lkml.org 
[lkml]   [2019]   [Jun]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v5 2/4] x86/entry: Simplify _TIF_SYSCALL_EMU handling
Date
The usage of emulated and _TIF_SYSCALL_EMU flags in syscall_trace_enter
is more complicated than required.

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
arch/x86/entry/common.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)

Hi Catalin,

I assume you can now pick up this patch.

Regards,
Sudeep

v4->v5: Updated changelog as suggested by tglx and added his Reviewed-by

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index a986b3c8294c..0a61705d62ec 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -72,23 +72,18 @@ static long syscall_trace_enter(struct pt_regs *regs)

struct thread_info *ti = current_thread_info();
unsigned long ret = 0;
- bool emulated = false;
u32 work;

if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
BUG_ON(regs != task_pt_regs(current));

- work = READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY;
+ work = READ_ONCE(ti->flags);

- if (unlikely(work & _TIF_SYSCALL_EMU))
- emulated = true;
-
- if ((emulated || (work & _TIF_SYSCALL_TRACE)) &&
- tracehook_report_syscall_entry(regs))
- return -1L;
-
- if (emulated)
- return -1L;
+ if (work & (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU)) {
+ ret = tracehook_report_syscall_entry(regs);
+ if (ret || (work & _TIF_SYSCALL_EMU))
+ return -1L;
+ }

#ifdef CONFIG_SECCOMP
/*
--
2.17.1
\
 
 \ /
  Last update: 2019-06-11 16:57    [W:0.103 / U:0.808 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site