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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Don Brace <don.brace@microsemi.com>,
	linux-scsi@vger.kernel.org
Subject: [PATCH 2/4] hpsa: don't bother with vmalloc for BIG_IOCTL_Command_struct
Date: Sat, 30 May 2020 00:40:26 +0100	[thread overview]
Message-ID: <20200529234028.46373-2-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200529234028.46373-1-viro@ZenIV.linux.org.uk>

From: Al Viro <viro@zeniv.linux.org.uk>

"BIG" in the name refers to the amount of data being transferred,
_not_ the size of structure itself; it's 140 or 144 bytes (for
32bit and 64bit hosts resp.).  IOCTL_Command_struct is 136 or
144 bytes large...

No point whatsoever turning that into dynamic allocation, let
alone vmalloc one.  Just keep it as local variable...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 drivers/scsi/hpsa.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 3344a06c938e..64fd97272109 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -6619,21 +6619,17 @@ static int hpsa_ioctl(struct scsi_device *dev, unsigned int cmd,
 		return rc;
 	}
 	case CCISS_BIG_PASSTHRU: {
-		BIG_IOCTL_Command_struct *ioc;
+		BIG_IOCTL_Command_struct ioc;
 		if (!argp)
 			return -EINVAL;
+		if (copy_from_user(&ioc, argp, sizeof(ioc)))
+			return -EFAULT;
 		if (atomic_dec_if_positive(&h->passthru_cmds_avail) < 0)
 			return -EAGAIN;
-		ioc = vmemdup_user(argp, sizeof(*ioc));
-		if (IS_ERR(ioc)) {
-			atomic_inc(&h->passthru_cmds_avail);
-			return PTR_ERR(ioc);
-		}
-		rc = hpsa_big_passthru_ioctl(h, ioc);
+		rc = hpsa_big_passthru_ioctl(h, &ioc);
 		atomic_inc(&h->passthru_cmds_avail);
-		if (!rc && copy_to_user(argp, ioc, sizeof(*ioc)))
+		if (!rc && copy_to_user(argp, &ioc, sizeof(ioc)))
 			rc = -EFAULT;
-		kvfree(ioc);
 		return rc;
 	}
 	default:
-- 
2.11.0


  reply	other threads:[~2020-05-29 23:40 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200528234025.GT23230@ZenIV.linux.org.uk>
2020-05-29 23:39 ` [PATCHES] uaccess hpsa Al Viro
2020-05-29 23:40   ` [PATCH 1/4] hpsa passthrough: lift {BIG_,}IOCTL_Command_struct copy{in,out} into hpsa_ioctl() Al Viro
2020-05-29 23:40     ` Al Viro [this message]
2020-05-29 23:40     ` [PATCH 3/4] hpsa: get rid of compat_alloc_user_space() Al Viro
2020-05-29 23:40     ` [PATCH 4/4] hpsa_ioctl(): tidy up a bit Al Viro
2020-06-03  1:57   ` [PATCHES] uaccess hpsa Martin K. Petersen
2020-06-03 18:37   ` Don.Brace
2020-06-03 19:17     ` Al Viro
2020-06-03 20:53       ` Martin K. Petersen
2020-06-03 20:54         ` Al Viro
2020-06-04 14:18           ` Martin K. Petersen

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