| Message ID | 1346360743-3628-9-git-send-email-paulmck@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Aug 30, 2012 at 02:05:26PM -0700, Paul E. McKenney wrote: > From: Frederic Weisbecker <fweisbec@gmail.com> > > Add necessary hooks to x86 exception for userspace > RCU extended quiescent state support. > > This includes traps, page fault, debug exceptions, etc... > > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> > Cc: Alessio Igor Bogani <abogani@kernel.org> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Avi Kivity <avi@redhat.com> > Cc: Chris Metcalf <cmetcalf@tilera.com> > Cc: Christoph Lameter <cl@linux.com> > Cc: Geoff Levand <geoff@infradead.org> > Cc: Gilad Ben Yossef <gilad@benyossef.com> > Cc: Hakan Akkan <hakanakkan@gmail.com> > Cc: H. Peter Anvin <hpa@zytor.com> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Josh Triplett <josh@joshtriplett.org> > Cc: Kevin Hilman <khilman@ti.com> > Cc: Max Krasnyansky <maxk@qualcomm.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Stephen Hemminger <shemminger@vyatta.com> > Cc: Steven Rostedt <rostedt@goodmis.org> > Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> > arch/x86/include/asm/rcu.h | 20 ++++++++++++++++++++ > arch/x86/kernel/traps.c | 30 ++++++++++++++++++++++-------- > arch/x86/mm/fault.c | 13 +++++++++++-- > 3 files changed, 53 insertions(+), 10 deletions(-) > create mode 100644 arch/x86/include/asm/rcu.h > > diff --git a/arch/x86/include/asm/rcu.h b/arch/x86/include/asm/rcu.h > new file mode 100644 > index 0000000..439815b > --- /dev/null > +++ b/arch/x86/include/asm/rcu.h > @@ -0,0 +1,20 @@ > +#ifndef _ASM_X86_RCU_H > +#define _ASM_X86_RCU_H > + > +#include <linux/rcupdate.h> > +#include <asm/ptrace.h> > + > +static inline void exception_enter(struct pt_regs *regs) > +{ > + rcu_user_exit(); > +} > + > +static inline void exception_exit(struct pt_regs *regs) > +{ > +#ifdef CONFIG_RCU_USER_QS > + if (user_mode(regs)) > + rcu_user_enter(); > +#endif > +} > + > +#endif > diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c > index b481341..ab82cbd 100644 > --- a/arch/x86/kernel/traps.c > +++ b/arch/x86/kernel/traps.c > @@ -55,6 +55,7 @@ > #include <asm/i387.h> > #include <asm/fpu-internal.h> > #include <asm/mce.h> > +#include <asm/rcu.h> > > #include <asm/mach_traps.h> > > @@ -180,11 +181,15 @@ vm86_trap: > #define DO_ERROR(trapnr, signr, str, name) \ > dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ > { \ > - if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ > - == NOTIFY_STOP) \ > + exception_enter(regs); \ > + if (notify_die(DIE_TRAP, str, regs, error_code, \ > + trapnr, signr) == NOTIFY_STOP) { \ > + exception_exit(regs); \ > return; \ > + } \ > conditional_sti(regs); \ > do_trap(trapnr, signr, str, regs, error_code, NULL); \ > + exception_exit(regs); \ > } > > #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ > @@ -195,11 +200,15 @@ dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ > info.si_errno = 0; \ > info.si_code = sicode; \ > info.si_addr = (void __user *)siaddr; \ > - if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ > - == NOTIFY_STOP) \ > + exception_enter(regs); \ > + if (notify_die(DIE_TRAP, str, regs, error_code, \ > + trapnr, signr) == NOTIFY_STOP) { \ > + exception_exit(regs); \ > return; \ > + } \ > conditional_sti(regs); \ > do_trap(trapnr, signr, str, regs, error_code, &info); \ > + exception_exit(regs); \ > } > > DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV, > @@ -312,6 +321,7 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co > ftrace_int3_handler(regs)) > return; > #endif > + exception_enter(regs); > #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP > if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, > SIGTRAP) == NOTIFY_STOP) > @@ -331,6 +341,7 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co > do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL); > preempt_conditional_cli(regs); > debug_stack_usage_dec(); > + exception_exit(regs); > } > > #ifdef CONFIG_X86_64 > @@ -391,6 +402,8 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) > unsigned long dr6; > int si_code; > > + exception_enter(regs); > + > get_debugreg(dr6, 6); > > /* Filter out all the reserved bits which are preset to 1 */ > @@ -406,7 +419,7 @@ 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); > @@ -421,7 +434,7 @@ 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; > > /* > * Let others (NMI) know that the debug stack is in use > @@ -437,7 +450,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) > X86_TRAP_DB); > preempt_conditional_cli(regs); > debug_stack_usage_dec(); > - return; > + goto exit; > } > > /* > @@ -458,7 +471,8 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) > preempt_conditional_cli(regs); > debug_stack_usage_dec(); > > - return; > +exit: > + exception_exit(regs); > } > > /* > diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c > index 76dcd9d..7dde46d 100644 > --- a/arch/x86/mm/fault.c > +++ b/arch/x86/mm/fault.c > @@ -18,6 +18,7 @@ > #include <asm/pgalloc.h> /* pgd_*(), ... */ > #include <asm/kmemcheck.h> /* kmemcheck_*(), ... */ > #include <asm/fixmap.h> /* VSYSCALL_START */ > +#include <asm/rcu.h> /* exception_enter(), ... */ > > /* > * Page fault error code bits: > @@ -1000,8 +1001,8 @@ 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; > @@ -1209,3 +1210,11 @@ good_area: > > up_read(&mm->mmap_sem); > } > + > +dotraplinkage void __kprobes > +do_page_fault(struct pt_regs *regs, unsigned long error_code) > +{ > + exception_enter(regs); > + __do_page_fault(regs, error_code); > + exception_exit(regs); > +} > -- > 1.7.8 >
diff --git a/arch/x86/include/asm/rcu.h b/arch/x86/include/asm/rcu.h new file mode 100644 index 0000000..439815b --- /dev/null +++ b/arch/x86/include/asm/rcu.h @@ -0,0 +1,20 @@ +#ifndef _ASM_X86_RCU_H +#define _ASM_X86_RCU_H + +#include <linux/rcupdate.h> +#include <asm/ptrace.h> + +static inline void exception_enter(struct pt_regs *regs) +{ + rcu_user_exit(); +} + +static inline void exception_exit(struct pt_regs *regs) +{ +#ifdef CONFIG_RCU_USER_QS + if (user_mode(regs)) + rcu_user_enter(); +#endif +} + +#endif diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index b481341..ab82cbd 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -55,6 +55,7 @@ #include <asm/i387.h> #include <asm/fpu-internal.h> #include <asm/mce.h> +#include <asm/rcu.h> #include <asm/mach_traps.h> @@ -180,11 +181,15 @@ vm86_trap: #define DO_ERROR(trapnr, signr, str, name) \ dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ { \ - if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ - == NOTIFY_STOP) \ + exception_enter(regs); \ + if (notify_die(DIE_TRAP, str, regs, error_code, \ + trapnr, signr) == NOTIFY_STOP) { \ + exception_exit(regs); \ return; \ + } \ conditional_sti(regs); \ do_trap(trapnr, signr, str, regs, error_code, NULL); \ + exception_exit(regs); \ } #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ @@ -195,11 +200,15 @@ dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ info.si_errno = 0; \ info.si_code = sicode; \ info.si_addr = (void __user *)siaddr; \ - if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ - == NOTIFY_STOP) \ + exception_enter(regs); \ + if (notify_die(DIE_TRAP, str, regs, error_code, \ + trapnr, signr) == NOTIFY_STOP) { \ + exception_exit(regs); \ return; \ + } \ conditional_sti(regs); \ do_trap(trapnr, signr, str, regs, error_code, &info); \ + exception_exit(regs); \ } DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV, @@ -312,6 +321,7 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co ftrace_int3_handler(regs)) return; #endif + exception_enter(regs); #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, SIGTRAP) == NOTIFY_STOP) @@ -331,6 +341,7 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL); preempt_conditional_cli(regs); debug_stack_usage_dec(); + exception_exit(regs); } #ifdef CONFIG_X86_64 @@ -391,6 +402,8 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) unsigned long dr6; int si_code; + exception_enter(regs); + get_debugreg(dr6, 6); /* Filter out all the reserved bits which are preset to 1 */ @@ -406,7 +419,7 @@ 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); @@ -421,7 +434,7 @@ 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; /* * Let others (NMI) know that the debug stack is in use @@ -437,7 +450,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) X86_TRAP_DB); preempt_conditional_cli(regs); debug_stack_usage_dec(); - return; + goto exit; } /* @@ -458,7 +471,8 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) preempt_conditional_cli(regs); debug_stack_usage_dec(); - return; +exit: + exception_exit(regs); } /* diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 76dcd9d..7dde46d 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -18,6 +18,7 @@ #include <asm/pgalloc.h> /* pgd_*(), ... */ #include <asm/kmemcheck.h> /* kmemcheck_*(), ... */ #include <asm/fixmap.h> /* VSYSCALL_START */ +#include <asm/rcu.h> /* exception_enter(), ... */ /* * Page fault error code bits: @@ -1000,8 +1001,8 @@ 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; @@ -1209,3 +1210,11 @@ good_area: up_read(&mm->mmap_sem); } + +dotraplinkage void __kprobes +do_page_fault(struct pt_regs *regs, unsigned long error_code) +{ + exception_enter(regs); + __do_page_fault(regs, error_code); + exception_exit(regs); +}