- 17 Oct, 2019 6 commits
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Johan Hovold authored
commit 5c290a5e upstream. Since commit c2b71462 ("USB: core: Fix bug caused by duplicate interface PM usage counter") USB drivers must always balance their runtime PM gets and puts, including when the driver has already been unbound from the interface. Leaving the interface with a positive PM usage counter would prevent a later bound driver from suspending the device. Fixes: c2b71462 ("USB: core: Fix bug caused by duplicate interface PM usage counter") Cc: stable <stable@vger.kernel.org> Signed-off-by:
Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20191001084908.2003-2-johan@kernel.orgSigned-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Johan Hovold authored
commit aafb00a9 upstream. The driver was using its struct usb_interface pointer as an inverted disconnected flag, but was setting it to NULL without making sure all code paths that used it were done with it. Before commit ef61eb43 ("USB: yurex: Fix protection fault after device removal") this included the interrupt-in completion handler, but there are further accesses in dev_err and dev_dbg statements in yurex_write() and the driver-data destructor (sic!). Fix this by unconditionally stopping also the control URB at disconnect and by using a dedicated disconnected flag. Note that we need to take a reference to the struct usb_interface to avoid a use-after-free in the destructor whenever the device was disconnected while the character device was still open. Fixes: aadd6472 ("USB: yurex.c: remove dbg() usage") Fixes: 45714104 ("USB: yurex.c: remove err() usage") Cc: stable <stable@vger.kernel.org> # 3.5: ef61eb43Signed-off-by:
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Alan Stern authored
commit 32a0721c upstream. According to Greg KH, it has been generally agreed that when a USB driver encounters an unknown error (or one it can't handle directly), it should just give up instead of going into a potentially infinite retry loop. The three codes -EPROTO, -EILSEQ, and -ETIME fall into this category. They can be caused by bus errors such as packet loss or corruption, attempting to communicate with a disconnected device, or by malicious firmware. Nowadays the extent of packet loss or corruption is negligible, so it should be safe for a driver to give up whenever one of these errors occurs. Although the yurex driver handles -EILSEQ errors in this way, it doesn't do the same for -EPROTO (as discovered by the syzbot fuzzer) or other unrecognized errors. This patch adjusts the driver so that it doesn't log an error message for -EPROTO or -ETIME, and it doesn't retry after any errors. Reported-and-tested-by: syzbot+b24d736f18a1541ad550@syzkaller.appspotmail.com Signed-off-by:
Alan Stern <stern@rowland.harvard.edu> CC: Tomoki Sekiyama <tomoki.sekiyama@gmail.com> CC: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1909171245410.1590-100000@iolanthe.rowland.orgSigned-off-by:
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Bastien Nocera authored
commit 015664d1 upstream. The Rio500 kernel driver has not been used by Rio500 owners since 2001 not long after the rio500 project added support for a user-space USB stack through the very first versions of usbdevfs and then libusb. Support for the kernel driver was removed from the upstream utilities in 2008: https://gitlab.freedesktop.org/hadess/rio500/commit/943f624ab721eb8281c287650fcc9e2026f6f5db Cc: Cesar Miquel <miquel@df.uba.ar> Signed-off-by:
Bastien Nocera <hadess@hadess.net> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/6251c17584d220472ce882a3d9c199c401a51a71.camel@hadess.netSigned-off-by:
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Icenowy Zheng authored
[ Upstream commit 38fb6d0e ] The kernel mount_block_root() function expects -EACESS or -EINVAL for a unmountable filesystem when trying to mount the root with different filesystem types. However, in 5.3-rc1 the behavior when F2FS code cannot find valid block changed to return -EFSCORRUPTED(-EUCLEAN), and this error code makes mount_block_root() fail when trying to probe F2FS. When the magic number of the superblock mismatches, it has a high probability that it's just not a F2FS. In this case return -EINVAL seems to be a better result, and this return value can make mount_block_root() probing work again. Return -EINVAL when the superblock has magic mismatch, -EFSCORRUPTED in other cases (the magic matches but the superblock cannot be recognized). Fixes: 10f966bb ("f2fs: use generic EFSBADCRC/EFSCORRUPTED") Signed-off-by:
Icenowy Zheng <icenowy@aosc.io> Reviewed-by:
Chao Yu <yuchao0@huawei.com> Signed-off-by:
Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by:
Sasha Levin <sashal@kernel.org>
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Will Deacon authored
commit 20bb759a upstream. Calling 'panic()' on a kernel with CONFIG_PREEMPT=y can leave the calling CPU in an infinite loop, but with interrupts and preemption enabled. From this state, userspace can continue to be scheduled, despite the system being "dead" as far as the kernel is concerned. This is easily reproducible on arm64 when booting with "nosmp" on the command line; a couple of shell scripts print out a periodic "Ping" message whilst another triggers a crash by writing to /proc/sysrq-trigger: | sysrq: Trigger a crash | Kernel panic - not syncing: sysrq triggered crash | CPU: 0 PID: 1 Comm: init Not tainted 5.2.15 #1 | Hardware name: linux,dummy-virt (DT) | Call trace: | dump_backtrace+0x0/0x148 | show_stack+0x14/0x20 | dump_stack+0xa0/0xc4 | panic+0x140/0x32c | sysrq_handle_reboot+0x0/0x20 | __handle_sysrq+0x124/0x190 | write_sysrq_trigger+0x64/0x88 | proc_reg_write+0x60/0xa8 | __vfs_write+0x18/0x40 | vfs_write+0xa4/0x1b8 | ksys_write+0x64/0xf0 | __arm64_sys_write+0x14/0x20 | el0_svc_common.constprop.0+0xb0/0x168 | el0_svc_handler+0x28/0x78 | el0_svc+0x8/0xc | Kernel Offset: disabled | CPU features: 0x0002,24002004 | Memory Limit: none | ---[ end Kernel panic - not syncing: sysrq triggered crash ]--- | Ping 2! | Ping 1! | Ping 1! | Ping 2! The issue can also be triggered on x86 kernels if CONFIG_SMP=n, otherwise local interrupts are disabled in 'smp_send_stop()'. Disable preemption in 'panic()' before re-enabling interrupts. Link: http://lkml.kernel.org/r/20191002123538.22609-1-will@kernel.org Link: https://lore.kernel.org/r/BX1W47JXPMR8.58IYW53H6M5N@dragonstoneSigned-off-by:
Will Deacon <will@kernel.org> Reported-by:
Xogium <contact@xogium.me> Reviewed-by:
Kees Cook <keescook@chromium.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Feng Tang <feng.tang@intel.com> Cc: <stable@vger.kernel.org> 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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- 11 Oct, 2019 34 commits
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Greg Kroah-Hartman authored
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Johannes Berg authored
commit f88eb7c0 upstream. We currently don't validate the beacon head, i.e. the header, fixed part and elements that are to go in front of the TIM element. This means that the variable elements there can be malformed, e.g. have a length exceeding the buffer size, but most downstream code from this assumes that this has already been checked. Add the necessary checks to the netlink policy. Cc: stable@vger.kernel.org Fixes: ed1b6cc7 ("cfg80211/nl80211: add beacon settings") Link: https://lore.kernel.org/r/1569009255-I7ac7fbe9436e9d8733439eab8acbbd35e55c74ef@changeidSigned-off-by:
Johannes Berg <johannes.berg@intel.com> Signed-off-by:
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Jouni Malinen authored
commit 7388afe0 upstream. Enforce the first argument to be a correct type of a pointer to struct element and avoid unnecessary typecasts from const to non-const pointers (the change in validate_ie_attr() is needed to make this part work). In addition, avoid signed/unsigned comparison within for_each_element() and mark struct element packed just in case. Signed-off-by:
Jouni Malinen <j@w1.fi> Signed-off-by:
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Johannes Berg authored
commit 0f3b07f0 upstream. Rather than always iterating elements from frames with pure u8 pointers, add a type "struct element" that encapsulates the id/datalen/data format of them. Then, add the element iteration macros * for_each_element * for_each_element_id * for_each_element_extid which take, as their first 'argument', such a structure and iterate through a given u8 array interpreting it as elements. While at it and since we'll need it, also add * for_each_subelement * for_each_subelement_id * for_each_subelement_extid which instead of taking data/length just take an outer element and use its data/datalen. Also add for_each_element_completed() to determine if any of the loops above completed, i.e. it was able to parse all of the elements successfully and no data remained. Use for_each_element_id() in cfg80211_find_ie_match() as the first user of this. Signed-off-by:
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Gao Xiang authored
commit e12a0ce2 upstream. As reported by erofs-utils fuzzer, currently, multiref (ondisk deduplication) hasn't been supported for now, we should forbid it properly. Fixes: 3883a79a ("staging: erofs: introduce VLE decompression support") Cc: <stable@vger.kernel.org> # 4.19+ Signed-off-by:
Gao Xiang <gaoxiang25@huawei.com> Reviewed-by:
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Gao Xiang authored
commit 138e1a09 upstream. As reported by erofs-utils fuzzer, these error handling path will be entered to handle corrupted images. Lack of erofs_workgroup_puts will cause unmounting unsuccessfully. Fix these return values to EFSCORRUPTED as well. Fixes: 3883a79a ("staging: erofs: introduce VLE decompression support") Cc: <stable@vger.kernel.org> # 4.19+ Signed-off-by:
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Gao Xiang authored
commit ee45197c upstream. As reported by erofs_utils fuzzer, a logical page can belong to at most 2 compressed clusters, if one compressed cluster is corrupted, but the other has been ready in submitting chain. The chain needs to submit anyway in order to keep the page working properly (page unlocked with PG_error set, PG_uptodate not set). Let's fix it now. Fixes: 3883a79a ("staging: erofs: introduce VLE decompression support") Cc: <stable@vger.kernel.org> # 4.19+ Signed-off-by:
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Gao Xiang authored
commit acb383f1 upstream. Richard observed a forever loop of erofs_read_raw_page() [1] which can be generated by forcely setting ->u.i_blkaddr to 0xdeadbeef (as my understanding block layer can handle access beyond end of device correctly). After digging into that, it seems the problem is highly related with directories and then I found the root cause is an improper error handling in erofs_readdir(). Let's fix it now. [1] https://lore.kernel.org/r/1163995781.68824.1566084358245.JavaMail.zimbra@nod.at/Reported-by:
Richard Weinberger <richard@nod.at> Fixes: 3aa8ec71 ("staging: erofs: add directory operations") Cc: <stable@vger.kernel.org> # 4.19+ Reviewed-by:
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Andrew Murray authored
commit 1004ce4c upstream. Synchronization is recommended before disabling the trace registers to prevent any start or stop points being speculative at the point of disabling the unit (section 7.3.77 of ARM IHI 0064D). Synchronization is also recommended after programming the trace registers to ensure all updates are committed prior to normal code resuming (section 4.3.7 of ARM IHI 0064D). Let's ensure these syncronization points are present in the code and clearly commented. Note that we could rely on the barriers in CS_LOCK and coresight_disclaim_device_unlocked or the context switch to user space - however coresight may be of use in the kernel. On armv8 the mb macro is defined as dsb(sy) - Given that the etm4x is only used on armv8 let's directly use dsb(sy) instead of mb(). This removes some ambiguity and makes it easier to correlate the code with the TRM. Signed-off-by:
Andrew Murray <andrew.murray@arm.com> Reviewed-by:
Suzuki K Poulose <suzuki.poulose@arm.com> [Fixed capital letter for "use" in title] Signed-off-by:
Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20190829202842.580-11-mathieu.poirier@linaro.org Cc: stable@vger.kernel.org # 4.9+ Signed-off-by:
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Eric Sandeen authored
commit cc3a7bfe upstream. Today, put_compat_statfs64() disallows nearly any field value over 2^32 if f_bsize is only 32 bits, but that makes no sense. compat_statfs64 is there for the explicit purpose of providing 64-bit fields for f_files, f_ffree, etc. And f_bsize is always only 32 bits. As a result, 32-bit userspace gets -EOVERFLOW for i.e. large file counts even with -D_FILE_OFFSET_BITS=64 set. In reality, only f_bsize and f_frsize can legitimately overflow (fields like f_type and f_namelen should never be large), so test only those fields. This bug was discussed at length some time ago, and this is the proposal Al suggested at https://lkml.org/lkml/2018/8/6/640. It seemed to get dropped amid the discussion of other related changes, but this part seems obviously correct on its own, so I've picked it up and sent it, for expediency. Fixes: 64d2ab32 ("vfs: fix put_compat_statfs64() does not handle errors") Signed-off-by:
Eric Sandeen <sandeen@redhat.com> Signed-off-by:
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Josh Poimboeuf authored
commit a111b7c0 upstream. Configure arm64 runtime CPU speculation bug mitigations in accordance with the 'mitigations=' cmdline option. This affects Meltdown, Spectre v2, and Speculative Store Bypass. The default behavior is unchanged. Signed-off-by:
Josh Poimboeuf <jpoimboe@redhat.com> [will: reorder checks so KASLR implies KPTI and SSBS is affected by cmdline] Signed-off-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by:
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Marc Zyngier authored
commit 517953c2 upstream. The SMCCC ARCH_WORKAROUND_1 service can indicate that although the firmware knows about the Spectre-v2 mitigation, this particular CPU is not vulnerable, and it is thus not necessary to call the firmware on this CPU. Let's use this information to our benefit. Signed-off-by:
Marc Zyngier <marc.zyngier@arm.com> Signed-off-by:
Jeremy Linton <jeremy.linton@arm.com> Reviewed-by:
Andre Przywara <andre.przywara@arm.com> Reviewed-by:
Catalin Marinas <catalin.marinas@arm.com> Tested-by:
Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by:
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Marc Zyngier authored
[ Upstream commit cbdf8a18 ] On a CPU that doesn't support SSBS, PSTATE[12] is RES0. In a system where only some of the CPUs implement SSBS, we end-up losing track of the SSBS bit across task migration. To address this issue, let's force the SSBS bit on context switch. Fixes: 8f04e8e6 ("arm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3") Signed-off-by:
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Will Deacon authored
[ Upstream commit eb337cdf ] SSBS provides a relatively cheap mitigation for SSB, but it is still a mitigation and its presence does not indicate that the CPU is unaffected by the vulnerability. Tweak the mitigation logic so that we report the correct string in sysfs. Signed-off-by:
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Jeremy Linton authored
[ Upstream commit 526e065d ] Return status based on ssbd_state and __ssb_safe. If the mitigation is disabled, or the firmware isn't responding then return the expected machine state based on a whitelist of known good cores. Given a heterogeneous machine, the overall machine vulnerability defaults to safe but is reset to unsafe when we miss the whitelist and the firmware doesn't explicitly tell us the core is safe. In order to make that work we delay transitioning to vulnerable until we know the firmware isn't responding to avoid a case where we miss the whitelist, but the firmware goes ahead and reports the core is not vulnerable. If all the cores in the machine have SSBS, then __ssb_safe will remain true. Tested-by:
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Jeremy Linton authored
[ Upstream commit d2532e27 ] Track whether all the cores in the machine are vulnerable to Spectre-v2, and whether all the vulnerable cores have been mitigated. We then expose this information to userspace via sysfs. Signed-off-by:
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Jeremy Linton authored
[ Upstream commit 8c1e3d2b ] Ensure we are always able to detect whether or not the CPU is affected by Spectre-v2, so that we can later advertise this to userspace. Signed-off-by:
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Marc Zyngier authored
[ Upstream commit 73f38166 ] We currently have a list of CPUs affected by Spectre-v2, for which we check that the firmware implements ARCH_WORKAROUND_1. It turns out that not all firmwares do implement the required mitigation, and that we fail to let the user know about it. Instead, let's slightly revamp our checks, and rely on a whitelist of cores that are known to be non-vulnerable, and let the user know the status of the mitigation in the kernel log. Signed-off-by:
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Jeremy Linton authored
[ Upstream commit e5ce5e72 ] There are various reasons, such as benchmarking, to disable spectrev2 mitigation on a machine. Provide a command-line option to do so. Signed-off-by:
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Jeremy Linton authored
[ Upstream commit d42281b6 ] Ensure we are always able to detect whether or not the CPU is affected by SSB, so that we can later advertise this to userspace. Signed-off-by:
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Mian Yousaf Kaukab authored
[ Upstream commit 61ae1321 ] Enable CPU vulnerabilty show functions for spectre_v1, spectre_v2, meltdown and store-bypass. Signed-off-by:
Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by:
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Jeremy Linton authored
[ Upstream commit 1b3ccf4b ] We implement page table isolation as a mitigation for meltdown. Report this to userspace via sysfs. Signed-off-by:
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Mian Yousaf Kaukab authored
[ Upstream commit 3891ebcc ] spectre-v1 has been mitigated and the mitigation is always active. Report this to userspace via sysfs Signed-off-by:
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Mark Rutland authored
[ Upstream commit f54dada8 ] In valid_user_regs() we treat SSBS as a RES0 bit, and consequently it is unexpectedly cleared when we restore a sigframe or fiddle with GPRs via ptrace. This patch fixes valid_user_regs() to account for this, updating the function to refer to the latest ARM ARM (ARM DDI 0487D.a). For AArch32 tasks, SSBS appears in bit 23 of SPSR_EL1, matching its position in the AArch32-native PSR format, and we don't need to translate it as we have to for DIT. There are no other bit assignments that we need to account for today. As the recent documentation describes the DIT bit, we can drop our comment regarding DIT. While removing SSBS from the RES0 masks, existing inconsistent whitespace is corrected. Fixes: d71be2b6 ("arm64: cpufeature: Detect SSBS and advertise to userspace") Signed-off-by:
Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by:
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Will Deacon authored
[ Upstream commit ee911761 ] We advertise the MRS/MSR instructions for toggling SSBS at EL0 using an HWCAP, so document it along with the others. Signed-off-by:
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Will Deacon authored
[ Upstream commit 7c36447a ] When running without VHE, it is necessary to set SCTLR_EL2.DSSBS if SSBD has been forcefully disabled on the kernel command-line. Acked-by:
Christoffer Dall <christoffer.dall@arm.com> Signed-off-by:
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Will Deacon authored
[ Upstream commit 8f04e8e6 ] On CPUs with support for PSTATE.SSBS, the kernel can toggle the SSBD state without needing to call into firmware. This patch hooks into the existing SSBD infrastructure so that SSBS is used on CPUs that support it, but it's all made horribly complicated by the very real possibility of big/little systems that don't uniformly provide the new capability. Signed-off-by:
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Vincent Chen authored
[ Upstream commit c82dd6d0 ] When the handle_exception function addresses an exception, the interrupts will be unconditionally enabled after finishing the context save. However, It may erroneously enable the interrupts if the interrupts are disabled before entering the handle_exception. For example, one of the WARN_ON() condition is satisfied in the scheduling where the interrupt is disabled and rq.lock is locked. The WARN_ON will trigger a break exception and the handle_exception function will enable the interrupts before entering do_trap_break function. During the procedure, if a timer interrupt is pending, it will be taken when interrupts are enabled. In this case, it may cause a deadlock problem if the rq.lock is locked again in the timer ISR. Hence, the handle_exception() can only enable interrupts when the state of sstatus.SPIE is 1. This patch is tested on HiFive Unleashed board. Signed-off-by:
Vincent Chen <vincent.chen@sifive.com> Reviewed-by:
Palmer Dabbelt <palmer@sifive.com> [paul.walmsley@sifive.com: updated to apply] Fixes: bcae803a ("RISC-V: Enable IRQ during exception handling") Cc: David Abdurachmanov <david.abdurachmanov@sifive.com> Cc: stable@vger.kernel.org Signed-off-by:
Paul Walmsley <paul.walmsley@sifive.com> Signed-off-by:
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Srikar Dronamraju authored
[ Upstream commit b63fd11c ] When using 'perf stat' with repeat and interval option, it shows wrong values for events. The wrong values will be shown for the first interval on the second and subsequent repetitions. Without the fix: # perf stat -r 3 -I 2000 -e faults -e sched:sched_switch -a sleep 5 2.000282489 53 faults 2.000282489 513 sched:sched_switch 4.005478208 3,721 faults 4.005478208 2,666 sched:sched_switch 5.025470933 395 faults 5.025470933 1,307 sched:sched_switch 2.009602825 1,84,46,74,40,73,70,95,47,520 faults <------ 2.009602825 1,84,46,74,40,73,70,95,49,568 sched:sched_switch <------ 4.019612206 4,730 faults 4.019612206 2,746 sched:sched_switch 5.039615484 3,953 faults 5.039615484 1,496 sched:sched_switch 2.000274620 1,84,46,74,40,73,70,95,47,520 faults <------ 2.000274620 1,84,46,74,40,73,70,95,47,520 sched:sched_switch <------ 4.000480342 4,282 faults 4.000480342 2,303 sched:sched_switch 5.000916811 1,322 faults 5.000916811 1,064 sched:sched_switch # prev_raw_counts is allocated when using intervals. This is used when calculating the difference in the counts of events when using interval. The current counts are stored in prev_raw_counts to calculate the differences in the next iteration. On the first interval of the second and subsequent repetitions, prev_raw_counts would be the values stored in the last interval of the previous repetitions, while the current counts will only be for the first interval of the current repetition. Hence there is a possibility of events showing up as big number. Fix this by resetting prev_raw_counts whenever perf stat repeats the command. With the fix: # perf stat -r 3 -I 2000 -e faults -e sched:sched_switch -a sleep 5 2.019349347 2,597 faults 2.019349347 2,753 sched:sched_switch 4.019577372 3,098 faults 4.019577372 2,532 sched:sched_switch 5.019415481 1,879 faults 5.019415481 1,356 sched:sched_switch 2.000178813 8,468 faults 2.000178813 2,254 sched:sched_switch 4.000404621 7,440 faults 4.000404621 1,266 sched:sched_switch 5.040196079 2,458 faults 5.040196079 556 sched:sched_switch 2.000191939 6,870 faults 2.000191939 1,170 sched:sched_switch 4.000414103 541 faults 4.000414103 902 sched:sched_switch 5.000809863 450 faults 5.000809863 364 sched:sched_switch # Committer notes: This was broken since the cset introducing the --interval feature, i.e. --repeat + --interval wasn't tested at that point, add the Fixes tag so that automatic scripts can pick this up. Fixes: 13370a9b ("perf stat: Add interval printing") Signed-off-by:
Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by:
Jiri Olsa <jolsa@kernel.org> Tested-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by:
Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Stephane Eranian <eranian@google.com> Cc: stable@vger.kernel.org # v3.9+ Link: http://lore.kernel.org/lkml/20190904094738.9558-2-srikar@linux.vnet.ibm.com [ Fixed up conflicts with libperf, i.e. some perf_{evsel,evlist} lost the 'perf' prefix ] Signed-off-by:
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Jiri Olsa authored
[ Upstream commit 0216234c ] We release wrong pointer on error path in cpu_cache_level__read function, leading to segfault: (gdb) r record ls Starting program: /root/perf/tools/perf/perf record ls ... [ perf record: Woken up 1 times to write data ] double free or corruption (out) Thread 1 "perf" received signal SIGABRT, Aborted. 0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6 (gdb) bt #0 0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6 #1 0x00007ffff7443bac in abort () from /lib64/power9/libc.so.6 #2 0x00007ffff74af8bc in __libc_message () from /lib64/power9/libc.so.6 #3 0x00007ffff74b92b8 in malloc_printerr () from /lib64/power9/libc.so.6 #4 0x00007ffff74bb874 in _int_free () from /lib64/power9/libc.so.6 #5 0x0000000010271260 in __zfree (ptr=0x7fffffffa0b0) at ../../lib/zalloc.. #6 0x0000000010139340 in cpu_cache_level__read (cache=0x7fffffffa090, cac.. #7 0x0000000010143c90 in build_caches (cntp=0x7fffffffa118, size=<optimiz.. ... Releasing the proper pointer. Fixes: 720e98b5 ("perf tools: Add perf data cache feature") Signed-off-by:
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Balasubramani Vivekanandan authored
[ Upstream commit b9023b91 ] When a cpu requests broadcasting, before starting the tick broadcast hrtimer, bc_set_next() checks if the timer callback (bc_handler) is active using hrtimer_try_to_cancel(). But hrtimer_try_to_cancel() does not provide the required synchronization when the callback is active on other core. The callback could have already executed tick_handle_oneshot_broadcast() and could have also returned. But still there is a small time window where the hrtimer_try_to_cancel() returns -1. In that case bc_set_next() returns without doing anything, but the next_event of the tick broadcast clock device is already set to a timeout value. In the race condition diagram below, CPU #1 is running the timer callback and CPU #2 is entering idle state and so calls bc_set_next(). In the worst case, the next_event will contain an expiry time, but the hrtimer will not be started which happens when the racing callback returns HRTIMER_NORESTART. The hrtimer might never recover if all further requests from the CPUs to subscribe to tick broadcast have timeout greater than the next_event of tick broadcast clock device. This leads to cascading of failures and finally noticed as rcu stall warnings Here is a depiction of the race condition CPU #1 (Running timer callback) CPU #2 (Enter idle and subscribe to tick broadcast) --------------------- --------------------- __run_hrtimer() tick_broadcast_enter() bc_handler() __tick_broadcast_oneshot_control() tick_handle_oneshot_broadcast() raw_spin_lock(&tick_broadcast_lock); dev->next_event = KTIME_MAX; //wait for tick_broadcast_lock //next_event for tick broadcast clock set to KTIME_MAX since no other cores subscribed to tick broadcasting raw_spin_unlock(&tick_broadcast_lock); if (dev->next_event == KTIME_MAX) return HRTIMER_NORESTART // callback function exits without restarting the hrtimer //tick_broadcast_lock acquired raw_spin_lock(&tick_broadcast_lock); tick_broadcast_set_event() clockevents_program_event() dev->next_event = expires; bc_set_next() hrtimer_try_to_cancel() //returns -1 since the timer callback is active. Exits without restarting the timer cpu_base->running = NULL; The comment that hrtimer cannot be armed from within the callback is wrong. It is fine to start the hrtimer from within the callback. Also it is safe to start the hrtimer from the enter/exit idle code while the broadcast handler is active. The enter/exit idle code and the broadcast handler are synchronized using tick_broadcast_lock. So there is no need for the existing try to cancel logic. All this can be removed which will eliminate the race condition as well. Fixes: 5d1638ac ("tick: Introduce hrtimer based broadcast") Originally-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
Balasubramani Vivekanandan <balasubramani_vivekanandan@mentor.com> Signed-off-by:
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Steven Rostedt (VMware) authored
[ Upstream commit e0d2615856b2046c2e8d5bfd6933f37f69703b0b ] If the re-allocation of tep->cmdlines succeeds, then the previous allocation of tep->cmdlines will be freed. If we later fail in add_new_comm(), we must not free cmdlines, and also should assign tep->cmdlines to the new allocation. Otherwise when freeing tep, the tep->cmdlines will be pointing to garbage. Fixes: a6d2a61a ("tools lib traceevent: Remove some die() calls") Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: linux-trace-devel@vger.kernel.org Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20190828191819.970121417@goodmis.orgSigned-off-by:
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Aneesh Kumar K.V authored
commit 09ce98ca upstream. Rename the #define to indicate this is related to store vs tlbie ordering issue. In the next patch, we will be adding another feature flag that is used to handles ERAT flush vs tlbie ordering issue. Fixes: a5d4b589 ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190924035254.24612-2-aneesh.kumar@linux.ibm.comSigned-off-by:
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Gautham R. Shenoy authored
[ Upstream commit c784be43 ] The calls to arch_add_memory()/arch_remove_memory() are always made with the read-side cpu_hotplug_lock acquired via memory_hotplug_begin(). On pSeries, arch_add_memory()/arch_remove_memory() eventually call resize_hpt() which in turn calls stop_machine() which acquires the read-side cpu_hotplug_lock again, thereby resulting in the recursive acquisition of this lock. In the absence of CONFIG_PROVE_LOCKING, we hadn't observed a system lockup during a memory hotplug operation because cpus_read_lock() is a per-cpu rwsem read, which, in the fast-path (in the absence of the writer, which in our case is a CPU-hotplug operation) simply increments the read_count on the semaphore. Thus a recursive read in the fast-path doesn't cause any problems. However, we can hit this problem in practice if there is a concurrent CPU-Hotplug operation in progress which is waiting to acquire the write-side of the lock. This will cause the second recursive read to block until the writer finishes. While the writer is blocked since the first read holds the lock. Thus both the reader as well as the writers fail to make any progress thereby blocking both CPU-Hotplug as well as Memory Hotplug operations. Memory-Hotplug CPU-Hotplug CPU 0 CPU 1 ------ ------ 1. down_read(cpu_hotplug_lock.rw_sem) [memory_hotplug_begin] 2. down_write(cpu_hotplug_lock.rw_sem) [cpu_up/cpu_down] 3. down_read(cpu_hotplug_lock.rw_sem) [stop_machine()] Lockdep complains as follows in these code-paths. swapper/0/1 is trying to acquire lock: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: stop_machine+0x2c/0x60 but task is already holding lock: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: mem_hotplug_begin+0x20/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(cpu_hotplug_lock.rw_sem); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by swapper/0/1: #0: (____ptrval____) (&dev->mutex){....}, at: __driver_attach+0x12c/0x1b0 #1: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: mem_hotplug_begin+0x20/0x50 #2: (____ptrval____) (mem_hotplug_lock.rw_sem){++++}, at: percpu_down_write+0x54/0x1a0 stack backtrace: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc5-58373-gbc99402235f3-dirty #166 Call Trace: dump_stack+0xe8/0x164 (unreliable) __lock_acquire+0x1110/0x1c70 lock_acquire+0x240/0x290 cpus_read_lock+0x64/0xf0 stop_machine+0x2c/0x60 pseries_lpar_resize_hpt+0x19c/0x2c0 resize_hpt_for_hotplug+0x70/0xd0 arch_add_memory+0x58/0xfc devm_memremap_pages+0x5e8/0x8f0 pmem_attach_disk+0x764/0x830 nvdimm_bus_probe+0x118/0x240 really_probe+0x230/0x4b0 driver_probe_device+0x16c/0x1e0 __driver_attach+0x148/0x1b0 bus_for_each_dev+0x90/0x130 driver_attach+0x34/0x50 bus_add_driver+0x1a8/0x360 driver_register+0x108/0x170 __nd_driver_register+0xd0/0xf0 nd_pmem_driver_init+0x34/0x48 do_one_initcall+0x1e0/0x45c kernel_init_freeable+0x540/0x64c kernel_init+0x2c/0x160 ret_from_kernel_thread+0x5c/0x68 Fix this issue by 1) Requiring all the calls to pseries_lpar_resize_hpt() be made with cpu_hotplug_lock held. 2) In pseries_lpar_resize_hpt() invoke stop_machine_cpuslocked() as a consequence of 1) 3) To satisfy 1), in hpt_order_set(), call mmu_hash_ops.resize_hpt() with cpu_hotplug_lock held. Fixes: dbcf929c ("powerpc/pseries: Add support for hash table resizing") Cc: stable@vger.kernel.org # v4.11+ Reported-by:
Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by:
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