linux/arch/x86/kernel/asm-offsets_32.c
Joerg Roedel a6b744f3ce 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
2018-07-20 01:11:36 +02:00

68 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
#ifndef __LINUX_KBUILD_H
# error "Please do not build this file directly, build asm-offsets.c instead"
#endif
#include <asm/ucontext.h>
#define __SYSCALL_I386(nr, sym, qual) [nr] = 1,
static char syscalls[] = {
#include <asm/syscalls_32.h>
};
/* workaround for a warning with -Wmissing-prototypes */
void foo(void);
void foo(void)
{
OFFSET(CPUINFO_x86, cpuinfo_x86, x86);
OFFSET(CPUINFO_x86_vendor, cpuinfo_x86, x86_vendor);
OFFSET(CPUINFO_x86_model, cpuinfo_x86, x86_model);
OFFSET(CPUINFO_x86_stepping, cpuinfo_x86, x86_stepping);
OFFSET(CPUINFO_cpuid_level, cpuinfo_x86, cpuid_level);
OFFSET(CPUINFO_x86_capability, cpuinfo_x86, x86_capability);
OFFSET(CPUINFO_x86_vendor_id, cpuinfo_x86, x86_vendor_id);
BLANK();
OFFSET(PT_EBX, pt_regs, bx);
OFFSET(PT_ECX, pt_regs, cx);
OFFSET(PT_EDX, pt_regs, dx);
OFFSET(PT_ESI, pt_regs, si);
OFFSET(PT_EDI, pt_regs, di);
OFFSET(PT_EBP, pt_regs, bp);
OFFSET(PT_EAX, pt_regs, ax);
OFFSET(PT_DS, pt_regs, ds);
OFFSET(PT_ES, pt_regs, es);
OFFSET(PT_FS, pt_regs, fs);
OFFSET(PT_GS, pt_regs, gs);
OFFSET(PT_ORIG_EAX, pt_regs, orig_ax);
OFFSET(PT_EIP, pt_regs, ip);
OFFSET(PT_CS, pt_regs, cs);
OFFSET(PT_EFLAGS, pt_regs, flags);
OFFSET(PT_OLDESP, pt_regs, sp);
OFFSET(PT_OLDSS, pt_regs, ss);
BLANK();
OFFSET(saved_context_gdt_desc, saved_context, gdt_desc);
BLANK();
/*
* Offset from the entry stack to task stack stored in TSS. Kernel entry
* happens on the per-cpu entry-stack, and the asm code switches to the
* task-stack pointer stored in x86_tss.sp1, which is a copy of
* task->thread.sp0 where entry code can find it.
*/
DEFINE(TSS_entry2task_stack,
offsetof(struct cpu_entry_area, tss.x86_tss.sp1) -
offsetofend(struct cpu_entry_area, entry_stack_page.stack));
#ifdef CONFIG_STACKPROTECTOR
BLANK();
OFFSET(stack_canary_offset, stack_canary, canary);
#endif
BLANK();
DEFINE(__NR_syscall_max, sizeof(syscalls) - 1);
DEFINE(NR_syscalls, sizeof(syscalls));
}