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Subject[PATCH 2/3] x86: make 64 bit ret_from_fork a little more similar to 32 bit
Date
The 64 bit version resets EFLAGS before calling schedule_tail() and
therefore leaves EFLAGS.IF clear. 32 bit resets EFLAGS after calling
schedule_tail() and therefore leaves EFLAGS.IF set. I don't think
there is any practical difference between the two approaches since
interrupts are actually reenabled within schedule_tail
(schedule_tail->finish_task_switch->finish_lock_switch->raw_spin_unlock_irq->...->local_irq_enable)
so arbitrarily pick the 32 bit version and make 64 bit look like that.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: x86@kernel.org
---
arch/x86/kernel/entry_64.S | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 18e4c59..b771c2f 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -398,13 +398,13 @@ ENTRY(ret_from_fork)

LOCK ; btr $TIF_FORK,TI_flags(%r8)

- push $0x0002
+ call schedule_tail # rdi: 'prev' task parameter
+
+ push $0x0202
CFI_ADJUST_CFA_OFFSET 8
popf # reset kernel eflags
CFI_ADJUST_CFA_OFFSET -8

- call schedule_tail # rdi: 'prev' task parameter
-
GET_THREAD_INFO(%rcx)

RESTORE_REST
--
1.5.6.5


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