user/sven/linux.git/kernel/kexec.c, branch v3.9

kexec: use Crash kernel for Crash kernel low

2013-04-17T19:35:34Z

We can extend kexec-tools to support multiple "Crash kernel" in /proc/iomem instead. So we can use "Crash kernel" instead of "Crash kernel low" in /proc/iomem. Suggested-by: Vivek Goyal Signed-off-by: Yinghai Lu Link: http://lkml.kernel.org/r/1366089828-19692-3-git-send-email-yinghai@kernel.org Acked-by: Vivek Goyal Signed-off-by: H. Peter Anvin

x86, kdump: Change crashkernel_high/low= to crashkernel=,high/low

2013-04-17T19:35:33Z

Per hpa, use crashkernel=X,high crashkernel=Y,low instead of crashkernel_hign=X crashkernel_low=Y. As that could be extensible. -v2: according to Vivek, change delimiter to ; -v3: let hign and low only handle simple form and it conforms to description in kernel-parameters.txt still keep crashkernel=X override any crashkernel=X,high crashkernel=Y,low -v4: update get_last_crashkernel returning and add more strict checking in parse_crashkernel_simple() found by HATAYAMA. -v5: Change delimiter back to , according to HPA. also separate parse_suffix from parse_simper according to vivek. so we can avoid @pos in that path. -v6: Tight the checking about crashkernel=X,highblahblah,high found by HTYAYAMA. Cc: HATAYAMA Daisuke Signed-off-by: Yinghai Lu Link: http://lkml.kernel.org/r/1366089828-19692-5-git-send-email-yinghai@kernel.org Acked-by: Vivek Goyal Signed-off-by: H. Peter Anvin

x86, kdump: Retore crashkernel= to allocate under 896M

2013-04-17T19:35:33Z

Vivek found old kexec-tools does not work new kernel anymore. So change back crashkernel= back to old behavoir, and add crashkernel_high= to let user decide if buffer could be above 4G, and also new kexec-tools will be needed. -v2: let crashkernel=X override crashkernel_high= update description about _high will be ignored by crashkernel=X -v3: update description about kernel-parameters.txt according to Vivek. Signed-off-by: Yinghai Lu Link: http://lkml.kernel.org/r/1366089828-19692-4-git-send-email-yinghai@kernel.org Acked-by: Vivek Goyal Signed-off-by: H. Peter Anvin

kexec: avoid freeing NULL pointer in image_crash_alloc()

2013-02-28T03:10:12Z

Though there is no error if we free a NULL pointer, I think we could avoid this behaviour. Change the code a little in kimage_crash_alloc() could avoid this kind of unnecessary free. Signed-off-by: Zhang Yanfei Cc: "Eric W. Biederman" Cc: Sasha Levin Reviewed-by: Simon Horman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: fix memory leak in function kimage_normal_alloc

2013-02-28T03:10:12Z

If kimage_normal_alloc() fails to alloc pages for image->swap_page, it should call kimage_free_page_list() to free allocated pages in image->control_pages list before it frees image. Signed-off-by: Zhang Yanfei Cc: "Eric W. Biederman" Cc: Sasha Levin Reviewed-by: Simon Horman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: prevent double free on image allocation failure

2013-02-28T03:10:12Z

If kimage_normal_alloc() fails to initialize an allocated kimage, it will free the image but would still set 'rimage', as a result kexec_load will try to free it again. This would explode as part of the freeing process is accessing internal members which point to uninitialized memory. Signed-off-by: Sasha Levin Cc: "Eric W. Biederman" Cc: Zhang Yanfei Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: export PG_hwpoison flag into vmcoreinfo

2013-02-28T03:10:12Z

This patch exports a PG_hwpoison into vmcoreinfo when CONFIG_MEMORY_FAILURE is defined. "makedumpfile" needs to read information of memory, such as 'mem_section', 'zone', 'pageflags' from vmcore. We introduce a function into "makedumpfile" to exclude hwpoison page from vmcore dump. In order to introduce this function, PG_hwpoison flag have to export into vmcoreinfo. Signed-off-by: Mitsuhiro Tanino Acked-by: "Eric W. Biederman" Cc: Mitsuhiro Tanino Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: get rid of duplicate check for hole_end

2013-02-28T03:10:12Z

hole_end has been checked to make sure it is <= crash_res.end in the while condition check, so the if condition check is duplicate. Signed-off-by: Zhang Yanfei Reviewed-by: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec: add the values related to buddy system for filtering free pages.

2013-02-28T03:10:12Z

tAdd adds the values related to buddy system to vmcoreinfo data so that makedumpfile (dump filtering command) can filter out all free pages with the new logic. It's faster than the current logic because it can distinguish free page by analyzing page structure at the same time as filtering for other unnecessary pages (e.g. anonymous page). OTOH, the current logic has to trace free_list to distinguish free pages while analyzing page structure to filter out other unnecessary pages. The new logic uses the fact that buddy page is marked by _mapcount == PAGE_BUDDY_MAPCOUNT_VALUE. But, _mapcount shares its memory with other fields for SLAB/SLUB when PG_slab is set, so we need to check if PG_slab is set or not before looking up _mapcount value. And we can get the order of buddy system from private field. To sum it up, the values below are required for this logic. Required values: - OFFSET(page._mapcount) - OFFSET(page.private) - NUMBER(PG_slab) - NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE) Changelog from v1 to v2: 1. remove SIZE(pageflags) The new logic was changed after I sent v1 patch. Accordingly, SIZE(pageflags) has been unnecessary for makedumpfile. What's makedumpfile: makedumpfile creates a small dumpfile by excluding unnecessary pages for the analysis. To distinguish unnecessary pages, makedumpfile gets the vmcoreinfo data which has the minimum debugging information only for dump filtering. Signed-off-by: Atsushi Kumagai Cc: "Eric W. Biederman" Acked-by: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

x86: Add Crash kernel low reservation

2013-01-30T03:32:58Z

During kdump kernel's booting stage, it need to find low ram for swiotlb buffer when system does not support intel iommu/dmar remapping. kexed-tools is appending memmap=exactmap and range from /proc/iomem with "Crash kernel", and that range is above 4G for 64bit after boot protocol 2.12. We need to add another range in /proc/iomem like "Crash kernel low", so kexec-tools could find that info and append to kdump kernel command line. Try to reserve some under 4G if the normal "Crash kernel" is above 4G. User could specify the size with crashkernel_low=XX[KMG]. -v2: fix warning that is found by Fengguang's test robot. -v3: move out get_mem_size change to another patch, to solve compiling warning that is found by Borislav Petkov -v4: user must specify crashkernel_low if system does not support intel or amd iommu. Signed-off-by: Yinghai Lu Link: http://lkml.kernel.org/r/1359058816-7615-31-git-send-email-yinghai@kernel.org Cc: Eric Biederman Cc: Rob Landley Signed-off-by: H. Peter Anvin