"CROSS_MEMORY_ATTACH" and mm/process_vm_access.c seems misnamed and misplaced. Actually it's a kind of IPC and it has no more relation to MM than sys_read(). This patch moves code into ipc/ and config option into init/Kconfig.
Signed-off-by: Konstantin Khlebnikov <[email protected]> --- init/Kconfig | 10 + ipc/Makefile | 1 ipc/process_vm_access.c | 383 +++++++++++++++++++++++++++++++++++++++++++++++ mm/Kconfig | 10 - mm/Makefile | 4 mm/process_vm_access.c | 383 ----------------------------------------------- 6 files changed, 394 insertions(+), 397 deletions(-) create mode 100644 ipc/process_vm_access.c delete mode 100644 mm/process_vm_access.c diff --git a/init/Kconfig b/init/Kconfig index 9d3585b..d6ddb7a 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -261,6 +261,16 @@ config POSIX_MQUEUE_SYSCTL depends on SYSCTL default y +config CROSS_MEMORY_ATTACH + bool "Enable process_vm_readv/writev syscalls" + depends on MMU + default y + help + Enabling this option adds the system calls process_vm_readv and + process_vm_writev which allow a process with the correct privileges + to directly read from or write to to another process's address space. + See the man page for more details. + config FHANDLE bool "open by fhandle syscalls" select EXPORTFS diff --git a/ipc/Makefile b/ipc/Makefile index 9075e17..6982d3e 100644 --- a/ipc/Makefile +++ b/ipc/Makefile @@ -9,4 +9,5 @@ obj_mq-$(CONFIG_COMPAT) += compat_mq.o obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o $(obj_mq-y) obj-$(CONFIG_IPC_NS) += namespace.o obj-$(CONFIG_POSIX_MQUEUE_SYSCTL) += mq_sysctl.o +obj-$(CONFIG_CROSS_MEMORY_ATTACH) += process_vm_access.o diff --git a/ipc/process_vm_access.c b/ipc/process_vm_access.c new file mode 100644 index 0000000..65aacea --- /dev/null +++ b/ipc/process_vm_access.c @@ -0,0 +1,383 @@ +/* + * linux/ipc/process_vm_access.c + * + * Copyright (C) 2010-2011 Christopher Yeoh <[email protected]>, IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/mm.h> +#include <linux/uio.h> +#include <linux/sched.h> +#include <linux/highmem.h> +#include <linux/ptrace.h> +#include <linux/slab.h> +#include <linux/syscalls.h> + +#ifdef CONFIG_COMPAT +#include <linux/compat.h> +#endif + +/** + * process_vm_rw_pages - read/write pages from task specified + * @pages: array of pointers to pages we want to copy + * @start_offset: offset in page to start copying from/to + * @len: number of bytes to copy + * @iter: where to copy to/from locally + * @vm_write: 0 means copy from, 1 means copy to + * Returns 0 on success, error code otherwise + */ +static int process_vm_rw_pages(struct page **pages, + unsigned offset, + size_t len, + struct iov_iter *iter, + int vm_write) +{ + /* Do the copy for each page */ + while (len && iov_iter_count(iter)) { + struct page *page = *pages++; + size_t copy = PAGE_SIZE - offset; + size_t copied; + + if (copy > len) + copy = len; + + if (vm_write) { + if (copy > iov_iter_count(iter)) + copy = iov_iter_count(iter); + copied = iov_iter_copy_from_user(page, iter, + offset, copy); + iov_iter_advance(iter, copied); + set_page_dirty_lock(page); + } else { + copied = copy_page_to_iter(page, offset, copy, iter); + } + len -= copied; + if (copied < copy && iov_iter_count(iter)) + return -EFAULT; + offset = 0; + } + return 0; +} + +/* Maximum number of pages kmalloc'd to hold struct page's during copy */ +#define PVM_MAX_KMALLOC_PAGES (PAGE_SIZE * 2) + +/** + * process_vm_rw_single_vec - read/write pages from task specified + * @addr: start memory address of target process + * @len: size of area to copy to/from + * @iter: where to copy to/from locally + * @process_pages: struct pages area that can store at least + * nr_pages_to_copy struct page pointers + * @mm: mm for task + * @task: task to read/write from + * @vm_write: 0 means copy from, 1 means copy to + * Returns 0 on success or on failure error code + */ +static int process_vm_rw_single_vec(unsigned long addr, + unsigned long len, + struct iov_iter *iter, + struct page **process_pages, + struct mm_struct *mm, + struct task_struct *task, + int vm_write) +{ + unsigned long pa = addr & PAGE_MASK; + unsigned long start_offset = addr - pa; + unsigned long nr_pages; + ssize_t rc = 0; + unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES + / sizeof(struct pages *); + + /* Work out address and page range required */ + if (len == 0) + return 0; + nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1; + + while (!rc && nr_pages && iov_iter_count(iter)) { + int pages = min(nr_pages, max_pages_per_loop); + size_t bytes; + + /* Get the pages we're interested in */ + down_read(&mm->mmap_sem); + pages = get_user_pages(task, mm, pa, pages, + vm_write, 0, process_pages, NULL); + up_read(&mm->mmap_sem); + + if (pages <= 0) + return -EFAULT; + + bytes = pages * PAGE_SIZE - start_offset; + if (bytes > len) + bytes = len; + + rc = process_vm_rw_pages(process_pages, + start_offset, bytes, iter, + vm_write); + len -= bytes; + start_offset = 0; + nr_pages -= pages; + pa += pages * PAGE_SIZE; + while (pages) + put_page(process_pages[--pages]); + } + + return rc; +} + +/* Maximum number of entries for process pages array + which lives on stack */ +#define PVM_MAX_PP_ARRAY_COUNT 16 + +/** + * process_vm_rw_core - core of reading/writing pages from task specified + * @pid: PID of process to read/write from/to + * @iter: where to copy to/from locally + * @rvec: iovec array specifying where to copy to/from in the other process + * @riovcnt: size of rvec array + * @flags: currently unused + * @vm_write: 0 if reading from other process, 1 if writing to other process + * Returns the number of bytes read/written or error code. May + * return less bytes than expected if an error occurs during the copying + * process. + */ +static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, + const struct iovec *rvec, + unsigned long riovcnt, + unsigned long flags, int vm_write) +{ + struct task_struct *task; + struct page *pp_stack[PVM_MAX_PP_ARRAY_COUNT]; + struct page **process_pages = pp_stack; + struct mm_struct *mm; + unsigned long i; + ssize_t rc = 0; + unsigned long nr_pages = 0; + unsigned long nr_pages_iov; + ssize_t iov_len; + size_t total_len = iov_iter_count(iter); + + /* + * Work out how many pages of struct pages we're going to need + * when eventually calling get_user_pages + */ + for (i = 0; i < riovcnt; i++) { + iov_len = rvec[i].iov_len; + if (iov_len > 0) { + nr_pages_iov = ((unsigned long)rvec[i].iov_base + + iov_len) + / PAGE_SIZE - (unsigned long)rvec[i].iov_base + / PAGE_SIZE + 1; + nr_pages = max(nr_pages, nr_pages_iov); + } + } + + if (nr_pages == 0) + return 0; + + if (nr_pages > PVM_MAX_PP_ARRAY_COUNT) { + /* For reliability don't try to kmalloc more than + 2 pages worth */ + process_pages = kmalloc(min_t(size_t, PVM_MAX_KMALLOC_PAGES, + sizeof(struct pages *)*nr_pages), + GFP_KERNEL); + + if (!process_pages) + return -ENOMEM; + } + + /* Get process information */ + rcu_read_lock(); + task = find_task_by_vpid(pid); + if (task) + get_task_struct(task); + rcu_read_unlock(); + if (!task) { + rc = -ESRCH; + goto free_proc_pages; + } + + mm = mm_access(task, PTRACE_MODE_ATTACH); + if (!mm || IS_ERR(mm)) { + rc = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH; + /* + * Explicitly map EACCES to EPERM as EPERM is a more a + * appropriate error code for process_vw_readv/writev + */ + if (rc == -EACCES) + rc = -EPERM; + goto put_task_struct; + } + + for (i = 0; i < riovcnt && iov_iter_count(iter) && !rc; i++) + rc = process_vm_rw_single_vec( + (unsigned long)rvec[i].iov_base, rvec[i].iov_len, + iter, process_pages, mm, task, vm_write); + + /* copied = space before - space after */ + total_len -= iov_iter_count(iter); + + /* If we have managed to copy any data at all then + we return the number of bytes copied. Otherwise + we return the error code */ + if (total_len) + rc = total_len; + + mmput(mm); + +put_task_struct: + put_task_struct(task); + +free_proc_pages: + if (process_pages != pp_stack) + kfree(process_pages); + return rc; +} + +/** + * process_vm_rw - check iovecs before calling core routine + * @pid: PID of process to read/write from/to + * @lvec: iovec array specifying where to copy to/from locally + * @liovcnt: size of lvec array + * @rvec: iovec array specifying where to copy to/from in the other process + * @riovcnt: size of rvec array + * @flags: currently unused + * @vm_write: 0 if reading from other process, 1 if writing to other process + * Returns the number of bytes read/written or error code. May + * return less bytes than expected if an error occurs during the copying + * process. + */ +static ssize_t process_vm_rw(pid_t pid, + const struct iovec __user *lvec, + unsigned long liovcnt, + const struct iovec __user *rvec, + unsigned long riovcnt, + unsigned long flags, int vm_write) +{ + struct iovec iovstack_l[UIO_FASTIOV]; + struct iovec iovstack_r[UIO_FASTIOV]; + struct iovec *iov_l = iovstack_l; + struct iovec *iov_r = iovstack_r; + struct iov_iter iter; + ssize_t rc; + + if (flags != 0) + return -EINVAL; + + /* Check iovecs */ + if (vm_write) + rc = rw_copy_check_uvector(WRITE, lvec, liovcnt, UIO_FASTIOV, + iovstack_l, &iov_l); + else + rc = rw_copy_check_uvector(READ, lvec, liovcnt, UIO_FASTIOV, + iovstack_l, &iov_l); + if (rc <= 0) + goto free_iovecs; + + iov_iter_init(&iter, iov_l, liovcnt, rc, 0); + + rc = rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV, + iovstack_r, &iov_r); + if (rc <= 0) + goto free_iovecs; + + rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write); + +free_iovecs: + if (iov_r != iovstack_r) + kfree(iov_r); + if (iov_l != iovstack_l) + kfree(iov_l); + + return rc; +} + +SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec, + unsigned long, liovcnt, const struct iovec __user *, rvec, + unsigned long, riovcnt, unsigned long, flags) +{ + return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 0); +} + +SYSCALL_DEFINE6(process_vm_writev, pid_t, pid, + const struct iovec __user *, lvec, + unsigned long, liovcnt, const struct iovec __user *, rvec, + unsigned long, riovcnt, unsigned long, flags) +{ + return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 1); +} + +#ifdef CONFIG_COMPAT + +static ssize_t +compat_process_vm_rw(compat_pid_t pid, + const struct compat_iovec __user *lvec, + unsigned long liovcnt, + const struct compat_iovec __user *rvec, + unsigned long riovcnt, + unsigned long flags, int vm_write) +{ + struct iovec iovstack_l[UIO_FASTIOV]; + struct iovec iovstack_r[UIO_FASTIOV]; + struct iovec *iov_l = iovstack_l; + struct iovec *iov_r = iovstack_r; + struct iov_iter iter; + ssize_t rc = -EFAULT; + + if (flags != 0) + return -EINVAL; + + if (vm_write) + rc = compat_rw_copy_check_uvector(WRITE, lvec, liovcnt, + UIO_FASTIOV, iovstack_l, + &iov_l); + else + rc = compat_rw_copy_check_uvector(READ, lvec, liovcnt, + UIO_FASTIOV, iovstack_l, + &iov_l); + if (rc <= 0) + goto free_iovecs; + iov_iter_init(&iter, iov_l, liovcnt, rc, 0); + rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, + UIO_FASTIOV, iovstack_r, + &iov_r); + if (rc <= 0) + goto free_iovecs; + + rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write); + +free_iovecs: + if (iov_r != iovstack_r) + kfree(iov_r); + if (iov_l != iovstack_l) + kfree(iov_l); + return rc; +} + +COMPAT_SYSCALL_DEFINE6(process_vm_readv, compat_pid_t, pid, + const struct compat_iovec __user *, lvec, + compat_ulong_t, liovcnt, + const struct compat_iovec __user *, rvec, + compat_ulong_t, riovcnt, + compat_ulong_t, flags) +{ + return compat_process_vm_rw(pid, lvec, liovcnt, rvec, + riovcnt, flags, 0); +} + +COMPAT_SYSCALL_DEFINE6(process_vm_writev, compat_pid_t, pid, + const struct compat_iovec __user *, lvec, + compat_ulong_t, liovcnt, + const struct compat_iovec __user *, rvec, + compat_ulong_t, riovcnt, + compat_ulong_t, flags) +{ + return compat_process_vm_rw(pid, lvec, liovcnt, rvec, + riovcnt, flags, 1); +} + +#endif diff --git a/mm/Kconfig b/mm/Kconfig index 1b5a95f..2ec35d7 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -430,16 +430,6 @@ choice benefit. endchoice -config CROSS_MEMORY_ATTACH - bool "Cross Memory Support" - depends on MMU - default y - help - Enabling this option adds the system calls process_vm_readv and - process_vm_writev which allow a process with the correct privileges - to directly read from or write to to another process's address space. - See the man page for more details. - # # UP and nommu archs use km based percpu allocator # diff --git a/mm/Makefile b/mm/Makefile index b484452..d624084 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -7,10 +7,6 @@ mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \ mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \ vmalloc.o pagewalk.o pgtable-generic.o -ifdef CONFIG_CROSS_MEMORY_ATTACH -mmu-$(CONFIG_MMU) += process_vm_access.o -endif - obj-y := filemap.o mempool.o oom_kill.o fadvise.o \ maccess.o page_alloc.o page-writeback.o \ readahead.o swap.o truncate.o vmscan.o shmem.o \ diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c deleted file mode 100644 index 8505c92..0000000 --- a/mm/process_vm_access.c +++ /dev/null @@ -1,383 +0,0 @@ -/* - * linux/mm/process_vm_access.c - * - * Copyright (C) 2010-2011 Christopher Yeoh <[email protected]>, IBM Corp. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ - -#include <linux/mm.h> -#include <linux/uio.h> -#include <linux/sched.h> -#include <linux/highmem.h> -#include <linux/ptrace.h> -#include <linux/slab.h> -#include <linux/syscalls.h> - -#ifdef CONFIG_COMPAT -#include <linux/compat.h> -#endif - -/** - * process_vm_rw_pages - read/write pages from task specified - * @pages: array of pointers to pages we want to copy - * @start_offset: offset in page to start copying from/to - * @len: number of bytes to copy - * @iter: where to copy to/from locally - * @vm_write: 0 means copy from, 1 means copy to - * Returns 0 on success, error code otherwise - */ -static int process_vm_rw_pages(struct page **pages, - unsigned offset, - size_t len, - struct iov_iter *iter, - int vm_write) -{ - /* Do the copy for each page */ - while (len && iov_iter_count(iter)) { - struct page *page = *pages++; - size_t copy = PAGE_SIZE - offset; - size_t copied; - - if (copy > len) - copy = len; - - if (vm_write) { - if (copy > iov_iter_count(iter)) - copy = iov_iter_count(iter); - copied = iov_iter_copy_from_user(page, iter, - offset, copy); - iov_iter_advance(iter, copied); - set_page_dirty_lock(page); - } else { - copied = copy_page_to_iter(page, offset, copy, iter); - } - len -= copied; - if (copied < copy && iov_iter_count(iter)) - return -EFAULT; - offset = 0; - } - return 0; -} - -/* Maximum number of pages kmalloc'd to hold struct page's during copy */ -#define PVM_MAX_KMALLOC_PAGES (PAGE_SIZE * 2) - -/** - * process_vm_rw_single_vec - read/write pages from task specified - * @addr: start memory address of target process - * @len: size of area to copy to/from - * @iter: where to copy to/from locally - * @process_pages: struct pages area that can store at least - * nr_pages_to_copy struct page pointers - * @mm: mm for task - * @task: task to read/write from - * @vm_write: 0 means copy from, 1 means copy to - * Returns 0 on success or on failure error code - */ -static int process_vm_rw_single_vec(unsigned long addr, - unsigned long len, - struct iov_iter *iter, - struct page **process_pages, - struct mm_struct *mm, - struct task_struct *task, - int vm_write) -{ - unsigned long pa = addr & PAGE_MASK; - unsigned long start_offset = addr - pa; - unsigned long nr_pages; - ssize_t rc = 0; - unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES - / sizeof(struct pages *); - - /* Work out address and page range required */ - if (len == 0) - return 0; - nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1; - - while (!rc && nr_pages && iov_iter_count(iter)) { - int pages = min(nr_pages, max_pages_per_loop); - size_t bytes; - - /* Get the pages we're interested in */ - down_read(&mm->mmap_sem); - pages = get_user_pages(task, mm, pa, pages, - vm_write, 0, process_pages, NULL); - up_read(&mm->mmap_sem); - - if (pages <= 0) - return -EFAULT; - - bytes = pages * PAGE_SIZE - start_offset; - if (bytes > len) - bytes = len; - - rc = process_vm_rw_pages(process_pages, - start_offset, bytes, iter, - vm_write); - len -= bytes; - start_offset = 0; - nr_pages -= pages; - pa += pages * PAGE_SIZE; - while (pages) - put_page(process_pages[--pages]); - } - - return rc; -} - -/* Maximum number of entries for process pages array - which lives on stack */ -#define PVM_MAX_PP_ARRAY_COUNT 16 - -/** - * process_vm_rw_core - core of reading/writing pages from task specified - * @pid: PID of process to read/write from/to - * @iter: where to copy to/from locally - * @rvec: iovec array specifying where to copy to/from in the other process - * @riovcnt: size of rvec array - * @flags: currently unused - * @vm_write: 0 if reading from other process, 1 if writing to other process - * Returns the number of bytes read/written or error code. May - * return less bytes than expected if an error occurs during the copying - * process. - */ -static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, - const struct iovec *rvec, - unsigned long riovcnt, - unsigned long flags, int vm_write) -{ - struct task_struct *task; - struct page *pp_stack[PVM_MAX_PP_ARRAY_COUNT]; - struct page **process_pages = pp_stack; - struct mm_struct *mm; - unsigned long i; - ssize_t rc = 0; - unsigned long nr_pages = 0; - unsigned long nr_pages_iov; - ssize_t iov_len; - size_t total_len = iov_iter_count(iter); - - /* - * Work out how many pages of struct pages we're going to need - * when eventually calling get_user_pages - */ - for (i = 0; i < riovcnt; i++) { - iov_len = rvec[i].iov_len; - if (iov_len > 0) { - nr_pages_iov = ((unsigned long)rvec[i].iov_base - + iov_len) - / PAGE_SIZE - (unsigned long)rvec[i].iov_base - / PAGE_SIZE + 1; - nr_pages = max(nr_pages, nr_pages_iov); - } - } - - if (nr_pages == 0) - return 0; - - if (nr_pages > PVM_MAX_PP_ARRAY_COUNT) { - /* For reliability don't try to kmalloc more than - 2 pages worth */ - process_pages = kmalloc(min_t(size_t, PVM_MAX_KMALLOC_PAGES, - sizeof(struct pages *)*nr_pages), - GFP_KERNEL); - - if (!process_pages) - return -ENOMEM; - } - - /* Get process information */ - rcu_read_lock(); - task = find_task_by_vpid(pid); - if (task) - get_task_struct(task); - rcu_read_unlock(); - if (!task) { - rc = -ESRCH; - goto free_proc_pages; - } - - mm = mm_access(task, PTRACE_MODE_ATTACH); - if (!mm || IS_ERR(mm)) { - rc = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH; - /* - * Explicitly map EACCES to EPERM as EPERM is a more a - * appropriate error code for process_vw_readv/writev - */ - if (rc == -EACCES) - rc = -EPERM; - goto put_task_struct; - } - - for (i = 0; i < riovcnt && iov_iter_count(iter) && !rc; i++) - rc = process_vm_rw_single_vec( - (unsigned long)rvec[i].iov_base, rvec[i].iov_len, - iter, process_pages, mm, task, vm_write); - - /* copied = space before - space after */ - total_len -= iov_iter_count(iter); - - /* If we have managed to copy any data at all then - we return the number of bytes copied. Otherwise - we return the error code */ - if (total_len) - rc = total_len; - - mmput(mm); - -put_task_struct: - put_task_struct(task); - -free_proc_pages: - if (process_pages != pp_stack) - kfree(process_pages); - return rc; -} - -/** - * process_vm_rw - check iovecs before calling core routine - * @pid: PID of process to read/write from/to - * @lvec: iovec array specifying where to copy to/from locally - * @liovcnt: size of lvec array - * @rvec: iovec array specifying where to copy to/from in the other process - * @riovcnt: size of rvec array - * @flags: currently unused - * @vm_write: 0 if reading from other process, 1 if writing to other process - * Returns the number of bytes read/written or error code. May - * return less bytes than expected if an error occurs during the copying - * process. - */ -static ssize_t process_vm_rw(pid_t pid, - const struct iovec __user *lvec, - unsigned long liovcnt, - const struct iovec __user *rvec, - unsigned long riovcnt, - unsigned long flags, int vm_write) -{ - struct iovec iovstack_l[UIO_FASTIOV]; - struct iovec iovstack_r[UIO_FASTIOV]; - struct iovec *iov_l = iovstack_l; - struct iovec *iov_r = iovstack_r; - struct iov_iter iter; - ssize_t rc; - - if (flags != 0) - return -EINVAL; - - /* Check iovecs */ - if (vm_write) - rc = rw_copy_check_uvector(WRITE, lvec, liovcnt, UIO_FASTIOV, - iovstack_l, &iov_l); - else - rc = rw_copy_check_uvector(READ, lvec, liovcnt, UIO_FASTIOV, - iovstack_l, &iov_l); - if (rc <= 0) - goto free_iovecs; - - iov_iter_init(&iter, iov_l, liovcnt, rc, 0); - - rc = rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV, - iovstack_r, &iov_r); - if (rc <= 0) - goto free_iovecs; - - rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write); - -free_iovecs: - if (iov_r != iovstack_r) - kfree(iov_r); - if (iov_l != iovstack_l) - kfree(iov_l); - - return rc; -} - -SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec, - unsigned long, liovcnt, const struct iovec __user *, rvec, - unsigned long, riovcnt, unsigned long, flags) -{ - return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 0); -} - -SYSCALL_DEFINE6(process_vm_writev, pid_t, pid, - const struct iovec __user *, lvec, - unsigned long, liovcnt, const struct iovec __user *, rvec, - unsigned long, riovcnt, unsigned long, flags) -{ - return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 1); -} - -#ifdef CONFIG_COMPAT - -static ssize_t -compat_process_vm_rw(compat_pid_t pid, - const struct compat_iovec __user *lvec, - unsigned long liovcnt, - const struct compat_iovec __user *rvec, - unsigned long riovcnt, - unsigned long flags, int vm_write) -{ - struct iovec iovstack_l[UIO_FASTIOV]; - struct iovec iovstack_r[UIO_FASTIOV]; - struct iovec *iov_l = iovstack_l; - struct iovec *iov_r = iovstack_r; - struct iov_iter iter; - ssize_t rc = -EFAULT; - - if (flags != 0) - return -EINVAL; - - if (vm_write) - rc = compat_rw_copy_check_uvector(WRITE, lvec, liovcnt, - UIO_FASTIOV, iovstack_l, - &iov_l); - else - rc = compat_rw_copy_check_uvector(READ, lvec, liovcnt, - UIO_FASTIOV, iovstack_l, - &iov_l); - if (rc <= 0) - goto free_iovecs; - iov_iter_init(&iter, iov_l, liovcnt, rc, 0); - rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, - UIO_FASTIOV, iovstack_r, - &iov_r); - if (rc <= 0) - goto free_iovecs; - - rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write); - -free_iovecs: - if (iov_r != iovstack_r) - kfree(iov_r); - if (iov_l != iovstack_l) - kfree(iov_l); - return rc; -} - -COMPAT_SYSCALL_DEFINE6(process_vm_readv, compat_pid_t, pid, - const struct compat_iovec __user *, lvec, - compat_ulong_t, liovcnt, - const struct compat_iovec __user *, rvec, - compat_ulong_t, riovcnt, - compat_ulong_t, flags) -{ - return compat_process_vm_rw(pid, lvec, liovcnt, rvec, - riovcnt, flags, 0); -} - -COMPAT_SYSCALL_DEFINE6(process_vm_writev, compat_pid_t, pid, - const struct compat_iovec __user *, lvec, - compat_ulong_t, liovcnt, - const struct compat_iovec __user *, rvec, - compat_ulong_t, riovcnt, - compat_ulong_t, flags) -{ - return compat_process_vm_rw(pid, lvec, liovcnt, rvec, - riovcnt, flags, 1); -} - -#endif -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
