Commit b23ff0e9 authored Jan 21, 2010 by Mahesh Salgaonkar Committed by Frederic Weisbecker Jan 28, 2010

hw_breakpoints: Release the bp slot if arch_validate_hwbkpt_settings() fails.



On a given architecture, when hardware breakpoint registration fails
due to un-supported access type (read/write/execute), we lose the bp
slot since register_perf_hw_breakpoint() does not release the bp slot
on failure.
Hence, any subsequent hardware breakpoint registration starts failing
with 'no space left on device' error.

This patch introduces error handling in register_perf_hw_breakpoint()
function and releases bp slot on error.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: K. Prasad <prasad@linux.vnet.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
LKML-Reference: <20100121125516.GA32521@in.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

parent 7f5102ca

kernel/hw_breakpoint.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -296,6 +296,10 @@ int register_perf_hw_breakpoint(struct perf_event *bp)
		if (!bp->attr.disabled \|\| !bp->overflow_handler)
		ret = arch_validate_hwbkpt_settings(bp, bp->ctx->task);

		/* if arch_validate_hwbkpt_settings() fails then release bp slot */
		if (ret)
		release_bp_slot(bp);

		return ret;
		}

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