linux.git/kernel/kexec.c, branch v3.9-rc2

kexec: avoid freeing NULL pointer in image_crash_alloc()

2013-02-28T03:10:12+00:00

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

2013-02-28T03:10:12+00:00

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

2013-02-28T03:10:12+00:00

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

2013-02-28T03:10:12+00:00

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

2013-02-28T03:10:12+00:00

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.

2013-02-28T03:10:12+00:00

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

2013-01-30T03:32:58+00:00

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

kdump: remove unneeded include

2012-10-05T18:05:19+00:00

The inclusion of  is unnecessary.

Signed-off-by: Wei Yongjun 
Reviewed-by: Simon Horman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kdump: append newline to the last lien of vmcoreinfo note

2012-07-31T00:25:20+00:00

The last line of vmcoreinfo note does not end with \n.  Parsing all the
lines in note becomes easier if all lines end with \n instead of trying to
special case the last line.

I know at least one tool, vmcore-dmesg in kexec-tools tree which made the
assumption that all lines end with \n.  I think it is a good idea to fix
it.

Signed-off-by: Vivek Goyal 
Cc: "Eric W. Biederman" 
Cc: Atsushi Kumagai 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'akpm' (Andrew's patch-bomb)

2012-03-29T00:19:28+00:00

Merge third batch of patches from Andrew Morton:
 - Some MM stragglers
 - core SMP library cleanups (on_each_cpu_mask)
 - Some IPI optimisations
 - kexec
 - kdump
 - IPMI
 - the radix-tree iterator work
 - various other misc bits.

 "That'll do for -rc1.  I still have ~10 patches for 3.4, will send
  those along when they've baked a little more."

* emailed from Andrew Morton : (35 commits)
  backlight: fix typo in tosa_lcd.c
  crc32: add help text for the algorithm select option
  mm: move hugepage test examples to tools/testing/selftests/vm
  mm: move slabinfo.c to tools/vm
  mm: move page-types.c from Documentation to tools/vm
  selftests/Makefile: make `run_tests' depend on `all'
  selftests: launch individual selftests from the main Makefile
  radix-tree: use iterators in find_get_pages* functions
  radix-tree: rewrite gang lookup using iterator
  radix-tree: introduce bit-optimized iterator
  fs/proc/namespaces.c: prevent crash when ns_entries[] is empty
  nbd: rename the nbd_device variable from lo to nbd
  pidns: add reboot_pid_ns() to handle the reboot syscall
  sysctl: use bitmap library functions
  ipmi: use locks on watchdog timeout set on reboot
  ipmi: simplify locking
  ipmi: fix message handling during panics
  ipmi: use a tasklet for handling received messages
  ipmi: increase KCS timeouts
  ipmi: decrease the IPMI message transaction time in interrupt mode
  ...