[PATCH 6.4 716/800] lib: dhry: fix sleeping allocations inside non-preemptable section

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From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

[ Upstream commit 8ba388c06bc8056935ec1814b2689bfb42f3b89a ]

The Smatch static checker reports the following warnings:

    lib/dhry_run.c:38 dhry_benchmark() warn: sleeping in atomic context
    lib/dhry_run.c:43 dhry_benchmark() warn: sleeping in atomic context

Indeed, dhry() does sleeping allocations inside the non-preemptable
section delimited by get_cpu()/put_cpu().

Fix this by using atomic allocations instead.
Add error handling, as atomic these allocations may fail.

Link: https://lkml.kernel.org/r/bac6d517818a7cd8efe217c1ad649fffab9cc371.1688568764.git.geert+renesas@xxxxxxxxx
Fixes: 13684e966d46283e ("lib: dhry: fix unstable smp_processor_id(_) usage")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Closes: https://lore.kernel.org/r/0469eb3a-02eb-4b41-b189-de20b931fa56@moroto.mountain
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 lib/dhry_1.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/dhry_1.c b/lib/dhry_1.c
index 83247106824cc..08edbbb19f573 100644
--- a/lib/dhry_1.c
+++ b/lib/dhry_1.c
@@ -139,8 +139,15 @@ int dhry(int n)
 
 	/* Initializations */
 
-	Next_Ptr_Glob = (Rec_Pointer)kzalloc(sizeof(Rec_Type), GFP_KERNEL);
-	Ptr_Glob = (Rec_Pointer)kzalloc(sizeof(Rec_Type), GFP_KERNEL);
+	Next_Ptr_Glob = (Rec_Pointer)kzalloc(sizeof(Rec_Type), GFP_ATOMIC);
+	if (!Next_Ptr_Glob)
+		return -ENOMEM;
+
+	Ptr_Glob = (Rec_Pointer)kzalloc(sizeof(Rec_Type), GFP_ATOMIC);
+	if (!Ptr_Glob) {
+		kfree(Next_Ptr_Glob);
+		return -ENOMEM;
+	}
 
 	Ptr_Glob->Ptr_Comp = Next_Ptr_Glob;
 	Ptr_Glob->Discr = Ident_1;
-- 
2.39.2






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