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

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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>
This commit is contained in:
Mahesh Salgaonkar 2010-01-21 18:25:16 +05:30 committed by Frederic Weisbecker
parent 7f5102ca4b
commit b23ff0e933
1 changed files with 4 additions and 0 deletions
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4
kernel/hw_breakpoint.c
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@ -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;
}