From 5809f9d442e9dbb23859e2c37d8c47043f6b5cc9 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 13 Feb 2007 13:26:21 +0100 Subject: [PATCH] x86-64: get rid of ARCH_HAVE_XTIME_LOCK ARCH_HAVE_XTIME_LOCK is used by x86_64 arch . This arch needs to place a read only copy of xtime_lock into vsyscall page. This read only copy is named __xtime_lock, and xtime_lock is defined in arch/x86_64/kernel/vmlinux.lds.S as an alias. So the declaration of xtime_lock in kernel/timer.c was guarded by ARCH_HAVE_XTIME_LOCK define, defined to true on x86_64. We can get same result with _attribute__((weak)) in the declaration. linker should do the job. Signed-off-by: Eric Dumazet Signed-off-by: Andi Kleen Cc: Andi Kleen Signed-off-by: Andrew Morton --- include/linux/time.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/time.h b/include/linux/time.h index 55cee172d72..eceb1a59b07 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -90,7 +90,7 @@ static inline struct timespec timespec_sub(struct timespec lhs, extern struct timespec xtime; extern struct timespec wall_to_monotonic; -extern seqlock_t xtime_lock; +extern seqlock_t xtime_lock __attribute__((weak)); void timekeeping_init(void); -- cgit v1.2.3-70-g09d2 From 5d0e600d903caa09e790824cc5812f0d97113b23 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 13 Feb 2007 13:26:24 +0100 Subject: [PATCH] x86: fix laptop bootup hang in init_acpi() During kernel bootup, a new T60 laptop (CoreDuo, 32-bit) hangs about 10%-20% of the time in acpi_init(): Calling initcall 0xc055ce1a: topology_init+0x0/0x2f() Calling initcall 0xc055d75e: mtrr_init_finialize+0x0/0x2c() Calling initcall 0xc05664f3: param_sysfs_init+0x0/0x175() Calling initcall 0xc014cb65: pm_sysrq_init+0x0/0x17() Calling initcall 0xc0569f99: init_bio+0x0/0xf4() Calling initcall 0xc056b865: genhd_device_init+0x0/0x50() Calling initcall 0xc056c4bd: fbmem_init+0x0/0x87() Calling initcall 0xc056dd74: acpi_init+0x0/0x1ee() It's a hard hang that not even an NMI could punch through! Frustratingly, adding printks or function tracing to the ACPI code made the hangs go away ... After some time an additional detail emerged: disabling the NMI watchdog made these occasional hangs go away. So i spent the better part of today trying to debug this and trying out various theories when i finally found the likely reason for the hang: if acpi_ns_initialize_devices() executes an _INI AML method and an NMI happens to hit that AML execution in the wrong moment, the machine would hang. (my theory is that this must be some sort of chipset setup method doing stores to chipset mmio registers?) Unfortunately given the characteristics of the hang it was sheer impossible to figure out which of the numerous AML methods is impacted by this problem. As a workaround i wrote an interface to disable chipset-based NMIs while executing _INI sections - and indeed this fixed the hang. I did a boot-loop of 100 separate reboots and none hung - while without the patch it would hang every 5-10 attempts. Out of caution i did not touch the nmi_watchdog=2 case (it's not related to the chipset anyway and didnt hang). I implemented this for both x86_64 and i686, tested the i686 laptop both with nmi_watchdog=1 [which triggered the hangs] and nmi_watchdog=2, and tested an Athlon64 box with the 64-bit kernel as well. Everything builds and works with the patch applied. Signed-off-by: Ingo Molnar Signed-off-by: Andi Kleen Cc: Andi Kleen Cc: Len Brown Signed-off-by: Andrew Morton --- arch/i386/kernel/nmi.c | 28 ++++++++++++++++++++++++++++ arch/x86_64/kernel/nmi.c | 27 +++++++++++++++++++++++++++ drivers/acpi/namespace/nsinit.c | 9 +++++++++ include/linux/nmi.h | 9 ++++++++- 4 files changed, 72 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c index 7d3f4e22d6f..b11abacc5cf 100644 --- a/arch/i386/kernel/nmi.c +++ b/arch/i386/kernel/nmi.c @@ -383,6 +383,34 @@ void enable_timer_nmi_watchdog(void) } } +static void __acpi_nmi_disable(void *__unused) +{ + apic_write_around(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED); +} + +/* + * Disable timer based NMIs on all CPUs: + */ +void acpi_nmi_disable(void) +{ + if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC) + on_each_cpu(__acpi_nmi_disable, NULL, 0, 1); +} + +static void __acpi_nmi_enable(void *__unused) +{ + apic_write_around(APIC_LVT0, APIC_DM_NMI); +} + +/* + * Enable timer based NMIs on all CPUs: + */ +void acpi_nmi_enable(void) +{ + if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC) + on_each_cpu(__acpi_nmi_enable, NULL, 0, 1); +} + #ifdef CONFIG_PM static int nmi_pm_active; /* nmi_active before suspend */ diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c index e59cda13416..269fe585e71 100644 --- a/arch/x86_64/kernel/nmi.c +++ b/arch/x86_64/kernel/nmi.c @@ -368,6 +368,33 @@ void enable_timer_nmi_watchdog(void) } } +static void __acpi_nmi_disable(void *__unused) +{ + apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED); +} + +/* + * Disable timer based NMIs on all CPUs: + */ +void acpi_nmi_disable(void) +{ + if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC) + on_each_cpu(__acpi_nmi_disable, NULL, 0, 1); +} + +static void __acpi_nmi_enable(void *__unused) +{ + apic_write(APIC_LVT0, APIC_DM_NMI); +} + +/* + * Enable timer based NMIs on all CPUs: + */ +void acpi_nmi_enable(void) +{ + if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC) + on_each_cpu(__acpi_nmi_enable, NULL, 0, 1); +} #ifdef CONFIG_PM static int nmi_pm_active; /* nmi_active before suspend */ diff --git a/drivers/acpi/namespace/nsinit.c b/drivers/acpi/namespace/nsinit.c index 326af8fc0ce..33db2241044 100644 --- a/drivers/acpi/namespace/nsinit.c +++ b/drivers/acpi/namespace/nsinit.c @@ -45,6 +45,7 @@ #include #include #include +#include #define _COMPONENT ACPI_NAMESPACE ACPI_MODULE_NAME("nsinit") @@ -534,7 +535,15 @@ acpi_ns_init_one_device(acpi_handle obj_handle, info->parameter_type = ACPI_PARAM_ARGS; info->flags = ACPI_IGNORE_RETURN_VALUE; + /* + * Some hardware relies on this being executed as atomically + * as possible (without an NMI being received in the middle of + * this) - so disable NMIs and initialize the device: + */ + acpi_nmi_disable(); status = acpi_ns_evaluate(info); + acpi_nmi_enable(); + if (ACPI_SUCCESS(status)) { walk_info->num_INI++; diff --git a/include/linux/nmi.h b/include/linux/nmi.h index acb4ed13024..29af2d5df09 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -17,8 +17,15 @@ #ifdef ARCH_HAS_NMI_WATCHDOG #include extern void touch_nmi_watchdog(void); +extern void acpi_nmi_disable(void); +extern void acpi_nmi_enable(void); #else -# define touch_nmi_watchdog() touch_softlockup_watchdog() +static inline void touch_nmi_watchdog(void) +{ + touch_softlockup_watchdog(); +} +static inline void acpi_nmi_disable(void) { } +static inline void acpi_nmi_enable(void) { } #endif #ifndef trigger_all_cpu_backtrace -- cgit v1.2.3-70-g09d2 From 9fbbd4dd17d0712054368e5e939e28b2456bfe1b Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 13 Feb 2007 13:26:26 +0100 Subject: [PATCH] x86: Don't require the vDSO for handling a.out signals and in other strange binfmts. vDSO is not necessarily mapped there. Signed-off-by: Andi Kleen --- arch/i386/kernel/signal.c | 6 +++++- arch/x86_64/ia32/ia32_signal.c | 7 ++++++- fs/binfmt_elf.c | 3 ++- include/linux/binfmts.h | 1 + 4 files changed, 14 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/arch/i386/kernel/signal.c b/arch/i386/kernel/signal.c index 8f4afcc7d2a..4f99e870c98 100644 --- a/arch/i386/kernel/signal.c +++ b/arch/i386/kernel/signal.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -349,7 +350,10 @@ static int setup_frame(int sig, struct k_sigaction *ka, goto give_sigsegv; } - restorer = (void *)VDSO_SYM(&__kernel_sigreturn); + if (current->binfmt->hasvdso) + restorer = (void *)VDSO_SYM(&__kernel_sigreturn); + else + restorer = (void *)&frame->retcode; if (ka->sa.sa_flags & SA_RESTORER) restorer = ka->sa.sa_restorer; diff --git a/arch/x86_64/ia32/ia32_signal.c b/arch/x86_64/ia32/ia32_signal.c index 490f7c1b7c8..359eacc3850 100644 --- a/arch/x86_64/ia32/ia32_signal.c +++ b/arch/x86_64/ia32/ia32_signal.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -449,7 +450,11 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka, /* Return stub is in 32bit vsyscall page */ { - void __user *restorer = VSYSCALL32_SIGRETURN; + void __user *restorer; + if (current->binfmt->hasvdso) + restorer = VSYSCALL32_SIGRETURN; + else + restorer = (void *)&frame->retcode; if (ka->sa.sa_flags & SA_RESTORER) restorer = ka->sa.sa_restorer; err |= __put_user(ptr_to_compat(restorer), &frame->pretcode); diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 669dbe5b031..51db1182b27 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -76,7 +76,8 @@ static struct linux_binfmt elf_format = { .load_binary = load_elf_binary, .load_shlib = load_elf_library, .core_dump = elf_core_dump, - .min_coredump = ELF_EXEC_PAGESIZE + .min_coredump = ELF_EXEC_PAGESIZE, + .hasvdso = 1 }; #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index c1e82c51444..2d956cd566a 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -59,6 +59,7 @@ struct linux_binfmt { int (*load_shlib)(struct file *); int (*core_dump)(long signr, struct pt_regs * regs, struct file * file); unsigned long min_coredump; /* minimal dump size */ + int hasvdso; }; extern int register_binfmt(struct linux_binfmt *); -- cgit v1.2.3-70-g09d2