| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1292858662-5650-12-git-send-email-fweisbec@gmail.com>
Date: Mon, 20 Dec 2010 16:24:18 +0100
From: Frederic Weisbecker <fweisbec@...il.com>
To: LKML <linux-kernel@...r.kernel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
Frederic Weisbecker <fweisbec@...il.com>,
Thomas Gleixner <tglx@...utronix.de>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
Ingo Molnar <mingo@...e.hu>,
Steven Rostedt <rostedt@...dmis.org>,
Lai Jiangshan <laijs@...fujitsu.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Anton Blanchard <anton@....ibm.com>,
Tim Pepper <lnxninja@...ux.vnet.ibm.com>
Subject: [RFC PATCH 11/15] x86: Nohz task support
Implement the thread flag, syscalls and exception hooks for
nohz task support.
Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@...e.hu>
Cc: Steven Rostedt <rostedt@...dmis.org>
Cc: Lai Jiangshan <laijs@...fujitsu.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Anton Blanchard <anton@....ibm.com>
Cc: Tim Pepper <lnxninja@...ux.vnet.ibm.com>
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/thread_info.h | 10 +++++++---
arch/x86/kernel/ptrace.c | 10 ++++++++++
arch/x86/kernel/traps.c | 22 +++++++++++++++-------
arch/x86/mm/fault.c | 13 +++++++++++--
5 files changed, 44 insertions(+), 12 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e330da2..37f59f2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -65,6 +65,7 @@ config X86
select HAVE_SPARSE_IRQ
select GENERIC_IRQ_PROBE
select GENERIC_PENDING_IRQ if SMP
+ select HAVE_NO_HZ_TASK
config INSTRUCTION_DECODER
def_bool (KPROBES || PERF_EVENTS)
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index f0b6e5d..eb6784c 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -87,6 +87,7 @@ struct thread_info {
#define TIF_NOTSC 16 /* TSC is not accessible in userland */
#define TIF_IA32 17 /* 32bit process */
#define TIF_FORK 18 /* ret_from_fork */
+#define TIF_NOHZ 19 /* in nohz userspace mode */
#define TIF_MEMDIE 20 /* is terminating due to OOM killer */
#define TIF_DEBUG 21 /* uses debug registers */
#define TIF_IO_BITMAP 22 /* uses I/O bitmap */
@@ -110,6 +111,7 @@ struct thread_info {
#define _TIF_NOTSC (1 << TIF_NOTSC)
#define _TIF_IA32 (1 << TIF_IA32)
#define _TIF_FORK (1 << TIF_FORK)
+#define _TIF_NOHZ (1 << TIF_NOHZ)
#define _TIF_DEBUG (1 << TIF_DEBUG)
#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
#define _TIF_FREEZE (1 << TIF_FREEZE)
@@ -121,12 +123,13 @@ struct thread_info {
/* work to do in syscall_trace_enter() */
#define _TIF_WORK_SYSCALL_ENTRY \
(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
- _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT)
+ _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT | \
+ _TIF_NOHZ)
/* work to do in syscall_trace_leave() */
#define _TIF_WORK_SYSCALL_EXIT \
(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \
- _TIF_SYSCALL_TRACEPOINT)
+ _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK \
@@ -136,7 +139,8 @@ struct thread_info {
/* work to do on any return to user space */
#define _TIF_ALLWORK_MASK \
- ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT)
+ ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT | \
+ _TIF_NOHZ)
/* Only used for 64 bit */
#define _TIF_DO_NOTIFY_MASK \
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 45892dc..b8b1c38 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -21,6 +21,7 @@
#include <linux/signal.h>
#include <linux/perf_event.h>
#include <linux/hw_breakpoint.h>
+#include <linux/tick.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
@@ -1351,6 +1352,9 @@ asmregparm long syscall_trace_enter(struct pt_regs *regs)
{
long ret = 0;
+ /* Notify nohz task syscall early so the rest can use rcu */
+ tick_nohz_task_enter_kernel();
+
/*
* If we stepped into a sysenter/syscall insn, it trapped in
* kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
@@ -1412,4 +1416,10 @@ asmregparm void syscall_trace_leave(struct pt_regs *regs)
!test_thread_flag(TIF_SYSCALL_EMU);
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, step);
+
+ /*
+ * Notify nohz task exit syscall at last so the rest can
+ * use rcu.
+ */
+ tick_nohz_task_exit_kernel();
}
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index cb838ca..b531c52 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -26,6 +26,7 @@
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/init.h>
+#include <linux/tick.h>
#include <linux/bug.h>
#include <linux/nmi.h>
#include <linux/mm.h>
@@ -459,24 +460,28 @@ void restart_nmi(void)
/* May run on IST stack. */
dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
{
+ tick_nohz_task_enter_exception(regs);
+
#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
== NOTIFY_STOP)
- return;
+ goto exit;
#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
#ifdef CONFIG_KPROBES
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
== NOTIFY_STOP)
- return;
+ goto exit;
#else
if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP)
== NOTIFY_STOP)
- return;
+ goto exit;
#endif
preempt_conditional_sti(regs);
do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
preempt_conditional_cli(regs);
+exit:
+ tick_nohz_task_exit_exception(regs);
}
#ifdef CONFIG_X86_64
@@ -537,6 +542,8 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
unsigned long dr6;
int si_code;
+ tick_nohz_task_enter_exception(regs);
+
get_debugreg(dr6, 6);
/* Filter out all the reserved bits which are preset to 1 */
@@ -552,7 +559,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
/* Catch kmemcheck conditions first of all! */
if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
- return;
+ goto exit;
/* DR6 may or may not be cleared by the CPU */
set_debugreg(0, 6);
@@ -567,7 +574,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code,
SIGTRAP) == NOTIFY_STOP)
- return;
+ goto exit;
/* It's safe to allow irq's after DR6 has been saved */
preempt_conditional_sti(regs);
@@ -576,7 +583,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
handle_vm86_trap((struct kernel_vm86_regs *) regs,
error_code, 1);
preempt_conditional_cli(regs);
- return;
+ goto exit;
}
/*
@@ -596,7 +603,8 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
send_sigtrap(tsk, regs, error_code, si_code);
preempt_conditional_cli(regs);
- return;
+exit:
+ tick_nohz_task_exit_exception(regs);
}
/*
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 7d90ceb..2b23b22 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -12,6 +12,7 @@
#include <linux/mmiotrace.h> /* kmmio_handler, ... */
#include <linux/perf_event.h> /* perf_sw_event */
#include <linux/hugetlb.h> /* hstate_index_to_shift */
+#include <linux/tick.h>
#include <asm/traps.h> /* dotraplinkage, ... */
#include <asm/pgalloc.h> /* pgd_*(), ... */
@@ -949,8 +950,8 @@ static int fault_in_kernel_space(unsigned long address)
* and the problem, and then passes it off to one of the appropriate
* routines.
*/
-dotraplinkage void __kprobes
-do_page_fault(struct pt_regs *regs, unsigned long error_code)
+static void __kprobes
+__do_page_fault(struct pt_regs *regs, unsigned long error_code)
{
struct vm_area_struct *vma;
struct task_struct *tsk;
@@ -1158,3 +1159,11 @@ good_area:
up_read(&mm->mmap_sem);
}
+
+dotraplinkage void __kprobes
+do_page_fault(struct pt_regs *regs, unsigned long error_code)
+{
+ tick_nohz_task_enter_exception(regs);
+ __do_page_fault(regs, error_code);
+ tick_nohz_task_exit_exception(regs);
+}
--
1.7.3.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists