[PATCH 2/3] powerpc: Dynamically calculate the dabrx based on kernel/user/hypervisor
From: Michael Neuling <hidden>
Date: 2012-09-07 07:24:57
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Currently we mark the DABRX to interrupt on all matches (hypervisor/kernel/user and then filter in software. We can be a lot smarter now that we can set the DABRX dynamically. This sets the DABRX based on the flags passed by the user. Signed-off-by: Michael Neuling <redacted> --- arch/powerpc/include/asm/hw_breakpoint.h | 1 + arch/powerpc/kernel/hw_breakpoint.c | 15 +++++++++++---- arch/powerpc/platforms/pseries/setup.c | 2 +- 3 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index c6f48eb..4234245 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h@@ -28,6 +28,7 @@ struct arch_hw_breakpoint { unsigned long address; + unsigned long dabrx; int type; u8 len; /* length of the target data symbol */ bool extraneous_interrupt;
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 6891d79..a89cae4 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c@@ -73,7 +73,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp) * If so, DABR will be populated in single_step_dabr_instruction(). */ if (current->thread.last_hit_ubp != bp) - set_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL); + set_dabr(info->address | info->type | DABR_TRANSLATION, info->dabrx); return 0; }
@@ -170,6 +170,13 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp) info->address = bp->attr.bp_addr; info->len = bp->attr.bp_len; + info->dabrx = DABRX_ALL; + if (bp->attr.exclude_user) + info->dabrx &= ~DABRX_USER; + if (bp->attr.exclude_kernel) + info->dabrx &= ~DABRX_KERNEL; + if (bp->attr.exclude_hv) + info->dabrx &= ~DABRX_HYP; /* * Since breakpoint length can be a maximum of HW_BREAKPOINT_LEN(8)
@@ -197,7 +204,7 @@ void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs) info = counter_arch_bp(tsk->thread.last_hit_ubp); regs->msr &= ~MSR_SE; - set_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL); + set_dabr(info->address | info->type | DABR_TRANSLATION, info->dabrx); tsk->thread.last_hit_ubp = NULL; }
@@ -281,7 +288,7 @@ int __kprobes hw_breakpoint_handler(struct die_args *args) if (!info->extraneous_interrupt) perf_bp_event(bp, regs); - set_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL); + set_dabr(info->address | info->type | DABR_TRANSLATION, info->dabrx); out: rcu_read_unlock(); return rc;
@@ -313,7 +320,7 @@ int __kprobes single_step_dabr_instruction(struct die_args *args) if (!info->extraneous_interrupt) perf_bp_event(bp, regs); - set_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL); + set_dabr(info->address | info->type | DABR_TRANSLATION, info->dabrx); current->thread.last_hit_ubp = NULL; /*
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index b90deaf..40b30e4 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c@@ -427,7 +427,7 @@ static int pseries_set_xdabr(unsigned long dabr, unsigned long dabrx) if (dabrx == 0 && dabr == 0) dabrx = DABRX_USER; /* PAPR says we can only set kernel and user bits */ - dabrx &= H_DABRX_KERNEL | H_DABRX_USER; + dabrx &= DABRX_KERNEL | DABRX_USER; return plpar_hcall_norets(H_SET_XDABR, dabr, dabrx); }
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1.7.9.5