gwj / at91sam9263 · Commits

Commit 38d840e6790c29f5928d8e62711b9f721b58b3dd

Authored by aurel32
1 parent a516e72d

linuw-user fix: read() and acct() on NULL arguments 

Returning efault in these cases is not correct. Originally
proposed by Thayne Harbaugh in 2007:
http://www.mail-archive.com/qemu-devel@nongnu.org/msg14658.html

Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6481 c046a42c-6fe2-441c-8c8c-71466251a162
Inline Side-by-side
Showing 1 changed file with 16 additions and 8 deletions
linux-user/syscall.c
  View file @38d840e
... ... @@ -3437,10 +3437,14 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
3437 3437 ret = 0; /* avoid warning */
3438 3438 break;
3439 3439 case TARGET_NR_read:
3440   - if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0)))
3441   - goto efault;
3442   - ret = get_errno(read(arg1, p, arg3));
3443   - unlock_user(p, arg2, ret);
  3440 + if (arg3 == 0)
  3441 + ret = 0;
  3442 + else {
  3443 + if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0)))
  3444 + goto efault;
  3445 + ret = get_errno(read(arg1, p, arg3));
  3446 + unlock_user(p, arg2, ret);
  3447 + }
3444 3448 break;
3445 3449 case TARGET_NR_write:
3446 3450 if (!(p = lock_user(VERIFY_READ, arg2, arg3, 1)))
... ... @@ -3941,10 +3945,14 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
3941 3945 goto unimplemented;
3942 3946 #endif
3943 3947 case TARGET_NR_acct:
3944   - if (!(p = lock_user_string(arg1)))
3945   - goto efault;
3946   - ret = get_errno(acct(path(p)));
3947   - unlock_user(p, arg1, 0);
  3948 + if (arg1 == 0) {
  3949 + ret = get_errno(acct(NULL));
  3950 + } else {
  3951 + if (!(p = lock_user_string(arg1)))
  3952 + goto efault;
  3953 + ret = get_errno(acct(path(p)));
  3954 + unlock_user(p, arg1, 0);
  3955 + }
3948 3956 break;
3949 3957 #ifdef TARGET_NR_umount2 /* not on alpha */
3950 3958 case TARGET_NR_umount2:
... ...