linux-kernel - [PATCH] rhashtable: Better error message on allocation failure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20231122233225.178910-1-kent.overstreet@linux.dev>
Date:   Wed, 22 Nov 2023 18:32:16 -0500
From:   Kent Overstreet <kent.overstreet@...ux.dev>
To:     linux-kernel@...r.kernel.org
Cc:     Kent Overstreet <kent.overstreet@...ux.dev>,
        Thomas Graf <tgraf@...g.ch>,
        Herbert Xu <herbert@...dor.apana.org.au>
Subject: [PATCH] rhashtable: Better error message on allocation failure

Memory allocation failures print backtraces by default, but when we're
running out of a rhashtable worker the backtrace is useless - it doesn't
tell us which hashtable the allocation failure was for.

This adds a dedicated warning that prints out functions from the
rhashtable params, which will be a bit more useful.

Signed-off-by: Kent Overstreet <kent.overstreet@...ux.dev>
Cc: Thomas Graf <tgraf@...g.ch>
Cc: Herbert Xu <herbert@...dor.apana.org.au>
---
 lib/rhashtable.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 6ae2ba8e06a2..d3fce9c8989a 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -360,9 +360,14 @@ static int rhashtable_rehash_alloc(struct rhashtable *ht,
 
 	ASSERT_RHT_MUTEX(ht);
 
-	new_tbl = bucket_table_alloc(ht, size, GFP_KERNEL);
-	if (new_tbl == NULL)
+	new_tbl = bucket_table_alloc(ht, size, GFP_KERNEL|__GFP_NOWARN);
+	if (new_tbl == NULL) {
+		WARN("rhashtable bucket table allocation failure for %ps",
+		     (void *) ht->p.hashfn ?:
+		     (void *) ht->p.obj_hashfn ?:
+		     (void *) ht->p.obj_cmpfn);
 		return -ENOMEM;
+	}
 
 	err = rhashtable_rehash_attach(ht, old_tbl, new_tbl);
 	if (err)
-- 
2.42.0