x86 vDSO: ia32 vsyscall removal (16f4bc73) · Commits · e / devices / android_kernel_xiaomi_markw

arch/x86/Makefile_64

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Original line number	Diff line number	Diff line
		@@ -117,9 +117,6 @@ install: vdso_install
		$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) $@

		vdso_install:
		ifeq ($(CONFIG_IA32_EMULATION),y)
		$(Q)$(MAKE) $(build)=arch/x86/ia32 $@
		endif
		$(Q)$(MAKE) $(build)=arch/x86/vdso $@

		archclean:

arch/x86/ia32/Makefile

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Original line number	Diff line number	Diff line
		@@ -12,40 +12,3 @@ obj-$(CONFIG_IA32_AOUT) += ia32_aout.o

		audit-class-$(CONFIG_AUDIT) := audit.o
		obj-$(CONFIG_IA32_EMULATION) += $(audit-class-y)

		$(obj)/syscall32_syscall.o: \
		$(foreach F,sysenter syscall,$(obj)/vsyscall-$F.so)

		# Teach kbuild about targets
		targets := $(foreach F,$(addprefix vsyscall-,sysenter syscall),\
		$F.o $F.so $F.so.dbg)

		# The DSO images are built using a special linker script
		quiet_cmd_syscall = SYSCALL $@
		cmd_syscall = $(CC) -m32 -nostdlib -shared \
		$(call ld-option, -Wl$(comma)--hash-style=sysv) \
		-Wl,-soname=linux-gate.so.1 -o $@ \
		-Wl,-T,$(filter-out FORCE,$^)

		$(obj)/%.so: OBJCOPYFLAGS := -S
		$(obj)/%.so: $(obj)/%.so.dbg FORCE
		$(call if_changed,objcopy)

		$(obj)/vsyscall-sysenter.so.dbg $(obj)/vsyscall-syscall.so.dbg: \
		$(obj)/vsyscall-%.so.dbg: $(src)/vsyscall.lds $(obj)/vsyscall-%.o FORCE
		$(call if_changed,syscall)

		AFLAGS_vsyscall-sysenter.o = -m32 -Wa,-32
		AFLAGS_vsyscall-syscall.o = -m32 -Wa,-32

		vdsos := vdso32-sysenter.so vdso32-syscall.so

		quiet_cmd_vdso_install = INSTALL $@
		cmd_vdso_install = cp $(@:vdso32-%.so=$(obj)/vsyscall-%.so.dbg) \
		$(MODLIB)/vdso/$@

		$(vdsos):
		@mkdir -p $(MODLIB)/vdso
		$(call cmd,vdso_install)

		vdso_install: $(vdsos)

arch/x86/ia32/syscall32.c

deleted100644 → 0

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Original line number	Diff line number	Diff line
		/*
		* Copyright 2002,2003 Andi Kleen, SuSE Labs
		*
		* vsyscall handling for 32bit processes. Map a stub page into it on
		* demand because 32bit cannot reach the kernel's fixmaps
		*/
		#include <linux/mm.h>
		#include <linux/string.h>
		#include <linux/kernel.h>
		#include <linux/gfp.h>
		#include <linux/init.h>
		#include <linux/stringify.h>
		#include <linux/security.h>
		#include <asm/proto.h>
		#include <asm/tlbflush.h>
		#include <asm/ia32_unistd.h>
		#include <asm/vsyscall32.h>

		extern unsigned char syscall32_syscall[], syscall32_syscall_end[];
		extern unsigned char syscall32_sysenter[], syscall32_sysenter_end[];
		extern int sysctl_vsyscall32;

		static struct page *syscall32_pages[1];
		static int use_sysenter = -1;

		struct linux_binprm;

		/* Setup a VMA at program startup for the vsyscall page */
		int syscall32_setup_pages(struct linux_binprm *bprm, int exstack)
		{
		struct mm_struct *mm = current->mm;
		int ret;

		down_write(&mm->mmap_sem);
		/*
		* MAYWRITE to allow gdb to COW and set breakpoints
		*
		* Make sure the vDSO gets into every core dump.
		* Dumping its contents makes post-mortem fully interpretable later
		* without matching up the same kernel and hardware config to see
		* what PC values meant.
		*/
		/* Could randomize here */
		ret = install_special_mapping(mm, VSYSCALL32_BASE, PAGE_SIZE,
		VM_READ\|VM_EXEC\|
		VM_MAYREAD\|VM_MAYWRITE\|VM_MAYEXEC\|
		VM_ALWAYSDUMP,
		syscall32_pages);
		if (ret == 0) {
		current->mm->context.vdso = (void __user *)VSYSCALL32_BASE;
		current_thread_info()->sysenter_return = VSYSCALL32_SYSEXIT;
		}
		up_write(&mm->mmap_sem);
		return ret;
		}

		static int __init init_syscall32(void)
		{
		char syscall32_page = (void )get_zeroed_page(GFP_KERNEL);

		if (!syscall32_page)
		panic("Cannot allocate syscall32 page");
		syscall32_pages[0] = virt_to_page(syscall32_page);
		if (use_sysenter > 0) {
		memcpy(syscall32_page, syscall32_sysenter,
		syscall32_sysenter_end - syscall32_sysenter);
		} else {
		memcpy(syscall32_page, syscall32_syscall,
		syscall32_syscall_end - syscall32_syscall);
		}
		return 0;
		}
		__initcall(init_syscall32);

		/* May not be __init: called during resume */
		void syscall32_cpu_init(void)
		{
		if (use_sysenter < 0)
		use_sysenter = (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL);

		/*
		* Load these always in case some future AMD CPU supports
		* SYSENTER from compat mode too.
		*/
		checking_wrmsrl(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
		checking_wrmsrl(MSR_IA32_SYSENTER_ESP, 0ULL);
		checking_wrmsrl(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);

		wrmsrl(MSR_CSTAR, ia32_cstar_target);
		}

arch/x86/ia32/syscall32_syscall.S

deleted100644 → 0

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Original line number	Diff line number	Diff line
		/* 32bit VDSOs mapped into user space. */

		.section ".init.data","aw"

		.globl syscall32_syscall
		.globl syscall32_syscall_end

		syscall32_syscall:
		.incbin "arch/x86/ia32/vsyscall-syscall.so"
		syscall32_syscall_end:

		.globl syscall32_sysenter
		.globl syscall32_sysenter_end

		syscall32_sysenter:
		.incbin "arch/x86/ia32/vsyscall-sysenter.so"
		syscall32_sysenter_end:

arch/x86/ia32/vsyscall-sigreturn.S

deleted100644 → 0

+0 −142

Original line number	Diff line number	Diff line
		/*
		* Common code for the sigreturn entry points on the vsyscall page.
		* This code uses SYSCALL_ENTER_KERNEL (either syscall or int $0x80)
		* to enter the kernel.
		* This file is #include'd by vsyscall-*.S to define them after the
		* vsyscall entry point. The addresses we get for these entry points
		* by doing ".balign 32" must match in both versions of the page.
		*/

		.code32
		.section .text.sigreturn,"ax"
		.balign 32
		.globl __kernel_sigreturn
		.type __kernel_sigreturn,@function
		__kernel_sigreturn:
		.LSTART_sigreturn:
		popl %eax
		movl $__NR_ia32_sigreturn, %eax
		SYSCALL_ENTER_KERNEL
		.LEND_sigreturn:
		.size __kernel_sigreturn,.-.LSTART_sigreturn

		.section .text.rtsigreturn,"ax"
		.balign 32
		.globl __kernel_rt_sigreturn
		.type __kernel_rt_sigreturn,@function
		__kernel_rt_sigreturn:
		.LSTART_rt_sigreturn:
		movl $__NR_ia32_rt_sigreturn, %eax
		SYSCALL_ENTER_KERNEL
		.LEND_rt_sigreturn:
		.size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn

		.section .eh_frame,"a",@progbits
		.LSTARTFRAMES:
		.long .LENDCIES-.LSTARTCIES
		.LSTARTCIES:
		.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 0x0c /* DW_CFA_def_cfa */
		.uleb128 4
		.uleb128 4
		.byte 0x88 /* DW_CFA_offset, column 0x8 */
		.uleb128 1
		.align 4
		.LENDCIES:

		.long .LENDFDE2-.LSTARTFDE2 /* Length FDE */
		.LSTARTFDE2:
		.long .LSTARTFDE2-.LSTARTFRAMES /* 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 length */
		/* 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
		.LENDFDE2:

		.long .LENDFDE3-.LSTARTFDE3 /* Length FDE */
		.LSTARTFDE3:
		.long .LSTARTFDE3-.LSTARTFRAMES /* 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
		.LENDFDE3:

		#include "../vdso/vdso32/note.S"