linux-toradex.git/include/linux/kexec.h, branch v4.6-rc7

kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE

2016-01-21T01:09:18+00:00

Move the stuff currently only used by the kexec file code within
CONFIG_KEXEC_FILE (and CONFIG_KEXEC_VERIFY_SIG).

Also move internal "struct kexec_sha_region" and "struct kexec_buf" into
"kexec_internal.h".

Signed-off-by: Xunlei Pang 
Cc: "Eric W. Biederman" 
Cc: Dave Young 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kexec: Fix race between panic() and crash_kexec()

2015-12-19T10:07:01+00:00

Currently, panic() and crash_kexec() can be called at the same time.
For example (x86 case):

CPU 0:
  oops_end()
    crash_kexec()
      mutex_trylock() // acquired
        nmi_shootdown_cpus() // stop other CPUs

CPU 1:
  panic()
    crash_kexec()
      mutex_trylock() // failed to acquire
    smp_send_stop() // stop other CPUs
    infinite loop

If CPU 1 calls smp_send_stop() before nmi_shootdown_cpus(), kdump
fails.

In another case:

CPU 0:
  oops_end()
    crash_kexec()
      mutex_trylock() // acquired
        
        io_check_error()
          panic()
            crash_kexec()
              mutex_trylock() // failed to acquire
            infinite loop

Clearly, this is an undesirable result.

To fix this problem, this patch changes crash_kexec() to exclude others
by using the panic_cpu atomic.

Signed-off-by: Hidehiro Kawai 
Acked-by: Michal Hocko 
Cc: Andrew Morton 
Cc: Baoquan He 
Cc: Dave Young 
Cc: "Eric W. Biederman" 
Cc: HATAYAMA Daisuke 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Jonathan Corbet 
Cc: kexec@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: Martin Schwidefsky 
Cc: Masami Hiramatsu 
Cc: Minfei Huang 
Cc: Peter Zijlstra 
Cc: Seth Jennings 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Cc: Vitaly Kuznetsov 
Cc: Vivek Goyal 
Cc: x86-ml 
Link: http://lkml.kernel.org/r/20151210014630.25437.94161.stgit@softrs
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner

kexec: split kexec_load syscall from kexec core code

2015-09-10T20:29:01+00:00

There are two kexec load syscalls, kexec_load another and kexec_file_load.
 kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
split kexec_load syscall code to kernel/kexec.c.

And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.

The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
kexec_load syscall can bypass the checking.

Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.

Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
kexec_load syscall.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young 
Cc: Eric W. Biederman 
Cc: Vivek Goyal 
Cc: Petr Tesarik 
Cc: Theodore Ts'o 
Cc: Josh Boyer 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kexec: split kexec_file syscall code to kexec_file.c

2015-09-10T20:29:01+00:00

Split kexec_file syscall related code to another file kernel/kexec_file.c
so that the #ifdef CONFIG_KEXEC_FILE in kexec.c can be dropped.

Sharing variables and functions are moved to kernel/kexec_internal.h per
suggestion from Vivek and Petr.

[akpm@linux-foundation.org: fix bisectability]
[akpm@linux-foundation.org: declare the various arch_kexec functions]
[akpm@linux-foundation.org: fix build]
Signed-off-by: Dave Young 
Cc: Eric W. Biederman 
Cc: Vivek Goyal 
Cc: Petr Tesarik 
Cc: Theodore Ts'o 
Cc: Josh Boyer 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kexec: define kexec_in_progress in !CONFIG_KEXEC case

2015-08-05T05:25:28+00:00

If some piece of code wants to check kexec_in_progress it has to be put
in #ifdef CONFIG_KEXEC block to not break the build in !CONFIG_KEXEC
case. Overcome this limitation by defining kexec_in_progress to false.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

kexec: allocate the kexec control page with KEXEC_CONTROL_MEMORY_GFP

2015-04-23T14:52:01+00:00

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

kexec: add IND_FLAGS macro

2015-02-17T22:34:51+00:00

Add a new kexec preprocessor macro IND_FLAGS, which is the bitwise OR of
all the possible kexec IND_ kimage_entry indirection flags.  Having this
macro allows for simplified code in the prosessing of the kexec
kimage_entry items.  Also, remove the local powerpc definition and use the
generic one.

Signed-off-by: Geoff Levand 
Acked-by: Benjamin Herrenschmidt 
Acked-by: Vivek Goyal 
Cc: Arnd Bergmann 
Cc: Maximilian Attems 
Cc: Michal Marek 
Cc: H. Peter Anvin 
Cc: Paul Bolle 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kexec: add bit definitions for kimage entry flags

2015-02-17T22:34:51+00:00

Define new kexec preprocessor macros IND_*_BIT that define the bit
position of the kimage entry flags.  Change the existing IND_* flag macros
to be defined as bit shifts of the corresponding IND_*_BIT macros.  Also
wrap all C language code in kexec.h with #if !defined(__ASSEMBLY__) so
assembly files can include kexec.h to get the IND_* and IND_*_BIT macros.

Some CPU instruction sets have tests for bit position which are convenient
in implementing routines that operate on the kimage entry list.  The
addition of these bit position macros in a common location will avoid
duplicate definitions and the chance that changes to the IND_* flags will
not be propagated to assembly files.

Signed-off-by: Geoff Levand 
Acked-by: Vivek Goyal 
Cc: Arnd Bergmann 
Cc: Benjamin Herrenschmidt 
Cc: H. Peter Anvin 
Cc: Maximilian Attems 
Cc: Michal Marek 
Cc: Paul Bolle 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kexec: remove never used member destination in kimage

2015-02-17T22:34:51+00:00

struct kimage has a member destination which is used to store the real
destination address of each page when load segment from user space buffer
to kernel.  But we never retrieve the value stored in kimage->destination,
so this member variable in kimage and its assignment operation are
redundent code.

I guess for_each_kimage_entry just does the work that kimage->destination
is expected to do.

So in this patch just make a cleanup to remove it.

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

kexec: take the segment adding out of locate_mem_hole functions

2014-10-14T00:18:21+00:00

In locate_mem_hole functions, a memory hole is located and added as
kexec_segment.  But from the name of locate_mem_hole, it should only take
responsibility of searching a available memory hole to contain data of a
specified size.

So in this patch add a new field 'mem' into kexec_buf, then take that
kexec segment adding code out of locate_mem_hole_top_down and
locate_mem_hole_bottom_up.  This make clear of the functionality of
locate_mem_hole just like it declars to do.  And by this
locate_mem_hole_callback chould be used later if anyone want to locate a
memory hole for other use.

Meanwhile Vivek suggested opening code function __kexec_add_segment(),
that way we have to retreive ksegment pointer once and it is easy to read.
 So just do it in this patch and remove __kexec_add_segment() since no one
use it anymore.

Signed-off-by: Baoquan He 
Acked-by: Vivek Goyal 
Cc: Eric W. Biederman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds