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| author | Steven J. Magnani <steve@digidescorp.com> | 2010-05-07 01:38:33 +0400 |
|---|---|---|
| committer | Michal Simek <monstr@monstr.eu> | 2010-05-13 11:21:14 +0400 |
| commit | 538722ca3b762023ac65cec214901a1ebff8b575 (patch) | |
| tree | 5d4ca0048a9351744fcfa6b5ca2cc25e090882f6 /arch/microblaze | |
| parent | 0d5961b7f612f8f54fd6fbe1942cdfb141cddfb9 (diff) | |
| download | linux-538722ca3b762023ac65cec214901a1ebff8b575.tar.xz | |
microblaze: fix get_user/put_user side-effects
The Microblaze implementations of get_user() and (MMU) put_user() evaluate
the address argument more than once. This causes unexpected side-effects for
invocations that include increment operators, i.e. get_user(foo, bar++).
This patch also removes the distinction between MMU and noMMU put_user().
Without the patch:
$ echo 1234567890 > /proc/sys/kernel/core_pattern
$ cat /proc/sys/kernel/core_pattern
12345
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Diffstat (limited to 'arch/microblaze')
| -rw-r--r-- | arch/microblaze/include/asm/uaccess.h | 87 |
1 files changed, 69 insertions, 18 deletions
diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h index 446bec29b142..26460d15b338 100644 --- a/arch/microblaze/include/asm/uaccess.h +++ b/arch/microblaze/include/asm/uaccess.h @@ -182,6 +182,39 @@ extern long __user_bad(void); * Returns zero on success, or -EFAULT on error. * On error, the variable @x is set to zero. */ +#define get_user(x, ptr) \ + __get_user_check((x), (ptr), sizeof(*(ptr))) + +#define __get_user_check(x, ptr, size) \ +({ \ + unsigned long __gu_val = 0; \ + const typeof(*(ptr)) __user *__gu_addr = (ptr); \ + int __gu_err = 0; \ + \ + if (access_ok(VERIFY_READ, __gu_addr, size)) { \ + switch (size) { \ + case 1: \ + __get_user_asm("lbu", __gu_addr, __gu_val, \ + __gu_err); \ + break; \ + case 2: \ + __get_user_asm("lhu", __gu_addr, __gu_val, \ + __gu_err); \ + break; \ + case 4: \ + __get_user_asm("lw", __gu_addr, __gu_val, \ + __gu_err); \ + break; \ + default: \ + __gu_err = __user_bad(); \ + break; \ + } \ + } else { \ + __gu_err = -EFAULT; \ + } \ + x = (typeof(*(ptr)))__gu_val; \ + __gu_err; \ +}) #define __get_user(x, ptr) \ ({ \ @@ -206,12 +239,6 @@ extern long __user_bad(void); }) -#define get_user(x, ptr) \ -({ \ - access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) \ - ? __get_user((x), (ptr)) : -EFAULT; \ -}) - #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ ({ \ __asm__ __volatile__ ( \ @@ -266,6 +293,42 @@ extern long __user_bad(void); * * Returns zero on success, or -EFAULT on error. */ +#define put_user(x, ptr) \ + __put_user_check((x), (ptr), sizeof(*(ptr))) + +#define __put_user_check(x, ptr, size) \ +({ \ + typeof(*(ptr)) __pu_val; \ + typeof(*(ptr)) __user *__pu_addr = (ptr); \ + int __pu_err = 0; \ + \ + __pu_val = (x); \ + if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \ + switch (size) { \ + case 1: \ + __put_user_asm("sb", __pu_addr, __pu_val, \ + __pu_err); \ + break; \ + case 2: \ + __put_user_asm("sh", __pu_addr, __pu_val, \ + __pu_err); \ + break; \ + case 4: \ + __put_user_asm("sw", __pu_addr, __pu_val, \ + __pu_err); \ + break; \ + case 8: \ + __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\ + break; \ + default: \ + __pu_err = __user_bad(); \ + break; \ + } \ + } else { \ + __pu_err = -EFAULT; \ + } \ + __pu_err; \ +}) #define __put_user(x, ptr) \ ({ \ @@ -290,18 +353,6 @@ extern long __user_bad(void); __gu_err; \ }) -#ifndef CONFIG_MMU - -#define put_user(x, ptr) __put_user((x), (ptr)) - -#else /* CONFIG_MMU */ - -#define put_user(x, ptr) \ -({ \ - access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) \ - ? __put_user((x), (ptr)) : -EFAULT; \ -}) -#endif /* CONFIG_MMU */ /* copy_to_from_user */ #define __copy_from_user(to, from, n) \ |