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authorAndreas Schwab <schwab@suse.de>2019-03-05 17:45:05 +0100
committerLaurent Vivier <laurent@vivier.eu>2019-03-07 10:57:29 +0100
commitba584f1de30e58b0d93cd81bd437271b894eefbf (patch)
tree0acddcc77db3ff6d4ded9942616c5a3969003f07 /linux-user/syscall.c
parent14c8a3a157b437e54fbe097d991dca86ac828a14 (diff)
downloadfocaccia-qemu-ba584f1de30e58b0d93cd81bd437271b894eefbf.tar.gz
focaccia-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/syscall.c')
-rw-r--r--linux-user/syscall.c4
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;