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[PATCH 3.14 78/79] mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1)

From Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups linux.kernel
Subject [PATCH 3.14 78/79] mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1)
Date 2015-10-18 05:20 +0200
Message-ID <qkMFQ-XR-21@gated-at.bofh.it> (permalink)
References <qkMw9-KI-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Joonsoo Kim <js1304@gmail.com>

commit 03a2d2a3eafe4015412cf4e9675ca0e2d9204074 upstream.

Commit description is copied from the original post of this bug:

  http://comments.gmane.org/gmane.linux.kernel.mm/135349

Kernels after v3.9 use kmalloc_size(INDEX_NODE + 1) to get the next
larger cache size than the size index INDEX_NODE mapping.  In kernels
3.9 and earlier we used malloc_sizes[INDEX_L3 + 1].cs_size.

However, sometimes we can't get the right output we expected via
kmalloc_size(INDEX_NODE + 1), causing a BUG().

The mapping table in the latest kernel is like:
    index = {0,   1,  2 ,  3,  4,   5,   6,   n}
     size = {0,   96, 192, 8, 16,  32,  64,   2^n}
The mapping table before 3.10 is like this:
    index = {0 , 1 , 2,   3,  4 ,  5 ,  6,   n}
    size  = {32, 64, 96, 128, 192, 256, 512, 2^(n+3)}

The problem on my mips64 machine is as follows:

(1) When configured DEBUG_SLAB && DEBUG_PAGEALLOC && DEBUG_LOCK_ALLOC
    && DEBUG_SPINLOCK, the sizeof(struct kmem_cache_node) will be "150",
    and the macro INDEX_NODE turns out to be "2": #define INDEX_NODE
    kmalloc_index(sizeof(struct kmem_cache_node))

(2) Then the result of kmalloc_size(INDEX_NODE + 1) is 8.

(3) Then "if(size >= kmalloc_size(INDEX_NODE + 1)" will lead to "size
    = PAGE_SIZE".

(4) Then "if ((size >= (PAGE_SIZE >> 3))" test will be satisfied and
    "flags |= CFLGS_OFF_SLAB" will be covered.

(5) if (flags & CFLGS_OFF_SLAB)" test will be satisfied and will go to
    "cachep->slabp_cache = kmalloc_slab(slab_size, 0u)", and the result
    here may be NULL while kernel bootup.

(6) Finally,"BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));" causes the
    BUG info as the following shows (may be only mips64 has this problem):

This patch fixes the problem of kmalloc_size(INDEX_NODE + 1) and removes
the BUG by adding 'size >= 256' check to guarantee that all necessary
small sized slabs are initialized regardless sequence of slab size in
mapping table.

Fixes: e33660165c90 ("slab: Use common kmalloc_index/kmalloc_size...")
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reported-by: Liuhailong <liu.hailong6@zte.com.cn>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 mm/slab.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2271,9 +2271,16 @@ __kmem_cache_create (struct kmem_cache *
 			size += BYTES_PER_WORD;
 	}
 #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
-	if (size >= kmalloc_size(INDEX_NODE + 1)
-	    && cachep->object_size > cache_line_size()
-	    && ALIGN(size, cachep->align) < PAGE_SIZE) {
+	/*
+	 * To activate debug pagealloc, off-slab management is necessary
+	 * requirement. In early phase of initialization, small sized slab
+	 * doesn't get initialized so it would not be possible. So, we need
+	 * to check size >= 256. It guarantees that all necessary small
+	 * sized slab is initialized in current slab initialization sequence.
+	 */
+	if (!slab_early_init && size >= kmalloc_size(INDEX_NODE) &&
+		size >= 256 && cachep->object_size > cache_line_size() &&
+		ALIGN(size, cachep->align) < PAGE_SIZE) {
 		cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align);
 		size = PAGE_SIZE;
 	}


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[PATCH 3.14 00/79] 3.14.55-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 50/79] ipvs: do not use random local source address for tunnels Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 69/79] vfs: Test for and handle paths that are unreachable from their mnt_root Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 38/79] netfilter: nf_conntrack: Support expectations in different zones Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 45/79] USB: whiteheat: fix potential null-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 44/79] drm: Reject DRI1 hw lock ioctl functions for kms drivers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 07/79] perf header: Fixup reading of HEADER_NRCPUS feature Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 54/79] regmap: debugfs: Ensure we dont underflow when printing access masks Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 08/79] hwmon: (nct6775) Swap STEP_UP_TIME and STEP_DOWN_TIME registers for most chips Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 46/79] usb: xhci: Clear XHCI_STATE_DYING on start Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 41/79] disabling oplocks/leases via module parm enable_oplocks broken for SMB3 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 37/79] dm raid: fix round up of default region size Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 39/79] netfilter: ctnetlink: put back references to master ct and expect objects Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 63/79] staging: comedi: usbduxsigma: dont clobber ao_timer in command test Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 35/79] staging: ion: fix corruption of ion_import_dma_buf Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 49/79] Initialize msg/shm IPC objects before doing ipc_addid() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 70/79] arm64: readahead: fault retry breaks mmap file read random detection Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 48/79] usb: xhci: Add support for URB_ZERO_PACKET to bulk/sg transfers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 42/79] drm/qxl: only report first monitor as connected if we have no state Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 52/79] cifs: use server timestamp for ntlmv2 authentication Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 68/79] dcache: Handle escaped paths in prepend_path Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 65/79] powerpc/MSI: Fix race condition in tearing down MSI interrupts Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:10 +0200
  [PATCH 3.14 56/79] security: fix typo in security_task_prctl Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 34/79] dm btree: add ref counting ops for the leaves of top level btrees Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 13/79] dmaengine: dw: properly read DWC_PARAMS register Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 76/79] dm cache: fix NULL pointer when switching from cleaner policy Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 36/79] USB: option: add ZTE PIDs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 62/79] staging: comedi: usbduxsigma: dont clobber ai_timer in command test Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 04/79] perf tools: Fix copying of /proc/kcore Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 30/79] ASoC: dwc: correct irq clear method Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 53/79] mtd: pxa3xx_nand: add a default chunk size Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 72/79] fib_rules: Fix dump_rules() not to exit early Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 78/79] mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1) Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 06/79] perf stat: Get correct cpu id for print_aggr Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 58/79] usb: Add device quirk for Logitech PTZ cameras Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 74/79] jbd2: avoid infinite loop when destroying aborted journal Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 27/79] ALSA: hda - Apply SPDIF pin ctl to MacBookPro 12,1 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 55/79] regmap: debugfs: Dont bother actually printing when calculating max length Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 29/79] ASoC: fix broken pxa SoC support Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 59/79] USB: Add reset-resume quirk for two Plantronics usb headphones. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 33/79] Btrfs: update fix for read corruption of compressed and shared extents Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 61/79] arch,hexagon: Convert smp_mb__*() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 57/79] usb: Use the USB_SS_MULT() macro to get the burst multiplier. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 09/79] ARM: fix Thumb2 signal handling when ARMv6 is enabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 77/79] staging: speakup: fix speakup-r regression Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 05/79] perf hists: Update the column width for the "srcline" sort key Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 32/79] Btrfs: fix read corruption of compressed and shared extents Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 31/79] btrfs: skip waiting on ordered range for special files Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 03/79] iser-target: remove command with state ISTATE_REMOVE Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 75/79] clk: ti: fix dual-registration of uart4_ick Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 25/79] mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 71/79] m68k: Define asmlinkage_protect Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 60/79] MIPS: dma-default: Fix 32-bit fall back to GFP_DMA Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 28/79] ASoC: pxa: pxa2xx-ac97: fix dma requestor lines Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 73/79] genirq: Fix race in register_irq_proc() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:20 +0200
  [PATCH 3.14 10/79] ARM: 8429/1: disable GCC SRA optimization Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 18/79] Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 22/79] sched/core: Fix TASK_DEAD race in finish_task_switch() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 14/79] x86/apic: Serialize LVTT and TSC_DEADLINE writes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 21/79] x86/xen: Support kexec/kdump in HVM guests by doing a soft reset Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 26/79] ALSA: synth: Fix conflicting OSS device registration on AWE32 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 01/79] kvm: fix zero length mmio searching Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 20/79] x86/mm: Set NX on gap between __ex_table and rodata Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 12/79] ARM: dts: omap5-uevm.dts: fix i2c5 pinctrl offsets Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 15/79] x86/platform: Fix Geode LX timekeeping in the generic x86 build Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 11/79] windfarm: decrement client count when unregistering Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 23/79] spi: Fix documentation of spi_alloc_master() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 02/79] scsi: fix scsi_error_handler vs. scsi_host_dev_release race Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 17/79] x86/nmi/64: Fix a paravirt stack-clobbering bug in the NMI code Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:30 +0200
  [PATCH 3.14 24/79] spi: spi-pxa2xx: Check status register to determine if SSSR_TINT is disabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:50 +0200
  [PATCH 3.14 19/79] x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-18 05:50 +0200
  Re: [PATCH 3.14 00/79] 3.14.55-stable review Guenter Roeck <linux@roeck-us.net> - 2015-10-19 06:20 +0200
    Re: [PATCH 3.14 00/79] 3.14.55-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-19 17:20 +0200
      Re: [PATCH 3.14 00/79] 3.14.55-stable review Richard Kuo <rkuo@codeaurora.org> - 2015-10-19 21:20 +0200
        Re: [PATCH 3.14 00/79] 3.14.55-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-19 22:10 +0200
          Re: [PATCH 3.14 00/79] 3.14.55-stable review Richard Kuo <rkuo@codeaurora.org> - 2015-10-19 23:40 +0200
  Re: [PATCH 3.14 00/79] 3.14.55-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2015-10-19 17:30 +0200

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