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Diffstat (limited to 'arch/um/kernel')
-rw-r--r--arch/um/kernel/skas/uaccess.c73
1 files changed, 27 insertions, 46 deletions
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
index 05b41dbc1dd..e22c96993db 100644
--- a/arch/um/kernel/skas/uaccess.c
+++ b/arch/um/kernel/skas/uaccess.c
@@ -58,9 +58,10 @@ static pte_t *maybe_map(unsigned long virt, int is_write)
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;
pte_t *pte;
- int n;
+ int n, faulted;
pte = maybe_map(addr, is_write);
if (pte == NULL)
@@ -70,82 +71,62 @@ static int do_op_one_page(unsigned long addr, int len, int is_write,
addr = (unsigned long) kmap_atomic(page, KM_UML_USERCOPY) +
(addr & ~PAGE_MASK);
- n = (*op)(addr, len, arg);
+ current->thread.fault_catcher = &buf;
+
+ faulted = UML_SETJMP(&buf);
+ if (faulted == 0)
+ n = (*op)(addr, len, arg);
+ else
+ n = -1;
+
+ current->thread.fault_catcher = NULL;
kunmap_atomic(page, KM_UML_USERCOPY);
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)