From 7cad45eea3849faeb34591b60d16b50d13a38d77 Mon Sep 17 00:00:00 2001 From: Vincent Stehlé Date: Fri, 22 Aug 2014 01:31:20 +0200 Subject: irq: Export handle_fasteoi_irq MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Export handle_fasteoi_irq to be able to use it in e.g. the Zynq gpio driver since commit 6dd859508336 ("gpio: zynq: Fix IRQ handlers"). This fixes the following link issue: ERROR: "handle_fasteoi_irq" [drivers/gpio/gpio-zynq.ko] undefined! Signed-off-by: Vincent Stehlé Acked-by: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org Cc: Vincent Stehle Cc: Lars-Peter Clausen Cc: Linus Walleij Link: http://lkml.kernel.org/r/1408663880-29179-1-git-send-email-vincent.stehle@laposte.net Signed-off-by: Thomas Gleixner --- kernel/irq/chip.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index a2b28a2fd7b1..6223fab9a9d2 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -517,6 +517,7 @@ out: chip->irq_eoi(&desc->irq_data); raw_spin_unlock(&desc->lock); } +EXPORT_SYMBOL_GPL(handle_fasteoi_irq); /** * handle_edge_irq - edge type IRQ handler -- cgit v1.2.3 From 4ce97dbf50245227add17c83d87dc838e7ca79d0 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Mon, 25 Aug 2014 13:59:41 -0400 Subject: trace: Fix epoll hang when we race with new entries Epoll on trace_pipe can sometimes hang in a weird case. If the ring buffer is empty when we set waiters_pending but an event shows up exactly at that moment we can miss being woken up by the ring buffers irq work. Since ring_buffer_empty() is inherently racey we will sometimes think that the buffer is not empty. So we don't get woken up and we don't think there are any events even though there were some ready when we added the watch, which makes us hang. This patch fixes this by making sure that we are actually on the wait list before we set waiters_pending, and add a memory barrier to make sure ring_buffer_empty() is going to be correct. Link: http://lkml.kernel.org/p/1408989581-23727-1-git-send-email-jbacik@fb.com Cc: stable@vger.kernel.org # 3.10+ Cc: Martin Lau Signed-off-by: Josef Bacik Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index afb04b9b818a..b38fb2b9e237 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -626,8 +626,22 @@ int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu, work = &cpu_buffer->irq_work; } - work->waiters_pending = true; poll_wait(filp, &work->waiters, poll_table); + work->waiters_pending = true; + /* + * There's a tight race between setting the waiters_pending and + * checking if the ring buffer is empty. Once the waiters_pending bit + * is set, the next event will wake the task up, but we can get stuck + * if there's only a single event in. + * + * FIXME: Ideally, we need a memory barrier on the writer side as well, + * but adding a memory barrier to all events will cause too much of a + * performance hit in the fast path. We only need a memory barrier when + * the buffer goes from empty to having content. But as this race is + * extremely small, and it's not a problem if another event comes in, we + * will fix it later. + */ + smp_mb(); if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) || (cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu))) -- cgit v1.2.3 From 800df627e2eabaf4a921d342a1d5162c843b7fc2 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Fri, 29 Aug 2014 15:18:29 -0700 Subject: resource: fix the case of null pointer access MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Richard and Daniel reported that UML is broken due to changes to resource traversal functions. Problem is that iomem_resource.child can be null and new code does not consider that possibility. Old code used a for loop and that loop will not even execute if p was null. Revert back to for() loop logic and bail out if p is null. I also moved sibling_only check out of resource_lock. There is no reason to keep it inside the lock. Following is backtrace of the UML crash. RIP: 0033:[<0000000060039b9f>] RSP: 0000000081459da0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 00000000219b3fff RCX: 000000006010d1d9 RDX: 0000000000000001 RSI: 00000000602dfb94 RDI: 0000000081459df8 RBP: 0000000081459de0 R08: 00000000601b59f4 R09: ffffffff0000ff00 R10: ffffffff0000ff00 R11: 0000000081459e88 R12: 0000000081459df8 R13: 00000000219b3fff R14: 00000000602dfb94 R15: 0000000000000000 Kernel panic - not syncing: Segfault with no mm CPU: 0 PID: 1 Comm: swapper Not tainted 3.16.0-10454-g58d08e3 #13 Stack: 00000000 000080d0 81459df0 219b3fff 81459e70 6010d1d9 ffffffff 6033e010 81459e50 6003a269 81459e30 00000000 Call Trace: [<6010d1d9>] ? kclist_add_private+0x0/0xe7 [<6003a269>] walk_system_ram_range+0x61/0xb7 [<6000e859>] ? proc_kcore_init+0x0/0xf1 [<6010d574>] kcore_update_ram+0x4c/0x168 [<6010d72e>] ? kclist_add+0x0/0x2e [<6000e943>] proc_kcore_init+0xea/0xf1 [<6000e859>] ? proc_kcore_init+0x0/0xf1 [<6000e859>] ? proc_kcore_init+0x0/0xf1 [<600189f0>] do_one_initcall+0x13c/0x204 [<6004ca46>] ? parse_args+0x1df/0x2e0 [<6004c82d>] ? parameq+0x0/0x3a [<601b5990>] ? strcpy+0x0/0x18 [<60001e1a>] kernel_init_freeable+0x240/0x31e [<6026f1c0>] kernel_init+0x12/0x148 [<60019fad>] new_thread_handler+0x81/0xa3 Fixes 8c86e70acead629aacb4a ("resource: provide new functions to walk through resources"). Reported-by: Daniel Walter Tested-by: Richard Weinberger Tested-by: Toralf Förster Tested-by: Daniel Walter Signed-off-by: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/resource.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/resource.c b/kernel/resource.c index da14b8d09296..60c5a3856ab7 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -351,15 +351,12 @@ static int find_next_iomem_res(struct resource *res, char *name, end = res->end; BUG_ON(start >= end); - read_lock(&resource_lock); - - if (first_level_children_only) { - p = iomem_resource.child; + if (first_level_children_only) sibling_only = true; - } else - p = &iomem_resource; - while ((p = next_resource(p, sibling_only))) { + read_lock(&resource_lock); + + for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) { if (p->flags != res->flags) continue; if (name && strcmp(p->name, name)) -- cgit v1.2.3 From 74ca317c26a3f8543203b61d262c0ab2e30c384e Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Fri, 29 Aug 2014 15:18:46 -0700 Subject: kexec: create a new config option CONFIG_KEXEC_FILE for new syscall Currently new system call kexec_file_load() and all the associated code compiles if CONFIG_KEXEC=y. But new syscall also compiles purgatory code which currently uses gcc option -mcmodel=large. This option seems to be available only gcc 4.4 onwards. Hiding new functionality behind a new config option will not break existing users of old gcc. Those who wish to enable new functionality will require new gcc. Having said that, I am trying to figure out how can I move away from using -mcmodel=large but that can take a while. I think there are other advantages of introducing this new config option. As this option will be enabled only on x86_64, other arches don't have to compile generic kexec code which will never be used. This new code selects CRYPTO=y and CRYPTO_SHA256=y. And all other arches had to do this for CONFIG_KEXEC. Now with introduction of new config option, we can remove crypto dependency from other arches. Now CONFIG_KEXEC_FILE is available only on x86_64. So whereever I had CONFIG_X86_64 defined, I got rid of that. For CONFIG_KEXEC_FILE, instead of doing select CRYPTO=y, I changed it to "depends on CRYPTO=y". This should be safer as "select" is not recursive. Signed-off-by: Vivek Goyal Cc: Eric Biederman Cc: H. Peter Anvin Tested-by: Shaun Ruffell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/Kbuild | 4 +--- arch/x86/Kconfig | 18 ++++++++++++++---- arch/x86/Makefile | 5 +---- arch/x86/kernel/Makefile | 2 +- arch/x86/kernel/crash.c | 6 ++---- arch/x86/kernel/machine_kexec_64.c | 11 +++++++++++ arch/x86/purgatory/Makefile | 5 +---- kernel/kexec.c | 11 +++++++++++ 8 files changed, 42 insertions(+), 20 deletions(-) (limited to 'kernel') diff --git a/arch/x86/Kbuild b/arch/x86/Kbuild index 61b6d51866f8..3942f74c92d7 100644 --- a/arch/x86/Kbuild +++ b/arch/x86/Kbuild @@ -17,6 +17,4 @@ obj-$(CONFIG_IA32_EMULATION) += ia32/ obj-y += platform/ obj-y += net/ -ifeq ($(CONFIG_X86_64),y) -obj-$(CONFIG_KEXEC) += purgatory/ -endif +obj-$(CONFIG_KEXEC_FILE) += purgatory/ diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5d0bf1aa9dcb..778178f4c7d1 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1585,9 +1585,6 @@ source kernel/Kconfig.hz config KEXEC bool "kexec system call" - select BUILD_BIN2C - select CRYPTO - select CRYPTO_SHA256 ---help--- kexec is a system call that implements the ability to shutdown your current kernel, and to start another kernel. It is like a reboot @@ -1602,9 +1599,22 @@ config KEXEC interface is strongly in flux, so no good recommendation can be made. +config KEXEC_FILE + bool "kexec file based system call" + select BUILD_BIN2C + depends on KEXEC + depends on X86_64 + depends on CRYPTO=y + depends on CRYPTO_SHA256=y + ---help--- + This is new version of kexec system call. This system call is + file based and takes file descriptors as system call argument + for kernel and initramfs as opposed to list of segments as + accepted by previous system call. + config KEXEC_VERIFY_SIG bool "Verify kernel signature during kexec_file_load() syscall" - depends on KEXEC + depends on KEXEC_FILE ---help--- This option makes kernel signature verification mandatory for kexec_file_load() syscall. If kernel is signature can not be diff --git a/arch/x86/Makefile b/arch/x86/Makefile index c1aa36887843..c96bcec544fc 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -184,11 +184,8 @@ archheaders: $(Q)$(MAKE) $(build)=arch/x86/syscalls all archprepare: -ifeq ($(CONFIG_KEXEC),y) -# Build only for 64bit. No loaders for 32bit yet. - ifeq ($(CONFIG_X86_64),y) +ifeq ($(CONFIG_KEXEC_FILE),y) $(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c - endif endif ### diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index b5ea75c4a4b4..ada2e2d6be3e 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -71,6 +71,7 @@ obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o obj-$(CONFIG_X86_TSC) += trace_clock.o obj-$(CONFIG_KEXEC) += machine_kexec_$(BITS).o obj-$(CONFIG_KEXEC) += relocate_kernel_$(BITS).o crash.o +obj-$(CONFIG_KEXEC_FILE) += kexec-bzimage64.o obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o obj-y += kprobes/ obj-$(CONFIG_MODULES) += module.o @@ -118,5 +119,4 @@ ifeq ($(CONFIG_X86_64),y) obj-$(CONFIG_PCI_MMCONFIG) += mmconf-fam10h_64.o obj-y += vsmp_64.o - obj-$(CONFIG_KEXEC) += kexec-bzimage64.o endif diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 0553a34fa0df..a618fcd2c07d 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -182,8 +182,7 @@ void native_machine_crash_shutdown(struct pt_regs *regs) crash_save_cpu(regs, safe_smp_processor_id()); } -#ifdef CONFIG_X86_64 - +#ifdef CONFIG_KEXEC_FILE static int get_nr_ram_ranges_callback(unsigned long start_pfn, unsigned long nr_pfn, void *arg) { @@ -696,5 +695,4 @@ int crash_load_segments(struct kimage *image) return ret; } - -#endif /* CONFIG_X86_64 */ +#endif /* CONFIG_KEXEC_FILE */ diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 8b04018e5d1f..485981059a40 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -25,9 +25,11 @@ #include #include +#ifdef CONFIG_KEXEC_FILE static struct kexec_file_ops *kexec_file_loaders[] = { &kexec_bzImage64_ops, }; +#endif static void free_transition_pgtable(struct kimage *image) { @@ -178,6 +180,7 @@ static void load_segments(void) ); } +#ifdef CONFIG_KEXEC_FILE /* Update purgatory as needed after various image segments have been prepared */ static int arch_update_purgatory(struct kimage *image) { @@ -209,6 +212,12 @@ static int arch_update_purgatory(struct kimage *image) return ret; } +#else /* !CONFIG_KEXEC_FILE */ +static inline int arch_update_purgatory(struct kimage *image) +{ + return 0; +} +#endif /* CONFIG_KEXEC_FILE */ int machine_kexec_prepare(struct kimage *image) { @@ -329,6 +338,7 @@ void arch_crash_save_vmcoreinfo(void) /* arch-dependent functionality related to kexec file-based syscall */ +#ifdef CONFIG_KEXEC_FILE int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len) { @@ -522,3 +532,4 @@ overflow: (int)ELF64_R_TYPE(rel[i].r_info), value); return -ENOEXEC; } +#endif /* CONFIG_KEXEC_FILE */ diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index 7fde9ee438a4..c4ae06e4ae74 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -24,7 +24,4 @@ $(obj)/kexec-purgatory.c: $(obj)/purgatory.ro FORCE $(call if_changed,bin2c) -# No loaders for 32bits yet. -ifeq ($(CONFIG_X86_64),y) - obj-$(CONFIG_KEXEC) += kexec-purgatory.o -endif +obj-$(CONFIG_KEXEC_FILE) += kexec-purgatory.o diff --git a/kernel/kexec.c b/kernel/kexec.c index 0b49a0a58102..2bee072268d9 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -64,7 +64,9 @@ bool kexec_in_progress = false; char __weak kexec_purgatory[0]; size_t __weak kexec_purgatory_size = 0; +#ifdef CONFIG_KEXEC_FILE static int kexec_calculate_store_digests(struct kimage *image); +#endif /* Location of the reserved area for the crash kernel */ struct resource crashk_res = { @@ -341,6 +343,7 @@ out_free_image: return ret; } +#ifdef CONFIG_KEXEC_FILE static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len) { struct fd f = fdget(fd); @@ -612,6 +615,9 @@ out_free_image: kfree(image); return ret; } +#else /* CONFIG_KEXEC_FILE */ +static inline void kimage_file_post_load_cleanup(struct kimage *image) { } +#endif /* CONFIG_KEXEC_FILE */ static int kimage_is_destination_range(struct kimage *image, unsigned long start, @@ -1375,6 +1381,7 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry, } #endif +#ifdef CONFIG_KEXEC_FILE SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, unsigned long, cmdline_len, const char __user *, cmdline_ptr, unsigned long, flags) @@ -1451,6 +1458,8 @@ out: return ret; } +#endif /* CONFIG_KEXEC_FILE */ + void crash_kexec(struct pt_regs *regs) { /* Take the kexec_mutex here to prevent sys_kexec_load @@ -2006,6 +2015,7 @@ static int __init crash_save_vmcoreinfo_init(void) subsys_initcall(crash_save_vmcoreinfo_init); +#ifdef CONFIG_KEXEC_FILE static int __kexec_add_segment(struct kimage *image, char *buf, unsigned long bufsz, unsigned long mem, unsigned long memsz) @@ -2682,6 +2692,7 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, return 0; } +#endif /* CONFIG_KEXEC_FILE */ /* * Move into place and start executing a preloaded standalone -- cgit v1.2.3