On a given architecture, when hardware breakpoint registration fails due
to un-supported access type (read/write/execute), we loose 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 <[email protected]>
---
kernel/hw_breakpoint.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 50dbd59..c030ae6 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -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;
}
On Thu, Jan 21, 2010 at 06:25:16PM +0530, Mahesh Salgaonkar wrote:
>
> On a given architecture, when hardware breakpoint registration fails due
> to un-supported access type (read/write/execute), we loose 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 <[email protected]>
Thanks. I'm queuing it.
Commit-ID: b23ff0e9330e4b11e18af984d50573598e10e7f9
Gitweb: http://git.kernel.org/tip/b23ff0e9330e4b11e18af984d50573598e10e7f9
Author: Mahesh Salgaonkar <[email protected]>
AuthorDate: Thu, 21 Jan 2010 18:25:16 +0530
Committer: Frederic Weisbecker <[email protected]>
CommitDate: Thu, 28 Jan 2010 14:15:51 +0100
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 <[email protected]>
Cc: Ananth N Mavinakayanahalli <[email protected]>
Cc: K. Prasad <[email protected]>
Cc: Maneesh Soni <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
---
kernel/hw_breakpoint.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 50dbd59..c030ae6 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -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;
}