From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Evan Green <evgreen@chromium.org>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Sasha Levin <sashal@kernel.org>,
rafael@kernel.org, pavel@ucw.cz, len.brown@intel.com,
linux-pm@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 11/14] PM: hibernate: Fix snapshot partial write lengths
Date: Tue, 30 Nov 2021 09:53:12 -0500 [thread overview]
Message-ID: <20211130145317.946676-11-sashal@kernel.org> (raw)
In-Reply-To: <20211130145317.946676-1-sashal@kernel.org>
From: Evan Green <evgreen@chromium.org>
[ Upstream commit 88a5045f176b78c33a269a30a7b146e99c550bd9 ]
snapshot_write() is inappropriately limiting the amount of data that can
be written in cases where a partial page has already been written. For
example, one would expect to be able to write 1 byte, then 4095 bytes to
the snapshot device, and have both of those complete fully (since now
we're aligned to a page again). But what ends up happening is we write 1
byte, then 4094/4095 bytes complete successfully.
The reason is that simple_write_to_buffer()'s second argument is the
total size of the buffer, not the size of the buffer minus the offset.
Since simple_write_to_buffer() accounts for the offset in its
implementation, snapshot_write() can just pass the full page size
directly down.
Signed-off-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/power/user.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 69017a569f302..ba6a028e0035d 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -183,7 +183,7 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
if (res <= 0)
goto unlock;
} else {
- res = PAGE_SIZE - pg_offp;
+ res = PAGE_SIZE;
}
if (!data_of(data->handle)) {
--
2.33.0
next prev parent reply other threads:[~2021-11-30 15:02 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-30 14:53 [PATCH AUTOSEL 4.14 01/14] ASoC: mediatek: mt8173-rt5650: Rename Speaker control to Ext Spk Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 02/14] xen/privcmd: make option visible in Kconfig Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 03/14] NFSv4.1: handle NFS4ERR_NOSPC by CREATE_SESSION Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 04/14] HID: multitouch: Fix Iiyama ProLite T1931SAW (0eef:0001 again!) Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 05/14] parisc: Provide an extru_safe() macro to extract unsigned bits Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 06/14] scsi: scsi_debug: Sanity check block descriptor length in resp_mode_select() Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 07/14] i2c: i801: Fix interrupt storm from SMB_ALERT signal Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 08/14] mmc: spi: Add device-tree SPI IDs Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 09/14] net: chelsio: cxgb4vf: Fix an error code in cxgb4vf_pci_probe() Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 10/14] smb2: clarify rc initialization in smb2_reconnect Sasha Levin
2021-11-30 14:53 ` Sasha Levin [this message]
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 12/14] net: qed: fix the array may be out of bound Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 13/14] net: ptp: add a definition for the UDP port for IEEE 1588 general messages Sasha Levin
2021-11-30 14:53 ` [PATCH AUTOSEL 4.14 14/14] fs: ntfs: Limit NTFS_RW to page sizes smaller than 64k Sasha Levin
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