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From: Oleg Nesterov <oleg@redhat.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Peter Zijlstra <peterz@infradead.org>, Tejun Heo <tj@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: parse_args() is too unforgivable?
Date: Mon, 24 Aug 2015 20:31:26 +0200	[thread overview]
Message-ID: <20150824183126.GA8388@redhat.com> (raw)
In-Reply-To: <20150824153431.GB24949@redhat.com>

On 08/24, Oleg Nesterov wrote:
>
> I booted the kernel with the additional patch below, and nothing bad has
> happened,

Until I tried reboot it once with "locktorture.verbose=true" paramater.
It didn't boot.

This is because parse_args() just aborts after it hits the error, so other
arguments at the same initcall level are simply ignored.

Fixed by the patch below, but I simply can't believe nobody hit this (imo)
bug before.

Why does parse_args() do this?? I simply can't understand why parse_args()
adds more random and hard-to-understand problems if one of the args ("=true"
in this particular case) is wrong.

Yes, the patch below is probably oversimplified / incomplete but imho the
current behaviour is confusing. At least I was greatly confused ;) At least
(I think) it makes sense to let the user know that the rest of command line
was probably ignored.

Oleg.
---

--- a/kernel/params.c
+++ b/kernel/params.c
@@ -220,19 +220,19 @@ char *parse_args(const char *doing,
 				doing, param);
 
 		switch (ret) {
+		case 0:
+			break;
 		case -ENOENT:
 			pr_err("%s: Unknown parameter `%s'\n", doing, param);
-			return ERR_PTR(ret);
+			break;
 		case -ENOSPC:
 			pr_err("%s: `%s' too large for parameter `%s'\n",
 			       doing, val ?: "", param);
-			return ERR_PTR(ret);
-		case 0:
 			break;
 		default:
 			pr_err("%s: `%s' invalid for parameter `%s'\n",
 			       doing, val ?: "", param);
-			return ERR_PTR(ret);
+			break;
 		}
 	}
 


  reply	other threads:[~2015-08-24 18:33 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-21 17:42 [PATCH v2 0/8] Add rcu_sync infrastructure to avoid _expedited() in percpu-rwsem Oleg Nesterov
2015-08-21 17:42 ` [PATCH v2 1/8] rcu: Create rcu_sync infrastructure Oleg Nesterov
2015-08-21 17:42 ` [PATCH v2 2/8] rcusync: Introduce struct rcu_sync_ops Oleg Nesterov
2015-08-21 17:42 ` [PATCH v2 3/8] rcusync: Add the CONFIG_PROVE_RCU checks Oleg Nesterov
2015-08-21 17:42 ` [PATCH v2 4/8] rcusync: Introduce rcu_sync_dtor() Oleg Nesterov
2015-08-21 17:42 ` [PATCH v2 5/8] percpu-rwsem: make percpu_free_rwsem() after kzalloc() safe Oleg Nesterov
2015-08-21 17:42 ` [PATCH v2 6/8] percpu-rwsem: change it to rely on rss_sync infrastructure Oleg Nesterov
2015-08-21 17:43 ` [PATCH v2 7/8] percpu-rwsem: fix the comments outdated by rcu_sync Oleg Nesterov
2015-08-21 17:43 ` [PATCH v2 8/8] percpu-rwsem: cleanup the lockdep annotations in percpu_down_read() Oleg Nesterov
2015-08-22 16:38 ` [PATCH v2 0/8] Add rcu_sync infrastructure to avoid _expedited() in percpu-rwsem Paul E. McKenney
2015-08-24 15:34   ` Oleg Nesterov
2015-08-24 18:31     ` Oleg Nesterov [this message]
2015-08-25  1:24       ` parse_args() is too unforgivable? Rusty Russell
2015-08-25 15:18         ` [PATCH 0/1] params: don't ignore the rest of cmdline if parse_one() fails Oleg Nesterov
2015-08-25 15:18           ` [PATCH 1/1] " Oleg Nesterov
2015-08-26  0:13             ` Rusty Russell
2015-08-26  0:22     ` [PATCH v2 0/8] Add rcu_sync infrastructure to avoid _expedited() in percpu-rwsem Paul E. McKenney
2015-08-26 12:16       ` Oleg Nesterov
2015-08-26 12:52         ` Oleg Nesterov
2015-08-26 14:29           ` Paul E. McKenney

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