From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Dan Carpenter <dan.carpenter@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Mel Gorman <mgorman@techsingularity.net>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH 5.4 61/65] mm, compaction: fully assume capture is not NULL in compact_zone_order()
Date: Tue, 7 Jul 2020 17:17:40 +0200 [thread overview]
Message-ID: <20200707145755.418273739@linuxfoundation.org> (raw)
In-Reply-To: <20200707145752.417212219@linuxfoundation.org>
From: Vlastimil Babka <vbabka@suse.cz>
commit 6467552ca64c4ddd2b83ed73192107d7145f533b upstream.
Dan reports:
The patch 5e1f0f098b46: "mm, compaction: capture a page under direct
compaction" from Mar 5, 2019, leads to the following Smatch complaint:
mm/compaction.c:2321 compact_zone_order()
error: we previously assumed 'capture' could be null (see line 2313)
mm/compaction.c
2288 static enum compact_result compact_zone_order(struct zone *zone, int order,
2289 gfp_t gfp_mask, enum compact_priority prio,
2290 unsigned int alloc_flags, int classzone_idx,
2291 struct page **capture)
^^^^^^^
2313 if (capture)
^^^^^^^
Check for NULL
2314 current->capture_control = &capc;
2315
2316 ret = compact_zone(&cc, &capc);
2317
2318 VM_BUG_ON(!list_empty(&cc.freepages));
2319 VM_BUG_ON(!list_empty(&cc.migratepages));
2320
2321 *capture = capc.page;
^^^^^^^^
Unchecked dereference.
2322 current->capture_control = NULL;
2323
In practice this is not an issue, as the only caller path passes non-NULL
capture:
__alloc_pages_direct_compact()
struct page *page = NULL;
try_to_compact_pages(capture = &page);
compact_zone_order(capture = capture);
So let's remove the unnecessary check, which should also make Smatch happy.
Fixes: 5e1f0f098b46 ("mm, compaction: capture a page under direct compaction")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Link: http://lkml.kernel.org/r/18b0df3c-0589-d96c-23fa-040798fee187@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
mm/compaction.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2310,8 +2310,7 @@ static enum compact_result compact_zone_
.page = NULL,
};
- if (capture)
- current->capture_control = &capc;
+ current->capture_control = &capc;
ret = compact_zone(&cc, &capc);
@@ -2333,6 +2332,7 @@ int sysctl_extfrag_threshold = 500;
* @alloc_flags: The allocation flags of the current allocation
* @ac: The context of current allocation
* @prio: Determines how hard direct compaction should try to succeed
+ * @capture: Pointer to free page created by compaction will be stored here
*
* This is the main entry point for direct page compaction.
*/
next prev parent reply other threads:[~2020-07-07 15:32 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-07 15:16 [PATCH 5.4 00/65] 5.4.51-rc1 review Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 01/65] io_uring: make sure async workqueue is canceled on exit Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 02/65] mm: fix swap cache node allocation mask Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 03/65] EDAC/amd64: Read back the scrub rate PCI register on F15h Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 04/65] usbnet: smsc95xx: Fix use-after-free after removal Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 05/65] sched/debug: Make sd->flags sysctl read-only Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 06/65] mm/slub.c: fix corrupted freechain in deactivate_slab() Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 07/65] mm/slub: fix stack overruns with SLUB_STATS Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 08/65] rxrpc: Fix race between incoming ACK parser and retransmitter Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 09/65] usb: usbtest: fix missing kfree(dev->buf) in usbtest_disconnect Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 10/65] tools lib traceevent: Add append() function helper for appending strings Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 11/65] tools lib traceevent: Handle __attribute__((user)) in field names Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 12/65] s390/debug: avoid kernel warning on too large number of pages Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 13/65] nvme-multipath: set bdi capabilities once Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 14/65] nvme: fix possible deadlock when I/O is blocked Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 15/65] nvme-multipath: fix deadlock between ana_work and scan_work Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 16/65] nvme-multipath: fix deadlock due to head->lock Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 17/65] nvme-multipath: fix bogus request queue reference put Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 18/65] kgdb: Avoid suspicious RCU usage warning Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 19/65] selftests: tpm: Use /bin/sh instead of /bin/bash Greg Kroah-Hartman
2020-07-07 15:16 ` [PATCH 5.4 20/65] tpm: Fix TIS locality timeout problems Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 21/65] crypto: af_alg - fix use-after-free in af_alg_accept() due to bh_lock_sock() Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 22/65] drm/msm/dpu: fix error return code in dpu_encoder_init Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 23/65] rxrpc: Fix afs large storage transmission performance drop Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 24/65] RDMA/counter: Query a counter before release Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 25/65] cxgb4: use unaligned conversion for fetching timestamp Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 26/65] cxgb4: parse TC-U32 key values and masks natively Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 27/65] cxgb4: fix endian conversions for L4 ports in filters Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 28/65] cxgb4: use correct type for all-mask IP address comparison Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 29/65] cxgb4: fix SGE queue dump destination buffer context Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 30/65] hwmon: (max6697) Make sure the OVERT mask is set correctly Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 31/65] hwmon: (acpi_power_meter) Fix potential memory leak in acpi_power_meter_add() Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 32/65] thermal/drivers/mediatek: Fix bank number settings on mt8183 Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 33/65] thermal/drivers/rcar_gen3: Fix undefined temperature if negative Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 34/65] kthread: save thread function Greg Kroah-Hartman
2020-07-07 15:31 ` J. Bruce Fields
2020-07-07 15:17 ` [PATCH 5.4 35/65] nfsd: clients dont need to break their own delegations Greg Kroah-Hartman
2020-07-07 15:31 ` J. Bruce Fields
2020-07-07 17:20 ` Sasha Levin
2020-07-07 17:29 ` Sasha Levin
2020-07-07 17:31 ` J. Bruce Fields
2020-07-07 15:17 ` [PATCH 5.4 36/65] nfsd4: fix nfsdfs reference count loop Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 37/65] nfsd: fix nfsdfs inode reference count leak Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 38/65] drm: sun4i: hdmi: Remove extra HPD polling Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 39/65] virtio-blk: free vblk-vqs in error path of virtblk_probe() Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 40/65] SMB3: Honor posix flag for multiuser mounts Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 41/65] nvme: fix identify error status silent ignore Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 42/65] nvme: fix a crash in nvme_mpath_add_disk Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 43/65] samples/vfs: avoid warning in statx override Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 44/65] i2c: algo-pca: Add 0x78 as SCL stuck low status for PCA9665 Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 45/65] i2c: mlxcpld: check correct size of maximum RECV_LEN packet Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 46/65] spi: spi-fsl-dspi: Fix external abort on interrupt in resume or exit paths Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 47/65] nfsd: apply umask on fs without ACL support Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 48/65] Revert "ALSA: usb-audio: Improve frames size computation" Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 49/65] SMB3: Honor seal flag for multiuser mounts Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 50/65] SMB3: Honor persistent/resilient handle flags " Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 51/65] SMB3: Honor lease disabling " Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 52/65] SMB3: Honor handletimeout flag " Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 53/65] cifs: Fix the target file was deleted when rename failed Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 54/65] MIPS: lantiq: xway: sysctrl: fix the GPHY clock alias names Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 55/65] MIPS: Add missing EHB in mtc0 -> mfc0 sequence for DSPen Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 56/65] drm/amd/display: Only revalidate bandwidth on medium and fast updates Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 57/65] drm/amdgpu: use %u rather than %d for sclk/mclk Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 58/65] drm/amdgpu/atomfirmware: fix vram_info fetching for renoir Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 59/65] dma-buf: Move dma_buf_release() from fops to dentry_ops Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 60/65] irqchip/gic: Atomically update affinity Greg Kroah-Hartman
2020-07-07 15:17 ` Greg Kroah-Hartman [this message]
2020-07-07 15:17 ` [PATCH 5.4 62/65] mm, compaction: make capture control handling safe wrt interrupts Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 63/65] x86/resctrl: Fix memory bandwidth counter width for AMD Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 64/65] dm zoned: assign max_io_len correctly Greg Kroah-Hartman
2020-07-07 15:17 ` [PATCH 5.4 65/65] efi: Make it possible to disable efivar_ssdt entirely Greg Kroah-Hartman
2020-07-08 5:30 ` [PATCH 5.4 00/65] 5.4.51-rc1 review Naresh Kamboju
2020-07-08 8:41 ` Jon Hunter
2020-07-08 15:15 ` Greg Kroah-Hartman
2020-07-08 16:58 ` Jon Hunter
2020-07-09 9:30 ` Greg Kroah-Hartman
2020-07-08 15:00 ` Shuah Khan
2020-07-08 17:53 ` Guenter Roeck
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