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Subject[PATCH 08/18] x86 vDSO: i386 vdso32
Date

This makes the i386 kernel use the new vDSO build in arch/x86/vdso/vdso32/
to replace the old one from arch/x86/kernel/.

Signed-off-by: Roland McGrath <roland@redhat.com>
---
arch/x86/Makefile_32 | 3 +-
arch/x86/kernel/Makefile_32 | 43 +--------------
arch/x86/kernel/asm-offsets_32.c | 2 -
arch/x86/kernel/signal_32.c | 5 +-
arch/x86/kernel/sysenter_32.c | 6 +-
arch/x86/kernel/vsyscall_32.lds.S | 67 ----------------------
arch/x86/vdso/Makefile | 8 ++-
arch/x86/{kernel/vsyscall_32.S => vdso/vdso32.S} | 4 +-
arch/x86/vdso/vdso32/note.S | 3 +-
arch/x86/vdso/vdso32/sysenter.S | 3 +-
arch/x86/xen/setup.c | 5 +-
include/asm-x86/elf.h | 13 +---
include/asm-x86/vdso.h | 14 +++++
13 files changed, 37 insertions(+), 139 deletions(-)
delete mode 100644 arch/x86/kernel/vsyscall_32.lds.S
rename arch/x86/{kernel/vsyscall_32.S => vdso/vdso32.S} (70%)

diff --git a/arch/x86/Makefile_32 b/arch/x86/Makefile_32
index 50394da..99dc511 100644
--- a/arch/x86/Makefile_32
+++ b/arch/x86/Makefile_32
@@ -114,7 +114,8 @@ libs-y += arch/x86/lib/
core-y += arch/x86/kernel/ \
arch/x86/mm/ \
$(mcore-y)/ \
- arch/x86/crypto/
+ arch/x86/crypto/ \
+ arch/x86/vdso/
drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
drivers-$(CONFIG_PCI) += arch/x86/pci/
# must be linked after kernel/
diff --git a/arch/x86/kernel/Makefile_32 b/arch/x86/kernel/Makefile_32
index 7791895..1ece642 100644
--- a/arch/x86/kernel/Makefile_32
+++ b/arch/x86/kernel/Makefile_32
@@ -33,7 +33,7 @@ obj-$(CONFIG_X86_NUMAQ) += numaq_32.o
obj-$(CONFIG_X86_SUMMIT_NUMA) += summit_32.o
obj-$(CONFIG_KPROBES) += kprobes_32.o
obj-$(CONFIG_MODULES) += module_32.o
-obj-y += sysenter_32.o vsyscall_32.o
+obj-y += sysenter_32.o
obj-$(CONFIG_ACPI_SRAT) += srat_32.o
obj-$(CONFIG_EFI) += efi_32.o efi_stub_32.o
obj-$(CONFIG_DOUBLEFAULT) += doublefault_32.o
@@ -48,44 +48,3 @@ obj-$(CONFIG_PARAVIRT) += paravirt_32.o
obj-y += pcspeaker.o

obj-$(CONFIG_SCx200) += scx200_32.o
-
-# vsyscall_32.o contains the vsyscall DSO images as __initdata.
-# We must build both images before we can assemble it.
-# Note: kbuild does not track this dependency due to usage of .incbin
-$(obj)/vsyscall_32.o: $(obj)/vsyscall-int80_32.so $(obj)/vsyscall-sysenter_32.so
-targets += $(foreach F,int80 sysenter,vsyscall-$F_32.o vsyscall-$F_32.so)
-targets += vsyscall-note_32.o vsyscall_32.lds
-
-$(obj)/vsyscall-%_32.o: $(src)/../vdso/vdso32/%.S
- $(call if_changed_dep,as_o_S)
-
-# The DSO images are built using a special linker script.
-quiet_cmd_syscall = SYSCALL $@
- cmd_syscall = $(CC) -m elf_i386 -nostdlib $(SYSCFLAGS_$(@F)) \
- -Wl,-T,$(filter-out FORCE,$^) -o $@
-
-export CPPFLAGS_vsyscall_32.lds += -P -C -Ui386
-
-vsyscall-flags = -shared -s -Wl,-soname=linux-gate.so.1 \
- $(call ld-option, -Wl$(comma)--hash-style=sysv)
-SYSCFLAGS_vsyscall-sysenter_32.so = $(vsyscall-flags)
-SYSCFLAGS_vsyscall-int80_32.so = $(vsyscall-flags)
-
-$(obj)/vsyscall-int80_32.so $(obj)/vsyscall-sysenter_32.so: \
-$(obj)/vsyscall-%.so: $(src)/vsyscall_32.lds \
- $(obj)/vsyscall-%.o $(obj)/vsyscall-note_32.o FORCE
- $(call if_changed,syscall)
-
-# We also create a special relocatable object that should mirror the symbol
-# table and layout of the linked DSO. With ld -R we can then refer to
-# these symbols in the kernel code rather than hand-coded addresses.
-extra-y += vsyscall-syms.o
-$(obj)/built-in.o: $(obj)/vsyscall-syms.o
-$(obj)/built-in.o: ld_flags += -R $(obj)/vsyscall-syms.o
-
-SYSCFLAGS_vsyscall-syms.o = -r
-$(obj)/vsyscall-syms.o: $(src)/vsyscall_32.lds \
- $(obj)/vsyscall-sysenter_32.o $(obj)/vsyscall-note_32.o FORCE
- $(call if_changed,syscall)
-
-
diff --git a/arch/x86/kernel/asm-offsets_32.c b/arch/x86/kernel/asm-offsets_32.c
index c578a2b..2784f2c 100644
--- a/arch/x86/kernel/asm-offsets_32.c
+++ b/arch/x86/kernel/asm-offsets_32.c
@@ -111,8 +111,6 @@ void foo(void)
DEFINE(PTRS_PER_PMD, PTRS_PER_PMD);
DEFINE(PTRS_PER_PGD, PTRS_PER_PGD);

- DEFINE(VDSO_PRELINK_asm, VDSO_PRELINK);
-
OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx);

#ifdef CONFIG_PARAVIRT
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 9bdd830..696cb89 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -23,6 +23,7 @@
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/i387.h>
+#include <asm/vdso.h>
#include "sigframe_32.h"

#define DEBUG_SIG 0
@@ -355,7 +356,7 @@ static int setup_frame(int sig, struct k_sigaction *ka,
}

if (current->binfmt->hasvdso)
- restorer = (void *)VDSO_SYM(&__kernel_sigreturn);
+ restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
else
restorer = (void *)&frame->retcode;
if (ka->sa.sa_flags & SA_RESTORER)
@@ -452,7 +453,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
goto give_sigsegv;

/* Set up to return from userspace. */
- restorer = (void *)VDSO_SYM(&__kernel_rt_sigreturn);
+ restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
err |= __put_user(restorer, &frame->pretcode);
diff --git a/arch/x86/kernel/sysenter_32.c b/arch/x86/kernel/sysenter_32.c
index 5a2d951..85c52d2 100644
--- a/arch/x86/kernel/sysenter_32.c
+++ b/arch/x86/kernel/sysenter_32.c
@@ -23,6 +23,7 @@
#include <asm/unistd.h>
#include <asm/elf.h>
#include <asm/tlbflush.h>
+#include <asm/vdso.h>

enum {
VDSO_DISABLED = 0,
@@ -259,9 +260,6 @@ int __init sysenter_setup(void)
return 0;
}

-/* Defined in vsyscall-sysenter.S */
-extern void SYSENTER_RETURN;
-
/* Setup a VMA at program startup for the vsyscall page */
int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack)
{
@@ -308,7 +306,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack)

current->mm->context.vdso = (void *)addr;
current_thread_info()->sysenter_return =
- (void *)VDSO_SYM(&SYSENTER_RETURN);
+ VDSO32_SYMBOL(addr, SYSENTER_RETURN);

up_fail:
up_write(&mm->mmap_sem);
diff --git a/arch/x86/kernel/vsyscall_32.lds.S b/arch/x86/kernel/vsyscall_32.lds.S
deleted file mode 100644
index 4a8b0ed..0000000
--- a/arch/x86/kernel/vsyscall_32.lds.S
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Linker script for vsyscall DSO. The vsyscall page is an ELF shared
- * object prelinked to its virtual address, and with only one read-only
- * segment (that fits in one page). This script controls its layout.
- */
-#include <asm/asm-offsets.h>
-
-SECTIONS
-{
- . = VDSO_PRELINK_asm + SIZEOF_HEADERS;
-
- .hash : { *(.hash) } :text
- .gnu.hash : { *(.gnu.hash) }
- .dynsym : { *(.dynsym) }
- .dynstr : { *(.dynstr) }
- .gnu.version : { *(.gnu.version) }
- .gnu.version_d : { *(.gnu.version_d) }
- .gnu.version_r : { *(.gnu.version_r) }
-
- /* This linker script is used both with -r and with -shared.
- For the layouts to match, we need to skip more than enough
- space for the dynamic symbol table et al. If this amount
- is insufficient, ld -shared will barf. Just increase it here. */
- . = VDSO_PRELINK_asm + 0x400;
-
- .text : { *(.text) } :text =0x90909090
- .note : { *(.note.*) } :text :note
- .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
- .eh_frame : { KEEP (*(.eh_frame)) } :text
- .dynamic : { *(.dynamic) } :text :dynamic
- .useless : {
- *(.got.plt) *(.got)
- *(.data .data.* .gnu.linkonce.d.*)
- *(.dynbss)
- *(.bss .bss.* .gnu.linkonce.b.*)
- } :text
-}
-
-/*
- * We must supply the ELF program headers explicitly to get just one
- * PT_LOAD segment, and set the flags explicitly to make segments read-only.
- */
-PHDRS
-{
- text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
- dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
- note PT_NOTE FLAGS(4); /* PF_R */
- eh_frame_hdr 0x6474e550; /* PT_GNU_EH_FRAME, but ld doesn't match the name */
-}
-
-/*
- * This controls what symbols we export from the DSO.
- */
-VERSION
-{
- LINUX_2.5 {
- global:
- __kernel_vsyscall;
- __kernel_sigreturn;
- __kernel_rt_sigreturn;
-
- local: *;
- };
-}
-
-/* The ELF entry point can be used to set the AT_SYSINFO value. */
-ENTRY(__kernel_vsyscall);
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index a1e0418..cabb0c2 100644
--- a/arch/x86/vdso/Makefile
+++ b/arch/x86/vdso/Makefile
@@ -14,7 +14,8 @@ vdso-install-$(VDSO32-y) += $(vdso32-y:=.so)
vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vvar.o

# files to link into kernel
-obj-y := vma.o vdso.o
+obj-$(VDSO64-y) += vma.o vdso.o
+obj-$(CONFIG_X86_32) += vdso32.o

vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)

@@ -52,7 +53,7 @@ $(obj)/vclock_gettime.o: KBUILD_CFLAGS = $(CFL)
$(obj)/vgetcpu.o: KBUILD_CFLAGS = $(CFL)

targets += vdso-syms.lds
-obj-y += vdso-syms.lds
+obj-$(VDSO64-y) += vdso-syms.lds

#
# Match symbols in the DSO that look like VDSO*; produce a file of constants.
@@ -68,6 +69,7 @@ $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
#
# Build multiple 32-bit vDSO images to choose from at boot time.
#
+obj-$(VDSO32-y) += vdso32-syms.lds
vdso32.so-$(CONFIG_X86_32) += int80
vdso32.so-$(VDSO32-y) += sysenter

@@ -84,6 +86,8 @@ targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o)

extra-y += $(vdso32.so-y:%=vdso32-%.so)

+$(obj)/vdso32.o: $(vdso32.so-y:%=$(obj)/vdso32-%.so)
+
$(vdso32.so-y:%=$(obj)/vdso32-%.so.dbg): asflags-$(CONFIG_X86_64) += -m32

$(vdso32.so-y:%=$(obj)/vdso32-%.so.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
diff --git a/arch/x86/kernel/vsyscall_32.S b/arch/x86/vdso/vdso32.S
similarity index 70%
rename from arch/x86/kernel/vsyscall_32.S
rename to arch/x86/vdso/vdso32.S
index a5ab3dc..cab020c 100644
--- a/arch/x86/kernel/vsyscall_32.S
+++ b/arch/x86/vdso/vdso32.S
@@ -4,12 +4,12 @@ __INITDATA

.globl vsyscall_int80_start, vsyscall_int80_end
vsyscall_int80_start:
- .incbin "arch/x86/kernel/vsyscall-int80_32.so"
+ .incbin "arch/x86/vdso/vdso32-int80.so"
vsyscall_int80_end:

.globl vsyscall_sysenter_start, vsyscall_sysenter_end
vsyscall_sysenter_start:
- .incbin "arch/x86/kernel/vsyscall-sysenter_32.so"
+ .incbin "arch/x86/vdso/vdso32-sysenter.so"
vsyscall_sysenter_end:

__FINIT
diff --git a/arch/x86/vdso/vdso32/note.S b/arch/x86/vdso/vdso32/note.S
index 0cf934f..c83f257 100644
--- a/arch/x86/vdso/vdso32/note.S
+++ b/arch/x86/vdso/vdso32/note.S
@@ -35,10 +35,9 @@ ELFNOTE_END

#include "../../xen/vdso.h" /* Defines VDSO_NOTE_NONEGSEG_BIT. */

- .globl VDSO_NOTE_MASK
ELFNOTE_START(GNU, 2, "a")
.long 1 /* ncaps */
-VDSO_NOTE_MASK:
+VDSO32_NOTE_MASK: /* Symbol used by arch/x86/xen/setup.c */
.long 0 /* mask */
.byte VDSO_NOTE_NONEGSEG_BIT; .asciz "nosegneg" /* bit, name */
ELFNOTE_END
diff --git a/arch/x86/vdso/vdso32/sysenter.S b/arch/x86/vdso/vdso32/sysenter.S
index 4b98fc4..109bfa3 100644
--- a/arch/x86/vdso/vdso32/sysenter.S
+++ b/arch/x86/vdso/vdso32/sysenter.S
@@ -45,8 +45,7 @@ __kernel_vsyscall:
/* 14: System call restart point is here! (SYSENTER_RETURN-2) */
jmp .Lenter_kernel
/* 16: System call normal return point is here! */
- .globl SYSENTER_RETURN /* Symbol used by sysenter.c */
-SYSENTER_RETURN:
+VDSO32_SYSENTER_RETURN: /* Symbol used by sysenter.c via vdso32-syms.h */
pop %ebp
.Lpop_ebp:
pop %edx
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index f84e772..fd91568 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -10,6 +10,7 @@
#include <linux/pm.h>

#include <asm/elf.h>
+#include <asm/vdso.h>
#include <asm/e820.h>
#include <asm/setup.h>
#include <asm/xen/hypervisor.h>
@@ -61,10 +62,8 @@ static void xen_idle(void)
*/
static void fiddle_vdso(void)
{
- extern u32 VDSO_NOTE_MASK; /* See ../kernel/vsyscall-note.S. */
extern char vsyscall_int80_start;
- u32 *mask = (u32 *) ((unsigned long) &VDSO_NOTE_MASK - VDSO_PRELINK +
- &vsyscall_int80_start);
+ u32 *mask = VDSO32_SYMBOL(&vsyscall_int80_start, NOTE_MASK);
*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
}

diff --git a/include/asm-x86/elf.h b/include/asm-x86/elf.h
index ec42a4d..0dd21ee 100644
--- a/include/asm-x86/elf.h
+++ b/include/asm-x86/elf.h
@@ -78,6 +78,7 @@ typedef struct user_fxsr_struct elf_fpxregset_t;
#include <asm/processor.h>
#include <asm/system.h> /* for savesegment */
#include <asm/desc.h>
+#include <asm/vdso.h>

/*
* This is used to ensure we don't load something for the wrong architecture.
@@ -247,17 +248,9 @@ extern int dump_task_extended_fpu (struct task_struct *,

#define VDSO_HIGH_BASE (__fix_to_virt(FIX_VDSO))
#define VDSO_CURRENT_BASE ((unsigned long)current->mm->context.vdso)
-#define VDSO_PRELINK 0

-#define VDSO_SYM(x) \
- (VDSO_CURRENT_BASE + (unsigned long)(x) - VDSO_PRELINK)
-
-#define VDSO_HIGH_EHDR ((const struct elfhdr *) VDSO_HIGH_BASE)
-#define VDSO_EHDR ((const struct elfhdr *) VDSO_CURRENT_BASE)
-
-extern void __kernel_vsyscall;
-
-#define VDSO_ENTRY VDSO_SYM(&__kernel_vsyscall)
+#define VDSO_ENTRY \
+ ((unsigned long) VDSO32_SYMBOL(VDSO_CURRENT_BASE, vsyscall))

/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */

diff --git a/include/asm-x86/vdso.h b/include/asm-x86/vdso.h
index 9379ec0..629bcb6 100644
--- a/include/asm-x86/vdso.h
+++ b/include/asm-x86/vdso.h
@@ -1,6 +1,7 @@
#ifndef _ASM_X86_VDSO_H
#define _ASM_X86_VDSO_H 1

+#ifdef CONFIG_X86_64
extern const char VDSO64_PRELINK[];

/*
@@ -10,5 +11,18 @@ extern const char VDSO64_PRELINK[];
#define VDSO64_SYMBOL(base, name) ({ \
extern const char VDSO64_##name[]; \
(void *) (VDSO64_##name - VDSO64_PRELINK + (unsigned long) (base)); })
+#endif
+
+#if defined CONFIG_X86_32 || defined CONFIG_COMPAT
+extern const char VDSO32_PRELINK[];
+
+/*
+ * Given a pointer to the vDSO image, find the pointer to VDSO32_name
+ * as that symbol is defined in the vDSO sources or linker script.
+ */
+#define VDSO32_SYMBOL(base, name) ({ \
+ extern const char VDSO32_##name[]; \
+ (void *) (VDSO32_##name - VDSO32_PRELINK + (unsigned long) (base)); })
+#endif

#endif /* asm-x86/vdso.h */
-
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