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authorMichael Neuling <mikey@neuling.org>2015-05-27 08:07:11 +0200
committerMichael Ellerman <mpe@ellerman.id.au>2015-06-03 05:27:18 +0200
commita6b07d825750f76eeb2972c70a8f0e6e62566954 (patch)
tree9daf5f8480eae903eac12f258cd239afb78b3555 /drivers/misc
parentcxl: Export some symbols (diff)
downloadlinux-a6b07d825750f76eeb2972c70a8f0e6e62566954.tar.xz
linux-a6b07d825750f76eeb2972c70a8f0e6e62566954.zip
cxl: Only check pid for userspace contexts
We only need to check the pid attached to this context for userspace contexts. Kernel contexts can skip this check. Signed-off-by: Michael Neuling <mikey@neuling.org> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/cxl/fault.c34
1 files changed, 19 insertions, 15 deletions
diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c
index 5286b8b704f5..25a5418c55cb 100644
--- a/drivers/misc/cxl/fault.c
+++ b/drivers/misc/cxl/fault.c
@@ -172,8 +172,8 @@ void cxl_handle_fault(struct work_struct *fault_work)
container_of(fault_work, struct cxl_context, fault_work);
u64 dsisr = ctx->dsisr;
u64 dar = ctx->dar;
- struct task_struct *task;
- struct mm_struct *mm;
+ struct task_struct *task = NULL;
+ struct mm_struct *mm = NULL;
if (cxl_p2n_read(ctx->afu, CXL_PSL_DSISR_An) != dsisr ||
cxl_p2n_read(ctx->afu, CXL_PSL_DAR_An) != dar ||
@@ -194,17 +194,19 @@ void cxl_handle_fault(struct work_struct *fault_work)
pr_devel("CXL BOTTOM HALF handling fault for afu pe: %i. "
"DSISR: %#llx DAR: %#llx\n", ctx->pe, dsisr, dar);
- if (!(task = get_pid_task(ctx->pid, PIDTYPE_PID))) {
- pr_devel("cxl_handle_fault unable to get task %i\n",
- pid_nr(ctx->pid));
- cxl_ack_ae(ctx);
- return;
- }
- if (!(mm = get_task_mm(task))) {
- pr_devel("cxl_handle_fault unable to get mm %i\n",
- pid_nr(ctx->pid));
- cxl_ack_ae(ctx);
- goto out;
+ if (!ctx->kernel) {
+ if (!(task = get_pid_task(ctx->pid, PIDTYPE_PID))) {
+ pr_devel("cxl_handle_fault unable to get task %i\n",
+ pid_nr(ctx->pid));
+ cxl_ack_ae(ctx);
+ return;
+ }
+ if (!(mm = get_task_mm(task))) {
+ pr_devel("cxl_handle_fault unable to get mm %i\n",
+ pid_nr(ctx->pid));
+ cxl_ack_ae(ctx);
+ goto out;
+ }
}
if (dsisr & CXL_PSL_DSISR_An_DS)
@@ -214,9 +216,11 @@ void cxl_handle_fault(struct work_struct *fault_work)
else
WARN(1, "cxl_handle_fault has nothing to handle\n");
- mmput(mm);
+ if (mm)
+ mmput(mm);
out:
- put_task_struct(task);
+ if (task)
+ put_task_struct(task);
}
static void cxl_prefault_one(struct cxl_context *ctx, u64 ea)