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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Matt Fleming
	<matt.fleming-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	Tom Gundersen <teg-B22kvLQNl6c@public.gmane.org>
Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	kernel-janitors-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: [patch] efi: locking fix in efivar_entry_set_safe()
Date: Tue, 30 Apr 2013 07:43:12 +0000	[thread overview]
Message-ID: <20130430074312.GD7237@elgon.mountain> (raw)

The intent is that if we aren't allowed to block because we're in an
NMI or an emergency then we only take the lock if it is uncontended.

Part of the problem is the test is reversed so we return -EBUSY if we
acquire the lock.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
Static checker stuff.  I haven't tested this.

diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 1d80c1c..f34d8fe 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -622,10 +622,12 @@ int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
 	if (!ops->query_variable_store)
 		return -ENOSYS;
 
-	if (!block && spin_trylock_irqsave(&__efivars->lock, flags))
-		return -EBUSY;
-	else
+	if (!block) {
+		if (!spin_trylock_irqsave(&__efivars->lock, flags))
+			return -EBUSY;
+	} else {
 		spin_lock_irqsave(&__efivars->lock, flags);
+	}
 
 	status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
 	if (status != EFI_SUCCESS) {

WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
To: Matt Fleming
	<matt.fleming-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	Tom Gundersen <teg-B22kvLQNl6c@public.gmane.org>
Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	kernel-janitors-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: [patch] efi: locking fix in efivar_entry_set_safe()
Date: Tue, 30 Apr 2013 10:43:12 +0300	[thread overview]
Message-ID: <20130430074312.GD7237@elgon.mountain> (raw)

The intent is that if we aren't allowed to block because we're in an
NMI or an emergency then we only take the lock if it is uncontended.

Part of the problem is the test is reversed so we return -EBUSY if we
acquire the lock.

Signed-off-by: Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
---
Static checker stuff.  I haven't tested this.

diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 1d80c1c..f34d8fe 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -622,10 +622,12 @@ int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
 	if (!ops->query_variable_store)
 		return -ENOSYS;
 
-	if (!block && spin_trylock_irqsave(&__efivars->lock, flags))
-		return -EBUSY;
-	else
+	if (!block) {
+		if (!spin_trylock_irqsave(&__efivars->lock, flags))
+			return -EBUSY;
+	} else {
 		spin_lock_irqsave(&__efivars->lock, flags);
+	}
 
 	status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
 	if (status != EFI_SUCCESS) {

             reply	other threads:[~2013-04-30  7:43 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-30  7:43 Dan Carpenter [this message]
2013-04-30  7:43 ` [patch] efi: locking fix in efivar_entry_set_safe() Dan Carpenter
     [not found] ` <20130430074312.GD7237-mgFCXtclrQlZLf2FXnZxJA@public.gmane.org>
2013-04-30 11:33   ` Matt Fleming
2013-04-30 11:33     ` Matt Fleming

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