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Date: Fri, 3 Apr 2015 15:51:54 -0700
From: Andy Lutomirski <luto@...nel.org>
To: Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
X86 ML <x86@...nel.org>, Ingo Molnar <mingo@...nel.org>
Cc: Denys Vlasenko <vda.linux@...glemail.com>,
Andy Lutomirski <luto@...nel.org>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Denys Vlasenko <dvlasenk@...hat.com>,
"H. Peter Anvin" <hpa@...or.com>, Borislav Petkov <bp@...en8.de>
Subject: [PATCH] x86, paravirt, xen: Remove the 64-bit irq_enable_sysexit pvop
We don't use irq_enable_sysexit on 64-bit kernels any more. Remove
all the paravirt and Xen machinery to support it on 64-bit kernels.
Signed-off-by: Andy Lutomirski <luto@...nel.org>
---
I haven't actually tested this on Xen, but it builds for me.
arch/x86/ia32/ia32entry.S | 6 ------
arch/x86/include/asm/paravirt_types.h | 7 ++++---
arch/x86/kernel/asm-offsets.c | 2 ++
arch/x86/kernel/paravirt.c | 4 +++-
arch/x86/kernel/paravirt_patch_64.c | 1 -
arch/x86/xen/enlighten.c | 3 ++-
arch/x86/xen/xen-asm_64.S | 16 ----------------
arch/x86/xen/xen-ops.h | 2 ++
8 files changed, 13 insertions(+), 28 deletions(-)
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 5d8f987a340d..eb1eb7b70f4b 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -77,12 +77,6 @@ ENTRY(native_usergs_sysret32)
swapgs
sysretl
ENDPROC(native_usergs_sysret32)
-
-ENTRY(native_irq_enable_sysexit)
- swapgs
- sti
- sysexit
-ENDPROC(native_irq_enable_sysexit)
#endif
/*
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 7549b8b369e4..38a0ff9ef06e 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -160,13 +160,14 @@ struct pv_cpu_ops {
u64 (*read_pmc)(int counter);
unsigned long long (*read_tscp)(unsigned int *aux);
+#ifdef CONFIG_X86_32
/*
* Atomically enable interrupts and return to userspace. This
- * is only ever used to return to 32-bit processes; in a
- * 64-bit kernel, it's used for 32-on-64 compat processes, but
- * never native 64-bit processes. (Jump, not call.)
+ * is only used in 32-bit kernels. 64-bit kernels use
+ * usergs_sysret32 instead.
*/
void (*irq_enable_sysexit)(void);
+#endif
/*
* Switch to usermode gs and return to 64-bit usermode using
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 9f6b9341950f..2d27ebf0aed8 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -49,7 +49,9 @@ void common(void) {
OFFSET(PV_IRQ_irq_disable, pv_irq_ops, irq_disable);
OFFSET(PV_IRQ_irq_enable, pv_irq_ops, irq_enable);
OFFSET(PV_CPU_iret, pv_cpu_ops, iret);
+#ifdef CONFIG_X86_32
OFFSET(PV_CPU_irq_enable_sysexit, pv_cpu_ops, irq_enable_sysexit);
+#endif
OFFSET(PV_CPU_read_cr0, pv_cpu_ops, read_cr0);
OFFSET(PV_MMU_read_cr2, pv_mmu_ops, read_cr2);
#endif
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 548d25f00c90..7563114d9c3a 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -154,7 +154,9 @@ 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) ||
+#ifdef CONFIG_X86_32
type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) ||
+#endif
type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) ||
type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64))
/* If operation requires a jmp, then jmp */
@@ -371,7 +373,7 @@ __visible struct pv_cpu_ops pv_cpu_ops = {
.load_sp0 = native_load_sp0,
-#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
+#if defined(CONFIG_X86_32)
.irq_enable_sysexit = native_irq_enable_sysexit,
#endif
#ifdef CONFIG_X86_64
diff --git a/arch/x86/kernel/paravirt_patch_64.c b/arch/x86/kernel/paravirt_patch_64.c
index a1da6737ba5b..0de21c62c348 100644
--- a/arch/x86/kernel/paravirt_patch_64.c
+++ b/arch/x86/kernel/paravirt_patch_64.c
@@ -49,7 +49,6 @@ 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, irq_enable_sysexit);
PATCH_SITE(pv_cpu_ops, usergs_sysret32);
PATCH_SITE(pv_cpu_ops, usergs_sysret64);
PATCH_SITE(pv_cpu_ops, swapgs);
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 81665c9f2132..3797b6b31f95 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1267,10 +1267,11 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
.read_tscp = native_read_tscp,
.iret = xen_iret,
- .irq_enable_sysexit = xen_sysexit,
#ifdef CONFIG_X86_64
.usergs_sysret32 = xen_sysret32,
.usergs_sysret64 = xen_sysret64,
+#else
+ .irq_enable_sysexit = xen_sysexit,
#endif
.load_tr_desc = paravirt_nop,
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index 985fc3ee0973..a2cabb8bd6bf 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -47,22 +47,6 @@ ENTRY(xen_iret)
ENDPATCH(xen_iret)
RELOC(xen_iret, 1b+1)
-/*
- * sysexit is not used for 64-bit processes, so it's only ever used to
- * return to 32-bit compat userspace.
- */
-ENTRY(xen_sysexit)
- pushq $__USER32_DS
- pushq %rcx
- pushq $X86_EFLAGS_IF
- pushq $__USER32_CS
- pushq %rdx
-
- pushq $0
-1: jmp hypercall_iret
-ENDPATCH(xen_sysexit)
-RELOC(xen_sysexit, 1b+1)
-
ENTRY(xen_sysret64)
/*
* We're already on the usermode stack at this point, but
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 9e195c683549..c20fe29e65f4 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -134,7 +134,9 @@ DECL_ASM(void, xen_restore_fl_direct, unsigned long);
/* These are not functions, and cannot be called normally */
__visible void xen_iret(void);
+#ifdef CONFIG_X86_32
__visible void xen_sysexit(void);
+#endif
__visible void xen_sysret32(void);
__visible void xen_sysret64(void);
__visible void xen_adjust_exception_frame(void);
--
2.3.0
--
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