_keepalive2; /* for writing keepalive2 -- cgit v1.2.3 From fff4dc84e72419196623f118312f571a2e057196 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 19 Jan 2016 12:18:41 -0500 Subject: cpuset: make mm migration asynchronous commit e93ad19d05648397ef3bcb838d26aec06c245dc0 upstream. If "cpuset.memory_migrate" is set, when a process is moved from one cpuset to another with a different memory node mask, pages in used by the process are migrated to the new set of nodes. This was performed synchronously in the ->attach() callback, which is synchronized against process management. Recently, the synchronization was changed from per-process rwsem to global percpu rwsem for simplicity and optimization. Combined with the synchronous mm migration, this led to deadlocks because mm migration could schedule a work item which may in turn try to create a new worker blocking on the process management lock held from cgroup process migration path. This heavy an operation shouldn't be performed synchronously from that deep inside cgroup migration in the first place. This patch punts the actual migration to an ordered workqueue and updates cgroup process migration and cpuset config update paths to flush the workqueue after all locks are released. This way, the operations still seem synchronous to userland without entangling mm migration with process management synchronization. CPU hotplug can also invoke mm migration but there's no reason for it to wait for mm migrations and thus doesn't synchronize against their completions. Signed-off-by: Tejun Heo Reported-and-tested-by: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman --- include/linux/cpuset.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index 85a868ccb493..fea160ee5803 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -137,6 +137,8 @@ static inline void set_mems_allowed(nodemask_t nodemask) task_unlock(current); } +extern void cpuset_post_attach_flush(void); + #else /* !CONFIG_CPUSETS */ static inline bool cpusets_enabled(void) { return false; } @@ -243,6 +245,10 @@ static inline bool read_mems_allowed_retry(unsigned int seq) return false; } +static inline void cpuset_post_attach_flush(void) +{ +} + #endif /* !CONFIG_CPUSETS */ #endif /* _LINUX_CPUSET_H */ -- cgit v1.2.3 From 4cbd196324c05809338c7f118b6f374d3c2db7a0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 21 Jan 2016 15:31:11 -0500 Subject: cgroup: make sure a parent css isn't offlined before its children commit aa226ff4a1ce79f229c6b7a4c0a14e17fececd01 upstream. There are three subsystem callbacks in css shutdown path - css_offline(), css_released() and css_free(). Except for css_released(), cgroup core didn't guarantee the order of invocation. css_offline() or css_free() could be called on a parent css before its children. This behavior is unexpected and led to bugs in cpu and memory controller. This patch updates offline path so that a parent css is never offlined before its children. Each css keeps online_cnt which reaches zero iff itself and all its children are offline and offline_css() is invoked only after online_cnt reaches zero. This fixes the memory controller bug and allows the fix for cpu controller. Signed-off-by: Tejun Heo Reported-and-tested-by: Christian Borntraeger Reported-by: Brian Christiansen Link: http://lkml.kernel.org/g/5698A023.9070703@de.ibm.com Link: http://lkml.kernel.org/g/CAKB58ikDkzc8REt31WBkD99+hxNzjK4+FBmhkgS+NVrC9vjMSg@mail.gmail.com Cc: Heiko Carstens Cc: Peter Zijlstra Signed-off-by: Greg Kroah-Hartman --- include/linux/cgroup-defs.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index 06b77f9dd3f2..8e30faeab183 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -133,6 +133,12 @@ struct cgroup_subsys_state { */ u64 serial_nr; + /* + * Incremented by online self and children. Used to guarantee that + * parents are not offlined before their children. + */ + atomic_t online_cnt; + /* percpu_ref killing and RCU release */ struct rcu_head rcu_head; struct work_struct destroy_work; -- cgit v1.2.3 From fd921e575636438b8996df1e3d885dea9be5b25c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 8 Feb 2016 21:11:50 +0100 Subject: nfs: fix nfs_size_to_loff_t commit 50ab8ec74a153eb30db26529088bc57dd700b24c upstream. See http: //www.infradead.org/rpr.html X-Evolution-Source: 1451162204.2173.11@leira.trondhjem.org Content-Transfer-Encoding: 8bit Mime-Version: 1.0 We support OFFSET_MAX just fine, so don't round down below it. Also switch to using min_t to make the helper more readable. Signed-off-by: Christoph Hellwig Fixes: 433c92379d9c ("NFS: Clean up nfs_size_to_loff_t()") Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- include/linux/nfs_fs.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index c0e961474a52..5455b660bd88 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -544,9 +544,7 @@ extern int nfs_readpage_async(struct nfs_open_context *, struct inode *, static inline loff_t nfs_size_to_loff_t(__u64 size) { - if (size > (__u64) OFFSET_MAX - 1) - return OFFSET_MAX - 1; - return (loff_t) size; + return min_t(u64, size, OFFSET_MAX); } static inline ino_t -- cgit v1.2.3 From 53729dbbd20a517c4ecb994cfe994bc832b30523 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 29 Feb 2016 12:12:46 -0500 Subject: use ->d_seq to get coherency between ->d_inode and ->d_flags commit a528aca7f359f4b0b1d72ae406097e491a5ba9ea upstream. Games with ordering and barriers are way too brittle. Just bump ->d_seq before and after updating ->d_inode and ->d_flags type bits, so that verifying ->d_seq would guarantee they are coherent. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- include/linux/dcache.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dcache.h b/include/linux/dcache.h index d67ae119cf4e..8a2e009c8a5a 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -409,9 +409,7 @@ static inline bool d_mountpoint(const struct dentry *dentry) */ static inline unsigned __d_entry_type(const struct dentry *dentry) { - unsigned type = READ_ONCE(dentry->d_flags); - smp_rmb(); - return type & DCACHE_ENTRY_TYPE; + return dentry->d_flags & DCACHE_ENTRY_TYPE; } static inline bool d_is_miss(const struct dentry *dentry) -- cgit v1.2.3 From b693f2ad0f7bf4b7080dc05da8d436eba8c47193 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 11 Feb 2016 14:16:27 +0100 Subject: libata: fix HDIO_GET_32BIT ioctl commit 287e6611ab1eac76c2c5ebf6e345e04c80ca9c61 upstream. As reported by Soohoon Lee, the HDIO_GET_32BIT ioctl does not work correctly in compat mode with libata. I have investigated the issue further and found multiple problems that all appeared with the same commit that originally introduced HDIO_GET_32BIT handling in libata back in linux-2.6.8 and presumably also linux-2.4, as the code uses "copy_to_user(arg, &val, 1)" to copy a 'long' variable containing either 0 or 1 to user space. The problems with this are: * On big-endian machines, this will always write a zero because it stores the wrong byte into user space. * In compat mode, the upper three bytes of the variable are updated by the compat_hdio_ioctl() function, but they now contain uninitialized stack data. * The hdparm tool calling this ioctl uses a 'static long' variable to store the result. This means at least the upper bytes are initialized to zero, but calling another ioctl like HDIO_GET_MULTCOUNT would fill them with data that remains stale when the low byte is overwritten. Fortunately libata doesn't implement any of the affected ioctl commands, so this would only happen when we query both an IDE and an ATA device in the same command such as "hdparm -N -c /dev/hda /dev/sda" * The libata code for unknown reasons started using ATA_IOC_GET_IO32 and ATA_IOC_SET_IO32 as aliases for HDIO_GET_32BIT and HDIO_SET_32BIT, while the ioctl commands that were added later use the normal HDIO_* names. This is harmless but rather confusing. This addresses all four issues by changing the code to use put_user() on an 'unsigned long' variable in HDIO_GET_32BIT, like the IDE subsystem does, and by clarifying the names of the ioctl commands. Signed-off-by: Arnd Bergmann Reported-by: Soohoon Lee Tested-by: Soohoon Lee Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- include/linux/ata.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ata.h b/include/linux/ata.h index d2992bfa1706..c1a2f345cbe6 100644 --- a/include/linux/ata.h +++ b/include/linux/ata.h @@ -487,8 +487,8 @@ enum ata_tf_protocols { }; enum ata_ioctls { - ATA_IOC_GET_IO32 = 0x309, - ATA_IOC_SET_IO32 = 0x324, + ATA_IOC_GET_IO32 = 0x309, /* HDIO_GET_32BIT */ + ATA_IOC_SET_IO32 = 0x324, /* HDIO_SET_32BIT */ }; /* core structures */ -- cgit v1.2.3 From cea2cbff57c5b65375adb6fe65612c10a7301327 Mon Sep 17 00:00:00 2001 From: Harvey Hunt Date: Wed, 24 Feb 2016 15:16:43 +0000 Subject: libata: Align ata_device's id on a cacheline commit 4ee34ea3a12396f35b26d90a094c75db95080baa upstream. The id buffer in ata_device is a DMA target, but it isn't explicitly cacheline aligned. Due to this, adjacent fields can be overwritten with stale data from memory on non coherent architectures. As a result, the kernel is sometimes unable to communicate with an ATA device. Fix this by ensuring that the id buffer is cacheline aligned. This issue is similar to that fixed by Commit 84bda12af31f ("libata: align ap->sector_buf"). Signed-off-by: Harvey Hunt Cc: linux-kernel@vger.kernel.org Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- include/linux/libata.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/libata.h b/include/linux/libata.h index 600c1e0626a5..b20a2752f934 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -718,7 +718,7 @@ struct ata_device { union { u16 id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */ u32 gscr[SATA_PMP_GSCR_DWORDS]; /* PMP GSCR block */ - }; + } ____cacheline_aligned; /* DEVSLP Timing Variables from Identify Device Data Log */ u8 devslp_timing[ATA_LOG_DEVSLP_SIZE]; -- cgit v1.2.3 From 7adb5cc0f39be29c16fae035d9e30e332095bbbc Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 26 Feb 2016 23:40:50 +0800 Subject: block: bio: introduce helpers to get the 1st and last bvec commit 7bcd79ac50d9d83350a835bdb91c04ac9e098412 upstream. The bio passed to bio_will_gap() may be fast cloned from upper layer(dm, md, bcache, fs, ...), or from bio splitting in block core. Unfortunately bio_will_gap() just figures out the last bvec via 'bi_io_vec[prev->bi_vcnt - 1]' directly, and this way is obviously wrong. This patch introduces two helpers for getting the first and last bvec of one bio for fixing the issue. Reported-by: Sagi Grimberg Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- include/linux/bio.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bio.h b/include/linux/bio.h index b9b6e046b52e..79cfaeef1b0d 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -310,6 +310,43 @@ static inline void bio_clear_flag(struct bio *bio, unsigned int bit) bio->bi_flags &= ~(1U << bit); } +static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv) +{ + *bv = bio_iovec(bio); +} + +static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv) +{ + struct bvec_iter iter = bio->bi_iter; + int idx; + + if (!bio_flagged(bio, BIO_CLONED)) { + *bv = bio->bi_io_vec[bio->bi_vcnt - 1]; + return; + } + + if (unlikely(!bio_multiple_segments(bio))) { + *bv = bio_iovec(bio); + return; + } + + bio_advance_iter(bio, &iter, iter.bi_size); + + if (!iter.bi_bvec_done) + idx = iter.bi_idx - 1; + else /* in the middle of bvec */ + idx = iter.bi_idx; + + *bv = bio->bi_io_vec[idx]; + + /* + * iter.bi_bvec_done records actual length of the last bvec + * if this bio ends in the middle of one io vector + */ + if (iter.bi_bvec_done) + bv->bv_len = iter.bi_bvec_done; +} + enum bip_flags { BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */ BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */ -- cgit v1.2.3 From c5cbbec54fe71c4de2d34f8c0ec8fbfdd7f17339 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 29 Feb 2016 18:28:53 -0500 Subject: writeback: flush inode cgroup wb switches instead of pinning super_block commit a1a0e23e49037c23ea84bc8cc146a03584d13577 upstream. If cgroup writeback is in use, inodes can be scheduled for asynchronous wb switching. Before 5ff8eaac1636 ("writeback: keep superblock pinned during cgroup writeback association switches"), this could race with umount leading to super_block being destroyed while inodes are pinned for wb switching. 5ff8eaac1636 fixed it by bumping s_active while wb switches are in flight; however, this allowed in-flight wb switches to make umounts asynchronous when the userland expected synchronosity - e.g. fsck immediately following umount may fail because the device is still busy. This patch removes the problematic super_block pinning and instead makes generic_shutdown_super() flush in-flight wb switches. wb switches are now executed on a dedicated isw_wq so that they can be flushed and isw_nr_in_flight keeps track of the number of in-flight wb switches so that flushing can be avoided in most cases. v2: Move cgroup_writeback_umount() further below and add MS_ACTIVE check in inode_switch_wbs() as Jan an Al suggested. Signed-off-by: Tejun Heo Reported-by: Tahsin Erdogan Cc: Jan Kara Cc: Al Viro Link: http://lkml.kernel.org/g/CAAeU0aNCq7LGODvVGRU-oU_o-6enii5ey0p1c26D1ZzYwkDc5A@mail.gmail.com Fixes: 5ff8eaac1636 ("writeback: keep superblock pinned during cgroup writeback association switches") Reviewed-by: Jan Kara Tested-by: Tahsin Erdogan Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- include/linux/writeback.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index b333c945e571..d0b5ca5d4e08 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -198,6 +198,7 @@ void wbc_attach_and_unlock_inode(struct writeback_control *wbc, void wbc_detach_inode(struct writeback_control *wbc); void wbc_account_io(struct writeback_control *wbc, struct page *page, size_t bytes); +void cgroup_writeback_umount(void); /** * inode_attach_wb - associate an inode with its wb @@ -301,6 +302,10 @@ static inline void wbc_account_io(struct writeback_control *wbc, { } +static inline void cgroup_writeback_umount(void) +{ +} + #endif /* CONFIG_CGROUP_WRITEBACK */ /* -- cgit v1.2.3 From 180c86a4f06231a09a00b8e6d1c07775341c94b8 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Thu, 3 Mar 2016 17:18:20 -0500 Subject: tracing: Do not have 'comm' filter override event 'comm' field commit e57cbaf0eb006eaa207395f3bfd7ce52c1b5539c upstream. Commit 9f61668073a8d "tracing: Allow triggers to filter for CPU ids and process names" added a 'comm' filter that will filter events based on the current tasks struct 'comm'. But this now hides the ability to filter events that have a 'comm' field too. For example, sched_migrate_task trace event. That has a 'comm' field of the task to be migrated. echo 'comm == "bash"' > events/sched_migrate_task/filter will now filter all sched_migrate_task events for tasks named "bash" that migrates other tasks (in interrupt context), instead of seeing when "bash" itself gets migrated. This fix requires a couple of changes. 1) Change the look up order for filter predicates to look at the events fields before looking at the generic filters. 2) Instead of basing the filter function off of the "comm" name, have the generic "comm" filter have its own filter_type (FILTER_COMM). Test against the type instead of the name to assign the filter function. 3) Add a new "COMM" filter that works just like "comm" but will filter based on the current task, even if the trace event contains a "comm" field. Do the same for "cpu" field, adding a FILTER_CPU and a filter "CPU". Fixes: 9f61668073a8d "tracing: Allow triggers to filter for CPU ids and process names" Reported-by: Matt Fleming Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- include/linux/trace_events.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 429fdfc3baf5..925730bc9fc1 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -568,6 +568,8 @@ enum { FILTER_DYN_STRING, FILTER_PTR_STRING, FILTER_TRACE_FN, + FILTER_COMM, + FILTER_CPU, }; extern int trace_event_raw_init(struct trace_event_call *call); -- cgit v1.2.3 From 0528bdbc4448afd76ca54eb7b4f81dafdf3ba68a Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 26 Feb 2016 23:40:51 +0800 Subject: block: check virt boundary in bio_will_gap() commit e0af29171aa8912e1ca95023b75ef336cd70d661 upstream. In the following patch, the way for figuring out the last bvec will be changed with a bit cost introduced, so return immediately if the queue doesn't have virt boundary limit. Actually most of devices have not this limit. Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- include/linux/blkdev.h | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c70e3588a48c..7f2f0f61d156 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1367,6 +1367,13 @@ static inline void put_dev_sector(Sector p) page_cache_release(p.v); } +static inline bool __bvec_gap_to_prev(struct request_queue *q, + struct bio_vec *bprv, unsigned int offset) +{ + return offset || + ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); +} + /* * Check if adding a bio_vec after bprv with offset would create a gap in * the SG list. Most drivers don't care about this, but some do. @@ -1376,18 +1383,17 @@ static inline bool bvec_gap_to_prev(struct request_queue *q, { if (!queue_virt_boundary(q)) return false; - return offset || - ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); + return __bvec_gap_to_prev(q, bprv, offset); } static inline bool bio_will_gap(struct request_queue *q, struct bio *prev, struct bio *next) { - if (!bio_has_data(prev)) + if (!bio_has_data(prev) || !queue_virt_boundary(q)) return false; - return bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1], - next->bi_io_vec[0].bv_offset); + return __bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1], + next->bi_io_vec[0].bv_offset); } static inline bool req_gap_back_merge(struct request *req, struct bio *bio) -- cgit v1.2.3 From f4f0cca3c121f80706aa05b08f17f661df6396fc Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 26 Feb 2016 23:40:52 +0800 Subject: block: get the 1st and last bvec via helpers commit 25e71a99f10e444cd00bb2ebccb11e1c9fb672b1 upstream. This patch applies the two introduced helpers to figure out the 1st and last bvec, and fixes the original way after bio splitting. Reported-by: Sagi Grimberg Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- include/linux/blkdev.h | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 7f2f0f61d156..168755791ec8 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1389,11 +1389,16 @@ static inline bool bvec_gap_to_prev(struct request_queue *q, static inline bool bio_will_gap(struct request_queue *q, struct bio *prev, struct bio *next) { - if (!bio_has_data(prev) || !queue_virt_boundary(q)) - return false; + if (bio_has_data(prev) && queue_virt_boundary(q)) { + struct bio_vec pb, nb; + + bio_get_last_bvec(prev, &pb); + bio_get_first_bvec(next, &nb); - return __bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1], - next->bi_io_vec[0].bv_offset); + return __bvec_gap_to_prev(q, &pb, nb.bv_offset); + } + + return false; } static inline bool req_gap_back_merge(struct request *req, struct bio *bio) -- cgit v1.2.3 From 610dde5afb2dbf7182eb0e6d56daa7e8700d52c4 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 3 Feb 2016 16:55:26 +1030 Subject: modules: fix longstanding /proc/kallsyms vs module insertion race. commit 8244062ef1e54502ef55f54cced659913f244c3e upstream. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). [ Rebased for 4.4-stable and older, because the following changes aren't in the older trees: - e0224418516b4d8a6c2160574bac18447c354ef0: adds arg to is_core_symbol - 7523e4dc5057e157212b4741abd6256e03404cf1: module_init/module_core/init_size/core_size become init_layout.base/core_layout.base/init_layout.size/core_layout.size. ] Reported-by: Weilong Chen Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman --- include/linux/module.h | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'include/linux') diff --git a/include/linux/module.h b/include/linux/module.h index 3a19c79918e0..b229a9961d02 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -302,6 +302,12 @@ struct mod_tree_node { struct latch_tree_node node; }; +struct mod_kallsyms { + Elf_Sym *symtab; + unsigned int num_symtab; + char *strtab; +}; + struct module { enum module_state state; @@ -411,14 +417,9 @@ struct module { #endif #ifdef CONFIG_KALLSYMS - /* - * We keep the symbol and string tables for kallsyms. - * The core_* fields below are temporary, loader-only (they - * could really be discarded after module init). - */ - Elf_Sym *symtab, *core_symtab; - unsigned int num_symtab, core_num_syms; - char *strtab, *core_strtab; + /* Protected by RCU and/or module_mutex: use rcu_dereference() */ + struct mod_kallsyms *kallsyms; + struct mod_kallsyms core_kallsyms; /* Section attributes */ struct module_sect_attrs *sect_attrs; -- cgit v1.2.3