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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-05-01 21:53:30 -0400 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-05-02 11:27:35 -0700 |
| commit | cc456c4e7cac3837a86aaa7ca3cb9f488d44d196 (patch) | |
| tree | ba510e7fcb4baab33f5853299fef12d73d23343a /arch/x86/power/hibernate_asm_32.S | |
| parent | 5a148af66932c31814e263366094b5812210b501 (diff) | |
| download | linux-cc456c4e7cac3837a86aaa7ca3cb9f488d44d196.tar.bz2 | |
x86, gdt, hibernate: Store/load GDT for hibernate path.
The git commite7a5cd063c7b4c58417f674821d63f5eb6747e37
("x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path
is not needed.") assumes that for the hibernate path the booting
kernel and the resuming kernel MUST be the same. That is certainly
the case for a 32-bit kernel (see check_image_kernel and
CONFIG_ARCH_HIBERNATION_HEADER config option).
However for 64-bit kernels it is OK to have a different kernel
version (and size of the image) of the booting and resuming kernels.
Hence the above mentioned git commit introduces an regression.
This patch fixes it by introducing a 'struct desc_ptr gdt_desc'
back in the 'struct saved_context'. However instead of having in the
'save_processor_state' and 'restore_processor_state' the
store/load_gdt calls, we are only saving the GDT in the
save_processor_state.
For the restore path the lgdt operation is done in
hibernate_asm_[32|64].S in the 'restore_registers' path.
The apt reader of this description will recognize that only 64-bit
kernels need this treatment, not 32-bit. This patch adds the logic
in the 32-bit path to be more similar to 64-bit so that in the future
the unification process can take advantage of this.
[ hpa: this also reverts an inadvertent on-disk format change ]
Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1367459610-9656-2-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/power/hibernate_asm_32.S')
| -rw-r--r-- | arch/x86/power/hibernate_asm_32.S | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S index ad47daeafa4e..1d0fa0e24070 100644 --- a/arch/x86/power/hibernate_asm_32.S +++ b/arch/x86/power/hibernate_asm_32.S @@ -75,6 +75,10 @@ done: pushl saved_context_eflags popfl + /* Saved in save_processor_state. */ + movl $saved_context, %eax + lgdt saved_context_gdt_desc(%eax) + xorl %eax, %eax ret |