The purgatory code defines global variables which are referenced via a
symbol lookup in the kexec code (core and arch).
A recent commit addressing sparse warnings made these static and thereby
broke kexec_file.
Why did this happen? Simply because the whole machinery is undocumented and
lacks any form of forward declarations. The variable names are unspecific
and lack a prefix, so adding forward declarations creates shadow variables
in the core code. Aside of that the code relies on magic constants and
duplicate struct definitions with no way to ensure that these things stay
in sync. The section placement of the purgatory variables happened by
chance and not by design.
Unbreak kexec and cleanup the mess:
- Add proper forward declarations and document the usage
- Use common struct definition
- Use the proper common defines instead of magic constants
- Add a purgatory_ prefix to have a proper name space
- Use ARRAY_SIZE() instead of a homebrewn reimplementation
- Add proper sections to the purgatory variables [ From Mike ]
Fixes: 72042a8c7b ("x86/purgatory: Make functions and variables static")
Reported-by: Mike Galbraith <<efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Tobin C. Harding" <me@tobin.cc>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1703101315140.3681@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Allow architectures to specify a different memory walking function for
kexec_add_buffer. x86 uses iomem to track reserved memory ranges, but
PowerPC uses the memblock subsystem.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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 <xlpang@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Thomas Gleixner
Thiago Jung Bauermann
Xunlei Pang
Dave Young