kernel/linux.git/Documentation, branch v4.9.303

bpf: Add kconfig knob for disabling unpriv bpf by default

2022-02-16T11:43:54+00:00

commit 08389d888287c3823f80b0216766b71e17f0aba5 upstream. Add a kconfig knob which allows for unprivileged bpf to be disabled by default. If set, the knob sets /proc/sys/kernel/unprivileged_bpf_disabled to value of 2. This still allows a transition of 2 -> {0,1} through an admin. Similarly, this also still keeps 1 -> {1} behavior intact, so that once set to permanently disabled, it cannot be undone aside from a reboot. We've also added extra2 with max of 2 for the procfs handler, so that an admin still has a chance to toggle between 0 <-> 2. Either way, as an additional alternative, applications can make use of CAP_BPF that we added a while ago. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net [fllinden@amazon.com: backported to 4.9] Signed-off-by: Frank van der Linden Signed-off-by: Greg Kroah-Hartman

KVM: X86: MMU: Use the correct inherited permissions to get shadow page

2022-01-29T09:15:58+00:00

commit b1bd5cba3306691c771d558e94baa73e8b0b96b7 upstream. When computing the access permissions of a shadow page, use the effective permissions of the walk up to that point, i.e. the logic AND of its parents' permissions. Two guest PxE entries that point at the same table gfn need to be shadowed with different shadow pages if their parents' permissions are different. KVM currently uses the effective permissions of the last non-leaf entry for all non-leaf entries. Because all non-leaf SPTEs have full ("uwx") permissions, and the effective permissions are recorded only in role.access and merged into the leaves, this can lead to incorrect reuse of a shadow page and eventually to a missing guest protection page fault. For example, here is a shared pagetable: pgd[] pud[] pmd[] virtual address pointers /->pmd1(u--)->pte1(uw-)->page1 <- ptr1 (u--) /->pud1(uw-)--->pmd2(uw-)->pte2(uw-)->page2 <- ptr2 (uw-) pgd-| (shared pmd[] as above) \->pud2(u--)--->pmd1(u--)->pte1(uw-)->page1 <- ptr3 (u--) \->pmd2(uw-)->pte2(uw-)->page2 <- ptr4 (u--) pud1 and pud2 point to the same pmd table, so: - ptr1 and ptr3 points to the same page. - ptr2 and ptr4 points to the same page. (pud1 and pud2 here are pud entries, while pmd1 and pmd2 here are pmd entries) - First, the guest reads from ptr1 first and KVM prepares a shadow page table with role.access=u--, from ptr1's pud1 and ptr1's pmd1. "u--" comes from the effective permissions of pgd, pud1 and pmd1, which are stored in pt->access. "u--" is used also to get the pagetable for pud1, instead of "uw-". - Then the guest writes to ptr2 and KVM reuses pud1 which is present. The hypervisor set up a shadow page for ptr2 with pt->access is "uw-" even though the pud1 pmd (because of the incorrect argument to kvm_mmu_get_page in the previous step) has role.access="u--". - Then the guest reads from ptr3. The hypervisor reuses pud1's shadow pmd for pud2, because both use "u--" for their permissions. Thus, the shadow pmd already includes entries for both pmd1 and pmd2. - At last, the guest writes to ptr4. This causes no vmexit or pagefault, because pud1's shadow page structures included an "uw-" page even though its role.access was "u--". Any kind of shared pagetable might have the similar problem when in virtual machine without TDP enabled if the permissions are different from different ancestors. In order to fix the problem, we change pt->access to be an array, and any access in it will not include permissions ANDed from child ptes. The test code is: https://lore.kernel.org/kvm/20210603050537.19605-1-jiangshanlai@gmail.com/ Remember to test it with TDP disabled. The problem had existed long before the commit 41074d07c78b ("KVM: MMU: Fix inherited permissions for emulated guest pte updates"), and it is hard to find which is the culprit. So there is no fixes tag here. Signed-off-by: Lai Jiangshan Message-Id: <20210603052455.21023-1-jiangshanlai@gmail.com> Cc: stable@vger.kernel.org Fixes: cea0f0e7ea54 ("[PATCH] KVM: MMU: Shadow page table caching") Signed-off-by: Paolo Bonzini [bwh: Backported to 4.9: - Keep passing vcpu argument to gpte_access functions - Adjust filenames, context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

rbtree: cache leftmost node internally

2022-01-27T07:47:42+00:00

commit cd9e61ed1eebbcd5dfad59475d41ec58d9b64b6a upstream. Patch series "rbtree: Cache leftmost node internally", v4. A series to extending rbtrees to internally cache the leftmost node such that we can have fast overlap check optimization for all interval tree users[1]. The benefits of this series are that: (i) Unify users that do internal leftmost node caching. (ii) Optimize all interval tree users. (iii) Convert at least two new users (epoll and procfs) to the new interface. This patch (of 16): Red-black tree semantics imply that nodes with smaller or greater (or equal for duplicates) keys always be to the left and right, respectively. For the kernel this is extremely evident when considering our rb_first() semantics. Enabling lookups for the smallest node in the tree in O(1) can save a good chunk of cycles in not having to walk down the tree each time. To this end there are a few core users that explicitly do this, such as the scheduler and rtmutexes. There is also the desire for interval trees to have this optimization allowing faster overlap checking. This patch introduces a new 'struct rb_root_cached' which is just the root with a cached pointer to the leftmost node. The reason why the regular rb_root was not extended instead of adding a new structure was that this allows the user to have the choice between memory footprint and actual tree performance. The new wrappers on top of the regular rb_root calls are: - rb_first_cached(cached_root) -- which is a fast replacement for rb_first. - rb_insert_color_cached(node, cached_root, new) - rb_erase_cached(node, cached_root) In addition, augmented cached interfaces are also added for basic insertion and deletion operations; which becomes important for the interval tree changes. With the exception of the inserts, which adds a bool for updating the new leftmost, the interfaces are kept the same. To this end, porting rb users to the cached version becomes really trivial, and keeping current rbtree semantics for users that don't care about the optimization requires zero overhead. Link: http://lkml.kernel.org/r/20170719014603.19029-2-dave@stgolabs.net Signed-off-by: Davidlohr Bueso Reviewed-by: Jan Kara Acked-by: Peter Zijlstra (Intel) Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

bonding: fix ad_actor_system option setting to default

2021-12-29T11:14:48+00:00

[ Upstream commit 1c15b05baea71a5ff98235783e3e4ad227760876 ] When 802.3ad bond mode is configured the ad_actor_system option is set to "00:00:00:00:00:00". But when trying to set the all-zeroes MAC as actors' system address it was failing with EINVAL. An all-zeroes ethernet address is valid, only multicast addresses are not valid values. Fixes: 171a42c38c6e ("bonding: add netlink support for sys prio, actor sys mac, and port key") Signed-off-by: Fernando Fernandez Mancera Acked-by: Jay Vosburgh Link: https://lore.kernel.org/r/20211221111345.2462-1-ffmancera@riseup.net Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

regulator: dt-bindings: samsung,s5m8767: correct s5m8767,pmic-buck-default-dvs-idx property

2021-11-26T10:48:22+00:00

commit a7fda04bc9b6ad9da8e19c9e6e3b1dab773d068a upstream. The driver was always parsing "s5m8767,pmic-buck-default-dvs-idx", not "s5m8767,pmic-buck234-default-dvs-idx". Cc: Fixes: 26aec009f6b6 ("regulator: add device tree support for s5m8767") Signed-off-by: Krzysztof Kozlowski Acked-by: Rob Herring Message-Id: <20211008113723.134648-3-krzysztof.kozlowski@canonical.com> Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

regulator: s5m8767: do not use reset value as DVS voltage if GPIO DVS is disabled

2021-11-26T10:48:22+00:00

commit b16bef60a9112b1e6daf3afd16484eb06e7ce792 upstream. The driver and its bindings, before commit 04f9f068a619 ("regulator: s5m8767: Modify parsing method of the voltage table of buck2/3/4") were requiring to provide at least one safe/default voltage for DVS registers if DVS GPIO is not being enabled. IOW, if s5m8767,pmic-buck2-uses-gpio-dvs is missing, the s5m8767,pmic-buck2-dvs-voltage should still be present and contain one voltage. This requirement was coming from driver behavior matching this condition (none of DVS GPIO is enabled): it was always initializing the DVS selector pins to 0 and keeping the DVS enable setting at reset value (enabled). Therefore if none of DVS GPIO is enabled in devicetree, driver was configuring the first DVS voltage for buck[234]. Mentioned commit 04f9f068a619 ("regulator: s5m8767: Modify parsing method of the voltage table of buck2/3/4") broke it because DVS voltage won't be parsed from devicetree if DVS GPIO is not enabled. After the change, driver will configure bucks to use the register reset value as voltage which might have unpleasant effects. Fix this by relaxing the bindings constrain: if DVS GPIO is not enabled in devicetree (therefore DVS voltage is also not parsed), explicitly disable it. Cc: Fixes: 04f9f068a619 ("regulator: s5m8767: Modify parsing method of the voltage table of buck2/3/4") Signed-off-by: Krzysztof Kozlowski Acked-by: Rob Herring Message-Id: <20211008113723.134648-2-krzysztof.kozlowski@canonical.com> Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

dt-bindings: mtd: gpmc: Fix the ECC bytes vs. OOB bytes equation

2021-09-22T09:43:09+00:00

[ Upstream commit 778cb8e39f6ec252be50fc3850d66f3dcbd5dd5a ] "PAGESIZE / 512" is the number of ECC chunks. "ECC_BYTES" is the number of bytes needed to store a single ECC code. "2" is the space reserved by the bad block marker. "2 + (PAGESIZE / 512) * ECC_BYTES" should of course be lower or equal than the total number of OOB bytes, otherwise it won't fit. Fix the equation by substituting s/>=/<=/. Suggested-by: Ryan J. Barnett Signed-off-by: Miquel Raynal Acked-by: Rob Herring Link: https://lore.kernel.org/linux-mtd/20210610143945.3504781-1-miquel.raynal@bootlin.com Signed-off-by: Sasha Levin

locks: print a warning when mount fails due to lack of "mand" support

2021-08-26T12:37:29+00:00

[ Upstream commit df2474a22c42ce419b67067c52d71da06c385501 ] Since 9e8925b67a ("locks: Allow disabling mandatory locking at compile time"), attempts to mount filesystems with "-o mand" will fail. Unfortunately, there is no other indiciation of the reason for the failure. Change how the function is defined for better readability. When CONFIG_MANDATORY_FILE_LOCKING is disabled, printk a warning when someone attempts to mount with -o mand. Also, add a blurb to the mandatory-locking.txt file to explain about the "mand" option, and the behavior one should expect when it is disabled. Reported-by: Jan Kara Reviewed-by: Jan Kara Signed-off-by: Jeff Layton Signed-off-by: Sasha Levin

tweewide: Fix most Shebang lines

2021-06-03T06:23:27+00:00

commit c25ce589dca10d64dde139ae093abc258a32869c upstream. Change every shebang which does not need an argument to use /usr/bin/env. This is needed as not every distro has everything under /usr/bin, sometimes not even bash. Signed-off-by: Finn Behrens Signed-off-by: Masahiro Yamada [nicolas@fjasle.eu: update contexts for v4.9, adapt for old scripts] Signed-off-by: Nicolas Schier Signed-off-by: Greg Kroah-Hartman

sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output

2021-03-07T10:25:58+00:00

commit 2efc459d06f1630001e3984854848a5647086232 upstream. Output defects can exist in sysfs content using sprintf and snprintf. sprintf does not know the PAGE_SIZE maximum of the temporary buffer used for outputting sysfs content and it's possible to overrun the PAGE_SIZE buffer length. Add a generic sysfs_emit function that knows that the size of the temporary buffer and ensures that no overrun is done. Add a generic sysfs_emit_at function that can be used in multiple call situations that also ensures that no overrun is done. Validate the output buffer argument to be page aligned. Validate the offset len argument to be within the PAGE_SIZE buf. Signed-off-by: Joe Perches Link: https://lore.kernel.org/r/884235202216d464d61ee975f7465332c86f76b2.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman