- 05 May, 2017 35 commits
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Omar Sandoval authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit c4baad50 upstream. put_chars() stuffs the buffer it gets into an sg, but that buffer may be on the stack. This breaks with CONFIG_VMAP_STACK=y (for me, it manifested as printks getting turned into NUL bytes). Signed-off-by:
Omar Sandoval <osandov@fb.com> Signed-off-by:
Michael S. Tsirkin <mst@redhat.com> Reviewed-by:
Amit Shah <amit.shah@redhat.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Brad Spengler <spender@grsecurity.net> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
Stefan Bader <stefan.bader@canonical.com> Signed-off-by:
Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
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Stefan Brüns authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 67b0503d upstream. The buffer allocation for the firmware data was changed in commit 43fab979 ("[media] dvb-usb: don't use stack for firmware load") but the same applies for the reset value. Fixes: 43fab979 ("[media] dvb-usb: don't use stack for firmware load") Signed-off-by:
Stefan Brüns <stefan.bruens@rwth-aachen.de> Signed-off-by:
Mauro Carvalho Chehab <mchehab@s-opensource.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Brad Spengler <spender@grsecurity.net> Signed-off-by:
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Mauro Carvalho Chehab authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 43fab979 upstream. As reported by Marc Duponcheel <marc@offline.be>, firmware load on dvb-usb is using the stack, with is not allowed anymore on default Kernel configurations: [ 1025.958836] dvb-usb: found a 'WideView WT-220U PenType Receiver (based on ZL353)' in cold state, will try to load a firmware [ 1025.958853] dvb-usb: downloading firmware from file 'dvb-usb-wt220u-zl0353-01.fw' [ 1025.958855] dvb-usb: could not stop the USB controller CPU. [ 1025.958856] dvb-usb: error while transferring firmware (transferred size: -11, block size: 3) [ 1025.958856] dvb-usb: firmware download failed at 8 with -22 [ 1025.958867] usbcore: registered new interface driver dvb_usb_dtt200u [ 2.789902] dvb-usb: downloading firmware from file 'dvb-usb-wt220u-zl0353-01.fw' [ 2.789905] ------------[ cut here ]------------ [ 2.789911] WARNING: CPU: 3 PID: 2196 at drivers/usb/core/hcd.c:1584 usb_hcd_map_urb_for_dma+0x430/0x560 [usbcore] [ 2.789912] transfer buffer not dma capable [ 2.789912] Modules linked in: btusb dvb_usb_dtt200u(+) dvb_usb_af9035(+) btrtl btbcm dvb_usb dvb_usb_v2 btintel dvb_core bluetooth rc_core rfkill x86_pkg_temp_thermal intel_powerclamp coretemp crc32_pclmul aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd drm_kms_helper syscopyarea sysfillrect pcspkr i2c_i801 sysimgblt fb_sys_fops drm i2c_smbus i2c_core r8169 lpc_ich mfd_core mii thermal fan rtc_cmos video button acpi_cpufreq processor snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd crc32c_intel ahci libahci libata xhci_pci ehci_pci xhci_hcd ehci_hcd usbcore usb_common dm_mirror dm_region_hash dm_log dm_mod [ 2.789936] CPU: 3 PID: 2196 Comm: systemd-udevd Not tainted 4.9.0-gentoo #1 [ 2.789937] Hardware name: ASUS All Series/H81I-PLUS, BIOS 0401 07/23/2013 [ 2.789938] ffffc9000339b690 ffffffff812bd397 ffffc9000339b6e0 0000000000000000 [ 2.789939] ffffc9000339b6d0 ffffffff81055c86 000006300339b6a0 ffff880116c0c000 [ 2.789941] 0000000000000000 0000000000000000 0000000000000001 ffff880116c08000 [ 2.789942] Call Trace: [ 2.789945] [<ffffffff812bd397>] dump_stack+0x4d/0x66 [ 2.789947] [<ffffffff81055c86>] __warn+0xc6/0xe0 [ 2.789948] [<ffffffff81055cea>] warn_slowpath_fmt+0x4a/0x50 [ 2.789952] [<ffffffffa006d460>] usb_hcd_map_urb_for_dma+0x430/0x560 [usbcore] [ 2.789954] [<ffffffff814ed5a8>] ? io_schedule_timeout+0xd8/0x110 [ 2.789956] [<ffffffffa006e09c>] usb_hcd_submit_urb+0x9c/0x980 [usbcore] [ 2.789958] [<ffffffff812d0ebf>] ? copy_page_to_iter+0x14f/0x2b0 [ 2.789960] [<ffffffff81126818>] ? pagecache_get_page+0x28/0x240 [ 2.789962] [<ffffffff8118c2a0>] ? touch_atime+0x20/0xa0 [ 2.789964] [<ffffffffa006f7c4>] usb_submit_urb+0x2c4/0x520 [usbcore] [ 2.789967] [<ffffffffa006feca>] usb_start_wait_urb+0x5a/0xe0 [usbcore] [ 2.789969] [<ffffffffa007000c>] usb_control_msg+0xbc/0xf0 [usbcore] [ 2.789970] [<ffffffffa067903d>] usb_cypress_writemem+0x3d/0x40 [dvb_usb] [ 2.789972] [<ffffffffa06791cf>] usb_cypress_load_firmware+0x4f/0x130 [dvb_usb] [ 2.789973] [<ffffffff8109dbbe>] ? console_unlock+0x2fe/0x5d0 [ 2.789974] [<ffffffff8109e10c>] ? vprintk_emit+0x27c/0x410 [ 2.789975] [<ffffffff8109e40a>] ? vprintk_default+0x1a/0x20 [ 2.789976] [<ffffffff81124d76>] ? printk+0x43/0x4b [ 2.789977] [<ffffffffa0679310>] dvb_usb_download_firmware+0x60/0xd0 [dvb_usb] [ 2.789979] [<ffffffffa0679898>] dvb_usb_device_init+0x3d8/0x610 [dvb_usb] [ 2.789981] [<ffffffffa069e302>] dtt200u_usb_probe+0x92/0xd0 [dvb_usb_dtt200u] [ 2.789984] [<ffffffffa007420c>] usb_probe_interface+0xfc/0x270 [usbcore] [ 2.789985] [<ffffffff8138bf95>] driver_probe_device+0x215/0x2d0 [ 2.789986] [<ffffffff8138c0e6>] __driver_attach+0x96/0xa0 [ 2.789987] [<ffffffff8138c050>] ? driver_probe_device+0x2d0/0x2d0 [ 2.789988] [<ffffffff81389ffb>] bus_for_each_dev+0x5b/0x90 [ 2.789989] [<ffffffff8138b7b9>] driver_attach+0x19/0x20 [ 2.789990] [<ffffffff8138b33c>] bus_add_driver+0x11c/0x220 [ 2.789991] [<ffffffff8138c91b>] driver_register+0x5b/0xd0 [ 2.789994] [<ffffffffa0072f6c>] usb_register_driver+0x7c/0x130 [usbcore] [ 2.789994] [<ffffffffa06a5000>] ? 0xffffffffa06a5000 [ 2.789996] [<ffffffffa06a501e>] dtt200u_usb_driver_init+0x1e/0x20 [dvb_usb_dtt200u] [ 2.789997] [<ffffffff81000408>] do_one_initcall+0x38/0x140 [ 2.789998] [<ffffffff8116001c>] ? __vunmap+0x7c/0xc0 [ 2.789999] [<ffffffff81124fb0>] ? do_init_module+0x22/0x1d2 [ 2.790000] [<ffffffff81124fe8>] do_init_module+0x5a/0x1d2 [ 2.790002] [<ffffffff810c96b1>] load_module+0x1e11/0x2580 [ 2.790003] [<ffffffff810c68b0>] ? show_taint+0x30/0x30 [ 2.790004] [<ffffffff81177250>] ? kernel_read_file+0x100/0x190 [ 2.790005] [<ffffffff810c9ffa>] SyS_finit_module+0xba/0xc0 [ 2.790007] [<ffffffff814f13e0>] entry_SYSCALL_64_fastpath+0x13/0x94 [ 2.790008] ---[ end trace c78a74e78baec6fc ]--- So, allocate the structure dynamically. Signed-off-by:
Ben Hutchings <ben@decadent.org.uk> Signed-off-by:
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Kees Cook authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit a4866aa8 upstream. Under CONFIG_STRICT_DEVMEM, reading System RAM through /dev/mem is disallowed. However, on x86, the first 1MB was always allowed for BIOS and similar things, regardless of it actually being System RAM. It was possible for heap to end up getting allocated in low 1MB RAM, and then read by things like x86info or dd, which would trip hardened usercopy: usercopy: kernel memory exposure attempt detected from ffff880000090000 (dma-kmalloc-256) (4096 bytes) This changes the x86 exception for the low 1MB by reading back zeros for System RAM areas instead of blindly allowing them. More work is needed to extend this to mmap, but currently mmap doesn't go through usercopy, so hardened usercopy won't Oops the kernel. Reported-by:
Tommi Rantala <tommi.t.rantala@nokia.com> Tested-by:
Kees Cook <keescook@chromium.org> Cc: Brad Spengler <spender@grsecurity.net> Signed-off-by:
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Thierry Reding authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 5fa40869 upstream. Accessing the registers of the RTC block on Tegra requires the module clock to be enabled. This only works because the RTC module clock will be enabled by default during early boot. However, because the clock is unused, the CCF will disable it at late_init time. This causes the RTC to become unusable afterwards. This can easily be reproduced by trying to use the RTC: $ hwclock --rtc /dev/rtc1 This will hang the system. I ran into this by following up on a report by Martin Michlmayr that reboot wasn't working on Tegra210 systems. It turns out that the rtc-tegra driver's ->shutdown() implementation will hang the CPU, because of the disabled clock, before the system can be rebooted. What confused me for a while is that the same driver is used on prior Tegra generations where the hang can not be observed. However, as Peter De Schrijver pointed out, this is because on 32-bit Tegra chips the RTC clock is enabled by the tegra20_timer.c clocksource driver, which uses the RTC to provide a persistent clock. This code is never enabled on 64-bit Tegra because the persistent clock infrastructure does not exist on 64-bit ARM. The proper fix for this is to add proper clock handling to the RTC driver in order to ensure that the clock is enabled when the driver requires it. All device trees contain the clock already, therefore no additional changes are required. Reported-by:
Martin Michlmayr <tbm@cyrius.com> Acked-By Peter De Schrijver <pdeschrijver@nvidia.com> Signed-off-by:
Thierry Reding <treding@nvidia.com> Signed-off-by:
Alexandre Belloni <alexandre.belloni@free-electrons.com> [bwh: Backported to 4.9: adjust context] Signed-off-by:
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Lee, Chun-Yi authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 98d610c3 upstream. The accelerometer event relies on the ACERWMID_EVENT_GUID notify. So, this patch changes the codes to setup accelerometer input device when detected ACERWMID_EVENT_GUID. It avoids that the accel input device created on every Acer machines. In addition, patch adds a clearly parsing logic of accelerometer hid to acer_wmi_get_handle_cb callback function. It is positive matching the "SENR" name with "BST0001" device to avoid non-supported hardware. Reported-by:
Bjørn Mork <bjorn@mork.no> Cc: Darren Hart <dvhart@infradead.org> Signed-off-by:
Lee, Chun-Yi <jlee@suse.com> [andy: slightly massage commit message] Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by:
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Daeho Jeong authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 05ac5aa1 upstream. We've fixed the race condition problem in calculating ext4 checksum value in commit b47820ed ("ext4: avoid modifying checksum fields directly during checksum veficationon"). However, by this change, when calculating the checksum value of inode whose i_extra_size is less than 4, we couldn't calculate the checksum value in a proper way. This problem was found and reported by Nix, Thank you. Reported-by:
Nix <nix@esperi.org.uk> Signed-off-by:
Daeho Jeong <daeho.jeong@samsung.com> Signed-off-by:
Youngjin Gil <youngjin.gil@samsung.com> Signed-off-by:
Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by:
Theodore Ts'o <tytso@mit.edu> Signed-off-by:
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Arnd Bergmann authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 00514537 upstream. I ran into a stack frame size warning because of the on-stack copy of the USB device structure: drivers/media/usb/dvb-usb-v2/dvb_usb_core.c: In function 'dvb_usbv2_disconnect': drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:1029:1: error: the frame size of 1104 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] Copying a device structure like this is wrong for a number of other reasons too aside from the possible stack overflow. One of them is that the dev_info() call will print the name of the device later, but AFAICT we have only copied a pointer to the name earlier and the actual name has been freed by the time it gets printed. This removes the on-stack copy of the device and instead copies the device name using kstrdup(). I'm ignoring the possible failure here as both printk() and kfree() are able to deal with NULL pointers. Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Miaoqing Pan authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 40bea976 upstream. relay_open() may return NULL, check the return value to avoid the crash. BUG: unable to handle kernel NULL pointer dereference at 0000000000000040 IP: [<ffffffffa01a95c5>] ath_cmn_process_fft+0xd5/0x700 [ath9k_common] PGD 41cf28067 PUD 41be92067 PMD 0 Oops: 0000 [#1] SMP CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.6+ #35 Hardware name: Hewlett-Packard h8-1080t/2A86, BIOS 6.15 07/04/2011 task: ffffffff81e0c4c0 task.stack: ffffffff81e00000 RIP: 0010:[<ffffffffa01a95c5>] [<ffffffffa01a95c5>] ath_cmn_process_fft+0xd5/0x700 [ath9k_common] RSP: 0018:ffff88041f203ca0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 000000000000059f RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffffffff81f0ca98 RBP: ffff88041f203dc8 R08: ffffffffffffffff R09: 00000000000000ff R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff81f0ca98 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88041f200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000040 CR3: 000000041b6ec000 CR4: 00000000000006f0 Stack: 0000000000000363 00000000000003f3 00000000000003f3 00000000000001f9 000000000000049a 0000000001252c04 ffff88041f203e44 ffff880417b4bfd0 0000000000000008 ffff88041785b9c0 0000000000000002 ffff88041613dc60 Call Trace: <IRQ> [<ffffffffa01b6441>] ath9k_tasklet+0x1b1/0x220 [ath9k] [<ffffffff8105d8dd>] tasklet_action+0x4d/0xf0 [<ffffffff8105dde2>] __do_softirq+0x92/0x2a0 Reported-by:
Devin Tuchsen <devin.tuchsen@gmail.com> Tested-by:
Miaoqing Pan <miaoqing@codeaurora.org> Signed-off-by:
Kalle Valo <kvalo@qca.qualcomm.com> Signed-off-by:
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Herbert Xu authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit ef0579b6 upstream. The ahash API modifies the request's callback function in order to clean up after itself in some corner cases (unaligned final and missing finup). When the request is complete ahash will restore the original callback and everything is fine. However, when the request gets an EBUSY on a full queue, an EINPROGRESS callback is made while the request is still ongoing. In this case the ahash API will incorrectly call its own callback. This patch fixes the problem by creating a temporary request object on the stack which is used to relay EINPROGRESS back to the original completion function. This patch also adds code to preserve the original flags value. Fixes: ab6bf4e5 ("crypto: hash - Fix the pointer voodoo in...") Reported-by:
Sabrina Dubroca <sd@queasysnail.net> Tested-by:
Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by:
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Benjamin Herrenschmidt authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 7ed23e1b upstream. On Power8 & Power9 the early CPU inititialisation in __init_HFSCR() turns on HFSCR[TM] (Hypervisor Facility Status and Control Register [Transactional Memory]), but that doesn't take into account that TM might be disabled by CPU features, or disabled by the kernel being built with CONFIG_PPC_TRANSACTIONAL_MEM=n. So later in boot, when we have setup the CPU features, clear HSCR[TM] if the TM CPU feature has been disabled. We use CPU_FTR_TM_COMP to account for the CONFIG_PPC_TRANSACTIONAL_MEM=n case. Without this a KVM guest might try use TM, even if told not to, and cause an oops in the host kernel. Typically the oops is seen in __kvmppc_vcore_entry() and may or may not be fatal to the host, but is always bad news. In practice all shipping CPU revisions do support TM, and all host kernels we are aware of build with TM support enabled, so no one should actually be able to hit this in the wild. Fixes: 2a3563b0 ("powerpc: Setup in HFSCR for POWER8") Cc: stable@vger.kernel.org # v3.10+ Signed-off-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by:
Sam Bobroff <sam.bobroff@au1.ibm.com> [mpe: Rewrite change log with input from Sam, add Fixes/stable] Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> [sb: Backported to linux-4.4.y: adjusted context] Signed-off-by:
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Minchan Kim authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit d72e9a7a upstream. The copy_page is optimized memcpy for page-alinged address. If it is used with non-page aligned address, it can corrupt memory which means system corruption. With zram, it can happen with 1. 64K architecture 2. partial IO 3. slub debug Partial IO need to allocate a page and zram allocates it via kmalloc. With slub debug, kmalloc(PAGE_SIZE) doesn't return page-size aligned address. And finally, copy_page(mem, cmem) corrupts memory. So, this patch changes it to memcpy. Actuaully, we don't need to change zram_bvec_write part because zsmalloc returns page-aligned address in case of PAGE_SIZE class but it's not good to rely on the internal of zsmalloc. Note: When this patch is merged to stable, clear_page should be fixed, too. Unfortunately, recent zram removes it by "same page merge" feature so it's hard to backport this patch to -stable tree. I will handle it when I receive the mail from stable tree maintainer to merge this patch to backport. Fixes: 42e99bd9 ("zram: optimize memory operations with clear_page()/copy_page()") Link: http://lkml.kernel.org/r/1492042622-12074-2-git-send-email-minchan@kernel.orgSigned-off-by:
Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Paolo Bonzini authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 06ce521a upstream. handle_vmon gets a reference on VMXON region page, but does not release it. Release the reference. Found by syzkaller; based on a patch by Dmitry. Reported-by:
Dmitry Vyukov <dvyukov@google.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: use skip_emulated_instruction()] Signed-off-by:
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Greg Kroah-Hartman authored
BugLink: http://bugs.launchpad.net/bugs/1687629 This reverts commit 6280ac93 which is commit 6c356eda upstream. It shouldn't have been included in a stable release. Reported-by:
Amit Pundir <amit.pundir@linaro.org> Cc: Felix Fietkau <nbd@nbd.name> Cc: John Crispin <john@phrozen.org> Cc: James Hogan <james.hogan@imgtec.com> Signed-off-by:
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Max Bires authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit f2cfa58b upstream. Without a bool string present, using "# CONFIG_DEVPORT is not set" in defconfig files would not actually unset devport. This esnured that /dev/port was always on, but there are reasons a user may wish to disable it (smaller kernel, attack surface reduction) if it's not being used. Adding a message here in order to make this user visible. Signed-off-by:
Max Bires <jbires@google.com> Acked-by:
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Geert Uytterhoeven authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 309124e2 upstream. According to full-history-linux commit d3794f4fa7c3edc3 ("[PATCH] M68k update (part 25)"), port operations are allowed on m68k if CONFIG_ISA is defined. However, commit 153dcc54 ("[PATCH] mem driver: fix conditional on isa i/o support") accidentally changed an "||" into an "&&", disabling it completely on m68k. This logic was retained when introducing the DEVPORT symbol in commit 4f911d64 ("Make /dev/port conditional on config symbol"). Drop the bogus dependency on !M68K to fix this. Fixes: 153dcc54 ("[PATCH] mem driver: fix conditional on isa i/o support") Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Tested-by:
Al Stone <ahs3@redhat.com> Signed-off-by:
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Steven Rostedt (VMware) authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 82cc4fc2 upstream. When two function probes are added to set_ftrace_filter, and then one of them is removed, the update to the function locations is not performed, and the record keeping of the function states are corrupted, and causes an ftrace_bug() to occur. This is easily reproducable by adding two probes, removing one, and then adding it back again. # cd /sys/kernel/debug/tracing # echo schedule:traceoff > set_ftrace_filter # echo do_IRQ:traceoff > set_ftrace_filter # echo \!do_IRQ:traceoff > /debug/tracing/set_ftrace_filter # echo do_IRQ:traceoff > set_ftrace_filter Causes: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1098 at kernel/trace/ftrace.c:2369 ftrace_get_addr_curr+0x143/0x220 Modules linked in: [...] CPU: 2 PID: 1098 Comm: bash Not tainted 4.10.0-test+ #405 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 Call Trace: dump_stack+0x68/0x9f __warn+0x111/0x130 ? trace_irq_work_interrupt+0xa0/0xa0 warn_slowpath_null+0x1d/0x20 ftrace_get_addr_curr+0x143/0x220 ? __fentry__+0x10/0x10 ftrace_replace_code+0xe3/0x4f0 ? ftrace_int3_handler+0x90/0x90 ? printk+0x99/0xb5 ? 0xffffffff81000000 ftrace_modify_all_code+0x97/0x110 arch_ftrace_update_code+0x10/0x20 ftrace_run_update_code+0x1c/0x60 ftrace_run_modify_code.isra.48.constprop.62+0x8e/0xd0 register_ftrace_function_probe+0x4b6/0x590 ? ftrace_startup+0x310/0x310 ? debug_lockdep_rcu_enabled.part.4+0x1a/0x30 ? update_stack_state+0x88/0x110 ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320 ? preempt_count_sub+0x18/0xd0 ? mutex_lock_nested+0x104/0x800 ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320 ? __unwind_start+0x1c0/0x1c0 ? _mutex_lock_nest_lock+0x800/0x800 ftrace_trace_probe_callback.isra.3+0xc0/0x130 ? func_set_flag+0xe0/0xe0 ? __lock_acquire+0x642/0x1790 ? __might_fault+0x1e/0x20 ? trace_get_user+0x398/0x470 ? strcmp+0x35/0x60 ftrace_trace_onoff_callback+0x48/0x70 ftrace_regex_write.isra.43.part.44+0x251/0x320 ? match_records+0x420/0x420 ftrace_filter_write+0x2b/0x30 __vfs_write+0xd7/0x330 ? do_loop_readv_writev+0x120/0x120 ? locks_remove_posix+0x90/0x2f0 ? do_lock_file_wait+0x160/0x160 ? __lock_is_held+0x93/0x100 ? rcu_read_lock_sched_held+0x5c/0xb0 ? preempt_count_sub+0x18/0xd0 ? __sb_start_write+0x10a/0x230 ? vfs_write+0x222/0x240 vfs_write+0xef/0x240 SyS_write+0xab/0x130 ? SyS_read+0x130/0x130 ? trace_hardirqs_on_caller+0x182/0x280 ? trace_hardirqs_on_thunk+0x1a/0x1c entry_SYSCALL_64_fastpath+0x18/0xad RIP: 0033:0x7fe61c157c30 RSP: 002b:00007ffe87890258 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: ffffffff8114a410 RCX: 00007fe61c157c30 RDX: 0000000000000010 RSI: 000055814798f5e0 RDI: 0000000000000001 RBP: ffff8800c9027f98 R08: 00007fe61c422740 R09: 00007fe61ca53700 R10: 0000000000000073 R11: 0000000000000246 R12: 0000558147a36400 R13: 00007ffe8788f160 R14: 0000000000000024 R15: 00007ffe8788f15c ? trace_hardirqs_off_caller+0xc0/0x110 ---[ end trace 99fa09b3d9869c2c ]--- Bad trampoline accounting at: ffffffff81cc3b00 (do_IRQ+0x0/0x150) Fixes: 59df055f ("ftrace: trace different functions with a different tracer") Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by:
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Tyler Baker authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 75eb5e1e upstream. The raw_spinlock in the IMX GPCV2 interupt chip is not initialized before usage. That results in a lockdep splat: INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. Add the missing raw_spin_lock_init() to the setup code. Fixes: e324c4dc ("irqchip/imx-gpcv2: IMX GPCv2 driver for wakeup sources") Signed-off-by:
Tyler Baker <tyler.baker@linaro.org> Reviewed-by:
Fabio Estevam <fabio.estevam@nxp.com> Cc: jason@lakedaemon.net Cc: marc.zyngier@arm.com Cc: shawnguo@kernel.org Cc: andrew.smirnov@gmail.com Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20170413222731.5917-1-tyler.baker@linaro.orgSigned-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Dan Williams authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 0beb2012 upstream. Holding the reconfig_mutex over a potential userspace fault sets up a lockdep dependency chain between filesystem-DAX and the libnvdimm ioctl path. Move the user access outside of the lock. [ INFO: possible circular locking dependency detected ] 4.11.0-rc3+ #13 Tainted: G W O ------------------------------------------------------- fallocate/16656 is trying to acquire lock: (&nvdimm_bus->reconfig_mutex){+.+.+.}, at: [<ffffffffa00080b1>] nvdimm_bus_lock+0x21/0x30 [libnvdimm] but task is already holding lock: (jbd2_handle){++++..}, at: [<ffffffff813b4944>] start_this_handle+0x104/0x460 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (jbd2_handle){++++..}: lock_acquire+0xbd/0x200 start_this_handle+0x16a/0x460 jbd2__journal_start+0xe9/0x2d0 __ext4_journal_start_sb+0x89/0x1c0 ext4_dirty_inode+0x32/0x70 __mark_inode_dirty+0x235/0x670 generic_update_time+0x87/0xd0 touch_atime+0xa9/0xd0 ext4_file_mmap+0x90/0xb0 mmap_region+0x370/0x5b0 do_mmap+0x415/0x4f0 vm_mmap_pgoff+0xd7/0x120 SyS_mmap_pgoff+0x1c5/0x290 SyS_mmap+0x22/0x30 entry_SYSCALL_64_fastpath+0x1f/0xc2 -> #1 (&mm->mmap_sem){++++++}: lock_acquire+0xbd/0x200 __might_fault+0x70/0xa0 __nd_ioctl+0x683/0x720 [libnvdimm] nvdimm_ioctl+0x8b/0xe0 [libnvdimm] do_vfs_ioctl+0xa8/0x740 SyS_ioctl+0x79/0x90 do_syscall_64+0x6c/0x200 return_from_SYSCALL_64+0x0/0x7a -> #0 (&nvdimm_bus->reconfig_mutex){+.+.+.}: __lock_acquire+0x16b6/0x1730 lock_acquire+0xbd/0x200 __mutex_lock+0x88/0x9b0 mutex_lock_nested+0x1b/0x20 nvdimm_bus_lock+0x21/0x30 [libnvdimm] nvdimm_forget_poison+0x25/0x50 [libnvdimm] nvdimm_clear_poison+0x106/0x140 [libnvdimm] pmem_do_bvec+0x1c2/0x2b0 [nd_pmem] pmem_make_request+0xf9/0x270 [nd_pmem] generic_make_request+0x118/0x3b0 submit_bio+0x75/0x150 Fixes: 62232e45 ("libnvdimm: control (ioctl) messages for nvdimm_bus and nvdimm devices") Cc: Dave Jiang <dave.jiang@intel.com> Reported-by:
Vishal Verma <vishal.l.verma@intel.com> Signed-off-by:
Dan Williams <dan.j.williams@intel.com> Signed-off-by:
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Juergen Gross authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 9121b15b upstream. Connecting to the backend isn't working reliably in xen-fbfront: in case XenbusStateInitWait of the backend has been missed the backend transition to XenbusStateConnected will trigger the connected state only without doing the actions required when the backend has connected. Signed-off-by:
Juergen Gross <jgross@suse.com> Reviewed-by:
Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by:
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by:
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Martin K. Petersen authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 7c856152 upstream. We previously made sure that the reported disk capacity was less than 0xffffffff blocks when the kernel was not compiled with large sector_t support (CONFIG_LBDAF). However, this check assumed that the capacity was reported in units of 512 bytes. Add a sanity check function to ensure that we only enable disks if the entire reported capacity can be expressed in terms of sector_t. Reported-by:
Steve Magnani <steve.magnani@digidescorp.com> Cc: Bart Van Assche <Bart.VanAssche@sandisk.com> Reviewed-by:
Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by:
Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by:
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Fam Zheng authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 67804145 upstream. If device reports a small max_xfer_blocks and a zero opt_xfer_blocks, we end up using BLK_DEF_MAX_SECTORS, which is wrong and r/w of that size may get error. [mkp: tweaked to avoid setting rw_max twice and added typecast] Fixes: ca369d51 ("block/sd: Fix device-imposed transfer length limits") Signed-off-by:
Fam Zheng <famz@redhat.com> Signed-off-by:
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Martin K. Petersen authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit a00a7862 upstream. Kefeng Wang discovered that old versions of the QEMU CD driver would return mangled mode data causing us to walk off the end of the buffer in an attempt to parse it. Sanity check the returned mode sense data. Reported-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Tested-by:
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Nicholas Bellinger authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 1c99de98 upstream. Once upon a time back in 2009, a work-around was added to support the GlobalSAN iSCSI initiator v3.3 for MacOSX, which during login did not propose nor respond to MaxBurstLength, FirstBurstLength, DefaultTime2Wait and DefaultTime2Retain keys. The work-around in iscsi_check_proposer_for_optional_reply() allowed the missing keys to be proposed, but did not require waiting for a response before moving to full feature phase operation. This allowed GlobalSAN v3.3 to work out-of-the box, and for many years we didn't run into login interopt issues with any other initiators.. Until recently, when Martin tried a QLogic 57840S iSCSI Offload HBA on Windows 2016 which completed login, but subsequently failed with: Got unknown iSCSI OpCode: 0x43 The issue was QLogic MSFT side did not propose DefaultTime2Wait + DefaultTime2Retain, so LIO proposes them itself, and immediately transitions to full feature phase because of the GlobalSAN hack. However, the QLogic MSFT side still attempts to respond to DefaultTime2Retain + DefaultTime2Wait, even though LIO has set ISCSI_FLAG_LOGIN_NEXT_STAGE3 + ISCSI_FLAG_LOGIN_TRANSIT in last login response. So while the QLogic MSFT side should have been proposing these two keys to start, it was doing the correct thing per RFC-3720 attempting to respond to proposed keys before transitioning to full feature phase. All that said, recent versions of GlobalSAN iSCSI (v5.3.0.541) does correctly propose the four keys during login, making the original work-around moot. So in order to allow QLogic MSFT to run unmodified as-is, go ahead and drop this long standing work-around. Reported-by:
Martin Svec <martin.svec@zoner.cz> Cc: Martin Svec <martin.svec@zoner.cz> Cc: Himanshu Madhani <Himanshu.Madhani@cavium.com> Cc: Arun Easi <arun.easi@cavium.com> Signed-off-by:
Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by:
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Nicholas Bellinger authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit efb2ea77 upstream. This patch fixes a iscsi-target specific TMR reference leak during session shutdown, that could occur when a TMR was quiesced before the hand-off back to iscsi-target code via transport_cmd_check_stop_to_fabric(). The reference leak happens because iscsit_free_cmd() was incorrectly skipping the final target_put_sess_cmd() for TMRs when transport_generic_free_cmd() returned zero because the se_cmd->cmd_kref did not reach zero, due to the missing se_cmd assignment in original code. The result was iscsi_cmd and it's associated se_cmd memory would be freed once se_sess->sess_cmd_map where released, but the associated se_tmr_req was leaked and remained part of se_device->dev_tmr_list. This bug would manfiest itself as kernel paging request OOPsen in core_tmr_lun_reset(), when a left-over se_tmr_req attempted to dereference it's se_cmd pointer that had already been released during normal session shutdown. To address this bug, go ahead and treat ISCSI_OP_SCSI_CMD and ISCSI_OP_SCSI_TMFUNC the same when there is an extra se_cmd->cmd_kref to drop in iscsit_free_cmd(), and use op_scsi to signal __iscsit_free_cmd() when the former needs to clear any further iscsi related I/O state. Reported-by:
Rob Millner <rlm@daterainc.com> Cc: Rob Millner <rlm@daterainc.com> Reported-by:
Chu Yuan Lin <cyl@datera.io> Cc: Chu Yuan Lin <cyl@datera.io> Tested-by:
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Dan Williams authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit b03b99a3 upstream. While reviewing the -stable patch for commit 86ef58a4 "nfit, libnvdimm: fix interleave set cookie calculation" Ben noted: "This is returning an int, thus it's effectively doing a 32-bit comparison and not the 64-bit comparison you say is needed." Update the compare operation to be immune to this integer demotion problem. Cc: Nicholas Moulin <nicholas.w.moulin@linux.intel.com> Fixes: 86ef58a4 ("nfit, libnvdimm: fix interleave set cookie calculation") Reported-by:
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Thomas Gleixner authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 6fdc6dd9 upstream. The vsyscall32 sysctl can racy against a concurrent fork when it switches from disabled to enabled: arch_setup_additional_pages() if (vdso32_enabled) --> No mapping sysctl.vsysscall32() --> vdso32_enabled = true create_elf_tables() ARCH_DLINFO_IA32 if (vdso32_enabled) { --> Add VDSO entry with NULL pointer Make ARCH_DLINFO_IA32 check whether the VDSO mapping has been set up for the newly forked process or not. Signed-off-by:
Andy Lutomirski <luto@amacapital.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mathias Krause <minipli@googlemail.com> Link: http://lkml.kernel.org/r/20170410151723.602367196@linutronix.deSigned-off-by:
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Mathias Krause authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit c06989da upstream. vdso_enabled can be set to arbitrary integer values via the kernel command line 'vdso32=' parameter or via 'sysctl abi.vsyscall32'. load_vdso32() only maps VDSO if vdso_enabled == 1, but ARCH_DLINFO_IA32 merily checks for vdso_enabled != 0. As a consequence the AT_SYSINFO_EHDR auxiliary vector for the VDSO_ENTRY is emitted with a NULL pointer which causes a segfault when the application tries to use the VDSO. Restrict the valid arguments on the command line and the sysctl to 0 and 1. Fixes: b0b49f26 ("x86, vdso: Remove compat vdso support") Signed-off-by:
Mathias Krause <minipli@googlemail.com> Acked-by:
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Peter Zijlstra authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit f2200ac3 upstream. When the perf_branch_entry::{in_tx,abort,cycles} fields were added, intel_pmu_lbr_read_32() wasn't updated to initialize them. Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Fixes: 135c5612 ("perf/x86/intel: Support Haswell/v4 LBR format") Signed-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Cameron Gutman authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 53763668 upstream. Signed-off-by:
Cameron Gutman <aicommander@gmail.com> Signed-off-by:
Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by:
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Germano Percossi authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 1fa839b4 upstream. This fixes Continuous Availability when errors during file reopen are encountered. cifs_user_readv and cifs_user_writev would wait for ever if results of cifs_reopen_file are not stored and for later inspection. In fact, results are checked and, in case of errors, a chain of function calls leading to reads and writes to be scheduled in a separate thread is skipped. These threads will wake up the corresponding waiters once reads and writes are done. However, given the return value is not stored, when rc is checked for errors a previous one (always zero) is inspected instead. This leads to pending reads/writes added to the list, making cifs_user_readv and cifs_user_writev wait for ever. Signed-off-by:
Germano Percossi <germano.percossi@citrix.com> Reviewed-by:
Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by:
Steve French <smfrench@gmail.com> Signed-off-by:
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Ilia Mirkin authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit f94773b9 upstream. The NV4A (aka NV44A) is an oddity in the family. It only comes in AGP and PCI varieties, rather than a core PCIE chip with a bridge for AGP/PCI as necessary. As a result, it appears that the MMU is also non-functional. For AGP cards, the vast majority of the NV4A lineup, this worked out since we force AGP cards to use the nv04 mmu. However for PCI variants, this did not work. Switching to the NV04 MMU makes it work like a charm. Thanks to mwk for the suggestion. This should be a no-op for NV4A AGP boards, as they were using it already. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70388Signed-off-by:
Ilia Mirkin <imirkin@alum.mit.edu> Signed-off-by:
Ben Skeggs <bskeggs@redhat.com> Signed-off-by:
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Ilia Mirkin authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 83bce9c2 upstream. Signed-off-by:
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Kirill A. Shutemov authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 5b7abeae upstream. Yet another instance of the same race. Fix is identical to change_huge_pmd(). See "thp: fix MADV_DONTNEED vs. numa balancing race" for more details. Link: http://lkml.kernel.org/r/20170302151034.27829-5-kirill.shutemov@linux.intel.comSigned-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by:
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Tejun Heo authored
BugLink: http://bugs.launchpad.net/bugs/1687629 commit 77f88796 upstream. Creation of a kthread goes through a couple interlocked stages between the kthread itself and its creator. Once the new kthread starts running, it initializes itself and wakes up the creator. The creator then can further configure the kthread and then let it start doing its job by waking it up. In this configuration-by-creator stage, the creator is the only one that can wake it up but the kthread is visible to userland. When altering the kthread's attributes from userland is allowed, this is fine; however, for cases where CPU affinity is critical, kthread_bind() is used to first disable affinity changes from userland and then set the affinity. This also prevents the kthread from being migrated into non-root cgroups as that can affect the CPU affinity and many other things. Unfortunately, the cgroup side of protection is racy. While the PF_NO_SETAFFINITY flag prevents further migrations, userland can win the race before the creator sets the flag with kthread_bind() and put the kthread in a non-root cgroup, which can lead to all sorts of problems including incorrect CPU affinity and starvation. This bug got triggered by userland which periodically tries to migrate all processes in the root cpuset cgroup to a non-root one. Per-cpu workqueue workers got caught while being created and ended up with incorrected CPU affinity breaking concurrency management and sometimes stalling workqueue execution. This patch adds task->no_cgroup_migration which disallows the task to be migrated by userland. kthreadd starts with the flag set making every child kthread start in the root cgroup with migration disallowed. The flag is cleared after the kthread finishes initialization by which time PF_NO_SETAFFINITY is set if the kthread should stay in the root cgroup. It'd be better to wait for the initialization instead of failing but I couldn't think of a way of implementing that without adding either a new PF flag, or sleeping and retrying from waiting side. Even if userland depends on changing cgroup membership of a kthread, it either has to be synchronized with kthread_create() or periodically repeat, so it's unlikely that this would break anything. v2: Switch to a simpler implementation using a new task_struct bit field suggested by Oleg. Signed-off-by:
Tejun Heo <tj@kernel.org> Suggested-by:
Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Reported-and-debugged-by:
Chris Mason <clm@fb.com> Signed-off-by:
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- 04 May, 2017 1 commit
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Thadeu Lima de Souza Cascardo authored
Ignore: yes Signed-off-by:
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- 27 Apr, 2017 4 commits
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Thadeu Lima de Souza Cascardo authored
Signed-off-by: -
Roman Pen authored
BugLink: http://bugs.launchpad.net/bugs/1683976 get_disk(),get_gendisk() calls have non explicit side effect: they increase the reference on the disk owner module. The following is the correct sequence how to get a disk reference and to put it: disk = get_gendisk(...); /* use disk */ owner = disk->fops->owner; put_disk(disk); module_put(owner); fs/block_dev.c is aware of this required module_put() call, but f.e. blkg_conf_finish(), which is located in block/blk-cgroup.c, does not put a module reference. To see a leakage in action cgroups throttle config can be used. In the following script I'm removing throttle for /dev/ram0 (actually this is NOP, because throttle was never set for this device): # lsmod | grep brd brd 5175 0 # i=100; while [ $i -gt 0 ]; do echo "1:0 0" > \ /sys/fs/cgroup/blkio/blkio.throttle.read_bps_device; i=$(($i - 1)); \ done # lsmod | grep brd brd 5175 100 Now brd module has 100 references. The issue is fixed by calling module_put() just right away put_disk(). Signed-off-by:
Roman Pen <roman.penyaev@profitbricks.com> Cc: Gi-Oh Kim <gi-oh.kim@profitbricks.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by:
Jens Axboe <axboe@fb.com> (cherry picked from commit 39a169b6) Signed-off-by:
Joseph Salisbury <joseph.salisbury@canonical.com> Acked-by:
Kamal Mostafa <kamal@canonical.com> Acked-by:
Colin Ian King <colin.king@canonical.com> Signed-off-by:
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Jan Kara authored
BugLink: http://bugs.launchpad.net/bugs/1659111 When device open races with device shutdown, we can get the following oops in scsi_disk_get(): [11863.044351] general protection fault: 0000 [#1] SMP [11863.045561] Modules linked in: scsi_debug xfs libcrc32c netconsole btrfs raid6_pq zlib_deflate lzo_compress xor [last unloaded: loop] [11863.047853] CPU: 3 PID: 13042 Comm: hald-probe-stor Tainted: G W 4.10.0-rc2-xen+ #35 [11863.048030] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [11863.048030] task: ffff88007f438200 task.stack: ffffc90000fd0000 [11863.048030] RIP: 0010:scsi_disk_get+0x43/0x70 [11863.048030] RSP: 0018:ffffc90000fd3a08 EFLAGS: 00010202 [11863.048030] RAX: 6b6b6b6b6b6b6b6b RBX: ffff88007f56d000 RCX: 0000000000000000 [11863.048030] RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff81a8d880 [11863.048030] RBP: ffffc90000fd3a18 R08: 0000000000000000 R09: 0000000000000001 [11863.059217] R10: 0000000000000000 R11: 0000000000000000 R12: 00000000fffffffa [11863.059217] R13: ffff880078872800 R14: ffff880070915540 R15: 000000000000001d [11863.059217] FS: 00007f2611f71800(0000) GS:ffff88007f0c0000(0000) knlGS:0000000000000000 [11863.059217] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [11863.059217] CR2: 000000000060e048 CR3: 00000000778d4000 CR4: 00000000000006e0 [11863.059217] Call Trace: [11863.059217] ? disk_get_part+0x22/0x1f0 [11863.059217] sd_open+0x39/0x130 [11863.059217] __blkdev_get+0x69/0x430 [11863.059217] ? bd_acquire+0x7f/0xc0 [11863.059217] ? bd_acquire+0x96/0xc0 [11863.059217] ? blkdev_get+0x350/0x350 [11863.059217] blkdev_get+0x126/0x350 [11863.059217] ? _raw_spin_unlock+0x2b/0x40 [11863.059217] ? bd_acquire+0x7f/0xc0 [11863.059217] ? blkdev_get+0x350/0x350 [11863.059217] blkdev_open+0x65/0x80 ... As you can see RAX value is already poisoned showing that gendisk we got is already freed. The problem is that get_gendisk() looks up device number in ext_devt_idr and then does get_disk() which does kobject_get() on the disks kobject. However the disk gets removed from ext_devt_idr only in disk_release() (through blk_free_devt()) at which moment it has already 0 refcount and is already on its way to be freed. Indeed we've got a warning from kobject_get() about 0 refcount shortly before the oops. We fix the problem by using kobject_get_unless_zero() in get_disk() so that get_disk() cannot get reference on a disk that is already being freed. Tested-by:
Lekshmi Pillai <lekshmicpillai@in.ibm.com> Reviewed-by:
Jan Kara <jack@suse.cz> Signed-off-by:
Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by:
Tim Gardner <tim.gardner@canonical.com> Acked-by:
Seth Forshee <seth.forshee@canonical.com> Acked-by:
Brad Figg <brad.figg@canonical.com> Signed-off-by:
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Jan Kara authored
BugLink: http://bugs.launchpad.net/bugs/1659111 Make the function available for outside use and fortify it against NULL kobject. CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by:
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