diff options
Diffstat (limited to 'arch/um/kernel/skas/uaccess.c')
| -rw-r--r-- | arch/um/kernel/skas/uaccess.c | 158 |
1 files changed, 83 insertions, 75 deletions
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c index 1d8b119f2d0..4ffb644d6c0 100644 --- a/arch/um/kernel/skas/uaccess.c +++ b/arch/um/kernel/skas/uaccess.c @@ -3,128 +3,131 @@ * Licensed under the GPL */ -#include "linux/err.h" -#include "linux/highmem.h" -#include "linux/mm.h" -#include "asm/current.h" -#include "asm/page.h" -#include "asm/pgtable.h" -#include "kern_util.h" -#include "os.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) +#include <linux/err.h> +#include <linux/highmem.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <asm/current.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <kern_util.h> +#include <os.h> + +pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr) { - pte_t pte; - int err; + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; - void *phys = um_virt_to_phys(current, virt, &pte); - int dummy_code; + if (mm == NULL) + return NULL; - if (IS_ERR(phys) || (is_write && !pte_write(pte))) { + pgd = pgd_offset(mm, addr); + if (!pgd_present(*pgd)) + return NULL; + + pud = pud_offset(pgd, addr); + if (!pud_present(*pud)) + return NULL; + + pmd = pmd_offset(pud, addr); + if (!pmd_present(*pmd)) + return NULL; + + return pte_offset_kernel(pmd, addr); +} + +static pte_t *maybe_map(unsigned long virt, int is_write) +{ + pte_t *pte = virt_to_pte(current->mm, virt); + int err, dummy_code; + + if ((pte == NULL) || !pte_present(*pte) || + (is_write && !pte_write(*pte))) { err = handle_page_fault(virt, 0, is_write, 1, &dummy_code); if (err) - return -1UL; - phys = um_virt_to_phys(current, virt, NULL); + return NULL; + pte = virt_to_pte(current->mm, virt); } - if (IS_ERR(phys)) - phys = (void *) -1; + if (!pte_present(*pte)) + pte = NULL; - return (unsigned long) phys; + return pte; } static int do_op_one_page(unsigned long addr, int len, int is_write, int (*op)(unsigned long addr, int len, void *arg), void *arg) { + jmp_buf buf; struct page *page; - int n; + pte_t *pte; + int n, faulted; - addr = maybe_map(addr, is_write); - if (addr == -1UL) + pte = maybe_map(addr, is_write); + if (pte == NULL) return -1; - page = phys_to_page(addr); - addr = (unsigned long) kmap_atomic(page, KM_UML_USERCOPY) + + page = pte_page(*pte); + addr = (unsigned long) kmap_atomic(page) + (addr & ~PAGE_MASK); - n = (*op)(addr, len, arg); + current->thread.fault_catcher = &buf; - kunmap_atomic(page, KM_UML_USERCOPY); + faulted = UML_SETJMP(&buf); + if (faulted == 0) + n = (*op)(addr, len, arg); + else + n = -1; + + current->thread.fault_catcher = NULL; + + kunmap_atomic((void *)addr); return n; } -static void do_buffer_op(void *jmpbuf, void *arg_ptr) +static int buffer_op(unsigned long addr, int len, int is_write, + int (*op)(unsigned long, int, void *), void *arg) { - va_list args; - unsigned long addr; - int len, is_write, size, remain, n; - int (*op)(unsigned long, int, void *); - void *arg; - int *res; - - 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); + int size, remain, n; + size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len); remain = len; - current->thread.fault_catcher = jmpbuf; n = do_op_one_page(addr, size, is_write, op, arg); if (n != 0) { - *res = (n < 0 ? remain : 0); + remain = (n < 0 ? remain : 0); goto out; } addr += size; remain -= size; - if (remain == 0) { - *res = 0; + if (remain == 0) goto out; - } - while(addr < ((addr + remain) & PAGE_MASK)) { + while (addr < ((addr + remain) & PAGE_MASK)) { n = do_op_one_page(addr, PAGE_SIZE, is_write, op, arg); if (n != 0) { - *res = (n < 0 ? remain : 0); + remain = (n < 0 ? remain : 0); goto out; } addr += PAGE_SIZE; remain -= PAGE_SIZE; } - if (remain == 0) { - *res = 0; + if (remain == 0) goto out; - } n = do_op_one_page(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; + if (n != 0) { + remain = (n < 0 ? remain : 0); + goto out; + } - return addr + len - (unsigned long) current->thread.fault_addr; + return 0; + out: + return remain; } static int copy_chunk_from_user(unsigned long from, int len, void *arg) @@ -147,6 +150,7 @@ int copy_from_user(void *to, const void __user *from, int n) buffer_op((unsigned long) from, n, 0, copy_chunk_from_user, &to): n; } +EXPORT_SYMBOL(copy_from_user); static int copy_chunk_to_user(unsigned long to, int len, void *arg) { @@ -168,6 +172,7 @@ int copy_to_user(void __user *to, const void *from, int n) buffer_op((unsigned long) to, n, 1, copy_chunk_to_user, &from) : n; } +EXPORT_SYMBOL(copy_to_user); static int strncpy_chunk_from_user(unsigned long from, int len, void *arg) { @@ -202,6 +207,7 @@ int strncpy_from_user(char *dst, const char __user *src, int count) return -EFAULT; return strnlen(dst, count); } +EXPORT_SYMBOL(strncpy_from_user); static int clear_chunk(unsigned long addr, int len, void *unused) { @@ -224,6 +230,7 @@ int clear_user(void __user *mem, int len) return access_ok(VERIFY_WRITE, mem, len) ? buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL) : len; } +EXPORT_SYMBOL(clear_user); static int strnlen_chunk(unsigned long str, int len, void *arg) { @@ -247,5 +254,6 @@ int strnlen_user(const void __user *str, int len) n = buffer_op((unsigned long) str, len, 0, strnlen_chunk, &count); if (n == 0) return count + 1; - return -EFAULT; + return 0; } +EXPORT_SYMBOL(strnlen_user); |