From: Thomas Gleixner Date: Thu, 11 Oct 2007 09:12:44 +0000 (+0200) Subject: i386: prepare shared kernel/vsyscall-sysenter.S X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=5bdef8fd610b8b07cf58ad2139f1f76bf127ad5d;p=deliverable%2Flinux.git i386: prepare shared kernel/vsyscall-sysenter.S Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile index 8c739b03eff8..4e4b1fa96157 100644 --- 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 index 1a36d26e15eb..000000000000 --- 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 index 000000000000..1a36d26e15eb --- /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"