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| author | Joerg Roedel <jroedel@suse.de> | 2018-07-18 11:40:40 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-07-20 01:11:36 +0200 |
| commit | a6b744f3ce9d017dd86b28355de2d8e0d36496d4 (patch) | |
| tree | e2fcd05628125b68ba6da8d71958fa69839f6064 /arch/x86/kernel/process_32.c | |
| parent | ae2e565bc6aaee3f3db420fec5fdd39755c9813e (diff) | |
| download | linux-a6b744f3ce9d017dd86b28355de2d8e0d36496d4.tar.bz2 | |
x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler
x86_tss.sp0 will be used to point to the entry stack later to use it as a
trampoline stack for other kernel entry points besides SYSENTER.
So store the real task stack pointer in x86_tss.sp1, which is otherwise
unused by the hardware, as Linux doesn't make use of Ring 1.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Pavel Machek <pavel@ucw.cz>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Waiman Long <llong@redhat.com>
Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
Cc: joro@8bytes.org
Link: https://lkml.kernel.org/r/1531906876-13451-4-git-send-email-joro@8bytes.org
Diffstat (limited to 'arch/x86/kernel/process_32.c')
| -rw-r--r-- | arch/x86/kernel/process_32.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 0ae659de21eb..ec62cc77388d 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -290,6 +290,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) this_cpu_write(cpu_current_top_of_stack, (unsigned long)task_stack_page(next_p) + THREAD_SIZE); + /* SYSENTER reads the task-stack from tss.sp1 */ + this_cpu_write(cpu_tss_rw.x86_tss.sp1, next_p->thread.sp0); /* * Restore %gs if needed (which is common) |