From 47d06e532e95b71c0db3839ebdef3fe8812fca2c Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Tue, 10 Sep 2013 10:52:35 -0400 Subject: random: run random_int_secret_init() run after all late_initcalls The some platforms (e.g., ARM) initializes their clocks as late_initcalls for some unknown reason. So make sure random_int_secret_init() is run after all of the late_initcalls are run. Cc: stable@vger.kernel.org Signed-off-by: "Theodore Ts'o" --- include/linux/random.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/random.h b/include/linux/random.h index 3b9377d6b7a5..6312dd9ba449 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -17,6 +17,7 @@ extern void add_interrupt_randomness(int irq, int irq_flags); extern void get_random_bytes(void *buf, int nbytes); extern void get_random_bytes_arch(void *buf, int nbytes); void generate_random_uuid(unsigned char uuid_out[16]); +extern int random_int_secret_init(void); #ifndef MODULE extern const struct file_operations random_fops, urandom_fops; -- cgit v1.2.3 From 19872d20c890073c5207d9e02bb8f14d451a11eb Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Mon, 9 Sep 2013 18:33:54 +0200 Subject: HID: uhid: allocate static minor udev has this nice feature of creating "dead" /dev/ device-nodes if it finds a devnode: modalias. Once the node is accessed, the kernel automatically loads the module that provides the node. However, this requires udev to know the major:minor code to use for the node. This feature was introduced by: commit 578454ff7eab61d13a26b568f99a89a2c9edc881 Author: Kay Sievers Date: Thu May 20 18:07:20 2010 +0200 driver core: add devname module aliases to allow module on-demand auto-loading However, uhid uses dynamic minor numbers so this doesn't actually work. We need to load uhid to know which minor it's going to use. Hence, allocate a static minor (just like uinput does) and we're good to go. Reported-by: Tom Gundersen Signed-off-by: David Herrmann Signed-off-by: Jiri Kosina --- drivers/hid/uhid.c | 3 ++- include/linux/miscdevice.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c index 5bf2fb785844..93b00d76374c 100644 --- a/drivers/hid/uhid.c +++ b/drivers/hid/uhid.c @@ -615,7 +615,7 @@ static const struct file_operations uhid_fops = { static struct miscdevice uhid_misc = { .fops = &uhid_fops, - .minor = MISC_DYNAMIC_MINOR, + .minor = UHID_MINOR, .name = UHID_NAME, }; @@ -634,4 +634,5 @@ module_exit(uhid_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("David Herrmann "); MODULE_DESCRIPTION("User-space I/O driver support for HID subsystem"); +MODULE_ALIAS_MISCDEV(UHID_MINOR); MODULE_ALIAS("devname:" UHID_NAME); diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h index 09c2300ddb37..cb358355ef43 100644 --- a/include/linux/miscdevice.h +++ b/include/linux/miscdevice.h @@ -45,6 +45,7 @@ #define MAPPER_CTRL_MINOR 236 #define LOOP_CTRL_MINOR 237 #define VHOST_NET_MINOR 238 +#define UHID_MINOR 239 #define MISC_DYNAMIC_MINOR 255 struct device; -- cgit v1.2.3 From 9886167d20c0720dcfb01e62cdff4d906b226f43 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 3 Oct 2013 16:02:23 +0200 Subject: perf: Fix perf_pmu_migrate_context While auditing the list_entry usage due to a trinity bug I found that perf_pmu_migrate_context violates the rules for perf_event::event_entry. The problem is that perf_event::event_entry is a RCU list element, and hence we must wait for a full RCU grace period before re-using the element after deletion. Therefore the usage in perf_pmu_migrate_context() which re-uses the entry immediately is broken. For now introduce another list_head into perf_event for this specific usage. This doesn't actually fix the trinity report because that never goes through this code. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-mkj72lxagw1z8fvjm648iznw@git.kernel.org Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 24 +++++++++++++++++++++++- kernel/events/core.c | 6 +++--- 2 files changed, 26 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 866e85c5eb94..c8ba627c1d60 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -294,9 +294,31 @@ struct ring_buffer; */ struct perf_event { #ifdef CONFIG_PERF_EVENTS - struct list_head group_entry; + /* + * entry onto perf_event_context::event_list; + * modifications require ctx->lock + * RCU safe iterations. + */ struct list_head event_entry; + + /* + * XXX: group_entry and sibling_list should be mutually exclusive; + * either you're a sibling on a group, or you're the group leader. + * Rework the code to always use the same list element. + * + * Locked for modification by both ctx->mutex and ctx->lock; holding + * either sufficies for read. + */ + struct list_head group_entry; struct list_head sibling_list; + + /* + * We need storage to track the entries in perf_pmu_migrate_context; we + * cannot use the event_entry because of RCU and we want to keep the + * group in tact which avoids us using the other two entries. + */ + struct list_head migrate_entry; + struct hlist_node hlist_entry; int nr_siblings; int group_flags; diff --git a/kernel/events/core.c b/kernel/events/core.c index cb4238e85b38..d49a9d29334c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7234,15 +7234,15 @@ void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) perf_remove_from_context(event); unaccount_event_cpu(event, src_cpu); put_ctx(src_ctx); - list_add(&event->event_entry, &events); + list_add(&event->migrate_entry, &events); } mutex_unlock(&src_ctx->mutex); synchronize_rcu(); mutex_lock(&dst_ctx->mutex); - list_for_each_entry_safe(event, tmp, &events, event_entry) { - list_del(&event->event_entry); + list_for_each_entry_safe(event, tmp, &events, migrate_entry) { + list_del(&event->migrate_entry); if (event->state >= PERF_EVENT_STATE_OFF) event->state = PERF_EVENT_STATE_INACTIVE; account_event_cpu(event, dst_cpu); -- cgit v1.2.3 From d623a0e19dcbc4e44a8db047158815d7f8c2b839 Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Mon, 7 Oct 2013 10:22:01 -0700 Subject: ARM: dts: Fix pinctrl mask for omap3 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The wake-up interrupt bit is available on omap3/4/5 processors unlike what we claim. Without fixing it we cannot use it on omap3 and the system configured for wake-up events will just hang on wake-up. Cc: Grygorii Strashko Cc: Benoît Cousson Cc: devicetree@vger.kernel.org Signed-off-by: Tony Lindgren --- arch/arm/boot/dts/omap3.dtsi | 4 ++-- arch/arm/mach-omap2/mux.h | 4 +--- include/dt-bindings/pinctrl/omap.h | 4 +--- 3 files changed, 4 insertions(+), 8 deletions(-) (limited to 'include') diff --git a/arch/arm/boot/dts/omap3.dtsi b/arch/arm/boot/dts/omap3.dtsi index 7d95cda1fae4..b41bd57f4328 100644 --- a/arch/arm/boot/dts/omap3.dtsi +++ b/arch/arm/boot/dts/omap3.dtsi @@ -108,7 +108,7 @@ #address-cells = <1>; #size-cells = <0>; pinctrl-single,register-width = <16>; - pinctrl-single,function-mask = <0x7f1f>; + pinctrl-single,function-mask = <0xff1f>; }; omap3_pmx_wkup: pinmux@0x48002a00 { @@ -117,7 +117,7 @@ #address-cells = <1>; #size-cells = <0>; pinctrl-single,register-width = <16>; - pinctrl-single,function-mask = <0x7f1f>; + pinctrl-single,function-mask = <0xff1f>; }; gpio1: gpio@48310000 { diff --git a/arch/arm/mach-omap2/mux.h b/arch/arm/mach-omap2/mux.h index 5d2080ef7923..16f78a990d04 100644 --- a/arch/arm/mach-omap2/mux.h +++ b/arch/arm/mach-omap2/mux.h @@ -28,7 +28,7 @@ #define OMAP_PULL_UP (1 << 4) #define OMAP_ALTELECTRICALSEL (1 << 5) -/* 34xx specific mux bit defines */ +/* omap3/4/5 specific mux bit defines */ #define OMAP_INPUT_EN (1 << 8) #define OMAP_OFF_EN (1 << 9) #define OMAP_OFFOUT_EN (1 << 10) @@ -36,8 +36,6 @@ #define OMAP_OFF_PULL_EN (1 << 12) #define OMAP_OFF_PULL_UP (1 << 13) #define OMAP_WAKEUP_EN (1 << 14) - -/* 44xx specific mux bit defines */ #define OMAP_WAKEUP_EVENT (1 << 15) /* Active pin states */ diff --git a/include/dt-bindings/pinctrl/omap.h b/include/dt-bindings/pinctrl/omap.h index edbd250809cb..bed35e36fd27 100644 --- a/include/dt-bindings/pinctrl/omap.h +++ b/include/dt-bindings/pinctrl/omap.h @@ -23,7 +23,7 @@ #define PULL_UP (1 << 4) #define ALTELECTRICALSEL (1 << 5) -/* 34xx specific mux bit defines */ +/* omap3/4/5 specific mux bit defines */ #define INPUT_EN (1 << 8) #define OFF_EN (1 << 9) #define OFFOUT_EN (1 << 10) @@ -31,8 +31,6 @@ #define OFF_PULL_EN (1 << 12) #define OFF_PULL_UP (1 << 13) #define WAKEUP_EN (1 << 14) - -/* 44xx specific mux bit defines */ #define WAKEUP_EVENT (1 << 15) /* Active pin states */ -- cgit v1.2.3 From 61875f30daf60305712e25b209ef41ced2635bad Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 21 Sep 2013 13:58:22 -0400 Subject: random: allow architectures to optionally define random_get_entropy() Allow architectures which have a disabled get_cycles() function to provide a random_get_entropy() function which provides a fine-grained, rapidly changing counter that can be used by the /dev/random driver. For example, an architecture might have a rapidly changing register used to control random TLB cache eviction, or DRAM refresh that doesn't meet the requirements of get_cycles(), but which is good enough for the needs of the random driver. Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org --- drivers/char/random.c | 8 ++++---- include/linux/timex.h | 14 ++++++++++++++ 2 files changed, 18 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/drivers/char/random.c b/drivers/char/random.c index 92e6c67e1ae6..2d5daf9b58e9 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -643,7 +643,7 @@ struct timer_rand_state { */ void add_device_randomness(const void *buf, unsigned int size) { - unsigned long time = get_cycles() ^ jiffies; + unsigned long time = random_get_entropy() ^ jiffies; mix_pool_bytes(&input_pool, buf, size, NULL); mix_pool_bytes(&input_pool, &time, sizeof(time), NULL); @@ -680,7 +680,7 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num) goto out; sample.jiffies = jiffies; - sample.cycles = get_cycles(); + sample.cycles = random_get_entropy(); sample.num = num; mix_pool_bytes(&input_pool, &sample, sizeof(sample), NULL); @@ -747,7 +747,7 @@ void add_interrupt_randomness(int irq, int irq_flags) struct fast_pool *fast_pool = &__get_cpu_var(irq_randomness); struct pt_regs *regs = get_irq_regs(); unsigned long now = jiffies; - __u32 input[4], cycles = get_cycles(); + __u32 input[4], cycles = random_get_entropy(); input[0] = cycles ^ jiffies; input[1] = irq; @@ -1485,7 +1485,7 @@ unsigned int get_random_int(void) hash = get_cpu_var(get_random_int_hash); - hash[0] += current->pid + jiffies + get_cycles(); + hash[0] += current->pid + jiffies + random_get_entropy(); md5_transform(hash, random_int_secret); ret = hash[0]; put_cpu_var(get_random_int_hash); diff --git a/include/linux/timex.h b/include/linux/timex.h index b3726e61368e..da4c32dbb2aa 100644 --- a/include/linux/timex.h +++ b/include/linux/timex.h @@ -64,6 +64,20 @@ #include +#ifndef random_get_entropy +/* + * The random_get_entropy() function is used by the /dev/random driver + * in order to extract entropy via the relative unpredictability of + * when an interrupt takes places versus a high speed, fine-grained + * timing source or cycle counter. Since it will be occurred on every + * single interrupt, it must have a very low cost/overhead. + * + * By default we use get_cycles() for this purpose, but individual + * architectures may override this in their asm/timex.h header file. + */ +#define random_get_entropy() get_cycles() +#endif + /* * SHIFT_PLL is used as a dampening factor to define how much we * adjust the frequency correction for a given offset in PLL mode. -- cgit v1.2.3 From 3f0116c3238a96bc18ad4b4acefe4e7be32fa861 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 10 Oct 2013 10:16:30 +0200 Subject: compiler/gcc4: Add quirk for 'asm goto' miscompilation bug Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto' constructs, as outlined here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 Implement a workaround suggested by Jakub Jelinek. Reported-and-tested-by: Fengguang Wu Reported-by: Oleg Nesterov Reported-by: Peter Zijlstra Suggested-by: Jakub Jelinek Reviewed-by: Richard Henderson Cc: Linus Torvalds Cc: Andrew Morton Cc: Signed-off-by: Ingo Molnar --- arch/arm/include/asm/jump_label.h | 2 +- arch/mips/include/asm/jump_label.h | 2 +- arch/powerpc/include/asm/jump_label.h | 2 +- arch/s390/include/asm/jump_label.h | 2 +- arch/sparc/include/asm/jump_label.h | 2 +- arch/x86/include/asm/cpufeature.h | 6 +++--- arch/x86/include/asm/jump_label.h | 2 +- arch/x86/include/asm/mutex_64.h | 4 ++-- include/linux/compiler-gcc4.h | 15 +++++++++++++++ 9 files changed, 26 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/arch/arm/include/asm/jump_label.h b/arch/arm/include/asm/jump_label.h index bfc198c75913..863c892b4aaa 100644 --- a/arch/arm/include/asm/jump_label.h +++ b/arch/arm/include/asm/jump_label.h @@ -16,7 +16,7 @@ static __always_inline bool arch_static_branch(struct static_key *key) { - asm goto("1:\n\t" + asm_volatile_goto("1:\n\t" JUMP_LABEL_NOP "\n\t" ".pushsection __jump_table, \"aw\"\n\t" ".word 1b, %l[l_yes], %c0\n\t" diff --git a/arch/mips/include/asm/jump_label.h b/arch/mips/include/asm/jump_label.h index 4d6d77ed9b9d..e194f957ca8c 100644 --- a/arch/mips/include/asm/jump_label.h +++ b/arch/mips/include/asm/jump_label.h @@ -22,7 +22,7 @@ static __always_inline bool arch_static_branch(struct static_key *key) { - asm goto("1:\tnop\n\t" + asm_volatile_goto("1:\tnop\n\t" "nop\n\t" ".pushsection __jump_table, \"aw\"\n\t" WORD_INSN " 1b, %l[l_yes], %0\n\t" diff --git a/arch/powerpc/include/asm/jump_label.h b/arch/powerpc/include/asm/jump_label.h index ae098c438f00..f016bb699b5f 100644 --- a/arch/powerpc/include/asm/jump_label.h +++ b/arch/powerpc/include/asm/jump_label.h @@ -19,7 +19,7 @@ static __always_inline bool arch_static_branch(struct static_key *key) { - asm goto("1:\n\t" + asm_volatile_goto("1:\n\t" "nop\n\t" ".pushsection __jump_table, \"aw\"\n\t" JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t" diff --git a/arch/s390/include/asm/jump_label.h b/arch/s390/include/asm/jump_label.h index 6c32190dc73e..346b1c85ffb4 100644 --- a/arch/s390/include/asm/jump_label.h +++ b/arch/s390/include/asm/jump_label.h @@ -15,7 +15,7 @@ static __always_inline bool arch_static_branch(struct static_key *key) { - asm goto("0: brcl 0,0\n" + asm_volatile_goto("0: brcl 0,0\n" ".pushsection __jump_table, \"aw\"\n" ASM_ALIGN "\n" ASM_PTR " 0b, %l[label], %0\n" diff --git a/arch/sparc/include/asm/jump_label.h b/arch/sparc/include/asm/jump_label.h index 5080d16a832f..ec2e2e2aba7d 100644 --- a/arch/sparc/include/asm/jump_label.h +++ b/arch/sparc/include/asm/jump_label.h @@ -9,7 +9,7 @@ static __always_inline bool arch_static_branch(struct static_key *key) { - asm goto("1:\n\t" + asm_volatile_goto("1:\n\t" "nop\n\t" "nop\n\t" ".pushsection __jump_table, \"aw\"\n\t" diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index d3f5c63078d8..89270b4318db 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -374,7 +374,7 @@ static __always_inline __pure bool __static_cpu_has(u16 bit) * Catch too early usage of this before alternatives * have run. */ - asm goto("1: jmp %l[t_warn]\n" + asm_volatile_goto("1: jmp %l[t_warn]\n" "2:\n" ".section .altinstructions,\"a\"\n" " .long 1b - .\n" @@ -388,7 +388,7 @@ static __always_inline __pure bool __static_cpu_has(u16 bit) #endif - asm goto("1: jmp %l[t_no]\n" + asm_volatile_goto("1: jmp %l[t_no]\n" "2:\n" ".section .altinstructions,\"a\"\n" " .long 1b - .\n" @@ -453,7 +453,7 @@ static __always_inline __pure bool _static_cpu_has_safe(u16 bit) * have. Thus, we force the jump to the widest, 4-byte, signed relative * offset even though the last would often fit in less bytes. */ - asm goto("1: .byte 0xe9\n .long %l[t_dynamic] - 2f\n" + asm_volatile_goto("1: .byte 0xe9\n .long %l[t_dynamic] - 2f\n" "2:\n" ".section .altinstructions,\"a\"\n" " .long 1b - .\n" /* src offset */ diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index 64507f35800c..6a2cefb4395a 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -18,7 +18,7 @@ static __always_inline bool arch_static_branch(struct static_key *key) { - asm goto("1:" + asm_volatile_goto("1:" ".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t" ".pushsection __jump_table, \"aw\" \n\t" _ASM_ALIGN "\n\t" diff --git a/arch/x86/include/asm/mutex_64.h b/arch/x86/include/asm/mutex_64.h index e7e6751648ed..07537a44216e 100644 --- a/arch/x86/include/asm/mutex_64.h +++ b/arch/x86/include/asm/mutex_64.h @@ -20,7 +20,7 @@ static inline void __mutex_fastpath_lock(atomic_t *v, void (*fail_fn)(atomic_t *)) { - asm volatile goto(LOCK_PREFIX " decl %0\n" + asm_volatile_goto(LOCK_PREFIX " decl %0\n" " jns %l[exit]\n" : : "m" (v->counter) : "memory", "cc" @@ -75,7 +75,7 @@ static inline int __mutex_fastpath_lock_retval(atomic_t *count) static inline void __mutex_fastpath_unlock(atomic_t *v, void (*fail_fn)(atomic_t *)) { - asm volatile goto(LOCK_PREFIX " incl %0\n" + asm_volatile_goto(LOCK_PREFIX " incl %0\n" " jg %l[exit]\n" : : "m" (v->counter) : "memory", "cc" diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index 842de225055f..ded429966c1f 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -65,6 +65,21 @@ #define __visible __attribute__((externally_visible)) #endif +/* + * GCC 'asm goto' miscompiles certain code sequences: + * + * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 + * + * Work it around via a compiler barrier quirk suggested by Jakub Jelinek. + * Fixed in GCC 4.8.2 and later versions. + * + * (asm goto is automatically volatile - the naming reflects this.) + */ +#if GCC_VERSION <= 40801 +# define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) +#else +# define asm_volatile_goto(x...) do { asm goto(x); } while (0) +#endif #ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP #if GCC_VERSION >= 40400 -- cgit v1.2.3