The patch titled
Allow times and time system calls to return small negative values
has been added to the -mm tree. Its filename is
allow-times-and-time-system-calls-to-return-small-negative-values.patch
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out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: Allow times and time system calls to return small negative values
From: Paul Mackerras <paulus@xxxxxxxxx>
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 <Joakim.Tjernlund@xxxxxxxxxxxx>
Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/compat.c | 5 ++++-
kernel/sys.c | 2 ++
kernel/time.c | 4 +++-
3 files changed, 9 insertions(+), 2 deletions(-)
diff -puN kernel/compat.c~allow-times-and-time-system-calls-to-return-small-negative-values kernel/compat.c
--- a/kernel/compat.c~allow-times-and-time-system-calls-to-return-small-negative-values
+++ a/kernel/compat.c
@@ -24,6 +24,7 @@
#include <linux/migrate.h>
#include <linux/posix-timers.h>
#include <linux/times.h>
+#include <linux/ptrace.h>
#include <asm/uaccess.h>
@@ -229,6 +230,7 @@ asmlinkage long compat_sys_times(struct
if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
return -EFAULT;
}
+ force_successful_syscall_return();
return compat_jiffies_to_clock_t(jiffies);
}
@@ -883,8 +885,9 @@ asmlinkage long compat_sys_time(compat_t
if (tloc) {
if (put_user(i,tloc))
- i = -EFAULT;
+ return -EFAULT;
}
+ force_successful_syscall_return();
return i;
}
diff -puN kernel/sys.c~allow-times-and-time-system-calls-to-return-small-negative-values kernel/sys.c
--- a/kernel/sys.c~allow-times-and-time-system-calls-to-return-small-negative-values
+++ a/kernel/sys.c
@@ -33,6 +33,7 @@
#include <linux/task_io_accounting_ops.h>
#include <linux/seccomp.h>
#include <linux/cpu.h>
+#include <linux/ptrace.h>
#include <linux/compat.h>
#include <linux/syscalls.h>
@@ -927,6 +928,7 @@ asmlinkage long sys_times(struct tms __u
if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
return -EFAULT;
}
+ force_successful_syscall_return();
return (long) jiffies_64_to_clock_t(get_jiffies_64());
}
diff -puN kernel/time.c~allow-times-and-time-system-calls-to-return-small-negative-values kernel/time.c
--- a/kernel/time.c~allow-times-and-time-system-calls-to-return-small-negative-values
+++ a/kernel/time.c
@@ -37,6 +37,7 @@
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/math64.h>
+#include <linux/ptrace.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
@@ -65,8 +66,9 @@ asmlinkage long sys_time(time_t __user *
if (tloc) {
if (put_user(i,tloc))
- i = -EFAULT;
+ return -EFAULT;
}
+ force_successful_syscall_return();
return i;
}
_
Patches currently in -mm which might be from paulus@xxxxxxxxx are
origin.patch
linux-next.patch
net-ppp_asynctty_ioctl-remove-dead-code.patch
allow-times-and-time-system-calls-to-return-small-negative-values.patch
kprobes-add-kprobe_insn_mutex-and-cleanup-arch_remove_kprobe.patch
unaligned-wire-up-trivial-arches-for-new-common-unaligned-header.patch
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