i386: prepare shared kernel/vsyscall-sysenter.S

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
index 8c739b03eff88bfe192417aa60b894fbfb794203..4e4b1fa961574fd5e97f52ffb229fc9fa9806498 100644 (file)
--- a/arch/i386/kernel/Makefile
+++ b/arch/i386/kernel/Makefile
@@ -50,7 +50,7 @@ obj-$(CONFIG_SCx200)          += scx200.o
 # vsyscall_32.o contains the vsyscall DSO images as __initdata.
 # We must build both images before we can assemble it.
 # Note: kbuild does not track this dependency due to usage of .incbin
-$(obj)/vsyscall_32.o: $(obj)/vsyscall-int80_32.so $(obj)/vsyscall-sysenter.so
+$(obj)/vsyscall_32.o: $(obj)/vsyscall-int80_32.so $(obj)/vsyscall-sysenter_32.so
 targets += $(foreach F,int80 sysenter,vsyscall-$F.o vsyscall-$F.so)
 targets += vsyscall-note.o vsyscall_32.lds
 
@@ -63,10 +63,10 @@ export CPPFLAGS_vsyscall_32.lds += -P -C -U$(ARCH)
 
 vsyscall-flags = -shared -s -Wl,-soname=linux-gate.so.1 \
                 $(call ld-option, -Wl$(comma)--hash-style=sysv)
-SYSCFLAGS_vsyscall-sysenter.so = $(vsyscall-flags)
+SYSCFLAGS_vsyscall-sysenter_32.so      = $(vsyscall-flags)
 SYSCFLAGS_vsyscall-int80_32.so = $(vsyscall-flags)
 
-$(obj)/vsyscall-int80_32.so $(obj)/vsyscall-sysenter.so: \
+$(obj)/vsyscall-int80_32.so $(obj)/vsyscall-sysenter_32.so: \
 $(obj)/vsyscall-%.so: $(src)/vsyscall_32.lds \
                      $(obj)/vsyscall-%.o $(obj)/vsyscall-note.o FORCE
        $(call if_changed,syscall)
@@ -80,7 +80,7 @@ $(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.o $(obj)/vsyscall-note.o FORCE
+                       $(obj)/vsyscall-sysenter_32.o $(obj)/vsyscall-note.o FORCE
        $(call if_changed,syscall)
 
 k8-y                      += ../../x86_64/kernel/k8.o

diff --git a/arch/i386/kernel/vsyscall-sysenter.S b/arch/i386/kernel/vsyscall-sysenter.S
deleted file mode 100644 (file)
index 1a36d26..0000000
--- a/arch/i386/kernel/vsyscall-sysenter.S
+++ /dev/null
@@ -1,122 +0,0 @@
-/*
- * Code for the vsyscall page.  This version uses the sysenter instruction.
- *
- * NOTE:
- * 1) __kernel_vsyscall _must_ be first in this page.
- * 2) there are alignment constraints on this stub, see vsyscall-sigreturn.S
- *    for details.
- */
-
-/*
- * The caller puts arg2 in %ecx, which gets pushed. The kernel will use
- * %ecx itself for arg2. The pushing is because the sysexit instruction
- * (found in entry.S) requires that we clobber %ecx with the desired %esp.
- * User code might expect that %ecx is unclobbered though, as it would be
- * for returning via the iret instruction, so we must push and pop.
- *
- * The caller puts arg3 in %edx, which the sysexit instruction requires
- * for %eip. Thus, exactly as for arg2, we must push and pop.
- *
- * Arg6 is different. The caller puts arg6 in %ebp. Since the sysenter
- * instruction clobbers %esp, the user's %esp won't even survive entry
- * into the kernel. We store %esp in %ebp. Code in entry.S must fetch
- * arg6 from the stack.
- *
- * You can not use this vsyscall for the clone() syscall because the
- * three dwords on the parent stack do not get copied to the child.
- */
-       .text
-       .globl __kernel_vsyscall
-       .type __kernel_vsyscall,@function
-__kernel_vsyscall:
-.LSTART_vsyscall:
-       push %ecx
-.Lpush_ecx:
-       push %edx
-.Lpush_edx:
-       push %ebp
-.Lenter_kernel:
-       movl %esp,%ebp
-       sysenter
-
-       /* 7: align return point with nop's to make disassembly easier */
-       .space 7,0x90
-
-       /* 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:
-       pop %ebp
-.Lpop_ebp:
-       pop %edx
-.Lpop_edx:
-       pop %ecx
-.Lpop_ecx:
-       ret
-.LEND_vsyscall:
-       .size __kernel_vsyscall,.-.LSTART_vsyscall
-       .previous
-
-       .section .eh_frame,"a",@progbits
-.LSTARTFRAMEDLSI:
-       .long .LENDCIEDLSI-.LSTARTCIEDLSI
-.LSTARTCIEDLSI:
-       .long 0                 /* CIE ID */
-       .byte 1                 /* Version number */
-       .string "zR"            /* NUL-terminated augmentation string */
-       .uleb128 1              /* Code alignment factor */
-       .sleb128 -4             /* Data alignment factor */
-       .byte 8                 /* Return address register column */
-       .uleb128 1              /* Augmentation value length */
-       .byte 0x1b              /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
-       .byte 0x0c              /* DW_CFA_def_cfa */
-       .uleb128 4
-       .uleb128 4
-       .byte 0x88              /* DW_CFA_offset, column 0x8 */
-       .uleb128 1
-       .align 4
-.LENDCIEDLSI:
-       .long .LENDFDEDLSI-.LSTARTFDEDLSI /* Length FDE */
-.LSTARTFDEDLSI:
-       .long .LSTARTFDEDLSI-.LSTARTFRAMEDLSI /* CIE pointer */
-       .long .LSTART_vsyscall-.        /* PC-relative start address */
-       .long .LEND_vsyscall-.LSTART_vsyscall
-       .uleb128 0
-       /* What follows are the instructions for the table generation.
-          We have to record all changes of the stack pointer.  */
-       .byte 0x04              /* DW_CFA_advance_loc4 */
-       .long .Lpush_ecx-.LSTART_vsyscall
-       .byte 0x0e              /* DW_CFA_def_cfa_offset */
-       .byte 0x08              /* RA at offset 8 now */
-       .byte 0x04              /* DW_CFA_advance_loc4 */
-       .long .Lpush_edx-.Lpush_ecx
-       .byte 0x0e              /* DW_CFA_def_cfa_offset */
-       .byte 0x0c              /* RA at offset 12 now */
-       .byte 0x04              /* DW_CFA_advance_loc4 */
-       .long .Lenter_kernel-.Lpush_edx
-       .byte 0x0e              /* DW_CFA_def_cfa_offset */
-       .byte 0x10              /* RA at offset 16 now */
-       .byte 0x85, 0x04        /* DW_CFA_offset %ebp -16 */
-       /* Finally the epilogue.  */
-       .byte 0x04              /* DW_CFA_advance_loc4 */
-       .long .Lpop_ebp-.Lenter_kernel
-       .byte 0x0e              /* DW_CFA_def_cfa_offset */
-       .byte 0x0c              /* RA at offset 12 now */
-       .byte 0xc5              /* DW_CFA_restore %ebp */
-       .byte 0x04              /* DW_CFA_advance_loc4 */
-       .long .Lpop_edx-.Lpop_ebp
-       .byte 0x0e              /* DW_CFA_def_cfa_offset */
-       .byte 0x08              /* RA at offset 8 now */
-       .byte 0x04              /* DW_CFA_advance_loc4 */
-       .long .Lpop_ecx-.Lpop_edx
-       .byte 0x0e              /* DW_CFA_def_cfa_offset */
-       .byte 0x04              /* RA at offset 4 now */
-       .align 4
-.LENDFDEDLSI:
-       .previous
-
-/*
- * Get the common code for the sigreturn entry points.
- */
-#include "vsyscall-sigreturn.S"

diff --git a/arch/i386/kernel/vsyscall-sysenter_32.S b/arch/i386/kernel/vsyscall-sysenter_32.S
new file mode 100644 (file)
index 0000000..1a36d26
--- /dev/null
+++ b/arch/i386/kernel/vsyscall-sysenter_32.S
@@ -0,0 +1,122 @@
+/*
+ * Code for the vsyscall page.  This version uses the sysenter instruction.
+ *
+ * NOTE:
+ * 1) __kernel_vsyscall _must_ be first in this page.
+ * 2) there are alignment constraints on this stub, see vsyscall-sigreturn.S
+ *    for details.
+ */
+
+/*
+ * The caller puts arg2 in %ecx, which gets pushed. The kernel will use
+ * %ecx itself for arg2. The pushing is because the sysexit instruction
+ * (found in entry.S) requires that we clobber %ecx with the desired %esp.
+ * User code might expect that %ecx is unclobbered though, as it would be
+ * for returning via the iret instruction, so we must push and pop.
+ *
+ * The caller puts arg3 in %edx, which the sysexit instruction requires
+ * for %eip. Thus, exactly as for arg2, we must push and pop.
+ *
+ * Arg6 is different. The caller puts arg6 in %ebp. Since the sysenter
+ * instruction clobbers %esp, the user's %esp won't even survive entry
+ * into the kernel. We store %esp in %ebp. Code in entry.S must fetch
+ * arg6 from the stack.
+ *
+ * You can not use this vsyscall for the clone() syscall because the
+ * three dwords on the parent stack do not get copied to the child.
+ */
+       .text
+       .globl __kernel_vsyscall
+       .type __kernel_vsyscall,@function
+__kernel_vsyscall:
+.LSTART_vsyscall:
+       push %ecx
+.Lpush_ecx:
+       push %edx
+.Lpush_edx:
+       push %ebp
+.Lenter_kernel:
+       movl %esp,%ebp
+       sysenter
+
+       /* 7: align return point with nop's to make disassembly easier */
+       .space 7,0x90
+
+       /* 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:
+       pop %ebp
+.Lpop_ebp:
+       pop %edx
+.Lpop_edx:
+       pop %ecx
+.Lpop_ecx:
+       ret
+.LEND_vsyscall:
+       .size __kernel_vsyscall,.-.LSTART_vsyscall
+       .previous
+
+       .section .eh_frame,"a",@progbits
+.LSTARTFRAMEDLSI:
+       .long .LENDCIEDLSI-.LSTARTCIEDLSI
+.LSTARTCIEDLSI:
+       .long 0                 /* CIE ID */
+       .byte 1                 /* Version number */
+       .string "zR"            /* NUL-terminated augmentation string */
+       .uleb128 1              /* Code alignment factor */
+       .sleb128 -4             /* Data alignment factor */
+       .byte 8                 /* Return address register column */
+       .uleb128 1              /* Augmentation value length */
+       .byte 0x1b              /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
+       .byte 0x0c              /* DW_CFA_def_cfa */
+       .uleb128 4
+       .uleb128 4
+       .byte 0x88              /* DW_CFA_offset, column 0x8 */
+       .uleb128 1
+       .align 4
+.LENDCIEDLSI:
+       .long .LENDFDEDLSI-.LSTARTFDEDLSI /* Length FDE */
+.LSTARTFDEDLSI:
+       .long .LSTARTFDEDLSI-.LSTARTFRAMEDLSI /* CIE pointer */
+       .long .LSTART_vsyscall-.        /* PC-relative start address */
+       .long .LEND_vsyscall-.LSTART_vsyscall
+       .uleb128 0
+       /* What follows are the instructions for the table generation.
+          We have to record all changes of the stack pointer.  */
+       .byte 0x04              /* DW_CFA_advance_loc4 */
+       .long .Lpush_ecx-.LSTART_vsyscall
+       .byte 0x0e              /* DW_CFA_def_cfa_offset */
+       .byte 0x08              /* RA at offset 8 now */
+       .byte 0x04              /* DW_CFA_advance_loc4 */
+       .long .Lpush_edx-.Lpush_ecx
+       .byte 0x0e              /* DW_CFA_def_cfa_offset */
+       .byte 0x0c              /* RA at offset 12 now */
+       .byte 0x04              /* DW_CFA_advance_loc4 */
+       .long .Lenter_kernel-.Lpush_edx
+       .byte 0x0e              /* DW_CFA_def_cfa_offset */
+       .byte 0x10              /* RA at offset 16 now */
+       .byte 0x85, 0x04        /* DW_CFA_offset %ebp -16 */
+       /* Finally the epilogue.  */
+       .byte 0x04              /* DW_CFA_advance_loc4 */
+       .long .Lpop_ebp-.Lenter_kernel
+       .byte 0x0e              /* DW_CFA_def_cfa_offset */
+       .byte 0x0c              /* RA at offset 12 now */
+       .byte 0xc5              /* DW_CFA_restore %ebp */
+       .byte 0x04              /* DW_CFA_advance_loc4 */
+       .long .Lpop_edx-.Lpop_ebp
+       .byte 0x0e              /* DW_CFA_def_cfa_offset */
+       .byte 0x08              /* RA at offset 8 now */
+       .byte 0x04              /* DW_CFA_advance_loc4 */
+       .long .Lpop_ecx-.Lpop_edx
+       .byte 0x0e              /* DW_CFA_def_cfa_offset */
+       .byte 0x04              /* RA at offset 4 now */
+       .align 4
+.LENDFDEDLSI:
+       .previous
+
+/*
+ * Get the common code for the sigreturn entry points.
+ */
+#include "vsyscall-sigreturn.S"