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-rw-r--r--arch/sh/kernel/vsyscall/Makefile36
-rw-r--r--arch/sh/kernel/vsyscall/vsyscall-note.S25
-rw-r--r--arch/sh/kernel/vsyscall/vsyscall-sigreturn.S39
-rw-r--r--arch/sh/kernel/vsyscall/vsyscall-syscall.S10
-rw-r--r--arch/sh/kernel/vsyscall/vsyscall-trapa.S42
-rw-r--r--arch/sh/kernel/vsyscall/vsyscall.c150
-rw-r--r--arch/sh/kernel/vsyscall/vsyscall.lds.S74
7 files changed, 376 insertions, 0 deletions
diff --git a/arch/sh/kernel/vsyscall/Makefile b/arch/sh/kernel/vsyscall/Makefile
new file mode 100644
index 000000000000..4bbce1cfa359
--- /dev/null
+++ b/arch/sh/kernel/vsyscall/Makefile
@@ -0,0 +1,36 @@
1obj-y += vsyscall.o vsyscall-syscall.o
2
3$(obj)/vsyscall-syscall.o: \
4 $(foreach F,trapa,$(obj)/vsyscall-$F.so)
5
6# Teach kbuild about targets
7targets += $(foreach F,trapa,vsyscall-$F.o vsyscall-$F.so)
8targets += vsyscall-note.o vsyscall.lds
9
10# The DSO images are built using a special linker script
11quiet_cmd_syscall = SYSCALL $@
12 cmd_syscall = $(CC) -nostdlib $(SYSCFLAGS_$(@F)) \
13 -Wl,-T,$(filter-out FORCE,$^) -o $@
14
15export CPPFLAGS_vsyscall.lds += -P -C -Ush
16
17vsyscall-flags = -shared -s -Wl,-soname=linux-gate.so.1 \
18 $(call ld-option, -Wl$(comma)--hash-style=sysv)
19
20SYSCFLAGS_vsyscall-trapa.so = $(vsyscall-flags)
21
22$(obj)/vsyscall-trapa.so: \
23$(obj)/vsyscall-%.so: $(src)/vsyscall.lds $(obj)/vsyscall-%.o FORCE
24 $(call if_changed,syscall)
25
26# We also create a special relocatable object that should mirror the symbol
27# table and layout of the linked DSO. With ld -R we can then refer to
28# these symbols in the kernel code rather than hand-coded addresses.
29extra-y += vsyscall-syms.o
30$(obj)/built-in.o: $(obj)/vsyscall-syms.o
31$(obj)/built-in.o: ld_flags += -R $(obj)/vsyscall-syms.o
32
33SYSCFLAGS_vsyscall-syms.o = -r
34$(obj)/vsyscall-syms.o: $(src)/vsyscall.lds \
35 $(obj)/vsyscall-trapa.o $(obj)/vsyscall-note.o FORCE
36 $(call if_changed,syscall)
diff --git a/arch/sh/kernel/vsyscall/vsyscall-note.S b/arch/sh/kernel/vsyscall/vsyscall-note.S
new file mode 100644
index 000000000000..d4b5be4f3d5f
--- /dev/null
+++ b/arch/sh/kernel/vsyscall/vsyscall-note.S
@@ -0,0 +1,25 @@
1/*
2 * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
3 * Here we can supply some information useful to userland.
4 */
5
6#include <linux/uts.h>
7#include <linux/version.h>
8
9#define ASM_ELF_NOTE_BEGIN(name, flags, vendor, type) \
10 .section name, flags; \
11 .balign 4; \
12 .long 1f - 0f; /* name length */ \
13 .long 3f - 2f; /* data length */ \
14 .long type; /* note type */ \
150: .asciz vendor; /* vendor name */ \
161: .balign 4; \
172:
18
19#define ASM_ELF_NOTE_END \
203: .balign 4; /* pad out section */ \
21 .previous
22
23 ASM_ELF_NOTE_BEGIN(".note.kernel-version", "a", UTS_SYSNAME, 0)
24 .long LINUX_VERSION_CODE
25 ASM_ELF_NOTE_END
diff --git a/arch/sh/kernel/vsyscall/vsyscall-sigreturn.S b/arch/sh/kernel/vsyscall/vsyscall-sigreturn.S
new file mode 100644
index 000000000000..555a64f124ca
--- /dev/null
+++ b/arch/sh/kernel/vsyscall/vsyscall-sigreturn.S
@@ -0,0 +1,39 @@
1#include <asm/unistd.h>
2
3 .text
4 .balign 32
5 .globl __kernel_sigreturn
6 .type __kernel_sigreturn,@function
7__kernel_sigreturn:
8.LSTART_sigreturn:
9 mov.w 1f, r3
10 trapa #0x10
11 or r0, r0
12 or r0, r0
13 or r0, r0
14 or r0, r0
15 or r0, r0
16
171: .short __NR_sigreturn
18.LEND_sigreturn:
19 .size __kernel_sigreturn,.-.LSTART_sigreturn
20
21 .balign 32
22 .globl __kernel_rt_sigreturn
23 .type __kernel_rt_sigreturn,@function
24__kernel_rt_sigreturn:
25.LSTART_rt_sigreturn:
26 mov.w 1f, r3
27 trapa #0x10
28 or r0, r0
29 or r0, r0
30 or r0, r0
31 or r0, r0
32 or r0, r0
33
341: .short __NR_rt_sigreturn
35.LEND_rt_sigreturn:
36 .size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn
37
38 .section .eh_frame,"a",@progbits
39 .previous
diff --git a/arch/sh/kernel/vsyscall/vsyscall-syscall.S b/arch/sh/kernel/vsyscall/vsyscall-syscall.S
new file mode 100644
index 000000000000..c2ac7f0282b3
--- /dev/null
+++ b/arch/sh/kernel/vsyscall/vsyscall-syscall.S
@@ -0,0 +1,10 @@
1#include <linux/init.h>
2
3__INITDATA
4
5 .globl vsyscall_trapa_start, vsyscall_trapa_end
6vsyscall_trapa_start:
7 .incbin "arch/sh/kernel/vsyscall/vsyscall-trapa.so"
8vsyscall_trapa_end:
9
10__FINIT
diff --git a/arch/sh/kernel/vsyscall/vsyscall-trapa.S b/arch/sh/kernel/vsyscall/vsyscall-trapa.S
new file mode 100644
index 000000000000..3b6eb34c43fa
--- /dev/null
+++ b/arch/sh/kernel/vsyscall/vsyscall-trapa.S
@@ -0,0 +1,42 @@
1 .text
2 .globl __kernel_vsyscall
3 .type __kernel_vsyscall,@function
4__kernel_vsyscall:
5.LSTART_vsyscall:
6 /* XXX: We'll have to do something here once we opt to use the vDSO
7 * page for something other than the signal trampoline.. as well as
8 * fill out .eh_frame -- PFM. */
9.LEND_vsyscall:
10 .size __kernel_vsyscall,.-.LSTART_vsyscall
11 .previous
12
13 .section .eh_frame,"a",@progbits
14.LCIE:
15 .ualong .LCIE_end - .LCIE_start
16.LCIE_start:
17 .ualong 0 /* CIE ID */
18 .byte 0x1 /* Version number */
19 .string "zRS" /* NUL-terminated augmentation string */
20 .uleb128 0x1 /* Code alignment factor */
21 .sleb128 -4 /* Data alignment factor */
22 .byte 0x11 /* Return address register column */
23 /* Augmentation length and data (none) */
24 .byte 0xc /* DW_CFA_def_cfa */
25 .uleb128 0xf /* r15 */
26 .uleb128 0x0 /* offset 0 */
27
28 .align 2
29.LCIE_end:
30
31 .ualong .LFDE_end-.LFDE_start /* Length FDE */
32.LFDE_start:
33 .ualong .LCIE /* CIE pointer */
34 .ualong .LSTART_vsyscall-. /* start address */
35 .ualong .LEND_vsyscall-.LSTART_vsyscall
36 .uleb128 0
37 .align 2
38.LFDE_end:
39 .previous
40
41/* Get the common code for the sigreturn entry points */
42#include "vsyscall-sigreturn.S"
diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c
new file mode 100644
index 000000000000..075d6cc1a2d7
--- /dev/null
+++ b/arch/sh/kernel/vsyscall/vsyscall.c
@@ -0,0 +1,150 @@
1/*
2 * arch/sh/kernel/vsyscall.c
3 *
4 * Copyright (C) 2006 Paul Mundt
5 *
6 * vDSO randomization
7 * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file "COPYING" in the main directory of this archive
11 * for more details.
12 */
13#include <linux/mm.h>
14#include <linux/slab.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/gfp.h>
18#include <linux/module.h>
19#include <linux/elf.h>
20
21/*
22 * Should the kernel map a VDSO page into processes and pass its
23 * address down to glibc upon exec()?
24 */
25unsigned int __read_mostly vdso_enabled = 1;
26EXPORT_SYMBOL_GPL(vdso_enabled);
27
28static int __init vdso_setup(char *s)
29{
30 vdso_enabled = simple_strtoul(s, NULL, 0);
31 return 1;
32}
33__setup("vdso=", vdso_setup);
34
35/*
36 * These symbols are defined by vsyscall.o to mark the bounds
37 * of the ELF DSO images included therein.
38 */
39extern const char vsyscall_trapa_start, vsyscall_trapa_end;
40static void *syscall_page;
41
42int __init vsyscall_init(void)
43{
44 syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);
45
46 /*
47 * XXX: Map this page to a fixmap entry if we get around
48 * to adding the page to ELF core dumps
49 */
50
51 memcpy(syscall_page,
52 &vsyscall_trapa_start,
53 &vsyscall_trapa_end - &vsyscall_trapa_start);
54
55 return 0;
56}
57
58static struct page *syscall_vma_nopage(struct vm_area_struct *vma,
59 unsigned long address, int *type)
60{
61 unsigned long offset = address - vma->vm_start;
62 struct page *page;
63
64 if (address < vma->vm_start || address > vma->vm_end)
65 return NOPAGE_SIGBUS;
66
67 page = virt_to_page(syscall_page + offset);
68
69 get_page(page);
70
71 return page;
72}
73
74/* Prevent VMA merging */
75static void syscall_vma_close(struct vm_area_struct *vma)
76{
77}
78
79static struct vm_operations_struct syscall_vm_ops = {
80 .nopage = syscall_vma_nopage,
81 .close = syscall_vma_close,
82};
83
84/* Setup a VMA at program startup for the vsyscall page */
85int arch_setup_additional_pages(struct linux_binprm *bprm,
86 int executable_stack)
87{
88 struct vm_area_struct *vma;
89 struct mm_struct *mm = current->mm;
90 unsigned long addr;
91 int ret;
92
93 down_write(&mm->mmap_sem);
94 addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
95 if (IS_ERR_VALUE(addr)) {
96 ret = addr;
97 goto up_fail;
98 }
99
100 vma = kmem_cache_zalloc(vm_area_cachep, SLAB_KERNEL);
101 if (!vma) {
102 ret = -ENOMEM;
103 goto up_fail;
104 }
105
106 vma->vm_start = addr;
107 vma->vm_end = addr + PAGE_SIZE;
108 /* MAYWRITE to allow gdb to COW and set breakpoints */
109 vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE;
110 vma->vm_flags |= mm->def_flags;
111 vma->vm_page_prot = protection_map[vma->vm_flags & 7];
112 vma->vm_ops = &syscall_vm_ops;
113 vma->vm_mm = mm;
114
115 ret = insert_vm_struct(mm, vma);
116 if (unlikely(ret)) {
117 kmem_cache_free(vm_area_cachep, vma);
118 goto up_fail;
119 }
120
121 current->mm->context.vdso = (void *)addr;
122
123 mm->total_vm++;
124up_fail:
125 up_write(&mm->mmap_sem);
126 return ret;
127}
128
129const char *arch_vma_name(struct vm_area_struct *vma)
130{
131 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
132 return "[vdso]";
133
134 return NULL;
135}
136
137struct vm_area_struct *get_gate_vma(struct task_struct *task)
138{
139 return NULL;
140}
141
142int in_gate_area(struct task_struct *task, unsigned long address)
143{
144 return 0;
145}
146
147int in_gate_area_no_task(unsigned long address)
148{
149 return 0;
150}
diff --git a/arch/sh/kernel/vsyscall/vsyscall.lds.S b/arch/sh/kernel/vsyscall/vsyscall.lds.S
new file mode 100644
index 000000000000..b13c3d439fee
--- /dev/null
+++ b/arch/sh/kernel/vsyscall/vsyscall.lds.S
@@ -0,0 +1,74 @@
1/*
2 * Linker script for vsyscall DSO. The vsyscall page is an ELF shared
3 * object prelinked to its virtual address, and with only one read-only
4 * segment (that fits in one page). This script controls its layout.
5 */
6#include <asm/asm-offsets.h>
7
8#ifdef CONFIG_CPU_LITTLE_ENDIAN
9OUTPUT_FORMAT("elf32-sh-linux", "elf32-sh-linux", "elf32-sh-linux")
10#else
11OUTPUT_FORMAT("elf32-shbig-linux", "elf32-shbig-linux", "elf32-shbig-linux")
12#endif
13OUTPUT_ARCH(sh)
14
15/* The ELF entry point can be used to set the AT_SYSINFO value. */
16ENTRY(__kernel_vsyscall);
17
18SECTIONS
19{
20 . = SIZEOF_HEADERS;
21
22 .hash : { *(.hash) } :text
23 .gnu.hash : { *(.gnu.hash) }
24 .dynsym : { *(.dynsym) }
25 .dynstr : { *(.dynstr) }
26 .gnu.version : { *(.gnu.version) }
27 .gnu.version_d : { *(.gnu.version_d) }
28 .gnu.version_r : { *(.gnu.version_r) }
29
30 /* This linker script is used both with -r and with -shared.
31 For the layouts to match, we need to skip more than enough
32 space for the dynamic symbol table et al. If this amount
33 is insufficient, ld -shared will barf. Just increase it here. */
34 . = 0x400;
35
36 .text : { *(.text) } :text =0x90909090
37 .note : { *(.note.*) } :text :note
38 .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
39 .eh_frame : { KEEP (*(.eh_frame)) } :text
40 .dynamic : { *(.dynamic) } :text :dynamic
41 .useless : {
42 *(.got.plt) *(.got)
43 *(.data .data.* .gnu.linkonce.d.*)
44 *(.dynbss)
45 *(.bss .bss.* .gnu.linkonce.b.*)
46 } :text
47}
48
49/*
50 * We must supply the ELF program headers explicitly to get just one
51 * PT_LOAD segment, and set the flags explicitly to make segments read-only.
52 */
53PHDRS
54{
55 text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
56 dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
57 note PT_NOTE FLAGS(4); /* PF_R */
58 eh_frame_hdr 0x6474e550; /* PT_GNU_EH_FRAME, but ld doesn't match the name */
59}
60
61/*
62 * This controls what symbols we export from the DSO.
63 */
64VERSION
65{
66 LINUX_2.6 {
67 global:
68 __kernel_vsyscall;
69 __kernel_sigreturn;
70 __kernel_rt_sigreturn;
71
72 local: *;
73 };
74}
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