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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/um/kernel/skas/uaccess.c | |
download | blackbird-op-linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz blackbird-op-linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/um/kernel/skas/uaccess.c')
-rw-r--r-- | arch/um/kernel/skas/uaccess.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c new file mode 100644 index 000000000000..7575ec489b63 --- /dev/null +++ b/arch/um/kernel/skas/uaccess.c @@ -0,0 +1,259 @@ +/* + * Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com) + * Licensed under the GPL + */ + +#include "linux/stddef.h" +#include "linux/kernel.h" +#include "linux/string.h" +#include "linux/fs.h" +#include "linux/highmem.h" +#include "asm/page.h" +#include "asm/pgtable.h" +#include "asm/uaccess.h" +#include "kern_util.h" +#include "user_util.h" + +extern void *um_virt_to_phys(struct task_struct *task, unsigned long addr, + pte_t *pte_out); + +static unsigned long maybe_map(unsigned long virt, int is_write) +{ + pte_t pte; + int err; + + void *phys = um_virt_to_phys(current, virt, &pte); + int dummy_code; + + if(IS_ERR(phys) || (is_write && !pte_write(pte))){ + err = handle_page_fault(virt, 0, is_write, 1, &dummy_code); + if(err) + return(0); + phys = um_virt_to_phys(current, virt, NULL); + } + return((unsigned long) phys); +} + +static int do_op(unsigned long addr, int len, int is_write, + int (*op)(unsigned long addr, int len, void *arg), void *arg) +{ + struct page *page; + int n; + + addr = maybe_map(addr, is_write); + if(addr == -1) + return(-1); + + page = phys_to_page(addr); + addr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK); + n = (*op)(addr, len, arg); + kunmap(page); + + return(n); +} + +static void do_buffer_op(void *jmpbuf, void *arg_ptr) +{ + va_list args; + unsigned long addr; + int len, is_write, size, remain, n; + int (*op)(unsigned long, int, void *); + void *arg; + int *res; + + /* Some old gccs recognize __va_copy, but not va_copy */ + __va_copy(args, *(va_list *)arg_ptr); + addr = va_arg(args, unsigned long); + len = va_arg(args, int); + is_write = va_arg(args, int); + op = va_arg(args, void *); + arg = va_arg(args, void *); + res = va_arg(args, int *); + va_end(args); + size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len); + remain = len; + + current->thread.fault_catcher = jmpbuf; + n = do_op(addr, size, is_write, op, arg); + if(n != 0){ + *res = (n < 0 ? remain : 0); + goto out; + } + + addr += size; + remain -= size; + if(remain == 0){ + *res = 0; + goto out; + } + + while(addr < ((addr + remain) & PAGE_MASK)){ + n = do_op(addr, PAGE_SIZE, is_write, op, arg); + if(n != 0){ + *res = (n < 0 ? remain : 0); + goto out; + } + + addr += PAGE_SIZE; + remain -= PAGE_SIZE; + } + if(remain == 0){ + *res = 0; + goto out; + } + + n = do_op(addr, remain, is_write, op, arg); + if(n != 0) + *res = (n < 0 ? remain : 0); + else *res = 0; + out: + current->thread.fault_catcher = NULL; +} + +static int buffer_op(unsigned long addr, int len, int is_write, + int (*op)(unsigned long addr, int len, void *arg), + void *arg) +{ + int faulted, res; + + faulted = setjmp_wrapper(do_buffer_op, addr, len, is_write, op, arg, + &res); + if(!faulted) + return(res); + + return(addr + len - (unsigned long) current->thread.fault_addr); +} + +static int copy_chunk_from_user(unsigned long from, int len, void *arg) +{ + unsigned long *to_ptr = arg, to = *to_ptr; + + memcpy((void *) to, (void *) from, len); + *to_ptr += len; + return(0); +} + +int copy_from_user_skas(void *to, const void __user *from, int n) +{ + if(segment_eq(get_fs(), KERNEL_DS)){ + memcpy(to, (__force void*)from, n); + return(0); + } + + return(access_ok_skas(VERIFY_READ, from, n) ? + buffer_op((unsigned long) from, n, 0, copy_chunk_from_user, &to): + n); +} + +static int copy_chunk_to_user(unsigned long to, int len, void *arg) +{ + unsigned long *from_ptr = arg, from = *from_ptr; + + memcpy((void *) to, (void *) from, len); + *from_ptr += len; + return(0); +} + +int copy_to_user_skas(void __user *to, const void *from, int n) +{ + if(segment_eq(get_fs(), KERNEL_DS)){ + memcpy((__force void*)to, from, n); + return(0); + } + + return(access_ok_skas(VERIFY_WRITE, to, n) ? + buffer_op((unsigned long) to, n, 1, copy_chunk_to_user, &from) : + n); +} + +static int strncpy_chunk_from_user(unsigned long from, int len, void *arg) +{ + char **to_ptr = arg, *to = *to_ptr; + int n; + + strncpy(to, (void *) from, len); + n = strnlen(to, len); + *to_ptr += n; + + if(n < len) + return(1); + return(0); +} + +int strncpy_from_user_skas(char *dst, const char __user *src, int count) +{ + int n; + char *ptr = dst; + + if(segment_eq(get_fs(), KERNEL_DS)){ + strncpy(dst, (__force void*)src, count); + return(strnlen(dst, count)); + } + + if(!access_ok_skas(VERIFY_READ, src, 1)) + return(-EFAULT); + + n = buffer_op((unsigned long) src, count, 0, strncpy_chunk_from_user, + &ptr); + if(n != 0) + return(-EFAULT); + return(strnlen(dst, count)); +} + +static int clear_chunk(unsigned long addr, int len, void *unused) +{ + memset((void *) addr, 0, len); + return(0); +} + +int __clear_user_skas(void __user *mem, int len) +{ + return(buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL)); +} + +int clear_user_skas(void __user *mem, int len) +{ + if(segment_eq(get_fs(), KERNEL_DS)){ + memset((__force void*)mem, 0, len); + return(0); + } + + return(access_ok_skas(VERIFY_WRITE, mem, len) ? + buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL) : len); +} + +static int strnlen_chunk(unsigned long str, int len, void *arg) +{ + int *len_ptr = arg, n; + + n = strnlen((void *) str, len); + *len_ptr += n; + + if(n < len) + return(1); + return(0); +} + +int strnlen_user_skas(const void __user *str, int len) +{ + int count = 0, n; + + if(segment_eq(get_fs(), KERNEL_DS)) + return(strnlen((__force char*)str, len) + 1); + + n = buffer_op((unsigned long) str, len, 0, strnlen_chunk, &count); + if(n == 0) + return(count + 1); + return(-EFAULT); +} + +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-file-style: "linux" + * End: + */ |