user/sven/linux.git/kernel/kexec.c, branch v3.12.59

kexec: allocate the kexec control page with KEXEC_CONTROL_MEMORY_GFP

2015-08-04T14:51:58Z

commit 7e01b5acd88b3f3108d8c4ce44e3205d67437202 upstream. Introduce KEXEC_CONTROL_MEMORY_GFP to allow the architecture code to override the gfp flags of the allocation for the kexec control page. The loop in kimage_alloc_normal_control_pages allocates pages with GFP_KERNEL until a page is found that happens to have an address smaller than the KEXEC_CONTROL_MEMORY_LIMIT. On systems with a large memory size but a small KEXEC_CONTROL_MEMORY_LIMIT the loop will keep allocating memory until the oom killer steps in. Signed-off-by: Martin Schwidefsky Signed-off-by: Jiri Slaby

powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST mode

2014-06-09T13:53:57Z

commit 011e4b02f1da156ac7fea28a9da878f3c23af739 upstream. If we try to perform a kexec when the machine is in ST (Single-Threaded) mode (ppc64_cpu --smt=off), the kexec operation doesn't succeed properly, and we get the following messages during boot: [ 0.089866] POWER8 performance monitor hardware support registered [ 0.089985] power8-pmu: PMAO restore workaround active. [ 5.095419] Processor 1 is stuck. [ 10.097933] Processor 2 is stuck. [ 15.100480] Processor 3 is stuck. [ 20.102982] Processor 4 is stuck. [ 25.105489] Processor 5 is stuck. [ 30.108005] Processor 6 is stuck. [ 35.110518] Processor 7 is stuck. [ 40.113369] Processor 9 is stuck. [ 45.115879] Processor 10 is stuck. [ 50.118389] Processor 11 is stuck. [ 55.120904] Processor 12 is stuck. [ 60.123425] Processor 13 is stuck. [ 65.125970] Processor 14 is stuck. [ 70.128495] Processor 15 is stuck. [ 75.131316] Processor 17 is stuck. Note that only the sibling threads are stuck, while the primary threads (0, 8, 16 etc) boot just fine. Looking closer at the previous step of kexec, we observe that kexec tries to wakeup (bring online) the sibling threads of all the cores, before performing kexec: [ 9464.131231] Starting new kernel [ 9464.148507] kexec: Waking offline cpu 1. [ 9464.148552] kexec: Waking offline cpu 2. [ 9464.148600] kexec: Waking offline cpu 3. [ 9464.148636] kexec: Waking offline cpu 4. [ 9464.148671] kexec: Waking offline cpu 5. [ 9464.148708] kexec: Waking offline cpu 6. [ 9464.148743] kexec: Waking offline cpu 7. [ 9464.148779] kexec: Waking offline cpu 9. [ 9464.148815] kexec: Waking offline cpu 10. [ 9464.148851] kexec: Waking offline cpu 11. [ 9464.148887] kexec: Waking offline cpu 12. [ 9464.148922] kexec: Waking offline cpu 13. [ 9464.148958] kexec: Waking offline cpu 14. [ 9464.148994] kexec: Waking offline cpu 15. [ 9464.149030] kexec: Waking offline cpu 17. Instrumenting this piece of code revealed that the cpu_up() operation actually fails with -EBUSY. Thus, only the primary threads of all the cores are online during kexec, and hence this is a sure-shot receipe for disaster, as explained in commit e8e5c2155b (powerpc/kexec: Fix orphaned offline CPUs across kexec), as well as in the comment above wake_offline_cpus(). It turns out that cpu_up() was returning -EBUSY because the variable 'cpu_hotplug_disabled' was set to 1; and this disabling of CPU hotplug was done by migrate_to_reboot_cpu() inside kernel_kexec(). Now, migrate_to_reboot_cpu() was originally written with the assumption that any further code will not need to perform CPU hotplug, since we are anyway in the reboot path. However, kexec is clearly not such a case, since we depend on onlining CPUs, atleast on powerpc. So re-enable cpu-hotplug after returning from migrate_to_reboot_cpu() in the kexec path, to fix this regression in kexec on powerpc. Also, wrap the cpu_up() in powerpc kexec code within a WARN_ON(), so that we can catch such issues more easily in the future. Fixes: c97102ba963 (kexec: migrate to reboot cpu) Signed-off-by: Srivatsa S. Bhat Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Jiri Slaby

kexec: migrate to reboot cpu

2014-01-09T20:25:07Z

commit c97102ba96324da330078ad8619ba4dfe840dbe3 upstream. Commit 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") moved reboot= handling to generic code. In the process it also removed the code in native_machine_shutdown() which are moving reboot process to reboot_cpu/cpu0. I guess that thought must have been that all reboot paths are calling migrate_to_reboot_cpu(), so we don't need this special handling. But kexec reboot path (kernel_kexec()) is not calling migrate_to_reboot_cpu() so above change broke kexec. Now reboot can happen on non-boot cpu and when INIT is sent in second kerneo to bring up BP, it brings down the machine. So start calling migrate_to_reboot_cpu() in kexec reboot path to avoid this problem. Bisected by WANG Chao. Reported-by: Matthew Whitehead Reported-by: Dave Young Signed-off-by: Vivek Goyal Tested-by: Baoquan He Tested-by: WANG Chao Acked-by: H. Peter Anvin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

PCI: Disable Bus Master only on kexec reboot

2013-12-20T15:48:54Z

commit 4fc9bbf98fd66f879e628d8537ba7c240be2b58e upstream. Add a flag to tell the PCI subsystem that kernel is shutting down in preparation to kexec a kernel. Add code in PCI subsystem to use this flag to clear Bus Master bit on PCI devices only in case of kexec reboot. This fixes a power-off problem on Acer Aspire V5-573G and likely other machines and avoids any other issues caused by clearing Bus Master bit on PCI devices in normal shutdown path. The problem was introduced by b566a22c2332 ("PCI: disable Bus Master on PCI device shutdown"). This patch is based on discussion at http://marc.info/?l=linux-pci&m=138425645204355&w=2 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63861 Reported-by: Chang Liu Signed-off-by: Khalid Aziz Signed-off-by: Bjorn Helgaas Acked-by: Konstantin Khlebnikov Signed-off-by: Greg Kroah-Hartman

kexec: remove unnecessary return

2013-09-11T22:59:10Z

Code can not run here forever, so remove the unnecessary return. Signed-off-by: Xishi Qiu Suggested-by: Zhang Yanfei Reviewed-by: Simon Horman Reviewed-by: Zhang Yanfei Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: Use min() and min_t() to simplify logic

2013-05-01T00:04:07Z

Simplify the logic of variable assignments. [akpm@linux-foundation.org: replace min_t with min, remove unneeded casts] Signed-off-by: Zhang Yanfei Cc: "Eric W. Biederman" Reviewed-by: Simon Horman Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: fix wrong types of some local variables

2013-05-01T00:04:07Z

The types of the following local variables: - ubytes/mbytes in kimage_load_crash_segment()/kimage_load_normal_segment() - r in vmcoreinfo_append_str() are wrong, so fix them. Signed-off-by: Zhang Yanfei Cc: "Eric W. Biederman" Cc: Simon Horman Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec, vmalloc: export additional vmalloc layer information

2013-04-29T22:54:34Z

Now, vmap_area_list is exported as VMCOREINFO for makedumpfile to get the start address of vmalloc region (vmalloc_start). The address which contains vmalloc_start value is represented as below: vmap_area_list.next - OFFSET(vmap_area.list) + OFFSET(vmap_area.va_start) However, both OFFSET(vmap_area.va_start) and OFFSET(vmap_area.list) aren't exported as VMCOREINFO. So this patch exports them externally with small cleanup. [akpm@linux-foundation.org: vmalloc.h should include list.h for list_head] Signed-off-by: Atsushi Kumagai Cc: Joonsoo Kim Cc: Joonsoo Kim Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: Atsushi Kumagai Cc: Chris Metcalf Cc: Dave Anderson Cc: Eric Biederman Cc: Guan Xuetao Cc: Ingo Molnar Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, vmalloc: export vmap_area_list, instead of vmlist

2013-04-29T22:54:34Z

Although our intention is to unexport internal structure entirely, but there is one exception for kexec. kexec dumps address of vmlist and makedumpfile uses this information. We are about to remove vmlist, then another way to retrieve information of vmalloc layer is needed for makedumpfile. For this purpose, we export vmap_area_list, instead of vmlist. Signed-off-by: Joonsoo Kim Signed-off-by: Joonsoo Kim Cc: Eric Biederman Cc: Dave Anderson Cc: Vivek Goyal Cc: Atsushi Kumagai Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: Chris Metcalf Cc: Guan Xuetao Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm,kexec: use common help functions to free reserved pages

2013-04-29T22:54:31Z

Use common help functions to free reserved pages. Signed-off-by: Jiang Liu Cc: Eric Biederman Reviewed-by: Zhang Yanfei Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds