From 38d840e6790c29f5928d8e62711b9f721b58b3dd Mon Sep 17 00:00:00 2001 From: aurel32 Date: Fri, 30 Jan 2009 19:48:17 +0000 Subject: [PATCH] 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 Signed-off-by: Aurelien Jarno git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6481 c046a42c-6fe2-441c-8c8c-71466251a162 --- linux-user/syscall.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 8296e5e..3e21bb3 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -3437,10 +3437,14 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, ret = 0; /* avoid warning */ break; case TARGET_NR_read: - if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0))) - goto efault; - ret = get_errno(read(arg1, p, arg3)); - unlock_user(p, arg2, ret); + if (arg3 == 0) + ret = 0; + else { + if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0))) + goto efault; + ret = get_errno(read(arg1, p, arg3)); + unlock_user(p, arg2, ret); + } break; case TARGET_NR_write: 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, goto unimplemented; #endif case TARGET_NR_acct: - if (!(p = lock_user_string(arg1))) - goto efault; - ret = get_errno(acct(path(p))); - unlock_user(p, arg1, 0); + if (arg1 == 0) { + ret = get_errno(acct(NULL)); + } else { + if (!(p = lock_user_string(arg1))) + goto efault; + ret = get_errno(acct(path(p))); + unlock_user(p, arg1, 0); + } break; #ifdef TARGET_NR_umount2 /* not on alpha */ case TARGET_NR_umount2: -- 1.7.9.5