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| author |   Ravi Bangoria <ravi.bangoria@linux.ibm.com> | 2020-05-14 16:47:39 +0530 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2020-05-19 00:14:45 +1000 |
| commit | 29da4f91c0c1fbda12b8a31be0d564930208c92e (patch) | |
| tree | 5ae2bc339c5d581722f099efd4110efa05dde5be /arch/powerpc/include | |
| parent | powerpc/watchpoint: Prepare handler to handle more than one watchpoint (diff) | |
| download | linux-dev-29da4f91c0c1fbda12b8a31be0d564930208c92e.tar.xz linux-dev-29da4f91c0c1fbda12b8a31be0d564930208c92e.zip | |
powerpc/watchpoint: Don't allow concurrent perf and ptrace events
With Book3s DAWR, ptrace and perf watchpoints on powerpc behaves
differently. Ptrace watchpoint works in one-shot mode and generates
signal before executing instruction. It's ptrace user's job to
single-step the instruction and re-enable the watchpoint. OTOH, in
case of perf watchpoint, kernel emulates/single-steps the instruction
and then generates event. If perf and ptrace creates two events with
same or overlapping address ranges, it's ambiguous to decide who
should single-step the instruction. Because of this issue, don't
allow perf and ptrace watchpoint at the same time if their address
range overlaps.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Michael Neuling <mikey@neuling.org>
Link: https://lore.kernel.org/r/20200514111741.97993-15-ravi.bangoria@linux.ibm.com
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/hw_breakpoint.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h index add5aa076919..f42a55eb77d2 100644 --- a/arch/powerpc/include/asm/hw_breakpoint.h +++ b/arch/powerpc/include/asm/hw_breakpoint.h @@ -70,6 +70,8 @@ extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused, unsigned long val, void *data); int arch_install_hw_breakpoint(struct perf_event *bp); void arch_uninstall_hw_breakpoint(struct perf_event *bp); +int arch_reserve_bp_slot(struct perf_event *bp); +void arch_release_bp_slot(struct perf_event *bp); void arch_unregister_hw_breakpoint(struct perf_event *bp); void hw_breakpoint_pmu_read(struct perf_event *bp); extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk); |