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-rw-r--r--arch/powerpc/include/asm/systbl.h2
-rw-r--r--arch/powerpc/include/asm/unistd.h4
-rw-r--r--arch/x86/ia32/ia32entry.S2
-rw-r--r--arch/x86/include/asm/unistd_32.h4
-rw-r--r--arch/x86/include/asm/unistd_64.h4
-rw-r--r--arch/x86/kernel/syscall_table_32.S2
-rw-r--r--fs/aio.c4
-rw-r--r--fs/compat.c7
-rw-r--r--fs/read_write.c8
-rw-r--r--include/linux/compat.h3
-rw-r--r--include/linux/fs.h7
-rw-r--r--include/linux/syscalls.h13
-rw-r--r--kernel/sys_ni.c4
-rw-r--r--mm/Makefile3
-rw-r--r--mm/process_vm_access.c496
-rw-r--r--security/keys/compat.c2
-rw-r--r--security/keys/keyctl.c2
17 files changed, 550 insertions, 17 deletions
diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h
index fa0d27a400de..559ae1ee6706 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -354,3 +354,5 @@ COMPAT_SYS_SPU(clock_adjtime)
354SYSCALL_SPU(syncfs) 354SYSCALL_SPU(syncfs)
355COMPAT_SYS_SPU(sendmmsg) 355COMPAT_SYS_SPU(sendmmsg)
356SYSCALL_SPU(setns) 356SYSCALL_SPU(setns)
357COMPAT_SYS(process_vm_readv)
358COMPAT_SYS(process_vm_writev)
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index b8b3f599362b..d3d1b5efd7eb 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -373,10 +373,12 @@
373#define __NR_syncfs 348 373#define __NR_syncfs 348
374#define __NR_sendmmsg 349 374#define __NR_sendmmsg 349
375#define __NR_setns 350 375#define __NR_setns 350
376#define __NR_process_vm_readv 351
377#define __NR_process_vm_writev 352
376 378
377#ifdef __KERNEL__ 379#ifdef __KERNEL__
378 380
379#define __NR_syscalls 351 381#define __NR_syscalls 353
380 382
381#define __NR__exit __NR_exit 383#define __NR__exit __NR_exit
382#define NR_syscalls __NR_syscalls 384#define NR_syscalls __NR_syscalls
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 54edb207ff3a..a6253ec1b284 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -850,4 +850,6 @@ ia32_sys_call_table:
850 .quad sys_syncfs 850 .quad sys_syncfs
851 .quad compat_sys_sendmmsg /* 345 */ 851 .quad compat_sys_sendmmsg /* 345 */
852 .quad sys_setns 852 .quad sys_setns
853 .quad compat_sys_process_vm_readv
854 .quad compat_sys_process_vm_writev
853ia32_syscall_end: 855ia32_syscall_end:
diff --git a/arch/x86/include/asm/unistd_32.h b/arch/x86/include/asm/unistd_32.h
index 593485b38ab3..599c77d38f33 100644
--- a/arch/x86/include/asm/unistd_32.h
+++ b/arch/x86/include/asm/unistd_32.h
@@ -352,10 +352,12 @@
352#define __NR_syncfs 344 352#define __NR_syncfs 344
353#define __NR_sendmmsg 345 353#define __NR_sendmmsg 345
354#define __NR_setns 346 354#define __NR_setns 346
355#define __NR_process_vm_readv 347
356#define __NR_process_vm_writev 348
355 357
356#ifdef __KERNEL__ 358#ifdef __KERNEL__
357 359
358#define NR_syscalls 347 360#define NR_syscalls 349
359 361
360#define __ARCH_WANT_IPC_PARSE_VERSION 362#define __ARCH_WANT_IPC_PARSE_VERSION
361#define __ARCH_WANT_OLD_READDIR 363#define __ARCH_WANT_OLD_READDIR
diff --git a/arch/x86/include/asm/unistd_64.h b/arch/x86/include/asm/unistd_64.h
index 0a6ba337a2eb..0431f193c3f2 100644
--- a/arch/x86/include/asm/unistd_64.h
+++ b/arch/x86/include/asm/unistd_64.h
@@ -682,6 +682,10 @@ __SYSCALL(__NR_sendmmsg, sys_sendmmsg)
682__SYSCALL(__NR_setns, sys_setns) 682__SYSCALL(__NR_setns, sys_setns)
683#define __NR_getcpu 309 683#define __NR_getcpu 309
684__SYSCALL(__NR_getcpu, sys_getcpu) 684__SYSCALL(__NR_getcpu, sys_getcpu)
685#define __NR_process_vm_readv 310
686__SYSCALL(__NR_process_vm_readv, sys_process_vm_readv)
687#define __NR_process_vm_writev 311
688__SYSCALL(__NR_process_vm_writev, sys_process_vm_writev)
685 689
686#ifndef __NO_STUBS 690#ifndef __NO_STUBS
687#define __ARCH_WANT_OLD_READDIR 691#define __ARCH_WANT_OLD_READDIR
diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S
index bc19be332bc9..9a0e31293920 100644
--- a/arch/x86/kernel/syscall_table_32.S
+++ b/arch/x86/kernel/syscall_table_32.S
@@ -346,3 +346,5 @@ ENTRY(sys_call_table)
346 .long sys_syncfs 346 .long sys_syncfs
347 .long sys_sendmmsg /* 345 */ 347 .long sys_sendmmsg /* 345 */
348 .long sys_setns 348 .long sys_setns
349 .long sys_process_vm_readv
350 .long sys_process_vm_writev
diff --git a/fs/aio.c b/fs/aio.c
index e29ec485af25..632b235f4fbe 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1387,13 +1387,13 @@ static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb, bool compat)
1387 ret = compat_rw_copy_check_uvector(type, 1387 ret = compat_rw_copy_check_uvector(type,
1388 (struct compat_iovec __user *)kiocb->ki_buf, 1388 (struct compat_iovec __user *)kiocb->ki_buf,
1389 kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec, 1389 kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec,
1390 &kiocb->ki_iovec); 1390 &kiocb->ki_iovec, 1);
1391 else 1391 else
1392#endif 1392#endif
1393 ret = rw_copy_check_uvector(type, 1393 ret = rw_copy_check_uvector(type,
1394 (struct iovec __user *)kiocb->ki_buf, 1394 (struct iovec __user *)kiocb->ki_buf,
1395 kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec, 1395 kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec,
1396 &kiocb->ki_iovec); 1396 &kiocb->ki_iovec, 1);
1397 if (ret < 0) 1397 if (ret < 0)
1398 goto out; 1398 goto out;
1399 1399
diff --git a/fs/compat.c b/fs/compat.c
index 302e761bd0aa..c98787536bb8 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -546,7 +546,7 @@ out:
546ssize_t compat_rw_copy_check_uvector(int type, 546ssize_t compat_rw_copy_check_uvector(int type,
547 const struct compat_iovec __user *uvector, unsigned long nr_segs, 547 const struct compat_iovec __user *uvector, unsigned long nr_segs,
548 unsigned long fast_segs, struct iovec *fast_pointer, 548 unsigned long fast_segs, struct iovec *fast_pointer,
549 struct iovec **ret_pointer) 549 struct iovec **ret_pointer, int check_access)
550{ 550{
551 compat_ssize_t tot_len; 551 compat_ssize_t tot_len;
552 struct iovec *iov = *ret_pointer = fast_pointer; 552 struct iovec *iov = *ret_pointer = fast_pointer;
@@ -593,7 +593,8 @@ ssize_t compat_rw_copy_check_uvector(int type,
593 } 593 }
594 if (len < 0) /* size_t not fitting in compat_ssize_t .. */ 594 if (len < 0) /* size_t not fitting in compat_ssize_t .. */
595 goto out; 595 goto out;
596 if (!access_ok(vrfy_dir(type), compat_ptr(buf), len)) { 596 if (check_access &&
597 !access_ok(vrfy_dir(type), compat_ptr(buf), len)) {
597 ret = -EFAULT; 598 ret = -EFAULT;
598 goto out; 599 goto out;
599 } 600 }
@@ -1107,7 +1108,7 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,
1107 goto out; 1108 goto out;
1108 1109
1109 tot_len = compat_rw_copy_check_uvector(type, uvector, nr_segs, 1110 tot_len = compat_rw_copy_check_uvector(type, uvector, nr_segs,
1110 UIO_FASTIOV, iovstack, &iov); 1111 UIO_FASTIOV, iovstack, &iov, 1);
1111 if (tot_len == 0) { 1112 if (tot_len == 0) {
1112 ret = 0; 1113 ret = 0;
1113 goto out; 1114 goto out;
diff --git a/fs/read_write.c b/fs/read_write.c
index dfd125798791..5ad4248b0cd8 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -633,7 +633,8 @@ ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov,
633ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, 633ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
634 unsigned long nr_segs, unsigned long fast_segs, 634 unsigned long nr_segs, unsigned long fast_segs,
635 struct iovec *fast_pointer, 635 struct iovec *fast_pointer,
636 struct iovec **ret_pointer) 636 struct iovec **ret_pointer,
637 int check_access)
637{ 638{
638 unsigned long seg; 639 unsigned long seg;
639 ssize_t ret; 640 ssize_t ret;
@@ -689,7 +690,8 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
689 ret = -EINVAL; 690 ret = -EINVAL;
690 goto out; 691 goto out;
691 } 692 }
692 if (unlikely(!access_ok(vrfy_dir(type), buf, len))) { 693 if (check_access
694 && unlikely(!access_ok(vrfy_dir(type), buf, len))) {
693 ret = -EFAULT; 695 ret = -EFAULT;
694 goto out; 696 goto out;
695 } 697 }
@@ -721,7 +723,7 @@ static ssize_t do_readv_writev(int type, struct file *file,
721 } 723 }
722 724
723 ret = rw_copy_check_uvector(type, uvector, nr_segs, 725 ret = rw_copy_check_uvector(type, uvector, nr_segs,
724 ARRAY_SIZE(iovstack), iovstack, &iov); 726 ARRAY_SIZE(iovstack), iovstack, &iov, 1);
725 if (ret <= 0) 727 if (ret <= 0)
726 goto out; 728 goto out;
727 729
diff --git a/include/linux/compat.h b/include/linux/compat.h
index c6e7523bf765..154bf5683015 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -547,7 +547,8 @@ extern ssize_t compat_rw_copy_check_uvector(int type,
547 const struct compat_iovec __user *uvector, 547 const struct compat_iovec __user *uvector,
548 unsigned long nr_segs, 548 unsigned long nr_segs,
549 unsigned long fast_segs, struct iovec *fast_pointer, 549 unsigned long fast_segs, struct iovec *fast_pointer,
550 struct iovec **ret_pointer); 550 struct iovec **ret_pointer,
551 int check_access);
551 552
552extern void __user *compat_alloc_user_space(unsigned long len); 553extern void __user *compat_alloc_user_space(unsigned long len);
553 554
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 14493a2d5a03..87b4c6b9692d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1633,9 +1633,10 @@ struct inode_operations {
1633struct seq_file; 1633struct seq_file;
1634 1634
1635ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, 1635ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
1636 unsigned long nr_segs, unsigned long fast_segs, 1636 unsigned long nr_segs, unsigned long fast_segs,
1637 struct iovec *fast_pointer, 1637 struct iovec *fast_pointer,
1638 struct iovec **ret_pointer); 1638 struct iovec **ret_pointer,
1639 int check_access);
1639 1640
1640extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *); 1641extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
1641extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *); 1642extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 1ff0ec2a5e8d..86a24b1166d1 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -844,4 +844,17 @@ asmlinkage long sys_open_by_handle_at(int mountdirfd,
844 struct file_handle __user *handle, 844 struct file_handle __user *handle,
845 int flags); 845 int flags);
846asmlinkage long sys_setns(int fd, int nstype); 846asmlinkage long sys_setns(int fd, int nstype);
847asmlinkage long sys_process_vm_readv(pid_t pid,
848 const struct iovec __user *lvec,
849 unsigned long liovcnt,
850 const struct iovec __user *rvec,
851 unsigned long riovcnt,
852 unsigned long flags);
853asmlinkage long sys_process_vm_writev(pid_t pid,
854 const struct iovec __user *lvec,
855 unsigned long liovcnt,
856 const struct iovec __user *rvec,
857 unsigned long riovcnt,
858 unsigned long flags);
859
847#endif 860#endif
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index a9a5de07c4f1..47bfa16430d7 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -145,6 +145,10 @@ cond_syscall(sys_io_submit);
145cond_syscall(sys_io_cancel); 145cond_syscall(sys_io_cancel);
146cond_syscall(sys_io_getevents); 146cond_syscall(sys_io_getevents);
147cond_syscall(sys_syslog); 147cond_syscall(sys_syslog);
148cond_syscall(sys_process_vm_readv);
149cond_syscall(sys_process_vm_writev);
150cond_syscall(compat_sys_process_vm_readv);
151cond_syscall(compat_sys_process_vm_writev);
148 152
149/* arch-specific weak syscall entries */ 153/* arch-specific weak syscall entries */
150cond_syscall(sys_pciconfig_read); 154cond_syscall(sys_pciconfig_read);
diff --git a/mm/Makefile b/mm/Makefile
index 836e4163c1bf..50ec00ef2a0e 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -5,7 +5,8 @@
5mmu-y := nommu.o 5mmu-y := nommu.o
6mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \ 6mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \
7 mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \ 7 mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \
8 vmalloc.o pagewalk.o pgtable-generic.o 8 vmalloc.o pagewalk.o pgtable-generic.o \
9 process_vm_access.o
9 10
10obj-y := filemap.o mempool.o oom_kill.o fadvise.o \ 11obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
11 maccess.o page_alloc.o page-writeback.o \ 12 maccess.o page_alloc.o page-writeback.o \
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
new file mode 100644
index 000000000000..e920aa3ce104
--- /dev/null
+++ b/mm/process_vm_access.c
@@ -0,0 +1,496 @@
1/*
2 * linux/mm/process_vm_access.c
3 *
4 * Copyright (C) 2010-2011 Christopher Yeoh <cyeoh@au1.ibm.com>, IBM Corp.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/mm.h>
13#include <linux/uio.h>
14#include <linux/sched.h>
15#include <linux/highmem.h>
16#include <linux/ptrace.h>
17#include <linux/slab.h>
18#include <linux/syscalls.h>
19
20#ifdef CONFIG_COMPAT
21#include <linux/compat.h>
22#endif
23
24/**
25 * process_vm_rw_pages - read/write pages from task specified
26 * @task: task to read/write from
27 * @mm: mm for task
28 * @process_pages: struct pages area that can store at least
29 * nr_pages_to_copy struct page pointers
30 * @pa: address of page in task to start copying from/to
31 * @start_offset: offset in page to start copying from/to
32 * @len: number of bytes to copy
33 * @lvec: iovec array specifying where to copy to/from
34 * @lvec_cnt: number of elements in iovec array
35 * @lvec_current: index in iovec array we are up to
36 * @lvec_offset: offset in bytes from current iovec iov_base we are up to
37 * @vm_write: 0 means copy from, 1 means copy to
38 * @nr_pages_to_copy: number of pages to copy
39 * @bytes_copied: returns number of bytes successfully copied
40 * Returns 0 on success, error code otherwise
41 */
42static int process_vm_rw_pages(struct task_struct *task,
43 struct mm_struct *mm,
44 struct page **process_pages,
45 unsigned long pa,
46 unsigned long start_offset,
47 unsigned long len,
48 const struct iovec *lvec,
49 unsigned long lvec_cnt,
50 unsigned long *lvec_current,
51 size_t *lvec_offset,
52 int vm_write,
53 unsigned int nr_pages_to_copy,
54 ssize_t *bytes_copied)
55{
56 int pages_pinned;
57 void *target_kaddr;
58 int pgs_copied = 0;
59 int j;
60 int ret;
61 ssize_t bytes_to_copy;
62 ssize_t rc = 0;
63
64 *bytes_copied = 0;
65
66 /* Get the pages we're interested in */
67 down_read(&mm->mmap_sem);
68 pages_pinned = get_user_pages(task, mm, pa,
69 nr_pages_to_copy,
70 vm_write, 0, process_pages, NULL);
71 up_read(&mm->mmap_sem);
72
73 if (pages_pinned != nr_pages_to_copy) {
74 rc = -EFAULT;
75 goto end;
76 }
77
78 /* Do the copy for each page */
79 for (pgs_copied = 0;
80 (pgs_copied < nr_pages_to_copy) && (*lvec_current < lvec_cnt);
81 pgs_copied++) {
82 /* Make sure we have a non zero length iovec */
83 while (*lvec_current < lvec_cnt
84 && lvec[*lvec_current].iov_len == 0)
85 (*lvec_current)++;
86 if (*lvec_current == lvec_cnt)
87 break;
88
89 /*
90 * Will copy smallest of:
91 * - bytes remaining in page
92 * - bytes remaining in destination iovec
93 */
94 bytes_to_copy = min_t(ssize_t, PAGE_SIZE - start_offset,
95 len - *bytes_copied);
96 bytes_to_copy = min_t(ssize_t, bytes_to_copy,
97 lvec[*lvec_current].iov_len
98 - *lvec_offset);
99
100 target_kaddr = kmap(process_pages[pgs_copied]) + start_offset;
101
102 if (vm_write)
103 ret = copy_from_user(target_kaddr,
104 lvec[*lvec_current].iov_base
105 + *lvec_offset,
106 bytes_to_copy);
107 else
108 ret = copy_to_user(lvec[*lvec_current].iov_base
109 + *lvec_offset,
110 target_kaddr, bytes_to_copy);
111 kunmap(process_pages[pgs_copied]);
112 if (ret) {
113 *bytes_copied += bytes_to_copy - ret;
114 pgs_copied++;
115 rc = -EFAULT;
116 goto end;
117 }
118 *bytes_copied += bytes_to_copy;
119 *lvec_offset += bytes_to_copy;
120 if (*lvec_offset == lvec[*lvec_current].iov_len) {
121 /*
122 * Need to copy remaining part of page into the
123 * next iovec if there are any bytes left in page
124 */
125 (*lvec_current)++;
126 *lvec_offset = 0;
127 start_offset = (start_offset + bytes_to_copy)
128 % PAGE_SIZE;
129 if (start_offset)
130 pgs_copied--;
131 } else {
132 start_offset = 0;
133 }
134 }
135
136end:
137 if (vm_write) {
138 for (j = 0; j < pages_pinned; j++) {
139 if (j < pgs_copied)
140 set_page_dirty_lock(process_pages[j]);
141 put_page(process_pages[j]);
142 }
143 } else {
144 for (j = 0; j < pages_pinned; j++)
145 put_page(process_pages[j]);
146 }
147
148 return rc;
149}
150
151/* Maximum number of pages kmalloc'd to hold struct page's during copy */
152#define PVM_MAX_KMALLOC_PAGES (PAGE_SIZE * 2)
153
154/**
155 * process_vm_rw_single_vec - read/write pages from task specified
156 * @addr: start memory address of target process
157 * @len: size of area to copy to/from
158 * @lvec: iovec array specifying where to copy to/from locally
159 * @lvec_cnt: number of elements in iovec array
160 * @lvec_current: index in iovec array we are up to
161 * @lvec_offset: offset in bytes from current iovec iov_base we are up to
162 * @process_pages: struct pages area that can store at least
163 * nr_pages_to_copy struct page pointers
164 * @mm: mm for task
165 * @task: task to read/write from
166 * @vm_write: 0 means copy from, 1 means copy to
167 * @bytes_copied: returns number of bytes successfully copied
168 * Returns 0 on success or on failure error code
169 */
170static int process_vm_rw_single_vec(unsigned long addr,
171 unsigned long len,
172 const struct iovec *lvec,
173 unsigned long lvec_cnt,
174 unsigned long *lvec_current,
175 size_t *lvec_offset,
176 struct page **process_pages,
177 struct mm_struct *mm,
178 struct task_struct *task,
179 int vm_write,
180 ssize_t *bytes_copied)
181{
182 unsigned long pa = addr & PAGE_MASK;
183 unsigned long start_offset = addr - pa;
184 unsigned long nr_pages;
185 ssize_t bytes_copied_loop;
186 ssize_t rc = 0;
187 unsigned long nr_pages_copied = 0;
188 unsigned long nr_pages_to_copy;
189 unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES
190 / sizeof(struct pages *);
191
192 *bytes_copied = 0;
193
194 /* Work out address and page range required */
195 if (len == 0)
196 return 0;
197 nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1;
198
199 while ((nr_pages_copied < nr_pages) && (*lvec_current < lvec_cnt)) {
200 nr_pages_to_copy = min(nr_pages - nr_pages_copied,
201 max_pages_per_loop);
202
203 rc = process_vm_rw_pages(task, mm, process_pages, pa,
204 start_offset, len,
205 lvec, lvec_cnt,
206 lvec_current, lvec_offset,
207 vm_write, nr_pages_to_copy,
208 &bytes_copied_loop);
209 start_offset = 0;
210 *bytes_copied += bytes_copied_loop;
211
212 if (rc < 0) {
213 return rc;
214 } else {
215 len -= bytes_copied_loop;
216 nr_pages_copied += nr_pages_to_copy;
217 pa += nr_pages_to_copy * PAGE_SIZE;
218 }
219 }
220
221 return rc;
222}
223
224/* Maximum number of entries for process pages array
225 which lives on stack */
226#define PVM_MAX_PP_ARRAY_COUNT 16
227
228/**
229 * process_vm_rw_core - core of reading/writing pages from task specified
230 * @pid: PID of process to read/write from/to
231 * @lvec: iovec array specifying where to copy to/from locally
232 * @liovcnt: size of lvec array
233 * @rvec: iovec array specifying where to copy to/from in the other process
234 * @riovcnt: size of rvec array
235 * @flags: currently unused
236 * @vm_write: 0 if reading from other process, 1 if writing to other process
237 * Returns the number of bytes read/written or error code. May
238 * return less bytes than expected if an error occurs during the copying
239 * process.
240 */
241static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
242 unsigned long liovcnt,
243 const struct iovec *rvec,
244 unsigned long riovcnt,
245 unsigned long flags, int vm_write)
246{
247 struct task_struct *task;
248 struct page *pp_stack[PVM_MAX_PP_ARRAY_COUNT];
249 struct page **process_pages = pp_stack;
250 struct mm_struct *mm;
251 unsigned long i;
252 ssize_t rc = 0;
253 ssize_t bytes_copied_loop;
254 ssize_t bytes_copied = 0;
255 unsigned long nr_pages = 0;
256 unsigned long nr_pages_iov;
257 unsigned long iov_l_curr_idx = 0;
258 size_t iov_l_curr_offset = 0;
259 ssize_t iov_len;
260
261 /*
262 * Work out how many pages of struct pages we're going to need
263 * when eventually calling get_user_pages
264 */
265 for (i = 0; i < riovcnt; i++) {
266 iov_len = rvec[i].iov_len;
267 if (iov_len > 0) {
268 nr_pages_iov = ((unsigned long)rvec[i].iov_base
269 + iov_len)
270 / PAGE_SIZE - (unsigned long)rvec[i].iov_base
271 / PAGE_SIZE + 1;
272 nr_pages = max(nr_pages, nr_pages_iov);
273 }
274 }
275
276 if (nr_pages == 0)
277 return 0;
278
279 if (nr_pages > PVM_MAX_PP_ARRAY_COUNT) {
280 /* For reliability don't try to kmalloc more than
281 2 pages worth */
282 process_pages = kmalloc(min_t(size_t, PVM_MAX_KMALLOC_PAGES,
283 sizeof(struct pages *)*nr_pages),
284 GFP_KERNEL);
285
286 if (!process_pages)
287 return -ENOMEM;
288 }
289
290 /* Get process information */
291 rcu_read_lock();
292 task = find_task_by_vpid(pid);
293 if (task)
294 get_task_struct(task);
295 rcu_read_unlock();
296 if (!task) {
297 rc = -ESRCH;
298 goto free_proc_pages;
299 }
300
301 task_lock(task);
302 if (__ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
303 task_unlock(task);
304 rc = -EPERM;
305 goto put_task_struct;
306 }
307 mm = task->mm;
308
309 if (!mm || (task->flags & PF_KTHREAD)) {
310 task_unlock(task);
311 rc = -EINVAL;
312 goto put_task_struct;
313 }
314
315 atomic_inc(&mm->mm_users);
316 task_unlock(task);
317
318 for (i = 0; i < riovcnt && iov_l_curr_idx < liovcnt; i++) {
319 rc = process_vm_rw_single_vec(
320 (unsigned long)rvec[i].iov_base, rvec[i].iov_len,
321 lvec, liovcnt, &iov_l_curr_idx, &iov_l_curr_offset,
322 process_pages, mm, task, vm_write, &bytes_copied_loop);
323 bytes_copied += bytes_copied_loop;
324 if (rc != 0) {
325 /* If we have managed to copy any data at all then
326 we return the number of bytes copied. Otherwise
327 we return the error code */
328 if (bytes_copied)
329 rc = bytes_copied;
330 goto put_mm;
331 }
332 }
333
334 rc = bytes_copied;
335put_mm:
336 mmput(mm);
337
338put_task_struct:
339 put_task_struct(task);
340
341free_proc_pages:
342 if (process_pages != pp_stack)
343 kfree(process_pages);
344 return rc;
345}
346
347/**
348 * process_vm_rw - check iovecs before calling core routine
349 * @pid: PID of process to read/write from/to
350 * @lvec: iovec array specifying where to copy to/from locally
351 * @liovcnt: size of lvec array
352 * @rvec: iovec array specifying where to copy to/from in the other process
353 * @riovcnt: size of rvec array
354 * @flags: currently unused
355 * @vm_write: 0 if reading from other process, 1 if writing to other process
356 * Returns the number of bytes read/written or error code. May
357 * return less bytes than expected if an error occurs during the copying
358 * process.
359 */
360static ssize_t process_vm_rw(pid_t pid,
361 const struct iovec __user *lvec,
362 unsigned long liovcnt,
363 const struct iovec __user *rvec,
364 unsigned long riovcnt,
365 unsigned long flags, int vm_write)
366{
367 struct iovec iovstack_l[UIO_FASTIOV];
368 struct iovec iovstack_r[UIO_FASTIOV];
369 struct iovec *iov_l = iovstack_l;
370 struct iovec *iov_r = iovstack_r;
371 ssize_t rc;
372
373 if (flags != 0)
374 return -EINVAL;
375
376 /* Check iovecs */
377 if (vm_write)
378 rc = rw_copy_check_uvector(WRITE, lvec, liovcnt, UIO_FASTIOV,
379 iovstack_l, &iov_l, 1);
380 else
381 rc = rw_copy_check_uvector(READ, lvec, liovcnt, UIO_FASTIOV,
382 iovstack_l, &iov_l, 1);
383 if (rc <= 0)
384 goto free_iovecs;
385
386 rc = rw_copy_check_uvector(READ, rvec, riovcnt, UIO_FASTIOV,
387 iovstack_r, &iov_r, 0);
388 if (rc <= 0)
389 goto free_iovecs;
390
391 rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags,
392 vm_write);
393
394free_iovecs:
395 if (iov_r != iovstack_r)
396 kfree(iov_r);
397 if (iov_l != iovstack_l)
398 kfree(iov_l);
399
400 return rc;
401}
402
403SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec,
404 unsigned long, liovcnt, const struct iovec __user *, rvec,
405 unsigned long, riovcnt, unsigned long, flags)
406{
407 return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 0);
408}
409
410SYSCALL_DEFINE6(process_vm_writev, pid_t, pid,
411 const struct iovec __user *, lvec,
412 unsigned long, liovcnt, const struct iovec __user *, rvec,
413 unsigned long, riovcnt, unsigned long, flags)
414{
415 return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 1);
416}
417
418#ifdef CONFIG_COMPAT
419
420asmlinkage ssize_t
421compat_process_vm_rw(compat_pid_t pid,
422 const struct compat_iovec __user *lvec,
423 unsigned long liovcnt,
424 const struct compat_iovec __user *rvec,
425 unsigned long riovcnt,
426 unsigned long flags, int vm_write)
427{
428 struct iovec iovstack_l[UIO_FASTIOV];
429 struct iovec iovstack_r[UIO_FASTIOV];
430 struct iovec *iov_l = iovstack_l;
431 struct iovec *iov_r = iovstack_r;
432 ssize_t rc = -EFAULT;
433
434 if (flags != 0)
435 return -EINVAL;
436
437 if (!access_ok(VERIFY_READ, lvec, liovcnt * sizeof(*lvec)))
438 goto out;
439
440 if (!access_ok(VERIFY_READ, rvec, riovcnt * sizeof(*rvec)))
441 goto out;
442
443 if (vm_write)
444 rc = compat_rw_copy_check_uvector(WRITE, lvec, liovcnt,
445 UIO_FASTIOV, iovstack_l,
446 &iov_l, 1);
447 else
448 rc = compat_rw_copy_check_uvector(READ, lvec, liovcnt,
449 UIO_FASTIOV, iovstack_l,
450 &iov_l, 1);
451 if (rc <= 0)
452 goto free_iovecs;
453 rc = compat_rw_copy_check_uvector(READ, rvec, riovcnt,
454 UIO_FASTIOV, iovstack_r,
455 &iov_r, 0);
456 if (rc <= 0)
457 goto free_iovecs;
458
459 rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags,
460 vm_write);
461
462free_iovecs:
463 if (iov_r != iovstack_r)
464 kfree(iov_r);
465 if (iov_l != iovstack_l)
466 kfree(iov_l);
467
468out:
469 return rc;
470}
471
472asmlinkage ssize_t
473compat_sys_process_vm_readv(compat_pid_t pid,
474 const struct compat_iovec __user *lvec,
475 unsigned long liovcnt,
476 const struct compat_iovec __user *rvec,
477 unsigned long riovcnt,
478 unsigned long flags)
479{
480 return compat_process_vm_rw(pid, lvec, liovcnt, rvec,
481 riovcnt, flags, 0);
482}
483
484asmlinkage ssize_t
485compat_sys_process_vm_writev(compat_pid_t pid,
486 const struct compat_iovec __user *lvec,
487 unsigned long liovcnt,
488 const struct compat_iovec __user *rvec,
489 unsigned long riovcnt,
490 unsigned long flags)
491{
492 return compat_process_vm_rw(pid, lvec, liovcnt, rvec,
493 riovcnt, flags, 1);
494}
495
496#endif
diff --git a/security/keys/compat.c b/security/keys/compat.c
index 338b510e9027..4c48e13448f8 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -38,7 +38,7 @@ long compat_keyctl_instantiate_key_iov(
38 38
39 ret = compat_rw_copy_check_uvector(WRITE, _payload_iov, ioc, 39 ret = compat_rw_copy_check_uvector(WRITE, _payload_iov, ioc,
40 ARRAY_SIZE(iovstack), 40 ARRAY_SIZE(iovstack),
41 iovstack, &iov); 41 iovstack, &iov, 1);
42 if (ret < 0) 42 if (ret < 0)
43 return ret; 43 return ret;
44 if (ret == 0) 44 if (ret == 0)
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index eca51918c951..0b3f5d72af1c 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1065,7 +1065,7 @@ long keyctl_instantiate_key_iov(key_serial_t id,
1065 goto no_payload; 1065 goto no_payload;
1066 1066
1067 ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc, 1067 ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
1068 ARRAY_SIZE(iovstack), iovstack, &iov); 1068 ARRAY_SIZE(iovstack), iovstack, &iov, 1);
1069 if (ret < 0) 1069 if (ret < 0)
1070 return ret; 1070 return ret;
1071 if (ret == 0) 1071 if (ret == 0)
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-15 10:27:59 -0500