From 0c2f51a7d2546f65e4198cccd6a56e2a8b857677 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:30:42 +0100 Subject: x86 vDSO: arch/x86/vdso/vdso32 This moves the i386 vDSO sources into arch/x86/vdso/vdso32/, a new directory. This patch is a pure renaming, but paves the way for consolidating the vDSO build logic. Signed-off-by: Roland McGrath Cc: Andrew Morton Cc: Linus Torvalds Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/ia32/vsyscall-sigreturn.S | 3 +- arch/x86/kernel/Makefile_32 | 3 + arch/x86/kernel/vsyscall-int80_32.S | 53 ------------ arch/x86/kernel/vsyscall-note_32.S | 45 ---------- arch/x86/kernel/vsyscall-sigreturn_32.S | 143 -------------------------------- arch/x86/kernel/vsyscall-sysenter_32.S | 122 --------------------------- arch/x86/vdso/vdso32/int80.S | 53 ++++++++++++ arch/x86/vdso/vdso32/note.S | 45 ++++++++++ arch/x86/vdso/vdso32/sigreturn.S | 143 ++++++++++++++++++++++++++++++++ arch/x86/vdso/vdso32/sysenter.S | 122 +++++++++++++++++++++++++++ 10 files changed, 367 insertions(+), 365 deletions(-) delete mode 100644 arch/x86/kernel/vsyscall-int80_32.S delete mode 100644 arch/x86/kernel/vsyscall-note_32.S delete mode 100644 arch/x86/kernel/vsyscall-sigreturn_32.S delete mode 100644 arch/x86/kernel/vsyscall-sysenter_32.S create mode 100644 arch/x86/vdso/vdso32/int80.S create mode 100644 arch/x86/vdso/vdso32/note.S create mode 100644 arch/x86/vdso/vdso32/sigreturn.S create mode 100644 arch/x86/vdso/vdso32/sysenter.S diff --git a/arch/x86/ia32/vsyscall-sigreturn.S b/arch/x86/ia32/vsyscall-sigreturn.S index b383be00bae..295eecf91f1 100644 --- a/arch/x86/ia32/vsyscall-sigreturn.S +++ b/arch/x86/ia32/vsyscall-sigreturn.S @@ -139,5 +139,4 @@ __kernel_rt_sigreturn: .align 4 .LENDFDE3: -#include "../../x86/kernel/vsyscall-note_32.S" - +#include "../vdso/vdso32/note.S" diff --git a/arch/x86/kernel/Makefile_32 b/arch/x86/kernel/Makefile_32 index eb2da53578d..f7c1c1c88dd 100644 --- a/arch/x86/kernel/Makefile_32 +++ b/arch/x86/kernel/Makefile_32 @@ -56,6 +56,9 @@ $(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)) \ diff --git a/arch/x86/kernel/vsyscall-int80_32.S b/arch/x86/kernel/vsyscall-int80_32.S deleted file mode 100644 index 103cab6aa7c..00000000000 --- a/arch/x86/kernel/vsyscall-int80_32.S +++ /dev/null @@ -1,53 +0,0 @@ -/* - * Code for the vsyscall page. This version uses the old int $0x80 method. - * - * NOTE: - * 1) __kernel_vsyscall _must_ be first in this page. - * 2) there are alignment constraints on this stub, see vsyscall-sigreturn.S - * for details. - */ - - .text - .globl __kernel_vsyscall - .type __kernel_vsyscall,@function -__kernel_vsyscall: -.LSTART_vsyscall: - int $0x80 - 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 - .align 4 -.LENDFDEDLSI: - .previous - -/* - * Get the common code for the sigreturn entry points. - */ -#include "vsyscall-sigreturn_32.S" diff --git a/arch/x86/kernel/vsyscall-note_32.S b/arch/x86/kernel/vsyscall-note_32.S deleted file mode 100644 index fcf376a37f7..00000000000 --- a/arch/x86/kernel/vsyscall-note_32.S +++ /dev/null @@ -1,45 +0,0 @@ -/* - * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text. - * Here we can supply some information useful to userland. - */ - -#include -#include - -/* Ideally this would use UTS_NAME, but using a quoted string here - doesn't work. Remember to change this when changing the - kernel's name. */ -ELFNOTE_START(Linux, 0, "a") - .long LINUX_VERSION_CODE -ELFNOTE_END - -#ifdef CONFIG_XEN -/* - * Add a special note telling glibc's dynamic linker a fake hardware - * flavor that it will use to choose the search path for libraries in the - * same way it uses real hardware capabilities like "mmx". - * We supply "nosegneg" as the fake capability, to indicate that we - * do not like negative offsets in instructions using segment overrides, - * since we implement those inefficiently. This makes it possible to - * install libraries optimized to avoid those access patterns in someplace - * like /lib/i686/tls/nosegneg. Note that an /etc/ld.so.conf.d/file - * corresponding to the bits here is needed to make ldconfig work right. - * It should contain: - * hwcap 1 nosegneg - * to match the mapping of bit to name that we give here. - * - * At runtime, the fake hardware feature will be considered to be present - * if its bit is set in the mask word. So, we start with the mask 0, and - * at boot time we set VDSO_NOTE_NONEGSEG_BIT if running under Xen. - */ - -#include "../../x86/xen/vdso.h" /* Defines VDSO_NOTE_NONEGSEG_BIT. */ - - .globl VDSO_NOTE_MASK -ELFNOTE_START(GNU, 2, "a") - .long 1 /* ncaps */ -VDSO_NOTE_MASK: - .long 0 /* mask */ - .byte VDSO_NOTE_NONEGSEG_BIT; .asciz "nosegneg" /* bit, name */ -ELFNOTE_END -#endif diff --git a/arch/x86/kernel/vsyscall-sigreturn_32.S b/arch/x86/kernel/vsyscall-sigreturn_32.S deleted file mode 100644 index e939253ad65..00000000000 --- a/arch/x86/kernel/vsyscall-sigreturn_32.S +++ /dev/null @@ -1,143 +0,0 @@ -/* - * Common code for the sigreturn entry points on the vsyscall page. - * So far this code is the same for both int80 and sysenter versions. - * This file is #include'd by vsyscall-*.S to define them after the - * vsyscall entry point. The kernel assumes that the addresses of these - * routines are constant for all vsyscall implementations. - */ - -#include -#include - - -/* XXX - Should these be named "_sigtramp" or something? -*/ - - .text - .org __kernel_vsyscall+32,0x90 - .globl __kernel_sigreturn - .type __kernel_sigreturn,@function -__kernel_sigreturn: -.LSTART_sigreturn: - popl %eax /* XXX does this mean it needs unwind info? */ - movl $__NR_sigreturn, %eax - int $0x80 -.LEND_sigreturn: - .size __kernel_sigreturn,.-.LSTART_sigreturn - - .balign 32 - .globl __kernel_rt_sigreturn - .type __kernel_rt_sigreturn,@function -__kernel_rt_sigreturn: -.LSTART_rt_sigreturn: - movl $__NR_rt_sigreturn, %eax - int $0x80 -.LEND_rt_sigreturn: - .size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn - .balign 32 - .previous - - .section .eh_frame,"a",@progbits -.LSTARTFRAMEDLSI1: - .long .LENDCIEDLSI1-.LSTARTCIEDLSI1 -.LSTARTCIEDLSI1: - .long 0 /* CIE ID */ - .byte 1 /* Version number */ - .string "zRS" /* 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 0 /* DW_CFA_nop */ - .align 4 -.LENDCIEDLSI1: - .long .LENDFDEDLSI1-.LSTARTFDEDLSI1 /* Length FDE */ -.LSTARTFDEDLSI1: - .long .LSTARTFDEDLSI1-.LSTARTFRAMEDLSI1 /* CIE pointer */ - /* HACK: The dwarf2 unwind routines will subtract 1 from the - return address to get an address in the middle of the - presumed call instruction. Since we didn't get here via - a call, we need to include the nop before the real start - to make up for it. */ - .long .LSTART_sigreturn-1-. /* PC-relative start address */ - .long .LEND_sigreturn-.LSTART_sigreturn+1 - .uleb128 0 /* Augmentation */ - /* What follows are the instructions for the table generation. - We record the locations of each register saved. This is - complicated by the fact that the "CFA" is always assumed to - be the value of the stack pointer in the caller. This means - that we must define the CFA of this body of code to be the - saved value of the stack pointer in the sigcontext. Which - also means that there is no fixed relation to the other - saved registers, which means that we must use DW_CFA_expression - to compute their addresses. It also means that when we - adjust the stack with the popl, we have to do it all over again. */ - -#define do_cfa_expr(offset) \ - .byte 0x0f; /* DW_CFA_def_cfa_expression */ \ - .uleb128 1f-0f; /* length */ \ -0: .byte 0x74; /* DW_OP_breg4 */ \ - .sleb128 offset; /* offset */ \ - .byte 0x06; /* DW_OP_deref */ \ -1: - -#define do_expr(regno, offset) \ - .byte 0x10; /* DW_CFA_expression */ \ - .uleb128 regno; /* regno */ \ - .uleb128 1f-0f; /* length */ \ -0: .byte 0x74; /* DW_OP_breg4 */ \ - .sleb128 offset; /* offset */ \ -1: - - do_cfa_expr(IA32_SIGCONTEXT_esp+4) - do_expr(0, IA32_SIGCONTEXT_eax+4) - do_expr(1, IA32_SIGCONTEXT_ecx+4) - do_expr(2, IA32_SIGCONTEXT_edx+4) - do_expr(3, IA32_SIGCONTEXT_ebx+4) - do_expr(5, IA32_SIGCONTEXT_ebp+4) - do_expr(6, IA32_SIGCONTEXT_esi+4) - do_expr(7, IA32_SIGCONTEXT_edi+4) - do_expr(8, IA32_SIGCONTEXT_eip+4) - - .byte 0x42 /* DW_CFA_advance_loc 2 -- nop; popl eax. */ - - do_cfa_expr(IA32_SIGCONTEXT_esp) - do_expr(0, IA32_SIGCONTEXT_eax) - do_expr(1, IA32_SIGCONTEXT_ecx) - do_expr(2, IA32_SIGCONTEXT_edx) - do_expr(3, IA32_SIGCONTEXT_ebx) - do_expr(5, IA32_SIGCONTEXT_ebp) - do_expr(6, IA32_SIGCONTEXT_esi) - do_expr(7, IA32_SIGCONTEXT_edi) - do_expr(8, IA32_SIGCONTEXT_eip) - - .align 4 -.LENDFDEDLSI1: - - .long .LENDFDEDLSI2-.LSTARTFDEDLSI2 /* Length FDE */ -.LSTARTFDEDLSI2: - .long .LSTARTFDEDLSI2-.LSTARTFRAMEDLSI1 /* CIE pointer */ - /* HACK: See above wrt unwind library assumptions. */ - .long .LSTART_rt_sigreturn-1-. /* PC-relative start address */ - .long .LEND_rt_sigreturn-.LSTART_rt_sigreturn+1 - .uleb128 0 /* Augmentation */ - /* What follows are the instructions for the table generation. - We record the locations of each register saved. This is - slightly less complicated than the above, since we don't - modify the stack pointer in the process. */ - - do_cfa_expr(IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_esp) - do_expr(0, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_eax) - do_expr(1, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ecx) - do_expr(2, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_edx) - do_expr(3, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ebx) - do_expr(5, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ebp) - do_expr(6, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_esi) - do_expr(7, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_edi) - do_expr(8, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_eip) - - .align 4 -.LENDFDEDLSI2: - .previous diff --git a/arch/x86/kernel/vsyscall-sysenter_32.S b/arch/x86/kernel/vsyscall-sysenter_32.S deleted file mode 100644 index ed879bf4299..00000000000 --- a/arch/x86/kernel/vsyscall-sysenter_32.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_32.S" diff --git a/arch/x86/vdso/vdso32/int80.S b/arch/x86/vdso/vdso32/int80.S new file mode 100644 index 00000000000..3c8e4c62ace --- /dev/null +++ b/arch/x86/vdso/vdso32/int80.S @@ -0,0 +1,53 @@ +/* + * Code for the vsyscall page. This version uses the old int $0x80 method. + * + * NOTE: + * 1) __kernel_vsyscall _must_ be first in this page. + * 2) there are alignment constraints on this stub, see vsyscall-sigreturn.S + * for details. + */ + + .text + .globl __kernel_vsyscall + .type __kernel_vsyscall,@function +__kernel_vsyscall: +.LSTART_vsyscall: + int $0x80 + 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 + .align 4 +.LENDFDEDLSI: + .previous + +/* + * Get the common code for the sigreturn entry points. + */ +#include "sigreturn.S" diff --git a/arch/x86/vdso/vdso32/note.S b/arch/x86/vdso/vdso32/note.S new file mode 100644 index 00000000000..0cf934f2633 --- /dev/null +++ b/arch/x86/vdso/vdso32/note.S @@ -0,0 +1,45 @@ +/* + * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text. + * Here we can supply some information useful to userland. + */ + +#include +#include + +/* Ideally this would use UTS_NAME, but using a quoted string here + doesn't work. Remember to change this when changing the + kernel's name. */ +ELFNOTE_START(Linux, 0, "a") + .long LINUX_VERSION_CODE +ELFNOTE_END + +#ifdef CONFIG_XEN +/* + * Add a special note telling glibc's dynamic linker a fake hardware + * flavor that it will use to choose the search path for libraries in the + * same way it uses real hardware capabilities like "mmx". + * We supply "nosegneg" as the fake capability, to indicate that we + * do not like negative offsets in instructions using segment overrides, + * since we implement those inefficiently. This makes it possible to + * install libraries optimized to avoid those access patterns in someplace + * like /lib/i686/tls/nosegneg. Note that an /etc/ld.so.conf.d/file + * corresponding to the bits here is needed to make ldconfig work right. + * It should contain: + * hwcap 1 nosegneg + * to match the mapping of bit to name that we give here. + * + * At runtime, the fake hardware feature will be considered to be present + * if its bit is set in the mask word. So, we start with the mask 0, and + * at boot time we set VDSO_NOTE_NONEGSEG_BIT if running under Xen. + */ + +#include "../../xen/vdso.h" /* Defines VDSO_NOTE_NONEGSEG_BIT. */ + + .globl VDSO_NOTE_MASK +ELFNOTE_START(GNU, 2, "a") + .long 1 /* ncaps */ +VDSO_NOTE_MASK: + .long 0 /* mask */ + .byte VDSO_NOTE_NONEGSEG_BIT; .asciz "nosegneg" /* bit, name */ +ELFNOTE_END +#endif diff --git a/arch/x86/vdso/vdso32/sigreturn.S b/arch/x86/vdso/vdso32/sigreturn.S new file mode 100644 index 00000000000..778f4649e32 --- /dev/null +++ b/arch/x86/vdso/vdso32/sigreturn.S @@ -0,0 +1,143 @@ +/* + * Common code for the sigreturn entry points on the vsyscall page. + * So far this code is the same for both int80 and sysenter versions. + * This file is #include'd by vsyscall-*.S to define them after the + * vsyscall entry point. The kernel assumes that the addresses of these + * routines are constant for all vsyscall implementations. + */ + +#include +#include + + +/* XXX + Should these be named "_sigtramp" or something? +*/ + + .text + .org __kernel_vsyscall+32,0x90 + .globl __kernel_sigreturn + .type __kernel_sigreturn,@function +__kernel_sigreturn: +.LSTART_sigreturn: + popl %eax /* XXX does this mean it needs unwind info? */ + movl $__NR_sigreturn, %eax + int $0x80 +.LEND_sigreturn: + .size __kernel_sigreturn,.-.LSTART_sigreturn + + .balign 32 + .globl __kernel_rt_sigreturn + .type __kernel_rt_sigreturn,@function +__kernel_rt_sigreturn: +.LSTART_rt_sigreturn: + movl $__NR_rt_sigreturn, %eax + int $0x80 +.LEND_rt_sigreturn: + .size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn + .balign 32 + .previous + + .section .eh_frame,"a",@progbits +.LSTARTFRAMEDLSI1: + .long .LENDCIEDLSI1-.LSTARTCIEDLSI1 +.LSTARTCIEDLSI1: + .long 0 /* CIE ID */ + .byte 1 /* Version number */ + .string "zRS" /* 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 0 /* DW_CFA_nop */ + .align 4 +.LENDCIEDLSI1: + .long .LENDFDEDLSI1-.LSTARTFDEDLSI1 /* Length FDE */ +.LSTARTFDEDLSI1: + .long .LSTARTFDEDLSI1-.LSTARTFRAMEDLSI1 /* CIE pointer */ + /* HACK: The dwarf2 unwind routines will subtract 1 from the + return address to get an address in the middle of the + presumed call instruction. Since we didn't get here via + a call, we need to include the nop before the real start + to make up for it. */ + .long .LSTART_sigreturn-1-. /* PC-relative start address */ + .long .LEND_sigreturn-.LSTART_sigreturn+1 + .uleb128 0 /* Augmentation */ + /* What follows are the instructions for the table generation. + We record the locations of each register saved. This is + complicated by the fact that the "CFA" is always assumed to + be the value of the stack pointer in the caller. This means + that we must define the CFA of this body of code to be the + saved value of the stack pointer in the sigcontext. Which + also means that there is no fixed relation to the other + saved registers, which means that we must use DW_CFA_expression + to compute their addresses. It also means that when we + adjust the stack with the popl, we have to do it all over again. */ + +#define do_cfa_expr(offset) \ + .byte 0x0f; /* DW_CFA_def_cfa_expression */ \ + .uleb128 1f-0f; /* length */ \ +0: .byte 0x74; /* DW_OP_breg4 */ \ + .sleb128 offset; /* offset */ \ + .byte 0x06; /* DW_OP_deref */ \ +1: + +#define do_expr(regno, offset) \ + .byte 0x10; /* DW_CFA_expression */ \ + .uleb128 regno; /* regno */ \ + .uleb128 1f-0f; /* length */ \ +0: .byte 0x74; /* DW_OP_breg4 */ \ + .sleb128 offset; /* offset */ \ +1: + + do_cfa_expr(IA32_SIGCONTEXT_esp+4) + do_expr(0, IA32_SIGCONTEXT_eax+4) + do_expr(1, IA32_SIGCONTEXT_ecx+4) + do_expr(2, IA32_SIGCONTEXT_edx+4) + do_expr(3, IA32_SIGCONTEXT_ebx+4) + do_expr(5, IA32_SIGCONTEXT_ebp+4) + do_expr(6, IA32_SIGCONTEXT_esi+4) + do_expr(7, IA32_SIGCONTEXT_edi+4) + do_expr(8, IA32_SIGCONTEXT_eip+4) + + .byte 0x42 /* DW_CFA_advance_loc 2 -- nop; popl eax. */ + + do_cfa_expr(IA32_SIGCONTEXT_esp) + do_expr(0, IA32_SIGCONTEXT_eax) + do_expr(1, IA32_SIGCONTEXT_ecx) + do_expr(2, IA32_SIGCONTEXT_edx) + do_expr(3, IA32_SIGCONTEXT_ebx) + do_expr(5, IA32_SIGCONTEXT_ebp) + do_expr(6, IA32_SIGCONTEXT_esi) + do_expr(7, IA32_SIGCONTEXT_edi) + do_expr(8, IA32_SIGCONTEXT_eip) + + .align 4 +.LENDFDEDLSI1: + + .long .LENDFDEDLSI2-.LSTARTFDEDLSI2 /* Length FDE */ +.LSTARTFDEDLSI2: + .long .LSTARTFDEDLSI2-.LSTARTFRAMEDLSI1 /* CIE pointer */ + /* HACK: See above wrt unwind library assumptions. */ + .long .LSTART_rt_sigreturn-1-. /* PC-relative start address */ + .long .LEND_rt_sigreturn-.LSTART_rt_sigreturn+1 + .uleb128 0 /* Augmentation */ + /* What follows are the instructions for the table generation. + We record the locations of each register saved. This is + slightly less complicated than the above, since we don't + modify the stack pointer in the process. */ + + do_cfa_expr(IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_esp) + do_expr(0, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_eax) + do_expr(1, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ecx) + do_expr(2, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_edx) + do_expr(3, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ebx) + do_expr(5, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ebp) + do_expr(6, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_esi) + do_expr(7, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_edi) + do_expr(8, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_eip) + + .align 4 +.LENDFDEDLSI2: + .previous diff --git a/arch/x86/vdso/vdso32/sysenter.S b/arch/x86/vdso/vdso32/sysenter.S new file mode 100644 index 00000000000..4b98fc41d3e --- /dev/null +++ b/arch/x86/vdso/vdso32/sysenter.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 "sigreturn.S" -- cgit v1.2.3