Messages in this thread Patch in this message | | | From | Nicolas Boichat <> | Date | Tue, 23 Jul 2019 16:13:46 +0800 | Subject | Re: [PATCH] kmemleak: Increase maximum early log entries to 1000000 |
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On Tue, Jul 23, 2019 at 3:46 PM Dmitry Vyukov <dvyukov@google.com> wrote: > > On Tue, Jul 23, 2019 at 9:26 AM Nicolas Boichat <drinkcat@chromium.org> wrote: > > > > When KASan is enabled, a lot of memory is allocated early on, > > and kmemleak complains (this is on a 4GB RAM system): > > kmemleak: Early log buffer exceeded (129846), please increase > > DEBUG_KMEMLEAK_EARLY_LOG_SIZE > > > > Let's increase the upper limit to 1M entry. That would take up > > 160MB of RAM at init (each early_log entry is 160 bytes), but > > the memory would later be freed (early_log is __initdata). > > Interesting. Is it on an arm64 system?
Yes arm64. And this is chromiumos-4.19 tree. I didn't try to track down where these allocations come from...
Slightly redacted dmesg until the error message: [ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd034] [ 0.000000] Linux version 4.19.59 (drinkcat@X) (Chromium OS 9.0_pre361749_p20190714-r2 clang version 9.0.0 (/var/cache/chromeos-cache/distfiles/host/egit-src/llvm-project c11de5eada2decd0a495ea02676b6f4838cd54fb) (based on LLVM 9.0.0svn)) #7 SMP PREEMPT Tue Jul 23 16:00:50 CST 2019 [ 0.000000] Machine model: XYZ [ 0.000000] Malformed early option 'console' [ 0.000000] Reserved memory: created DMA memory pool at 0x0000000050000000, size 41 MiB [ 0.000000] OF: reserved mem: initialized node scp_mem_region, compatible id shared-dma-pool [ 0.000000] On node 0 totalpages: 1031920 [ 0.000000] DMA32 zone: 12288 pages used for memmap [ 0.000000] DMA32 zone: 0 pages reserved [ 0.000000] DMA32 zone: 769776 pages, LIFO batch:63 [ 0.000000] Normal zone: 4096 pages used for memmap [ 0.000000] Normal zone: 262144 pages, LIFO batch:63 [ 0.000000] kmemleak: Kernel memory leak detector disabled [ 0.000000] kasan: KernelAddressSanitizer initialized [ 0.000000] psci: probing for conduit method from DT. [ 0.000000] psci: PSCIv1.1 detected in firmware. [ 0.000000] psci: Using standard PSCI v0.2 function IDs [ 0.000000] psci: MIGRATE_INFO_TYPE not supported. [ 0.000000] psci: SMC Calling Convention v1.1 [ 0.000000] random: get_random_bytes called from start_kernel+0x8c/0x384 with crng_init=0 [ 0.000000] percpu: Embedded 32 pages/cpu s92904 r8192 d29976 u131072 [ 0.000000] pcpu-alloc: s92904 r8192 d29976 u131072 alloc=32*4096 [ 0.000000] pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3 [0] 4 [0] 5 [0] 6 [0] 7 [ 0.000000] Detected VIPT I-cache on CPU0 [ 0.000000] CPU features: enabling workaround for ARM erratum 845719 [ 0.000000] Speculative Store Bypass Disable mitigation not required [ 0.000000] CPU features: detected: Kernel page table isolation (KPTI) [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 1015536 [ 0.000000] Kernel command line: cros_secure cros_secure console= loglevel=7 init=/sbin/init cros_secure root=PARTUUID=45e54c6a-06a8-374c-a934-a07e23b37225/PARTNROFF=1 rootwait rw dm_verity.error_behavior=3 dm_verity.max_bios=-1 dm_verity.dev_wait=0 dm="1 vroot none ro 1,0 4710400 verity payload=ROOT_DEV hashtree=HASH_DEV hashstart=4710400 alg=sha256 root_hexdigest=443fe95947f3b3f3cb54a10a53a4c7bb600ea1dd26d002066821236efa2419f4 salt=ba17ba7736672036f119b0c925aa43e10ae1a960591a5b8bc85b21c166a49132" noinitrd cros_debug vt.global_cursor_default=0 kern_guid=45e54c6a-06a8-374c-a934-a07e23b37225 [ 0.000000] device-mapper: init: will configure 1 devices [ 0.000000] Dentry cache hash table entries: 524288 (order: 10, 4194304 bytes) [ 0.000000] Inode-cache hash table entries: 262144 (order: 9, 2097152 bytes) [ 0.000000] software IO TLB: mapped [mem 0xfbdff000-0xffdff000] (64MB) [ 0.000000] Memory: 3439892K/4127680K available (9726K kernel code, 1106K rwdata, 3064K rodata, 4096K init, 8893K bss, 687788K reserved, 0K cma-reserved) [ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=8, Nodes=1 [ 0.000000] ftrace: allocating 34965 entries in 137 pages [ 0.000000] rcu: Preemptible hierarchical RCU implementation. [ 0.000000] Tasks RCU enabled. [ 0.000000] NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0 [ 0.000000] GICv3: GIC: Using split EOI/Deactivate mode [ 0.000000] GICv3: Distributor has no Range Selector support [ 0.000000] GICv3: no VLPI support, no direct LPI support [ 0.000000] GICv3: CPU0: found redistributor 0 region 0:0x000000000c100000 [ 0.000000] GICv3: GIC: PPI partition interrupt-partition-0[0] { /cpus/cpu@0[0] /cpus/cpu@1[1] /cpus/cpu@2[2] /cpus/cpu@3[3] } [ 0.000000] GICv3: GIC: PPI partition interrupt-partition-1[1] { /cpus/cpu@100[4] /cpus/cpu@101[5] /cpus/cpu@102[6] /cpus/cpu@103[7] } [ 0.000000] arch_timer: cp15 timer(s) running at 13.00MHz (phys). [ 0.000000] clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x2ff89eacb, max_idle_ns: 440795202429 ns [ 0.000003] sched_clock: 56 bits at 13MHz, resolution 76ns, wraps every 4398046511101ns [ 0.000441] kmemleak: Early log buffer exceeded (131217), please increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE
> On syzbot we use 16000 and it's > enough for a very beefy config: > > https://github.com/google/syzkaller/blob/master/dashboard/config/upstream-leak.config > > If it's freed later, I would increase the default as well.
Sure I can do that as part of a v2, at least to 16K, maybe more if we have no reason to believe there is another issue with my configuration.
> 400 never > worked for me and I've seen people being confused and wasn't able to > use kmemleak, e.g.: > > https://groups.google.com/forum/#!searchin/syzkaller/CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE|sort:date/syzkaller/Rzf2ZRC9Qxw/tLog4DHXAgAJ > > https://groups.google.com/forum/#!searchin/syzkaller/CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE|sort:date/syzkaller/5HxmTuQ7U4A/XM8s2o2CCAAJ > > > > > Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> > > --- > > lib/Kconfig.debug | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > > index f567875b87657de..1a197b8125768b9 100644 > > --- a/lib/Kconfig.debug > > +++ b/lib/Kconfig.debug > > @@ -595,7 +595,7 @@ config DEBUG_KMEMLEAK > > config DEBUG_KMEMLEAK_EARLY_LOG_SIZE > > int "Maximum kmemleak early log entries" > > depends on DEBUG_KMEMLEAK > > - range 200 40000 > > + range 200 1000000 > > default 400 > > help > > Kmemleak must track all the memory allocations to avoid > > -- > > 2.22.0.657.g960e92d24f-goog > >
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