The patch titled
uml: arch_prctl should set thread fs
has been added to the -mm tree. Its filename is
uml-arch_prctl-should-set-thread-fs.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: uml: arch_prctl should set thread fs
From: Jeff Dike <jdike@xxxxxxxxxxx>
In my previous x86_64 thread fix, I forgot to initialize thread.arch.fs in
arch_prctl. A process calling arch_prctl to set %fs would lose it on the
next context switch.
It also turns out that you can switch to a process which is in the process
of exiting and which has lost its mm. In this case, it's worse than
useless to try to call arch_prctl on the host process.
Signed-off-by: Jeff Dike <jdike@xxxxxxxxxxxxxxx>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/um/sys-x86_64/syscalls.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff -puN arch/um/sys-x86_64/syscalls.c~uml-arch_prctl-should-set-thread-fs arch/um/sys-x86_64/syscalls.c
--- a/arch/um/sys-x86_64/syscalls.c~uml-arch_prctl-should-set-thread-fs
+++ a/arch/um/sys-x86_64/syscalls.c
@@ -103,6 +103,9 @@ long arch_prctl_skas(struct task_struct
switch(code){
case ARCH_SET_FS:
+ current->thread.arch.fs = (unsigned long) ptr;
+ save_registers(pid, ¤t->thread.regs.regs);
+ break;
case ARCH_SET_GS:
save_registers(pid, ¤t->thread.regs.regs);
break;
@@ -140,9 +143,8 @@ long sys_clone(unsigned long clone_flags
void arch_switch_to_skas(struct task_struct *from, struct task_struct *to)
{
- if(to->thread.arch.fs == 0)
+ if((to->thread.arch.fs == 0) || (to->mm == NULL))
return;
arch_prctl_skas(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
}
-
_
Patches currently in -mm which might be from jdike@xxxxxxxxxxx are
uml-hostfs-fix-double-free.patch
uml-hostfs-make-hostfs=-option-work-as-a-jail-as-intended.patch
uml-fix-a-memory-leak-in-the-multicast-driver.patch
uml-remove-dead-code-about-os_usr1_signal-and-os_usr1_process.patch
uml-mark-both-consoles-as-con_anytime.patch
uml-fix-confusion-irq-early-reenabling.patch
uml-activate_fd-return-enomem-only-when-appropriate.patch
uml-fix-errno-usage.patch
uml-arch_prctl-should-set-thread-fs.patch
div64_64-common-code.patch
remove-hardcoding-of-hard_smp_processor_id-on-up.patch
uml-delete-unused-code.patch
uml-formatting-fixes.patch
uml-host_info-tidying.patch
uml-mark-tt-mode-code-for-future-removal.patch
uml-print-coredump-limits.patch
uml-handle-block-device-hotplug-errors.patch
uml-driver-formatting-fixes.patch
uml-driver-formatting-fixes-fix.patch
uml-network-interface-hotplug-error-handling.patch
uml-fix-prototypes.patch
-
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