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authorAlex Smith <alex.smith@imgtec.com>2015-10-21 04:54:38 -0400
committerRalf Baechle <ralf@linux-mips.org>2015-11-11 02:36:36 -0500
commitebb5e78cc63417a35254a791de66e1cc84f963cc (patch)
tree49814946abe594cb8e7a11ce8d0a5fdaabb49d31
parent22773aa9b95657f0adc2b5342428d9da7a6d5d02 (diff)
MIPS: Initial implementation of a VDSO
Add an initial implementation of a proper (i.e. an ELF shared library) VDSO. With this commit it does not export any symbols, it only replaces the current signal return trampoline page. A later commit will add user implementations of gettimeofday()/clock_gettime(). To support both new toolchains and old ones which don't generate ABI flags section, we define its content manually and then use a tool (genvdso) to patch up the section to have the correct name and type. genvdso also extracts symbol offsets ({,rt_}sigreturn) needed by the kernel, and generates a C file containing a "struct mips_vdso_image" containing both the VDSO data and these offsets. This C file is compiled into the kernel. On 64-bit kernels we require a different VDSO for each supported ABI, so we may build up to 3 different VDSOs. The VDSO to use is selected by the mips_abi structure. A kernel/user shared data page is created and mapped below the VDSO image. This is currently empty, but will be used by the user time function implementations which are added later. [markos.chandras@imgtec.com: - Add more comments - Move abi detection in genvdso.h since it's the get_symbol function that needs it. - Add an R6 specific way to calculate the base address of VDSO in order to avoid the branch instruction which affects performance. - Do not patch .gnu.attributes since it's not needed for dynamic linking. - Simplify Makefile a little bit. - checkpatch fixes - Restrict VDSO support for binutils < 2.25 for pre-R6 - Include atomic64.h for O32 variant on MIPS64] Signed-off-by: Alex Smith <alex.smith@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11337/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat
-rw-r--r--arch/mips/Kbuild1
-rw-r--r--arch/mips/include/asm/abi.h5
-rw-r--r--arch/mips/include/asm/elf.h7
-rw-r--r--arch/mips/include/asm/processor.h8
-rw-r--r--arch/mips/include/asm/vdso.h73
-rw-r--r--arch/mips/include/uapi/asm/Kbuild2
-rw-r--r--arch/mips/include/uapi/asm/auxvec.h17
-rw-r--r--arch/mips/kernel/signal.c12
-rw-r--r--arch/mips/kernel/signal32.c7
-rw-r--r--arch/mips/kernel/signal_n32.c5
-rw-r--r--arch/mips/kernel/vdso.c160
-rw-r--r--arch/mips/vdso/.gitignore4
-rw-r--r--arch/mips/vdso/Makefile160
-rw-r--r--arch/mips/vdso/elf.S68
-rw-r--r--arch/mips/vdso/genvdso.c293
-rw-r--r--arch/mips/vdso/genvdso.h187
-rw-r--r--arch/mips/vdso/sigreturn.S49
-rw-r--r--arch/mips/vdso/vdso.h80
-rw-r--r--arch/mips/vdso/vdso.lds.S100
19 files changed, 1114 insertions, 124 deletions
diff --git a/arch/mips/Kbuild b/arch/mips/Kbuild
index dd295335891a..5c3f688a5232 100644
--- a/arch/mips/Kbuild
+++ b/arch/mips/Kbuild
@@ -17,6 +17,7 @@ obj- := $(platform-)
17obj-y += kernel/ 17obj-y += kernel/
18obj-y += mm/ 18obj-y += mm/
19obj-y += net/ 19obj-y += net/
20obj-y += vdso/
20 21
21ifdef CONFIG_KVM 22ifdef CONFIG_KVM
22obj-y += kvm/ 23obj-y += kvm/
diff --git a/arch/mips/include/asm/abi.h b/arch/mips/include/asm/abi.h
index 37f84078e78a..940760844e2f 100644
--- a/arch/mips/include/asm/abi.h
+++ b/arch/mips/include/asm/abi.h
@@ -11,19 +11,20 @@
11 11
12#include <asm/signal.h> 12#include <asm/signal.h>
13#include <asm/siginfo.h> 13#include <asm/siginfo.h>
14#include <asm/vdso.h>
14 15
15struct mips_abi { 16struct mips_abi {
16 int (* const setup_frame)(void *sig_return, struct ksignal *ksig, 17 int (* const setup_frame)(void *sig_return, struct ksignal *ksig,
17 struct pt_regs *regs, sigset_t *set); 18 struct pt_regs *regs, sigset_t *set);
18 const unsigned long signal_return_offset;
19 int (* const setup_rt_frame)(void *sig_return, struct ksignal *ksig, 19 int (* const setup_rt_frame)(void *sig_return, struct ksignal *ksig,
20 struct pt_regs *regs, sigset_t *set); 20 struct pt_regs *regs, sigset_t *set);
21 const unsigned long rt_signal_return_offset;
22 const unsigned long restart; 21 const unsigned long restart;
23 22
24 unsigned off_sc_fpregs; 23 unsigned off_sc_fpregs;
25 unsigned off_sc_fpc_csr; 24 unsigned off_sc_fpc_csr;
26 unsigned off_sc_used_math; 25 unsigned off_sc_used_math;
26
27 struct mips_vdso_image *vdso;
27}; 28};
28 29
29#endif /* _ASM_ABI_H */ 30#endif /* _ASM_ABI_H */
diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index 53b26933b12c..b01a6ff468e0 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -8,6 +8,7 @@
8#ifndef _ASM_ELF_H 8#ifndef _ASM_ELF_H
9#define _ASM_ELF_H 9#define _ASM_ELF_H
10 10
11#include <linux/auxvec.h>
11#include <linux/fs.h> 12#include <linux/fs.h>
12#include <uapi/linux/elf.h> 13#include <uapi/linux/elf.h>
13 14
@@ -419,6 +420,12 @@ extern const char *__elf_platform;
419#define ELF_ET_DYN_BASE (TASK_SIZE / 3 * 2) 420#define ELF_ET_DYN_BASE (TASK_SIZE / 3 * 2)
420#endif 421#endif
421 422
423#define ARCH_DLINFO \
424do { \
425 NEW_AUX_ENT(AT_SYSINFO_EHDR, \
426 (unsigned long)current->mm->context.vdso); \
427} while (0)
428
422#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1 429#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
423struct linux_binprm; 430struct linux_binprm;
424extern int arch_setup_additional_pages(struct linux_binprm *bprm, 431extern int arch_setup_additional_pages(struct linux_binprm *bprm,
diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h
index 59ee6dcf6eed..3f832c3dd8f5 100644
--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -36,12 +36,6 @@ extern unsigned int vced_count, vcei_count;
36 */ 36 */
37#define HAVE_ARCH_PICK_MMAP_LAYOUT 1 37#define HAVE_ARCH_PICK_MMAP_LAYOUT 1
38 38
39/*
40 * A special page (the vdso) is mapped into all processes at the very
41 * top of the virtual memory space.
42 */
43#define SPECIAL_PAGES_SIZE PAGE_SIZE
44
45#ifdef CONFIG_32BIT 39#ifdef CONFIG_32BIT
46#ifdef CONFIG_KVM_GUEST 40#ifdef CONFIG_KVM_GUEST
47/* User space process size is limited to 1GB in KVM Guest Mode */ 41/* User space process size is limited to 1GB in KVM Guest Mode */
@@ -80,7 +74,7 @@ extern unsigned int vced_count, vcei_count;
80 74
81#endif 75#endif
82 76
83#define STACK_TOP ((TASK_SIZE & PAGE_MASK) - SPECIAL_PAGES_SIZE) 77#define STACK_TOP (TASK_SIZE & PAGE_MASK)
84 78
85/* 79/*
86 * This decides where the kernel will search for a free chunk of vm 80 * This decides where the kernel will search for a free chunk of vm
diff --git a/arch/mips/include/asm/vdso.h b/arch/mips/include/asm/vdso.h
index cca56aa40ff4..db2d45be8f2e 100644
--- a/arch/mips/include/asm/vdso.h
+++ b/arch/mips/include/asm/vdso.h
@@ -1,29 +1,70 @@
1/* 1/*
2 * This file is subject to the terms and conditions of the GNU General Public 2 * Copyright (C) 2015 Imagination Technologies
3 * License. See the file "COPYING" in the main directory of this archive 3 * Author: Alex Smith <alex.smith@imgtec.com>
4 * for more details.
5 * 4 *
6 * Copyright (C) 2009 Cavium Networks 5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
7 */ 9 */
8 10
9#ifndef __ASM_VDSO_H 11#ifndef __ASM_VDSO_H
10#define __ASM_VDSO_H 12#define __ASM_VDSO_H
11 13
12#include <linux/types.h> 14#include <linux/mm_types.h>
13 15
16/**
17 * struct mips_vdso_image - Details of a VDSO image.
18 * @data: Pointer to VDSO image data (page-aligned).
19 * @size: Size of the VDSO image data (page-aligned).
20 * @off_sigreturn: Offset of the sigreturn() trampoline.
21 * @off_rt_sigreturn: Offset of the rt_sigreturn() trampoline.
22 * @mapping: Special mapping structure.
23 *
24 * This structure contains details of a VDSO image, including the image data
25 * and offsets of certain symbols required by the kernel. It is generated as
26 * part of the VDSO build process, aside from the mapping page array, which is
27 * populated at runtime.
28 */
29struct mips_vdso_image {
30 void *data;
31 unsigned long size;
14 32
15#ifdef CONFIG_32BIT 33 unsigned long off_sigreturn;
16struct mips_vdso { 34 unsigned long off_rt_sigreturn;
17 u32 signal_trampoline[2]; 35
18 u32 rt_signal_trampoline[2]; 36 struct vm_special_mapping mapping;
19}; 37};
20#else /* !CONFIG_32BIT */ 38
21struct mips_vdso { 39/*
22 u32 o32_signal_trampoline[2]; 40 * The following structures are auto-generated as part of the build for each
23 u32 o32_rt_signal_trampoline[2]; 41 * ABI by genvdso, see arch/mips/vdso/Makefile.
24 u32 rt_signal_trampoline[2]; 42 */
25 u32 n32_rt_signal_trampoline[2]; 43
44extern struct mips_vdso_image vdso_image;
45
46#ifdef CONFIG_MIPS32_O32
47extern struct mips_vdso_image vdso_image_o32;
48#endif
49
50#ifdef CONFIG_MIPS32_N32
51extern struct mips_vdso_image vdso_image_n32;
52#endif
53
54/**
55 * union mips_vdso_data - Data provided by the kernel for the VDSO.
56 *
57 * This structure contains data needed by functions within the VDSO. It is
58 * populated by the kernel and mapped read-only into user memory.
59 *
60 * Note: Care should be taken when modifying as the layout must remain the same
61 * for both 64- and 32-bit (for 32-bit userland on 64-bit kernel).
62 */
63union mips_vdso_data {
64 struct {
65 };
66
67 u8 page[PAGE_SIZE];
26}; 68};
27#endif /* CONFIG_32BIT */
28 69
29#endif /* __ASM_VDSO_H */ 70#endif /* __ASM_VDSO_H */
diff --git a/arch/mips/include/uapi/asm/Kbuild b/arch/mips/include/uapi/asm/Kbuild
index 96fe7395ed8d..f2cf41461146 100644
--- a/arch/mips/include/uapi/asm/Kbuild
+++ b/arch/mips/include/uapi/asm/Kbuild
@@ -1,9 +1,9 @@
1# UAPI Header export list 1# UAPI Header export list
2include include/uapi/asm-generic/Kbuild.asm 2include include/uapi/asm-generic/Kbuild.asm
3 3
4generic-y += auxvec.h
5generic-y += ipcbuf.h 4generic-y += ipcbuf.h
6 5
6header-y += auxvec.h
7header-y += bitfield.h 7header-y += bitfield.h
8header-y += bitsperlong.h 8header-y += bitsperlong.h
9header-y += break.h 9header-y += break.h
diff --git a/arch/mips/include/uapi/asm/auxvec.h b/arch/mips/include/uapi/asm/auxvec.h
new file mode 100644
index 000000000000..c9c7195272c4
--- /dev/null
+++ b/arch/mips/include/uapi/asm/auxvec.h
@@ -0,0 +1,17 @@
1/*
2 * Copyright (C) 2015 Imagination Technologies
3 * Author: Alex Smith <alex.smith@imgtec.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 */
10
11#ifndef __ASM_AUXVEC_H
12#define __ASM_AUXVEC_H
13
14/* Location of VDSO image. */
15#define AT_SYSINFO_EHDR 33
16
17#endif /* __ASM_AUXVEC_H */
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 2fec67bfc457..bf792e2839a6 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -36,7 +36,6 @@
36#include <asm/ucontext.h> 36#include <asm/ucontext.h>
37#include <asm/cpu-features.h> 37#include <asm/cpu-features.h>
38#include <asm/war.h> 38#include <asm/war.h>
39#include <asm/vdso.h>
40#include <asm/dsp.h> 39#include <asm/dsp.h>
41#include <asm/inst.h> 40#include <asm/inst.h>
42#include <asm/msa.h> 41#include <asm/msa.h>
@@ -752,16 +751,15 @@ static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
752struct mips_abi mips_abi = { 751struct mips_abi mips_abi = {
753#ifdef CONFIG_TRAD_SIGNALS 752#ifdef CONFIG_TRAD_SIGNALS
754 .setup_frame = setup_frame, 753 .setup_frame = setup_frame,
755 .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
756#endif 754#endif
757 .setup_rt_frame = setup_rt_frame, 755 .setup_rt_frame = setup_rt_frame,
758 .rt_signal_return_offset =
759 offsetof(struct mips_vdso, rt_signal_trampoline),
760 .restart = __NR_restart_syscall, 756 .restart = __NR_restart_syscall,
761 757
762 .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs), 758 .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
763 .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr), 759 .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
764 .off_sc_used_math = offsetof(struct sigcontext, sc_used_math), 760 .off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
761
762 .vdso = &vdso_image,
765}; 763};
766 764
767static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) 765static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
@@ -801,11 +799,11 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
801 } 799 }
802 800
803 if (sig_uses_siginfo(&ksig->ka)) 801 if (sig_uses_siginfo(&ksig->ka))
804 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset, 802 ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn,
805 ksig, regs, oldset); 803 ksig, regs, oldset);
806 else 804 else
807 ret = abi->setup_frame(vdso + abi->signal_return_offset, ksig, 805 ret = abi->setup_frame(vdso + abi->vdso->off_sigreturn,
808 regs, oldset); 806 ksig, regs, oldset);
809 807
810 signal_setup_done(ret, ksig, 0); 808 signal_setup_done(ret, ksig, 0);
811} 809}
diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c
index f7e89524e316..4909639aa35b 100644
--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -31,7 +31,6 @@
31#include <asm/ucontext.h> 31#include <asm/ucontext.h>
32#include <asm/fpu.h> 32#include <asm/fpu.h>
33#include <asm/war.h> 33#include <asm/war.h>
34#include <asm/vdso.h>
35#include <asm/dsp.h> 34#include <asm/dsp.h>
36 35
37#include "signal-common.h" 36#include "signal-common.h"
@@ -406,14 +405,12 @@ static int setup_rt_frame_32(void *sig_return, struct ksignal *ksig,
406 */ 405 */
407struct mips_abi mips_abi_32 = { 406struct mips_abi mips_abi_32 = {
408 .setup_frame = setup_frame_32, 407 .setup_frame = setup_frame_32,
409 .signal_return_offset =
410 offsetof(struct mips_vdso, o32_signal_trampoline),
411 .setup_rt_frame = setup_rt_frame_32, 408 .setup_rt_frame = setup_rt_frame_32,
412 .rt_signal_return_offset =
413 offsetof(struct mips_vdso, o32_rt_signal_trampoline),
414 .restart = __NR_O32_restart_syscall, 409 .restart = __NR_O32_restart_syscall,
415 410
416 .off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs), 411 .off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs),
417 .off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr), 412 .off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr),
418 .off_sc_used_math = offsetof(struct sigcontext32, sc_used_math), 413 .off_sc_used_math = offsetof(struct sigcontext32, sc_used_math),
414
415 .vdso = &vdso_image_o32,
419}; 416};
diff --git a/arch/mips/kernel/signal_n32.c b/arch/mips/kernel/signal_n32.c
index 0d017fdcaf07..a7bc38430500 100644
--- a/arch/mips/kernel/signal_n32.c
+++ b/arch/mips/kernel/signal_n32.c
@@ -38,7 +38,6 @@
38#include <asm/fpu.h> 38#include <asm/fpu.h>
39#include <asm/cpu-features.h> 39#include <asm/cpu-features.h>
40#include <asm/war.h> 40#include <asm/war.h>
41#include <asm/vdso.h>
42 41
43#include "signal-common.h" 42#include "signal-common.h"
44 43
@@ -151,11 +150,11 @@ static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig,
151 150
152struct mips_abi mips_abi_n32 = { 151struct mips_abi mips_abi_n32 = {
153 .setup_rt_frame = setup_rt_frame_n32, 152 .setup_rt_frame = setup_rt_frame_n32,
154 .rt_signal_return_offset =
155 offsetof(struct mips_vdso, n32_rt_signal_trampoline),
156 .restart = __NR_N32_restart_syscall, 153 .restart = __NR_N32_restart_syscall,
157 154
158 .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs), 155 .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
159 .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr), 156 .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
160 .off_sc_used_math = offsetof(struct sigcontext, sc_used_math), 157 .off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
158
159 .vdso = &vdso_image_n32,
161}; 160};
diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
index ed2a278722a9..56cc3c4377fb 100644
--- a/arch/mips/kernel/vdso.c
+++ b/arch/mips/kernel/vdso.c
@@ -1,122 +1,116 @@
1/* 1/*
2 * This file is subject to the terms and conditions of the GNU General Public 2 * Copyright (C) 2015 Imagination Technologies
3 * License. See the file "COPYING" in the main directory of this archive 3 * Author: Alex Smith <alex.smith@imgtec.com>
4 * for more details.
5 * 4 *
6 * Copyright (C) 2009, 2010 Cavium Networks, Inc. 5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
7 */ 9 */
8 10
9
10#include <linux/kernel.h>
11#include <linux/err.h>
12#include <linux/sched.h>
13#include <linux/mm.h>
14#include <linux/init.h>
15#include <linux/binfmts.h> 11#include <linux/binfmts.h>
16#include <linux/elf.h> 12#include <linux/elf.h>
17#include <linux/vmalloc.h> 13#include <linux/err.h>
18#include <linux/unistd.h> 14#include <linux/init.h>
19#include <linux/random.h> 15#include <linux/mm.h>
16#include <linux/sched.h>
17#include <linux/slab.h>
20 18
19#include <asm/abi.h>
21#include <asm/vdso.h> 20#include <asm/vdso.h>
22#include <asm/uasm.h> 21
23#include <asm/processor.h> 22/* Kernel-provided data used by the VDSO. */
23static union mips_vdso_data vdso_data __page_aligned_data;
24 24
25/* 25/*
26 * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... 26 * Mapping for the VDSO data pages. The real pages are mapped manually, as
27 * what we map and where within the area they are mapped is determined at
28 * runtime.
27 */ 29 */
28#define __NR_O32_sigreturn 4119 30static struct page *no_pages[] = { NULL };
29#define __NR_O32_rt_sigreturn 4193 31static struct vm_special_mapping vdso_vvar_mapping = {
30#define __NR_N32_rt_sigreturn 6211 32 .name = "[vvar]",
33 .pages = no_pages,
34};
31 35
32static struct page *vdso_page; 36static void __init init_vdso_image(struct mips_vdso_image *image)
33
34static void __init install_trampoline(u32 *tramp, unsigned int sigreturn)
35{ 37{
36 uasm_i_addiu(&tramp, 2, 0, sigreturn); /* li v0, sigreturn */ 38 unsigned long num_pages, i;
37 uasm_i_syscall(&tramp, 0); 39
40 BUG_ON(!PAGE_ALIGNED(image->data));
41 BUG_ON(!PAGE_ALIGNED(image->size));
42
43 num_pages = image->size / PAGE_SIZE;
44
45 for (i = 0; i < num_pages; i++) {
46 image->mapping.pages[i] =
47 virt_to_page(image->data + (i * PAGE_SIZE));
48 }
38} 49}
39 50
40static int __init init_vdso(void) 51static int __init init_vdso(void)
41{ 52{
42 struct mips_vdso *vdso; 53 init_vdso_image(&vdso_image);
43 54
44 vdso_page = alloc_page(GFP_KERNEL); 55#ifdef CONFIG_MIPS32_O32
45 if (!vdso_page) 56 init_vdso_image(&vdso_image_o32);
46 panic("Cannot allocate vdso");
47
48 vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
49 if (!vdso)
50 panic("Cannot map vdso");
51 clear_page(vdso);
52
53 install_trampoline(vdso->rt_signal_trampoline, __NR_rt_sigreturn);
54#ifdef CONFIG_32BIT
55 install_trampoline(vdso->signal_trampoline, __NR_sigreturn);
56#else
57 install_trampoline(vdso->n32_rt_signal_trampoline,
58 __NR_N32_rt_sigreturn);
59 install_trampoline(vdso->o32_signal_trampoline, __NR_O32_sigreturn);
60 install_trampoline(vdso->o32_rt_signal_trampoline,
61 __NR_O32_rt_sigreturn);
62#endif 57#endif
63 58
64 vunmap(vdso); 59#ifdef CONFIG_MIPS32_N32
60 init_vdso_image(&vdso_image_n32);
61#endif
65 62
66 return 0; 63 return 0;
67} 64}
68subsys_initcall(init_vdso); 65subsys_initcall(init_vdso);
69 66
70static unsigned long vdso_addr(unsigned long start)
71{
72 unsigned long offset = 0UL;
73
74 if (current->flags & PF_RANDOMIZE) {
75 offset = get_random_int();
76 offset <<= PAGE_SHIFT;
77 if (TASK_IS_32BIT_ADDR)
78 offset &= 0xfffffful;
79 else
80 offset &= 0xffffffful;
81 }
82
83 return STACK_TOP + offset;
84}
85
86int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 67int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
87{ 68{
88 int ret; 69 struct mips_vdso_image *image = current->thread.abi->vdso;
89 unsigned long addr;
90 struct mm_struct *mm = current->mm; 70 struct mm_struct *mm = current->mm;
71 unsigned long base, vdso_addr;
72 struct vm_area_struct *vma;
73 int ret;
91 74
92 down_write(&mm->mmap_sem); 75 down_write(&mm->mmap_sem);
93 76
94 addr = vdso_addr(mm->start_stack); 77 base = get_unmapped_area(NULL, 0, PAGE_SIZE + image->size, 0, 0);
95 78 if (IS_ERR_VALUE(base)) {
96 addr = get_unmapped_area(NULL, addr, PAGE_SIZE, 0, 0); 79 ret = base;
97 if (IS_ERR_VALUE(addr)) { 80 goto out;
98 ret = addr;
99 goto up_fail;
100 } 81 }
101 82
102 ret = install_special_mapping(mm, addr, PAGE_SIZE, 83 vdso_addr = base + PAGE_SIZE;
103 VM_READ|VM_EXEC| 84
104 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, 85 vma = _install_special_mapping(mm, base, PAGE_SIZE,
105 &vdso_page); 86 VM_READ | VM_MAYREAD,
87 &vdso_vvar_mapping);
88 if (IS_ERR(vma)) {
89 ret = PTR_ERR(vma);
90 goto out;
91 }
106 92
93 /* Map data page. */
94 ret = remap_pfn_range(vma, base,
95 virt_to_phys(&vdso_data) >> PAGE_SHIFT,
96 PAGE_SIZE, PAGE_READONLY);
107 if (ret) 97 if (ret)
108 goto up_fail; 98 goto out;
99
100 /* Map VDSO image. */
101 vma = _install_special_mapping(mm, vdso_addr, image->size,
102 VM_READ | VM_EXEC |
103 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
104 &image->mapping);
105 if (IS_ERR(vma)) {
106 ret = PTR_ERR(vma);
107 goto out;
108 }
109 109
110 mm->context.vdso = (void *)addr; 110 mm->context.vdso = (void *)vdso_addr;
111 ret = 0;
111 112
112up_fail: 113out:
113 up_write(&mm->mmap_sem); 114 up_write(&mm->mmap_sem);
114 return ret; 115 return ret;
115} 116}
116
117const char *arch_vma_name(struct vm_area_struct *vma)
118{
119 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
120 return "[vdso]";
121 return NULL;
122}
diff --git a/arch/mips/vdso/.gitignore b/arch/mips/vdso/.gitignore
new file mode 100644
index 000000000000..5286a7d73d79
--- /dev/null
+++ b/arch/mips/vdso/.gitignore
@@ -0,0 +1,4 @@
1*.so*
2vdso-*image.c
3genvdso
4vdso*.lds
diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile
new file mode 100644
index 000000000000..ef5f348f386a
--- /dev/null
+++ b/arch/mips/vdso/Makefile
@@ -0,0 +1,160 @@
1# Objects to go into the VDSO.
2obj-vdso-y := elf.o gettimeofday.o sigreturn.o
3
4# Common compiler flags between ABIs.
5ccflags-vdso := \
6 $(filter -I%,$(KBUILD_CFLAGS)) \
7 $(filter -E%,$(KBUILD_CFLAGS)) \
8 $(filter -march=%,$(KBUILD_CFLAGS))
9cflags-vdso := $(ccflags-vdso) \
10 $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
11 -O2 -g -fPIC -fno-common -fno-builtin -G 0 -DDISABLE_BRANCH_PROFILING \
12 $(call cc-option, -fno-stack-protector)
13aflags-vdso := $(ccflags-vdso) \
14 $(filter -I%,$(KBUILD_CFLAGS)) \
15 $(filter -E%,$(KBUILD_CFLAGS)) \
16 -D__ASSEMBLY__ -Wa,-gdwarf-2
17
18#
19# For the pre-R6 code in arch/mips/vdso/vdso.h for locating
20# the base address of VDSO, the linker will emit a R_MIPS_PC32
21# relocation in binutils > 2.25 but it will fail with older versions
22# because that relocation is not supported for that symbol. As a result
23# of which we are forced to disable the VDSO symbols when building
24# with < 2.25 binutils on pre-R6 kernels. For more references on why we
25# can't use other methods to get the base address of VDSO please refer to
26# the comments on that file.
27#
28ifndef CONFIG_CPU_MIPSR6
29 ifeq ($(call ld-ifversion, -gt, 22400000, y),)
30 $(warning MIPS VDSO requires binutils > 2.24)
31 obj-vdso-y := $(filter-out gettimeofday.o, $(obj-vdso-y))
32 ccflags-vdso += -DDISABLE_MIPS_VDSO
33 endif
34endif
35
36# VDSO linker flags.
37VDSO_LDFLAGS := \
38 -Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1 \
39 -nostdlib -shared \
40 $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
41 $(call cc-ldoption, -Wl$(comma)--build-id)
42
43GCOV_PROFILE := n
44
45#
46# Shared build commands.
47#
48
49quiet_cmd_vdsold = VDSO $@
50 cmd_vdsold = $(CC) $(c_flags) $(VDSO_LDFLAGS) \
51 -Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@
52
53hostprogs-y := genvdso
54
55quiet_cmd_genvdso = GENVDSO $@
56define cmd_genvdso
57 cp $< $(<:%.dbg=%) && \
58 $(OBJCOPY) -S $< $(<:%.dbg=%) && \
59 $(obj)/genvdso $< $(<:%.dbg=%) $@ $(VDSO_NAME)
60endef
61
62#
63# Build native VDSO.
64#
65
66native-abi := $(filter -mabi=%,$(KBUILD_CFLAGS))
67
68targets += $(obj-vdso-y)
69targets += vdso.lds vdso.so.dbg vdso.so vdso-image.c
70
71obj-vdso := $(obj-vdso-y:%.o=$(obj)/%.o)
72
73$(obj-vdso): KBUILD_CFLAGS := $(cflags-vdso) $(native-abi)
74$(obj-vdso): KBUILD_AFLAGS := $(aflags-vdso) $(native-abi)
75
76$(obj)/vdso.lds: KBUILD_CPPFLAGS := $(native-abi)
77
78$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
79 $(call if_changed,vdsold)
80
81$(obj)/vdso-image.c: $(obj)/vdso.so.dbg $(obj)/genvdso FORCE
82 $(call if_changed,genvdso)
83
84obj-y += vdso-image.o
85
86#
87# Build O32 VDSO.
88#
89
90# Define these outside the ifdef to ensure they are picked up by clean.
91targets += $(obj-vdso-y:%.o=%-o32.o)
92targets += vdso-o32.lds vdso-o32.so.dbg vdso-o32.so vdso-o32-image.c
93
94ifdef CONFIG_MIPS32_O32
95
96obj-vdso-o32 := $(obj-vdso-y:%.o=$(obj)/%-o32.o)
97
98$(obj-vdso-o32): KBUILD_CFLAGS := $(cflags-vdso) -mabi=32
99$(obj-vdso-o32): KBUILD_AFLAGS := $(aflags-vdso) -mabi=32
100
101$(obj)/%-o32.o: $(src)/%.S FORCE
102 $(call if_changed_dep,as_o_S)
103
104$(obj)/%-o32.o: $(src)/%.c FORCE
105 $(call cmd,force_checksrc)
106 $(call if_changed_rule,cc_o_c)
107
108$(obj)/vdso-o32.lds: KBUILD_CPPFLAGS := -mabi=32
109$(obj)/vdso-o32.lds: $(src)/vdso.lds.S FORCE
110 $(call if_changed_dep,cpp_lds_S)
111
112$(obj)/vdso-o32.so.dbg: $(obj)/vdso-o32.lds $(obj-vdso-o32) FORCE
113 $(call if_changed,vdsold)
114
115$(obj)/vdso-o32-image.c: VDSO_NAME := o32
116$(obj)/vdso-o32-image.c: $(obj)/vdso-o32.so.dbg $(obj)/genvdso FORCE
117 $(call if_changed,genvdso)
118
119obj-y += vdso-o32-image.o
120
121endif
122
123#
124# Build N32 VDSO.
125#
126
127targets += $(obj-vdso-y:%.o=%-n32.o)
128targets += vdso-n32.lds vdso-n32.so.dbg vdso-n32.so vdso-n32-image.c
129
130ifdef CONFIG_MIPS32_N32
131
132obj-vdso-n32 := $(obj-vdso-y:%.o=$(obj)/%-n32.o)
133
134$(obj-vdso-n32): KBUILD_CFLAGS := $(cflags-vdso) -mabi=n32
135$(obj-vdso-n32): KBUILD_AFLAGS := $(aflags-vdso) -mabi=n32
136
137$(obj)/%-n32.o: $(src)/%.S FORCE
138 $(call if_changed_dep,as_o_S)
139
140$(obj)/%-n32.o: $(src)/%.c FORCE
141 $(call cmd,force_checksrc)
142 $(call if_changed_rule,cc_o_c)
143
144$(obj)/vdso-n32.lds: KBUILD_CPPFLAGS := -mabi=n32
145$(obj)/vdso-n32.lds: $(src)/vdso.lds.S FORCE
146 $(call if_changed_dep,cpp_lds_S)
147
148$(obj)/vdso-n32.so.dbg: $(obj)/vdso-n32.lds $(obj-vdso-n32) FORCE
149 $(call if_changed,vdsold)
150
151$(obj)/vdso-n32-image.c: VDSO_NAME := n32
152$(obj)/vdso-n32-image.c: $(obj)/vdso-n32.so.dbg $(obj)/genvdso FORCE
153 $(call if_changed,genvdso)
154
155obj-y += vdso-n32-image.o
156
157endif
158
159# FIXME: Need install rule for debug.
160# Needs to deal with dependency for generation of dbg by cmd_genvdso...
diff --git a/arch/mips/vdso/elf.S b/arch/mips/vdso/elf.S
new file mode 100644
index 000000000000..be37bbb1f061
--- /dev/null
+++ b/arch/mips/vdso/elf.S
@@ -0,0 +1,68 @@
1/*
2 * Copyright (C) 2015 Imagination Technologies
3 * Author: Alex Smith <alex.smith@imgtec.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 */
10
11#include "vdso.h"
12
13#include <linux/elfnote.h>
14#include <linux/version.h>
15
16ELFNOTE_START(Linux, 0, "a")
17 .long LINUX_VERSION_CODE
18ELFNOTE_END
19
20/*
21 * The .MIPS.abiflags section must be defined with the FP ABI flags set
22 * to 'any' to be able to link with both old and new libraries.
23 * Newer toolchains are capable of automatically generating this, but we want
24 * to work with older toolchains as well. Therefore, we define the contents of
25 * this section here (under different names), and then genvdso will patch
26 * it to have the correct name and type.
27 *
28 * We base the .MIPS.abiflags section on preprocessor definitions rather than
29 * CONFIG_* because we need to match the particular ABI we are building the
30 * VDSO for.
31 *
32 * See https://dmz-portal.mips.com/wiki/MIPS_O32_ABI_-_FR0_and_FR1_Interlinking
33 * for the .MIPS.abiflags section description.
34 */
35
36 .section .mips_abiflags, "a"
37 .align 3
38__mips_abiflags:
39 .hword 0 /* version */
40 .byte __mips /* isa_level */
41
42 /* isa_rev */
43#ifdef __mips_isa_rev
44 .byte __mips_isa_rev
45#else
46 .byte 0
47#endif
48
49 /* gpr_size */
50#ifdef __mips64
51 .byte 2 /* AFL_REG_64 */
52#else
53 .byte 1 /* AFL_REG_32 */
54#endif
55
56 /* cpr1_size */
57#if (defined(__mips_isa_rev) && __mips_isa_rev >= 6) || defined(__mips64)
58 .byte 2 /* AFL_REG_64 */
59#else
60 .byte 1 /* AFL_REG_32 */
61#endif
62
63 .byte 0 /* cpr2_size (AFL_REG_NONE) */
64 .byte 0 /* fp_abi (Val_GNU_MIPS_ABI_FP_ANY) */
65 .word 0 /* isa_ext */
66 .word 0 /* ases */
67 .word 0 /* flags1 */
68 .word 0 /* flags2 */
diff --git a/arch/mips/vdso/genvdso.c b/arch/mips/vdso/genvdso.c
new file mode 100644
index 000000000000..530a36f465ce
--- /dev/null
+++ b/arch/mips/vdso/genvdso.c
@@ -0,0 +1,293 @@
1/*
2 * Copyright (C) 2015 Imagination Technologies
3 * Author: Alex Smith <alex.smith@imgtec.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 */
10
11/*
12 * This tool is used to generate the real VDSO images from the raw image. It
13 * first patches up the MIPS ABI flags and GNU attributes sections defined in
14 * elf.S to have the correct name and type. It then generates a C source file
15 * to be compiled into the kernel containing the VDSO image data and a
16 * mips_vdso_image struct for it, including symbol offsets extracted from the
17 * image.
18 *
19 * We need to be passed both a stripped and unstripped VDSO image. The stripped
20 * image is compiled into the kernel, but we must also patch up the unstripped
21 * image's ABI flags sections so that it can be installed and used for
22 * debugging.
23 */
24
25#include <sys/mman.h>
26#include <sys/stat.h>
27#include <sys/types.h>
28
29#include <byteswap.h>
30#include <elf.h>
31#include <errno.h>
32#include <fcntl.h>
33#include <inttypes.h>
34#include <stdarg.h>
35#include <stdbool.h>
36#include <stdio.h>
37#include <stdlib.h>
38#include <string.h>
39#include <unistd.h>
40
41/* Define these in case the system elf.h is not new enough to have them. */
42#ifndef SHT_GNU_ATTRIBUTES
43# define SHT_GNU_ATTRIBUTES 0x6ffffff5
44#endif
45#ifndef SHT_MIPS_ABIFLAGS
46# define SHT_MIPS_ABIFLAGS 0x7000002a
47#endif
48
49enum {
50 ABI_O32 = (1 << 0),
51 ABI_N32 = (1 << 1),
52 ABI_N64 = (1 << 2),
53
54 ABI_ALL = ABI_O32 | ABI_N32 | ABI_N64,
55};
56
57/* Symbols the kernel requires offsets for. */
58static struct {
59 const char *name;
60 const char *offset_name;
61 unsigned int abis;
62} vdso_symbols[] = {
63 { "__vdso_sigreturn", "off_sigreturn", ABI_O32 },
64 { "__vdso_rt_sigreturn", "off_rt_sigreturn", ABI_ALL },
65 {}
66};
67
68static const char *program_name;
69static const char *vdso_name;
70static unsigned char elf_class;
71static unsigned int elf_abi;
72static bool need_swap;
73static FILE *out_file;
74
75#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
76# define HOST_ORDER ELFDATA2LSB
77#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
78# define HOST_ORDER ELFDATA2MSB
79#endif
80
81#define BUILD_SWAP(bits) \
82 static uint##bits##_t swap_uint##bits(uint##bits##_t val) \
83 { \
84 return need_swap ? bswap_##bits(val) : val; \
85 }
86
87BUILD_SWAP(16)
88BUILD_SWAP(32)
89BUILD_SWAP(64)
90
91#define __FUNC(name, bits) name##bits
92#define _FUNC(name, bits) __FUNC(name, bits)
93#define FUNC(name) _FUNC(name, ELF_BITS)
94
95#define __ELF(x, bits) Elf##bits##_##x
96#define _ELF(x, bits) __ELF(x, bits)
97#define ELF(x) _ELF(x, ELF_BITS)
98
99/*
100 * Include genvdso.h twice with ELF_BITS defined differently to get functions
101 * for both ELF32 and ELF64.
102 */
103
104#define ELF_BITS 64
105#include "genvdso.h"
106#undef ELF_BITS
107
108#define ELF_BITS 32
109#include "genvdso.h"
110#undef ELF_BITS
111
112static void *map_vdso(const char *path, size_t *_size)
113{
114 int fd;
115 struct stat stat;
116 void *addr;
117 const Elf32_Ehdr *ehdr;
118
119 fd = open(path, O_RDWR);
120 if (fd < 0) {
121 fprintf(stderr, "%s: Failed to open '%s': %s\n", program_name,
122 path, strerror(errno));
123 return NULL;
124 }
125
126 if (fstat(fd, &stat) != 0) {
127 fprintf(stderr, "%s: Failed to stat '%s': %s\n", program_name,
128 path, strerror(errno));
129 return NULL;
130 }
131
132 addr = mmap(NULL, stat.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
133 0);
134 if (addr == MAP_FAILED) {
135 fprintf(stderr, "%s: Failed to map '%s': %s\n", program_name,
136 path, strerror(errno));
137 return NULL;
138 }
139
140 /* ELF32/64 header formats are the same for the bits we're checking. */
141 ehdr = addr;
142
143 if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0) {
144 fprintf(stderr, "%s: '%s' is not an ELF file\n", program_name,
145 path);
146 return NULL;
147 }
148
149 elf_class = ehdr->e_ident[EI_CLASS];
150 switch (elf_class) {
151 case ELFCLASS32:
152 case ELFCLASS64:
153 break;
154 default:
155 fprintf(stderr, "%s: '%s' has invalid ELF class\n",
156 program_name, path);
157 return NULL;
158 }
159
160 switch (ehdr->e_ident[EI_DATA]) {
161 case ELFDATA2LSB:
162 case ELFDATA2MSB:
163 need_swap = ehdr->e_ident[EI_DATA] != HOST_ORDER;
164 break;
165 default:
166 fprintf(stderr, "%s: '%s' has invalid ELF data order\n",
167 program_name, path);
168 return NULL;
169 }
170
171 if (swap_uint16(ehdr->e_machine) != EM_MIPS) {
172 fprintf(stderr,
173 "%s: '%s' has invalid ELF machine (expected EM_MIPS)\n",
174 program_name, path);
175 return NULL;
176 } else if (swap_uint16(ehdr->e_type) != ET_DYN) {
177 fprintf(stderr,
178 "%s: '%s' has invalid ELF type (expected ET_DYN)\n",
179 program_name, path);
180 return NULL;
181 }
182
183 *_size = stat.st_size;
184 return addr;
185}
186
187static bool patch_vdso(const char *path, void *vdso)
188{
189 if (elf_class == ELFCLASS64)
190 return patch_vdso64(path, vdso);
191 else
192 return patch_vdso32(path, vdso);
193}
194
195static bool get_symbols(const char *path, void *vdso)
196{
197 if (elf_class == ELFCLASS64)
198 return get_symbols64(path, vdso);
199 else
200 return get_symbols32(path, vdso);
201}
202
203int main(int argc, char **argv)
204{
205 const char *dbg_vdso_path, *vdso_path, *out_path;
206 void *dbg_vdso, *vdso;
207 size_t dbg_vdso_size, vdso_size, i;
208
209 program_name = argv[0];
210
211 if (argc < 4 || argc > 5) {
212 fprintf(stderr,
213 "Usage: %s <debug VDSO> <stripped VDSO> <output file> [<name>]\n",
214 program_name);
215 return EXIT_FAILURE;
216 }
217
218 dbg_vdso_path = argv[1];
219 vdso_path = argv[2];
220 out_path = argv[3];
221 vdso_name = (argc > 4) ? argv[4] : "";
222
223 dbg_vdso = map_vdso(dbg_vdso_path, &dbg_vdso_size);
224 if (!dbg_vdso)
225 return EXIT_FAILURE;
226
227 vdso = map_vdso(vdso_path, &vdso_size);
228 if (!vdso)
229 return EXIT_FAILURE;
230
231 /* Patch both the VDSOs' ABI flags sections. */
232 if (!patch_vdso(dbg_vdso_path, dbg_vdso))
233 return EXIT_FAILURE;
234 if (!patch_vdso(vdso_path, vdso))
235 return EXIT_FAILURE;
236
237 if (msync(dbg_vdso, dbg_vdso_size, MS_SYNC) != 0) {
238 fprintf(stderr, "%s: Failed to sync '%s': %s\n", program_name,
239 dbg_vdso_path, strerror(errno));
240 return EXIT_FAILURE;
241 } else if (msync(vdso, vdso_size, MS_SYNC) != 0) {
242 fprintf(stderr, "%s: Failed to sync '%s': %s\n", program_name,
243 vdso_path, strerror(errno));
244 return EXIT_FAILURE;
245 }
246
247 out_file = fopen(out_path, "w");
248 if (!out_file) {
249 fprintf(stderr, "%s: Failed to open '%s': %s\n", program_name,
250 out_path, strerror(errno));
251 return EXIT_FAILURE;
252 }
253
254 fprintf(out_file, "/* Automatically generated - do not edit */\n");
255 fprintf(out_file, "#include <linux/linkage.h>\n");
256 fprintf(out_file, "#include <linux/mm.h>\n");
257 fprintf(out_file, "#include <asm/vdso.h>\n");
258
259 /* Write out the stripped VDSO data. */
260 fprintf(out_file,
261 "static unsigned char vdso_data[PAGE_ALIGN(%zu)] __page_aligned_data = {\n\t",
262 vdso_size);
263 for (i = 0; i < vdso_size; i++) {
264 if (!(i % 10))
265 fprintf(out_file, "\n\t");
266 fprintf(out_file, "0x%02x, ", ((unsigned char *)vdso)[i]);
267 }
268 fprintf(out_file, "\n};\n");
269
270 /* Preallocate a page array. */
271 fprintf(out_file,
272 "static struct page *vdso_pages[PAGE_ALIGN(%zu) / PAGE_SIZE];\n",
273 vdso_size);
274
275 fprintf(out_file, "struct mips_vdso_image vdso_image%s%s = {\n",
276 (vdso_name[0]) ? "_" : "", vdso_name);
277 fprintf(out_file, "\t.data = vdso_data,\n");
278 fprintf(out_file, "\t.size = PAGE_ALIGN(%zu),\n", vdso_size);
279 fprintf(out_file, "\t.mapping = {\n");
280 fprintf(out_file, "\t\t.name = \"[vdso]\",\n");
281 fprintf(out_file, "\t\t.pages = vdso_pages,\n");
282 fprintf(out_file, "\t},\n");
283
284 /* Calculate and write symbol offsets to <output file> */
285 if (!get_symbols(dbg_vdso_path, dbg_vdso)) {
286 unlink(out_path);
287 return EXIT_FAILURE;
288 }
289
290 fprintf(out_file, "};\n");
291
292 return EXIT_SUCCESS;
293}
diff --git a/arch/mips/vdso/genvdso.h b/arch/mips/vdso/genvdso.h
new file mode 100644
index 000000000000..94334727059a
--- /dev/null
+++ b/arch/mips/vdso/genvdso.h
@@ -0,0 +1,187 @@
1/*
2 * Copyright (C) 2015 Imagination Technologies
3 * Author: Alex Smith <alex.smith@imgtec.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 */
10
11static inline bool FUNC(patch_vdso)(const char *path, void *vdso)
12{
13 const ELF(Ehdr) *ehdr = vdso;
14 void *shdrs;
15 ELF(Shdr) *shdr;
16 char *shstrtab, *name;
17 uint16_t sh_count, sh_entsize, i;
18 unsigned int local_gotno, symtabno, gotsym;
19 ELF(Dyn) *dyn = NULL;
20
21 shdrs = vdso + FUNC(swap_uint)(ehdr->e_shoff);
22 sh_count = swap_uint16(ehdr->e_shnum);
23 sh_entsize = swap_uint16(ehdr->e_shentsize);
24
25 shdr = shdrs + (sh_entsize * swap_uint16(ehdr->e_shstrndx));
26 shstrtab = vdso + FUNC(swap_uint)(shdr->sh_offset);
27
28 for (i = 0; i < sh_count; i++) {
29 shdr = shdrs + (i * sh_entsize);
30 name = shstrtab + swap_uint32(shdr->sh_name);
31
32 /*
33 * Ensure there are no relocation sections - ld.so does not
34 * relocate the VDSO so if there are relocations things will
35 * break.
36 */
37 switch (swap_uint32(shdr->sh_type)) {
38 case SHT_REL:
39 case SHT_RELA:
40 fprintf(stderr,
41 "%s: '%s' contains relocation sections\n",
42 program_name, path);
43 return false;
44 case SHT_DYNAMIC:
45 dyn = vdso + FUNC(swap_uint)(shdr->sh_offset);
46 break;
47 }
48
49 /* Check for existing sections. */
50 if (strcmp(name, ".MIPS.abiflags") == 0) {
51 fprintf(stderr,
52 "%s: '%s' already contains a '.MIPS.abiflags' section\n",
53 program_name, path);
54 return false;
55 }
56
57 if (strcmp(name, ".mips_abiflags") == 0) {
58 strcpy(name, ".MIPS.abiflags");
59 shdr->sh_type = swap_uint32(SHT_MIPS_ABIFLAGS);
60 shdr->sh_entsize = shdr->sh_size;
61 }
62 }
63
64 /*
65 * Ensure the GOT has no entries other than the standard 2, for the same
66 * reason we check that there's no relocation sections above.
67 * The standard two entries are:
68 * - Lazy resolver
69 * - Module pointer
70 */
71 if (dyn) {
72 local_gotno = symtabno = gotsym = 0;
73
74 while (FUNC(swap_uint)(dyn->d_tag) != DT_NULL) {
75 switch (FUNC(swap_uint)(dyn->d_tag)) {
76 /*
77 * This member holds the number of local GOT entries.
78 */
79 case DT_MIPS_LOCAL_GOTNO:
80 local_gotno = FUNC(swap_uint)(dyn->d_un.d_val);
81 break;
82 /*
83 * This member holds the number of entries in the
84 * .dynsym section.
85 */
86 case DT_MIPS_SYMTABNO:
87 symtabno = FUNC(swap_uint)(dyn->d_un.d_val);
88 break;
89 /*
90 * This member holds the index of the first dynamic
91 * symbol table entry that corresponds to an entry in
92 * the GOT.
93 */
94 case DT_MIPS_GOTSYM:
95 gotsym = FUNC(swap_uint)(dyn->d_un.d_val);
96 break;
97 }
98
99 dyn++;
100 }
101
102 if (local_gotno > 2 || symtabno - gotsym) {
103 fprintf(stderr,
104 "%s: '%s' contains unexpected GOT entries\n",
105 program_name, path);
106 return false;
107 }
108 }
109
110 return true;
111}
112
113static inline bool FUNC(get_symbols)(const char *path, void *vdso)
114{
115 const ELF(Ehdr) *ehdr = vdso;
116 void *shdrs, *symtab;
117 ELF(Shdr) *shdr;
118 const ELF(Sym) *sym;
119 char *strtab, *name;
120 uint16_t sh_count, sh_entsize, st_count, st_entsize, i, j;
121 uint64_t offset;
122 uint32_t flags;
123
124 shdrs = vdso + FUNC(swap_uint)(ehdr->e_shoff);
125 sh_count = swap_uint16(ehdr->e_shnum);
126 sh_entsize = swap_uint16(ehdr->e_shentsize);
127
128 for (i = 0; i < sh_count; i++) {
129 shdr = shdrs + (i * sh_entsize);
130
131 if (swap_uint32(shdr->sh_type) == SHT_SYMTAB)
132 break;
133 }
134
135 if (i == sh_count) {
136 fprintf(stderr, "%s: '%s' has no symbol table\n", program_name,
137 path);
138 return false;
139 }
140
141 /* Get flags */
142 flags = swap_uint32(ehdr->e_flags);
143 if (elf_class == ELFCLASS64)
144 elf_abi = ABI_N64;
145 else if (flags & EF_MIPS_ABI2)
146 elf_abi = ABI_N32;
147 else
148 elf_abi = ABI_O32;
149
150 /* Get symbol table. */
151 symtab = vdso + FUNC(swap_uint)(shdr->sh_offset);
152 st_entsize = FUNC(swap_uint)(shdr->sh_entsize);
153 st_count = FUNC(swap_uint)(shdr->sh_size) / st_entsize;
154
155 /* Get string table. */
156 shdr = shdrs + (swap_uint32(shdr->sh_link) * sh_entsize);
157 strtab = vdso + FUNC(swap_uint)(shdr->sh_offset);
158
159 /* Write offsets for symbols needed by the kernel. */
160 for (i = 0; vdso_symbols[i].name; i++) {
161 if (!(vdso_symbols[i].abis & elf_abi))
162 continue;
163
164 for (j = 0; j < st_count; j++) {
165 sym = symtab + (j * st_entsize);
166 name = strtab + swap_uint32(sym->st_name);
167
168 if (!strcmp(name, vdso_symbols[i].name)) {
169 offset = FUNC(swap_uint)(sym->st_value);
170
171 fprintf(out_file,
172 "\t.%s = 0x%" PRIx64 ",\n",
173 vdso_symbols[i].offset_name, offset);
174 break;
175 }
176 }
177
178 if (j == st_count) {
179 fprintf(stderr,
180 "%s: '%s' is missing required symbol '%s'\n",
181 program_name, path, vdso_symbols[i].name);
182 return false;
183 }
184 }
185
186 return true;
187}
diff --git a/arch/mips/vdso/sigreturn.S b/arch/mips/vdso/sigreturn.S
new file mode 100644
index 000000000000..715bf5993529
--- /dev/null
+++ b/arch/mips/vdso/sigreturn.S
@@ -0,0 +1,49 @@
1/*
2 * Copyright (C) 2015 Imagination Technologies
3 * Author: Alex Smith <alex.smith@imgtec.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 */
10
11#include "vdso.h"
12
13#include <uapi/asm/unistd.h>
14
15#include <asm/regdef.h>
16#include <asm/asm.h>
17
18 .section .text
19 .cfi_sections .debug_frame
20
21LEAF(__vdso_rt_sigreturn)
22 .cfi_startproc
23 .frame sp, 0, ra
24 .mask 0x00000000, 0
25 .fmask 0x00000000, 0
26 .cfi_signal_frame
27
28 li v0, __NR_rt_sigreturn
29 syscall
30
31 .cfi_endproc
32 END(__vdso_rt_sigreturn)
33
34#if _MIPS_SIM == _MIPS_SIM_ABI32
35
36LEAF(__vdso_sigreturn)
37 .cfi_startproc
38 .frame sp, 0, ra
39 .mask 0x00000000, 0
40 .fmask 0x00000000, 0
41 .cfi_signal_frame
42
43 li v0, __NR_sigreturn
44 syscall
45
46 .cfi_endproc
47 END(__vdso_sigreturn)
48
49#endif
diff --git a/arch/mips/vdso/vdso.h b/arch/mips/vdso/vdso.h
new file mode 100644
index 000000000000..0bb6b1adc385
--- /dev/null
+++ b/arch/mips/vdso/vdso.h
@@ -0,0 +1,80 @@
1/*
2 * Copyright (C) 2015 Imagination Technologies
3 * Author: Alex Smith <alex.smith@imgtec.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 */
10
11#include <asm/sgidefs.h>
12
13#if _MIPS_SIM != _MIPS_SIM_ABI64 && defined(CONFIG_64BIT)
14
15/* Building 32-bit VDSO for the 64-bit kernel. Fake a 32-bit Kconfig. */
16#undef CONFIG_64BIT
17#define CONFIG_32BIT 1
18#ifndef __ASSEMBLY__
19#include <asm-generic/atomic64.h>
20#endif
21#endif
22
23#ifndef __ASSEMBLY__
24
25#include <asm/asm.h>
26#include <asm/page.h>
27#include <asm/vdso.h>
28
29static inline unsigned long get_vdso_base(void)
30{
31 unsigned long addr;
32
33 /*
34 * We can't use cpu_has_mips_r6 since it needs the cpu_data[]
35 * kernel symbol.
36 */
37#ifdef CONFIG_CPU_MIPSR6
38 /*
39 * lapc <symbol> is an alias to addiupc reg, <symbol> - .
40 *
41 * We can't use addiupc because there is no label-label
42 * support for the addiupc reloc
43 */
44 __asm__("lapc %0, _start \n"
45 : "=r" (addr) : :);
46#else
47 /*
48 * Get the base load address of the VDSO. We have to avoid generating
49 * relocations and references to the GOT because ld.so does not peform
50 * relocations on the VDSO. We use the current offset from the VDSO base
51 * and perform a PC-relative branch which gives the absolute address in
52 * ra, and take the difference. The assembler chokes on
53 * "li %0, _start - .", so embed the offset as a word and branch over
54 * it.
55 *
56 */
57
58 __asm__(
59 " .set push \n"
60 " .set noreorder \n"
61 " bal 1f \n"
62 " nop \n"
63 " .word _start - . \n"
64 "1: lw %0, 0($31) \n"
65 " " STR(PTR_ADDU) " %0, $31, %0 \n"
66 " .set pop \n"
67 : "=r" (addr)
68 :
69 : "$31");
70#endif /* CONFIG_CPU_MIPSR6 */
71
72 return addr;
73}
74
75static inline const union mips_vdso_data *get_vdso_data(void)
76{
77 return (const union mips_vdso_data *)(get_vdso_base() - PAGE_SIZE);
78}
79
80#endif /* __ASSEMBLY__ */
diff --git a/arch/mips/vdso/vdso.lds.S b/arch/mips/vdso/vdso.lds.S
new file mode 100644
index 000000000000..21655b6fefc5
--- /dev/null
+++ b/arch/mips/vdso/vdso.lds.S
@@ -0,0 +1,100 @@
1/*
2 * Copyright (C) 2015 Imagination Technologies
3 * Author: Alex Smith <alex.smith@imgtec.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 */
10
11#include <asm/sgidefs.h>
12
13#if _MIPS_SIM == _MIPS_SIM_ABI64
14OUTPUT_FORMAT("elf64-tradlittlemips", "elf64-tradbigmips", "elf64-tradlittlemips")
15#elif _MIPS_SIM == _MIPS_SIM_NABI32
16OUTPUT_FORMAT("elf32-ntradlittlemips", "elf32-ntradbigmips", "elf32-ntradlittlemips")
17#else
18OUTPUT_FORMAT("elf32-tradlittlemips", "elf32-tradbigmips", "elf32-tradlittlemips")
19#endif
20
21OUTPUT_ARCH(mips)
22
23SECTIONS
24{
25 PROVIDE(_start = .);
26 . = SIZEOF_HEADERS;
27
28 /*
29 * In order to retain compatibility with older toolchains we provide the
30 * ABI flags section ourself. Newer assemblers will automatically
31 * generate .MIPS.abiflags sections so we discard such input sections,
32 * and then manually define our own section here. genvdso will patch
33 * this section to have the correct name/type.
34 */
35 .mips_abiflags : { *(.mips_abiflags) } :text :abiflags
36
37 .reginfo : { *(.reginfo) } :text :reginfo
38
39 .hash : { *(.hash) } :text
40 .gnu.hash : { *(.gnu.hash) }
41 .dynsym : { *(.dynsym) }
42 .dynstr : { *(.dynstr) }
43 .gnu.version : { *(.gnu.version) }
44 .gnu.version_d : { *(.gnu.version_d) }
45 .gnu.version_r : { *(.gnu.version_r) }
46
47 .note : { *(.note.*) } :text :note
48
49 .text : { *(.text*) } :text
50 PROVIDE (__etext = .);
51 PROVIDE (_etext = .);
52 PROVIDE (etext = .);
53
54 .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
55 .eh_frame : { KEEP (*(.eh_frame)) } :text
56
57 .dynamic : { *(.dynamic) } :text :dynamic
58
59 .rodata : { *(.rodata*) } :text
60
61 _end = .;
62 PROVIDE(end = .);
63
64 /DISCARD/ : {
65 *(.MIPS.abiflags)
66 *(.gnu.attributes)
67 *(.note.GNU-stack)
68 *(.data .data.* .gnu.linkonce.d.* .sdata*)
69 *(.bss .sbss .dynbss .dynsbss)
70 }
71}
72
73PHDRS
74{
75 /*
76 * Provide a PT_MIPS_ABIFLAGS header to assign the ABI flags section
77 * to. We can specify the header type directly here so no modification
78 * is needed later on.
79 */
80 abiflags 0x70000003;
81
82 /*
83 * The ABI flags header must exist directly after the PT_INTERP header,
84 * so we must explicitly place the PT_MIPS_REGINFO header after it to
85 * stop the linker putting one in at the start.
86 */
87 reginfo 0x70000000;
88
89 text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
90 dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
91 note PT_NOTE FLAGS(4); /* PF_R */
92 eh_frame_hdr PT_GNU_EH_FRAME;
93}
94
95VERSION
96{
97 LINUX_2.6 {
98 local: *;
99 };
100}
generated by cgit v1.2.2 (git 2.25.0) at 2025-08-11 15:02:58 -0400