Message ID | 20090525011650.GE11078@in.ibm.com (mailing list archive) |
---|---|
State | Superseded, archived |
Delegated to: | David Gibson |
Headers | show |
On Mon, May 25, 2009 at 06:46:50AM +0530, K.Prasad wrote: > Modify process handling code to recognise hardware debug registers during copy > and flush operations. Introduce a new TIF_DEBUG task flag to indicate a > process's use of debug register. Load the debug register values into a > new CPU during initialisation. [snip] > Index: linux-2.6-tip.hbkpt/arch/powerpc/kernel/process.c > =================================================================== > --- linux-2.6-tip.hbkpt.orig/arch/powerpc/kernel/process.c > +++ linux-2.6-tip.hbkpt/arch/powerpc/kernel/process.c > @@ -50,6 +50,7 @@ > #include <asm/syscalls.h> > #ifdef CONFIG_PPC64 > #include <asm/firmware.h> > +#include <asm/hw_breakpoint.h> > #endif > #include <linux/kprobes.h> > #include <linux/kdebug.h> > @@ -254,8 +255,10 @@ void do_dabr(struct pt_regs *regs, unsig > 11, SIGSEGV) == NOTIFY_STOP) > return; > > +#ifndef CONFIG_PPC64 > if (debugger_dabr_match(regs)) > return; > +#endif > > /* Clear the DAC and struct entries. One shot trigger */ > #if defined(CONFIG_BOOKE) > @@ -372,8 +375,13 @@ struct task_struct *__switch_to(struct t > > #endif /* CONFIG_SMP */ > > +#ifdef CONFIG_PPC64 > + if (unlikely(test_tsk_thread_flag(new, TIF_DEBUG))) > + arch_install_thread_hw_breakpoint(new); > +#else > if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) > set_dabr(new->thread.dabr); > +#endif /* CONFIG_PPC64 */ > > #if defined(CONFIG_BOOKE) > /* If new thread DAC (HW breakpoint) is the same then leave it */ > @@ -550,6 +558,10 @@ void show_regs(struct pt_regs * regs) > void exit_thread(void) > { > discard_lazy_cpu_state(); > +#ifdef CONFIG_PPC64 > + if (unlikely(test_tsk_thread_flag(current, TIF_DEBUG))) > + flush_thread_hw_breakpoint(current); > +#endif /* CONFIG_PPC64 */ > } > > void flush_thread(void) > @@ -605,6 +617,9 @@ int copy_thread(unsigned long clone_flag > struct pt_regs *childregs, *kregs; > extern void ret_from_fork(void); > unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; > +#ifdef CONFIG_PPC64 > + struct task_struct *tsk = current; I don't see any point to adding this variable, just reference current directly below. > +#endif > > CHECK_FULL_REGS(regs); > /* Copy registers */ > @@ -672,6 +687,9 @@ int copy_thread(unsigned long clone_flag > * function. > */ > kregs->nip = *((unsigned long *)ret_from_fork); > + > + if (unlikely(test_tsk_thread_flag(tsk, TIF_DEBUG))) > + copy_thread_hw_breakpoint(tsk, p, clone_flags); > #else > kregs->nip = (unsigned long)ret_from_fork; > #endif
Index: linux-2.6-tip.hbkpt/arch/powerpc/include/asm/thread_info.h =================================================================== --- linux-2.6-tip.hbkpt.orig/arch/powerpc/include/asm/thread_info.h +++ linux-2.6-tip.hbkpt/arch/powerpc/include/asm/thread_info.h @@ -114,6 +114,7 @@ static inline struct thread_info *curren #define TIF_FREEZE 14 /* Freezing for suspend */ #define TIF_RUNLATCH 15 /* Is the runlatch enabled? */ #define TIF_ABI_PENDING 16 /* 32/64 bit switch needed */ +#define TIF_DEBUG 17 /* uses debug registers */ /* as above, but as bit values */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) @@ -132,6 +133,7 @@ static inline struct thread_info *curren #define _TIF_FREEZE (1<<TIF_FREEZE) #define _TIF_RUNLATCH (1<<TIF_RUNLATCH) #define _TIF_ABI_PENDING (1<<TIF_ABI_PENDING) +#define _TIF_DEBUG (1<<TIF_DEBUG) #define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP) #define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \ Index: linux-2.6-tip.hbkpt/arch/powerpc/kernel/process.c =================================================================== --- linux-2.6-tip.hbkpt.orig/arch/powerpc/kernel/process.c +++ linux-2.6-tip.hbkpt/arch/powerpc/kernel/process.c @@ -50,6 +50,7 @@ #include <asm/syscalls.h> #ifdef CONFIG_PPC64 #include <asm/firmware.h> +#include <asm/hw_breakpoint.h> #endif #include <linux/kprobes.h> #include <linux/kdebug.h> @@ -254,8 +255,10 @@ void do_dabr(struct pt_regs *regs, unsig 11, SIGSEGV) == NOTIFY_STOP) return; +#ifndef CONFIG_PPC64 if (debugger_dabr_match(regs)) return; +#endif /* Clear the DAC and struct entries. One shot trigger */ #if defined(CONFIG_BOOKE) @@ -372,8 +375,13 @@ struct task_struct *__switch_to(struct t #endif /* CONFIG_SMP */ +#ifdef CONFIG_PPC64 + if (unlikely(test_tsk_thread_flag(new, TIF_DEBUG))) + arch_install_thread_hw_breakpoint(new); +#else if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) set_dabr(new->thread.dabr); +#endif /* CONFIG_PPC64 */ #if defined(CONFIG_BOOKE) /* If new thread DAC (HW breakpoint) is the same then leave it */ @@ -550,6 +558,10 @@ void show_regs(struct pt_regs * regs) void exit_thread(void) { discard_lazy_cpu_state(); +#ifdef CONFIG_PPC64 + if (unlikely(test_tsk_thread_flag(current, TIF_DEBUG))) + flush_thread_hw_breakpoint(current); +#endif /* CONFIG_PPC64 */ } void flush_thread(void) @@ -605,6 +617,9 @@ int copy_thread(unsigned long clone_flag struct pt_regs *childregs, *kregs; extern void ret_from_fork(void); unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; +#ifdef CONFIG_PPC64 + struct task_struct *tsk = current; +#endif CHECK_FULL_REGS(regs); /* Copy registers */ @@ -672,6 +687,9 @@ int copy_thread(unsigned long clone_flag * function. */ kregs->nip = *((unsigned long *)ret_from_fork); + + if (unlikely(test_tsk_thread_flag(tsk, TIF_DEBUG))) + copy_thread_hw_breakpoint(tsk, p, clone_flags); #else kregs->nip = (unsigned long)ret_from_fork; #endif Index: linux-2.6-tip.hbkpt/arch/powerpc/kernel/smp.c =================================================================== --- linux-2.6-tip.hbkpt.orig/arch/powerpc/kernel/smp.c +++ linux-2.6-tip.hbkpt/arch/powerpc/kernel/smp.c @@ -48,6 +48,7 @@ #include <asm/vdso_datapage.h> #ifdef CONFIG_PPC64 #include <asm/paca.h> +#include <asm/hw_breakpoint.h> #endif #ifdef DEBUG @@ -536,6 +537,7 @@ int __devinit start_secondary(void *unus local_irq_enable(); + load_debug_registers(); cpu_idle(); return 0; }
Modify process handling code to recognise hardware debug registers during copy and flush operations. Introduce a new TIF_DEBUG task flag to indicate a process's use of debug register. Load the debug register values into a new CPU during initialisation. Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> --- arch/powerpc/include/asm/thread_info.h | 2 ++ arch/powerpc/kernel/process.c | 18 ++++++++++++++++++ arch/powerpc/kernel/smp.c | 2 ++ 3 files changed, 22 insertions(+)