From e3d5a27d5862b6425d0879272e24abecf7245105 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Tue, 6 Jan 2009 14:41:02 -0800 Subject: Allow times and time system calls to return small negative values At the moment, the times() system call will appear to fail for a period shortly after boot, while the value it want to return is between -4095 and -1. The same thing will also happen for the time() system call on 32-bit platforms some time in 2106 or so. On some platforms, such as x86, this is unavoidable because of the system call ABI, but other platforms such as powerpc have a separate error indication from the return value, so system calls can in fact return small negative values without indicating an error. On those platforms, force_successful_syscall_return() provides a way to indicate that the system call return value should not be treated as an error even if it is in the range which would normally be taken as a negative error number. This adds a force_successful_syscall_return() call to the time() and times() system calls plus their 32-bit compat versions, so that they don't erroneously indicate an error on those platforms whose system call ABI has a separate error indication. This will not affect anything on other platforms. Joakim Tjernlund added the fix for time() and the compat versions of time() and times(), after I did the fix for times(). Signed-off-by: Joakim Tjernlund Signed-off-by: Paul Mackerras Acked-by: David S. Miller Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/compat.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel/compat.c') diff --git a/kernel/compat.c b/kernel/compat.c index d52e2ec..42d5654 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -24,6 +24,7 @@ #include #include #include +#include #include @@ -229,6 +230,7 @@ asmlinkage long compat_sys_times(struct compat_tms __user *tbuf) if (copy_to_user(tbuf, &tmp, sizeof(tmp))) return -EFAULT; } + force_successful_syscall_return(); return compat_jiffies_to_clock_t(jiffies); } @@ -894,8 +896,9 @@ asmlinkage long compat_sys_time(compat_time_t __user * tloc) if (tloc) { if (put_user(i,tloc)) - i = -EFAULT; + return -EFAULT; } + force_successful_syscall_return(); return i; } -- cgit v1.1