diff options
| author | Andreas Schwab | 2019-03-05 17:45:05 +0100 |
|---|---|---|
| committer | Laurent Vivier | 2019-03-07 10:57:29 +0100 |
| commit | ba584f1de30e58b0d93cd81bd437271b894eefbf (patch) | |
| tree | 0acddcc77db3ff6d4ded9942616c5a3969003f07 /linux-user | |
| parent | Fix breakpoint support in Nios II user-mode emulation. (diff) | |
| download | qemu-ba584f1de30e58b0d93cd81bd437271b894eefbf.tar.gz qemu-ba584f1de30e58b0d93cd81bd437271b894eefbf.tar.xz qemu-ba584f1de30e58b0d93cd81bd437271b894eefbf.zip | |
linux-user: don't short-circuit read with zero length
A zero-length read still needs to do the usual checks, thus it may return
errors like EBADF. This makes the read syscall emulation consistent with
the pread64 syscall emulation.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <mvm5zsxz2we.fsf@suse.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Diffstat (limited to 'linux-user')
| -rw-r--r-- | linux-user/syscall.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 5f72209deb..9f7eb7d7a8 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -7009,8 +7009,8 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1, _exit(arg1); return 0; /* avoid warning */ case TARGET_NR_read: - if (arg3 == 0) { - return 0; + if (arg2 == 0 && arg3 == 0) { + return get_errno(safe_read(arg1, 0, 0)); } else { if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0))) return -TARGET_EFAULT; |