From: Frederic Barrat <frederic.barrat@fr.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: imunsie@au1.ibm.com, Frederic Barrat <frederic.barrat@fr.ibm.com>
Subject: [PATCH] cxl: Fix reference count on struct pid when attaching
Date: Thu, 29 Oct 2015 13:39:03 +0100 [thread overview]
Message-ID: <1446122343-26068-1-git-send-email-frederic.barrat@fr.ibm.com> (raw)
When the cxl driver creates a context, it stores the pid of the
calling task, incrementing the reference count on the struct
pid. Current code mistakenly increments the reference count twice,
once through get_task_pid(), once through get_pid(). The reference
count is only decremented once on detach, thus the struct pid of the
task attaching is never freed. The fix is to simply remove the call to
get_pid().
Signed-off-by: Frederic Barrat <frederic.barrat@fr.ibm.com>
---
drivers/misc/cxl/api.c | 1 -
drivers/misc/cxl/file.c | 2 +-
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index 103baf0..94b6627 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -176,7 +176,6 @@ int cxl_start_context(struct cxl_context *ctx, u64 wed,
if (task) {
ctx->pid = get_task_pid(task, PIDTYPE_PID);
- get_pid(ctx->pid);
kernel = false;
}
diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c
index 7ccd299..97003ee 100644
--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -199,7 +199,7 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
* behalf of another process, so the AFU's mm gets bound to the process
* that performs this ioctl and not the process that opened the file.
*/
- ctx->pid = get_pid(get_task_pid(current, PIDTYPE_PID));
+ ctx->pid = get_task_pid(current, PIDTYPE_PID);
trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
--
1.9.1
next reply other threads:[~2015-10-29 12:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-29 12:39 Frederic Barrat [this message]
2015-10-30 0:31 ` [PATCH] cxl: Fix reference count on struct pid when attaching Andrew Donnellan
2015-10-30 2:56 ` Ian Munsie
2015-11-02 0:53 ` Michael Ellerman
2015-11-02 23:48 ` Ian Munsie
2015-11-03 1:00 ` Michael Ellerman
2015-11-03 8:17 ` Frederic Barrat
2015-11-03 9:11 ` Michael Ellerman
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