From bcda53faf5814c0c6025a0bd47108adfcbe9f199 Mon Sep 17 00:00:00 2001 From: "Srivatsa S. Bhat" Date: Wed, 7 Dec 2011 22:29:54 +0100 Subject: PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep() Using [un]lock_system_sleep() is safer than directly using mutex_[un]lock() on 'pm_mutex', since the latter could lead to freezing failures. Hence convert all the present users of mutex_[un]lock(&pm_mutex) to use these safe APIs instead. Suggested-by: Tejun Heo Signed-off-by: Srivatsa S. Bhat Reviewed-by: Simon Horman Signed-off-by: Rafael J. Wysocki --- kernel/kexec.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/kexec.c') diff --git a/kernel/kexec.c b/kernel/kexec.c index dc7bc0829286..090ee10d9604 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -1523,7 +1523,7 @@ int kernel_kexec(void) #ifdef CONFIG_KEXEC_JUMP if (kexec_image->preserve_context) { - mutex_lock(&pm_mutex); + lock_system_sleep(); pm_prepare_console(); error = freeze_processes(); if (error) { @@ -1576,7 +1576,7 @@ int kernel_kexec(void) thaw_processes(); Restore_console: pm_restore_console(); - mutex_unlock(&pm_mutex); + unlock_system_sleep(); } #endif -- cgit v1.2.3 From a3dd3323058d281abd584b15ad4c5b65064d7a61 Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Thu, 12 Jan 2012 17:20:11 -0800 Subject: kexec: remove KMSG_DUMP_KEXEC KMSG_DUMP_KEXEC is useless because we already save kernel messages inside /proc/vmcore, and it is unsafe to allow modules to do other stuffs in a crash dump scenario. [akpm@linux-foundation.org: fix powerpc build] Signed-off-by: WANG Cong Reported-by: Vivek Goyal Acked-by: Vivek Goyal Acked-by: Jarod Wilson Cc: "Eric W. Biederman" Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/powerpc/platforms/pseries/nvram.c | 1 - drivers/char/ramoops.c | 3 +-- drivers/mtd/mtdoops.c | 3 +-- include/linux/kmsg_dump.h | 1 - kernel/kexec.c | 3 --- 5 files changed, 2 insertions(+), 9 deletions(-) (limited to 'kernel/kexec.c') diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c index 330a57b7c17c..36f957f31842 100644 --- a/arch/powerpc/platforms/pseries/nvram.c +++ b/arch/powerpc/platforms/pseries/nvram.c @@ -638,7 +638,6 @@ static void oops_to_nvram(struct kmsg_dumper *dumper, /* These are almost always orderly shutdowns. */ return; case KMSG_DUMP_OOPS: - case KMSG_DUMP_KEXEC: break; case KMSG_DUMP_PANIC: panicking = true; diff --git a/drivers/char/ramoops.c b/drivers/char/ramoops.c index 7c7f42a1f880..feda90cdac9f 100644 --- a/drivers/char/ramoops.c +++ b/drivers/char/ramoops.c @@ -83,8 +83,7 @@ static void ramoops_do_dump(struct kmsg_dumper *dumper, struct timeval timestamp; if (reason != KMSG_DUMP_OOPS && - reason != KMSG_DUMP_PANIC && - reason != KMSG_DUMP_KEXEC) + reason != KMSG_DUMP_PANIC) return; /* Only dump oopses if dump_oops is set */ diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c index db8e8272d69b..3ce99e00a49e 100644 --- a/drivers/mtd/mtdoops.c +++ b/drivers/mtd/mtdoops.c @@ -315,8 +315,7 @@ static void mtdoops_do_dump(struct kmsg_dumper *dumper, char *dst; if (reason != KMSG_DUMP_OOPS && - reason != KMSG_DUMP_PANIC && - reason != KMSG_DUMP_KEXEC) + reason != KMSG_DUMP_PANIC) return; /* Only dump oopses if dump_oops is set */ diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h index ee0c952188de..fee66317e071 100644 --- a/include/linux/kmsg_dump.h +++ b/include/linux/kmsg_dump.h @@ -18,7 +18,6 @@ enum kmsg_dump_reason { KMSG_DUMP_OOPS, KMSG_DUMP_PANIC, - KMSG_DUMP_KEXEC, KMSG_DUMP_RESTART, KMSG_DUMP_HALT, KMSG_DUMP_POWEROFF, diff --git a/kernel/kexec.c b/kernel/kexec.c index 090ee10d9604..20ed47ae252f 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -32,7 +32,6 @@ #include #include #include -#include #include #include @@ -1094,8 +1093,6 @@ void crash_kexec(struct pt_regs *regs) if (kexec_crash_image) { struct pt_regs fixed_regs; - kmsg_dump(KMSG_DUMP_KEXEC); - crash_setup_regs(&fixed_regs, regs); crash_save_vmcoreinfo(); machine_crash_shutdown(&fixed_regs); -- cgit v1.2.3 From 6480e5a0923756b500634d9777ec4189492fbbfe Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Thu, 12 Jan 2012 17:20:14 -0800 Subject: kdump: add missing RAM resource in crash_shrink_memory() When shrinking crashkernel memory using /sys/kernel/kexec_crash_size for the newly added memory no RAM resource is created at the moment. Example: $ cat /proc/iomem 00000000-bfffffff : System RAM 00000000-005b7ac3 : Kernel code 005b7ac4-009743bf : Kernel data 009bb000-00a85c33 : Kernel bss c0000000-cfffffff : Crash kernel d0000000-ffffffff : System RAM $ echo 0 > /sys/kernel/kexec_crash_size $ cat /proc/iomem 00000000-bfffffff : System RAM 00000000-005b7ac3 : Kernel code 005b7ac4-009743bf : Kernel data 009bb000-00a85c33 : Kernel bss <<-- here is System RAM missing d0000000-ffffffff : System RAM One result of this bug is that the memory chunk can never be set offline using memory hotplug. With this patch I insert a new "System RAM" resource for the released memory. Then the upper example looks like the following: $ echo 0 > /sys/kernel/kexec_crash_size $ cat /proc/iomem 00000000-bfffffff : System RAM 00000000-005b7ac3 : Kernel code 005b7ac4-009743bf : Kernel data 009bb000-00a85c33 : Kernel bss c0000000-cfffffff : System RAM <<-- new rescoure d0000000-ffffffff : System RAM And now I can set chunk c0000000-cfffffff offline. Signed-off-by: Michael Holzheu Cc: Vivek Goyal Cc: "Eric W. Biederman" Cc: Heiko Carstens Cc: Martin Schwidefsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kexec.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'kernel/kexec.c') diff --git a/kernel/kexec.c b/kernel/kexec.c index 20ed47ae252f..60bf181b3eae 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -1129,6 +1129,7 @@ int crash_shrink_memory(unsigned long new_size) { int ret = 0; unsigned long start, end; + struct resource *ram_res; mutex_lock(&kexec_mutex); @@ -1146,6 +1147,12 @@ int crash_shrink_memory(unsigned long new_size) goto unlock; } + ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); + if (!ram_res) { + ret = -ENOMEM; + goto unlock; + } + start = roundup(start, KEXEC_CRASH_MEM_ALIGN); end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN); @@ -1154,7 +1161,15 @@ int crash_shrink_memory(unsigned long new_size) if ((start == end) && (crashk_res.parent != NULL)) release_resource(&crashk_res); + + ram_res->start = end; + ram_res->end = crashk_res.end; + ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM; + ram_res->name = "System RAM"; + crashk_res.end = end - 1; + + insert_resource(&iomem_resource, ram_res); crash_unmap_reserved_pages(); unlock: -- cgit v1.2.3 From bec013c40bc89671d8d457944fdf7d2b8e79d651 Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Thu, 12 Jan 2012 17:20:15 -0800 Subject: kdump: crashk_res init check for /sys/kernel/kexec_crash_size Currently it is possible to set the crash_size via the sysfs /sys/kernel/kexec_crash_size even if no crash kernel memory has been defined with the "crashkernel" parameter. In this case "crashk_res" is not initialized and crashk_res.start = crashk_res.end = 0. Unfortunately resource_size(&crashk_res) returns 1 in this case. This breaks the s390 implementation of crash_(un)map_reserved_pages(). To fix the problem the correct "old_size" is now calculated in crash_shrink_memory(). "old_size is set to "0" if crashk_res is not initialized. With this change crash_shrink_memory() will do nothing, when "crashk_res" is not initialized. It will return "0" for "echo 0 > /sys/kernel/kexec_crash_size" and -EINVAL for "echo [not zero] > /sys/kernel/kexec_crash_size". In addition to that this patch also simplifies the "ret = -EINVAL" vs. "ret = 0" logic as suggested by Simon Horman. Signed-off-by: Michael Holzheu Reviewed-by: Dave Young Reviewed-by: WANG Cong Reviewed-by: Simon Horman Cc: Vivek Goyal Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kexec.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'kernel/kexec.c') diff --git a/kernel/kexec.c b/kernel/kexec.c index 60bf181b3eae..7b0886786701 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -1129,6 +1129,7 @@ int crash_shrink_memory(unsigned long new_size) { int ret = 0; unsigned long start, end; + unsigned long old_size; struct resource *ram_res; mutex_lock(&kexec_mutex); @@ -1139,11 +1140,9 @@ int crash_shrink_memory(unsigned long new_size) } start = crashk_res.start; end = crashk_res.end; - - if (new_size >= end - start + 1) { - ret = -EINVAL; - if (new_size == end - start + 1) - ret = 0; + old_size = (end == 0) ? 0 : end - start + 1; + if (new_size >= old_size) { + ret = (new_size == old_size) ? 0 : -EINVAL; goto unlock; } -- cgit v1.2.3