powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers
This is a rewrite so that we don't assume we are using the DABR throughout the
code. We now use the arch_hw_breakpoint to store the breakpoint in a generic
manner in the thread_struct, rather than storing the raw DABR value.
The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from
userspace. We keep this functionality, so that future changes (like the POWER8
DAWR), will still fake the DABR to userspace.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 3065d17..c16c1c2 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -271,7 +271,7 @@
force_sig_info(SIGTRAP, &info, current);
}
#else /* !CONFIG_PPC_ADV_DEBUG_REGS */
-void do_dabr(struct pt_regs *regs, unsigned long address,
+void do_break (struct pt_regs *regs, unsigned long address,
unsigned long error_code)
{
siginfo_t info;
@@ -281,11 +281,11 @@
11, SIGSEGV) == NOTIFY_STOP)
return;
- if (debugger_dabr_match(regs))
+ if (debugger_break_match(regs))
return;
- /* Clear the DABR */
- set_dabr(0, 0);
+ /* Clear the breakpoint */
+ hw_breakpoint_disable();
/* Deliver the signal to userspace */
info.si_signo = SIGTRAP;
@@ -296,7 +296,7 @@
}
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
-static DEFINE_PER_CPU(unsigned long, current_dabr);
+static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
/*
@@ -364,39 +364,72 @@
#ifndef CONFIG_HAVE_HW_BREAKPOINT
static void set_debug_reg_defaults(struct thread_struct *thread)
{
- if (thread->dabr) {
- thread->dabr = 0;
- thread->dabrx = 0;
- set_dabr(0, 0);
- }
+ thread->hw_brk.address = 0;
+ thread->hw_brk.type = 0;
+ set_break(&thread->hw_brk);
}
#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
-int set_dabr(unsigned long dabr, unsigned long dabrx)
-{
- __get_cpu_var(current_dabr) = dabr;
-
- if (ppc_md.set_dabr)
- return ppc_md.set_dabr(dabr, dabrx);
-
- /* XXX should we have a CPU_FTR_HAS_DABR ? */
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
+{
mtspr(SPRN_DAC1, dabr);
#ifdef CONFIG_PPC_47x
isync();
#endif
+ return 0;
+}
#elif defined(CONFIG_PPC_BOOK3S)
+static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
+{
mtspr(SPRN_DABR, dabr);
mtspr(SPRN_DABRX, dabrx);
-#endif
return 0;
}
+#else
+static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
+{
+ return -EINVAL;
+}
+#endif
+
+static inline int set_dabr(struct arch_hw_breakpoint *brk)
+{
+ unsigned long dabr, dabrx;
+
+ dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
+ dabrx = ((brk->type >> 3) & 0x7);
+
+ if (ppc_md.set_dabr)
+ return ppc_md.set_dabr(dabr, dabrx);
+
+ return __set_dabr(dabr, dabrx);
+}
+
+int set_break(struct arch_hw_breakpoint *brk)
+{
+ __get_cpu_var(current_brk) = *brk;
+
+ return set_dabr(brk);
+}
#ifdef CONFIG_PPC64
DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
#endif
+static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
+ struct arch_hw_breakpoint *b)
+{
+ if (a->address != b->address)
+ return false;
+ if (a->type != b->type)
+ return false;
+ if (a->len != b->len)
+ return false;
+ return true;
+}
+
struct task_struct *__switch_to(struct task_struct *prev,
struct task_struct *new)
{
@@ -481,8 +514,8 @@
* schedule DABR
*/
#ifndef CONFIG_HAVE_HW_BREAKPOINT
- if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
- set_dabr(new->thread.dabr, new->thread.dabrx);
+ if (unlikely(hw_brk_match(&__get_cpu_var(current_brk), &new->thread.hw_brk)))
+ set_break(&new->thread.hw_brk);
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif