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x86/entry, x86/paravirt: Remove the unused usergs_sysret32 PV op

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As result of commit "x86/xen: Avoid fast syscall path for Xen PV
guests", usergs_sysret32 pv op is not called by Xen PV guests
anymore and since they were the only ones who used it we can
safely remove it.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: david.vrabel@citrix.com
Cc: konrad.wilk@oracle.com
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1447970147-1733-4-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Boris Ostrovsky 2015-11-19 16:55:47 -05:00 committed by Ingo Molnar
parent 88c15ec90f
commit 75ef82190d
7 changed files with 2 additions and 48 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
arch/x86/entry/entry_64_compat.S
View file

@ -18,13 +18,6 @@
.section .entry.text, "ax"
#ifdef CONFIG_PARAVIRT
ENTRY(native_usergs_sysret32)
swapgs
sysretl
ENDPROC(native_usergs_sysret32)
#endif
/*
* 32-bit SYSENTER instruction entry.
*
@ -238,7 +231,8 @@ sysret32_from_system_call:
xorq %r9, %r9
xorq %r10, %r10
movq RSP-ORIG_RAX(%rsp), %rsp
USERGS_SYSRET32
swapgs
sysretl
END(entry_SYSCALL_compat)
/*

5
arch/x86/include/asm/paravirt.h
View file

@ -922,11 +922,6 @@ extern void default_banner(void);
call PARA_INDIRECT(pv_irq_ops+PV_IRQ_irq_enable); \
PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE);)
#define USERGS_SYSRET32 \
PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usergs_sysret32), \
CLBR_NONE, \
jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_usergs_sysret32))
#ifdef CONFIG_X86_32
#define GET_CR0_INTO_EAX \
push %ecx; push %edx; \

8
arch/x86/include/asm/paravirt_types.h
View file

@ -165,14 +165,6 @@ struct pv_cpu_ops {
*/
void (*usergs_sysret64)(void);
/*
* Switch to usermode gs and return to 32-bit usermode using
* sysret. Used to return to 32-on-64 compat processes.
* Other usermode register state, including %esp, must already
* be restored.
*/
void (*usergs_sysret32)(void);
/* Normal iret. Jump to this with the standard iret stack
frame set up. */
void (*iret)(void);

1
arch/x86/kernel/asm-offsets_64.c
View file

@ -23,7 +23,6 @@ int main(void)
{
#ifdef CONFIG_PARAVIRT
OFFSET(PV_IRQ_adjust_exception_frame, pv_irq_ops, adjust_exception_frame);
OFFSET(PV_CPU_usergs_sysret32, pv_cpu_ops, usergs_sysret32);
OFFSET(PV_CPU_usergs_sysret64, pv_cpu_ops, usergs_sysret64);
OFFSET(PV_CPU_swapgs, pv_cpu_ops, swapgs);
BLANK();

5
arch/x86/kernel/paravirt.c
View file

@ -162,7 +162,6 @@ unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf,
ret = paravirt_patch_ident_64(insnbuf, len);
else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) ||
type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) ||
type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64))
/* If operation requires a jmp, then jmp */
ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len);
@ -217,7 +216,6 @@ static u64 native_steal_clock(int cpu)
/* These are in entry.S */
extern void native_iret(void);
extern void native_usergs_sysret32(void);
extern void native_usergs_sysret64(void);
static struct resource reserve_ioports = {
@ -376,9 +374,6 @@ __visible struct pv_cpu_ops pv_cpu_ops = {
.load_sp0 = native_load_sp0,
#ifdef CONFIG_X86_64
#ifdef CONFIG_IA32_EMULATION
.usergs_sysret32 = native_usergs_sysret32,
#endif
.usergs_sysret64 = native_usergs_sysret64,
#endif
.iret = native_iret,

2
arch/x86/kernel/paravirt_patch_64.c
View file

@ -14,7 +14,6 @@ DEF_NATIVE(pv_cpu_ops, clts, "clts");
DEF_NATIVE(pv_cpu_ops, wbinvd, "wbinvd");
DEF_NATIVE(pv_cpu_ops, usergs_sysret64, "swapgs; sysretq");
DEF_NATIVE(pv_cpu_ops, usergs_sysret32, "swapgs; sysretl");
DEF_NATIVE(pv_cpu_ops, swapgs, "swapgs");
DEF_NATIVE(, mov32, "mov %edi, %eax");
@ -54,7 +53,6 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
PATCH_SITE(pv_irq_ops, save_fl);
PATCH_SITE(pv_irq_ops, irq_enable);
PATCH_SITE(pv_irq_ops, irq_disable);
PATCH_SITE(pv_cpu_ops, usergs_sysret32);
PATCH_SITE(pv_cpu_ops, usergs_sysret64);
PATCH_SITE(pv_cpu_ops, swapgs);
PATCH_SITE(pv_mmu_ops, read_cr2);

19
arch/x86/xen/xen-asm_64.S
View file

@ -68,25 +68,6 @@ ENTRY(xen_sysret64)
ENDPATCH(xen_sysret64)
RELOC(xen_sysret64, 1b+1)
ENTRY(xen_sysret32)
/*
* We're already on the usermode stack at this point, but
* still with the kernel gs, so we can easily switch back
*/
movq %rsp, PER_CPU_VAR(rsp_scratch)
movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
pushq $__USER32_DS
pushq PER_CPU_VAR(rsp_scratch)
pushq %r11
pushq $__USER32_CS
pushq %rcx
pushq $0
1: jmp hypercall_iret
ENDPATCH(xen_sysret32)
RELOC(xen_sysret32, 1b+1)
/*
* Xen handles syscall callbacks much like ordinary exceptions, which
* means we have: