summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/entry_64.S
diff options
context:
space:
mode:
authorDavid S. Miller <davem@davemloft.net>2015-04-02 16:16:53 -0400
committerDavid S. Miller <davem@davemloft.net>2015-04-02 16:16:53 -0400
commit9f0d34bc344889c2e6c593bd949d7ab821f0f4a5 (patch)
treee5bfc776a09315afa4dbcae97ac04f2cca239c96 /arch/x86/kernel/entry_64.S
parente4a924f5768c55002c02ceba9b9f86824c35f956 (diff)
parent0a4812798fae4f6bfcaab51e31b3898ff5ea3108 (diff)
downloadop-kernel-dev-9f0d34bc344889c2e6c593bd949d7ab821f0f4a5.zip
op-kernel-dev-9f0d34bc344889c2e6c593bd949d7ab821f0f4a5.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: drivers/net/usb/asix_common.c drivers/net/usb/sr9800.c drivers/net/usb/usbnet.c include/linux/usb/usbnet.h net/ipv4/tcp_ipv4.c net/ipv6/tcp_ipv6.c The TCP conflicts were overlapping changes. In 'net' we added a READ_ONCE() to the socket cached RX route read, whilst in 'net-next' Eric Dumazet touched the surrounding code dealing with how mini sockets are handled. With USB, it's a case of the same bug fix first going into net-next and then I cherry picked it back into net. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
-rw-r--r--arch/x86/kernel/entry_64.S18
1 files changed, 14 insertions, 4 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 1d74d16..2babb39 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -364,12 +364,21 @@ system_call_fastpath:
* Has incomplete stack frame and undefined top of stack.
*/
ret_from_sys_call:
- testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
- jnz int_ret_from_sys_call_fixup /* Go the the slow path */
-
LOCKDEP_SYS_EXIT
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
+
+ /*
+ * We must check ti flags with interrupts (or at least preemption)
+ * off because we must *never* return to userspace without
+ * processing exit work that is enqueued if we're preempted here.
+ * In particular, returning to userspace with any of the one-shot
+ * flags (TIF_NOTIFY_RESUME, TIF_USER_RETURN_NOTIFY, etc) set is
+ * very bad.
+ */
+ testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
+ jnz int_ret_from_sys_call_fixup /* Go the the slow path */
+
CFI_REMEMBER_STATE
/*
* sysretq will re-enable interrupts:
@@ -386,7 +395,7 @@ ret_from_sys_call:
int_ret_from_sys_call_fixup:
FIXUP_TOP_OF_STACK %r11, -ARGOFFSET
- jmp int_ret_from_sys_call
+ jmp int_ret_from_sys_call_irqs_off
/* Do syscall tracing */
tracesys:
@@ -432,6 +441,7 @@ tracesys_phase2:
GLOBAL(int_ret_from_sys_call)
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
+int_ret_from_sys_call_irqs_off:
movl $_TIF_ALLWORK_MASK,%edi
/* edi: mask to check */
GLOBAL(int_with_check)
OpenPOWER on IntegriCloud