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2022-04-26bug: Have __warn() prototype defined unconditionallyShida Zhang1-5/+6
The __warn() prototype is declared in CONFIG_BUG scope but the function definition in panic.c is unconditional. The IBT enablement started using it unconditionally but a CONFIG_X86_KERNEL_IBT=y, CONFIG_BUG=n .config will trigger a arch/x86/kernel/traps.c: In function ‘__exc_control_protection’: arch/x86/kernel/traps.c:249:17: error: implicit declaration of function \ ‘__warn’; did you mean ‘pr_warn’? [-Werror=implicit-function-declaration] Pull up the declarations so that they're unconditionally visible too. [ bp: Rewrite commit message. ] Fixes: 991625f3dd2c ("x86/ibt: Add IBT feature, MSR and #CP handling") Suggested-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Shida Zhang <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-26tee: remove flags TEE_IOCTL_SHM_MAPPED and TEE_IOCTL_SHM_DMA_BUFAndrew Davis1-4/+0
These look to be leftover from an early edition of this driver. Userspace does not need this information. Checking all users of this that I have access to I have verified no one is using them. They leak internal use flags out to userspace. Even more they are not correct anymore after a45ea4efa358. Lets drop these flags before someone does try to use them for something and they become ABI. Signed-off-by: Andrew Davis <[email protected]> Acked-by: Sumit Garg <[email protected]> Signed-off-by: Jens Wiklander <[email protected]>
2022-04-26tee: remove tee_shm_va2pa() and tee_shm_pa2va()Andrew Davis1-18/+0
We should not need to index into SHMs based on absolute VA/PA. These functions are not used and this kind of usage should not be encouraged anyway. Remove these functions. Signed-off-by: Andrew Davis <[email protected]> Reviewed-by: Sumit Garg <[email protected]> Signed-off-by: Jens Wiklander <[email protected]>
2022-04-25bpf: Make BTF type match stricter for release argumentsKumar Kartikeya Dwivedi1-1/+2
The current of behavior of btf_struct_ids_match for release arguments is that when type match fails, it retries with first member type again (recursively). Since the offset is already 0, this is akin to just casting the pointer in normal C, since if type matches it was just embedded inside parent sturct as an object. However, we want to reject cases for release function type matching, be it kfunc or BPF helpers. An example is the following: struct foo { struct bar b; }; struct foo *v = acq_foo(); rel_bar(&v->b); // btf_struct_ids_match fails btf_types_are_same, then // retries with first member type and succeeds, while // it should fail. Hence, don't walk the struct and only rely on btf_types_are_same for strict mode. All users of strict mode must be dealing with zero offset anyway, since otherwise they would want the struct to be walked. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-04-25bpf: Teach verifier about kptr_get kfunc helpersKumar Kartikeya Dwivedi1-0/+2
We introduce a new style of kfunc helpers, namely *_kptr_get, where they take pointer to the map value which points to a referenced kernel pointer contained in the map. Since this is referenced, only bpf_kptr_xchg from BPF side and xchg from kernel side is allowed to change the current value, and each pointer that resides in that location would be referenced, and RCU protected (this must be kept in mind while adding kernel types embeddable as reference kptr in BPF maps). This means that if do the load of the pointer value in an RCU read section, and find a live pointer, then as long as we hold RCU read lock, it won't be freed by a parallel xchg + release operation. This allows us to implement a safe refcount increment scheme. Hence, enforce that first argument of all such kfunc is a proper PTR_TO_MAP_VALUE pointing at the right offset to referenced pointer. For the rest of the arguments, they are subjected to typical kfunc argument checks, hence allowing some flexibility in passing more intent into how the reference should be taken. For instance, in case of struct nf_conn, it is not freed until RCU grace period ends, but can still be reused for another tuple once refcount has dropped to zero. Hence, a bpf_ct_kptr_get helper not only needs to call refcount_inc_not_zero, but also do a tuple match after incrementing the reference, and when it fails to match it, put the reference again and return NULL. This can be implemented easily if we allow passing additional parameters to the bpf_ct_kptr_get kfunc, like a struct bpf_sock_tuple * and a tuple__sz pair. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-04-25bpf: Wire up freeing of referenced kptrKumar Kartikeya Dwivedi2-0/+6
A destructor kfunc can be defined as void func(type *), where type may be void or any other pointer type as per convenience. In this patch, we ensure that the type is sane and capture the function pointer into off_desc of ptr_off_tab for the specific pointer offset, with the invariant that the dtor pointer is always set when 'kptr_ref' tag is applied to the pointer's pointee type, which is indicated by the flag BPF_MAP_VALUE_OFF_F_REF. Note that only BTF IDs whose destructor kfunc is registered, thus become the allowed BTF IDs for embedding as referenced kptr. Hence it serves the purpose of finding dtor kfunc BTF ID, as well acting as a check against the whitelist of allowed BTF IDs for this purpose. Finally, wire up the actual freeing of the referenced pointer if any at all available offsets, so that no references are leaked after the BPF map goes away and the BPF program previously moved the ownership a referenced pointer into it. The behavior is similar to BPF timers, where bpf_map_{update,delete}_elem will free any existing referenced kptr. The same case is with LRU map's bpf_lru_push_free/htab_lru_push_free functions, which are extended to reset unreferenced and free referenced kptr. Note that unlike BPF timers, kptr is not reset or freed when map uref drops to zero. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-04-25bpf: Populate pairs of btf_id and destructor kfunc in btfKumar Kartikeya Dwivedi1-0/+17
To support storing referenced PTR_TO_BTF_ID in maps, we require associating a specific BTF ID with a 'destructor' kfunc. This is because we need to release a live referenced pointer at a certain offset in map value from the map destruction path, otherwise we end up leaking resources. Hence, introduce support for passing an array of btf_id, kfunc_btf_id pairs that denote a BTF ID and its associated release function. Then, add an accessor 'btf_find_dtor_kfunc' which can be used to look up the destructor kfunc of a certain BTF ID. If found, we can use it to free the object from the map free path. The registration of these pairs also serve as a whitelist of structures which are allowed as referenced PTR_TO_BTF_ID in a BPF map, because without finding the destructor kfunc, we will bail and return an error. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-04-25bpf: Adapt copy_map_value for multiple offset caseKumar Kartikeya Dwivedi1-26/+30
Since now there might be at most 10 offsets that need handling in copy_map_value, the manual shuffling and special case is no longer going to work. Hence, let's generalise the copy_map_value function by using a sorted array of offsets to skip regions that must be avoided while copying into and out of a map value. When the map is created, we populate the offset array in struct map, Then, copy_map_value uses this sorted offset array is used to memcpy while skipping timer, spin lock, and kptr. The array is allocated as in most cases none of these special fields would be present in map value, hence we can save on space for the common case by not embedding the entire object inside bpf_map struct. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-04-25bpf: Prevent escaping of kptr loaded from mapsKumar Kartikeya Dwivedi1-1/+9
While we can guarantee that even for unreferenced kptr, the object pointer points to being freed etc. can be handled by the verifier's exception handling (normal load patching to PROBE_MEM loads), we still cannot allow the user to pass these pointers to BPF helpers and kfunc, because the same exception handling won't be done for accesses inside the kernel. The same is true if a referenced pointer is loaded using normal load instruction. Since the reference is not guaranteed to be held while the pointer is used, it must be marked as untrusted. Hence introduce a new type flag, PTR_UNTRUSTED, which is used to mark all registers loading unreferenced and referenced kptr from BPF maps, and ensure they can never escape the BPF program and into the kernel by way of calling stable/unstable helpers. In check_ptr_to_btf_access, the !type_may_be_null check to reject type flags is still correct, as apart from PTR_MAYBE_NULL, only MEM_USER, MEM_PERCPU, and PTR_UNTRUSTED may be set for PTR_TO_BTF_ID. The first two are checked inside the function and rejected using a proper error message, but we still want to allow dereference of untrusted case. Also, we make sure to inherit PTR_UNTRUSTED when chain of pointers are walked, so that this flag is never dropped once it has been set on a PTR_TO_BTF_ID (i.e. trusted to untrusted transition can only be in one direction). In convert_ctx_accesses, extend the switch case to consider untrusted PTR_TO_BTF_ID in addition to normal PTR_TO_BTF_ID for PROBE_MEM conversion for BPF_LDX. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-04-25bpf: Allow storing referenced kptr in mapKumar Kartikeya Dwivedi2-0/+20
Extending the code in previous commits, introduce referenced kptr support, which needs to be tagged using 'kptr_ref' tag instead. Unlike unreferenced kptr, referenced kptr have a lot more restrictions. In addition to the type matching, only a newly introduced bpf_kptr_xchg helper is allowed to modify the map value at that offset. This transfers the referenced pointer being stored into the map, releasing the references state for the program, and returning the old value and creating new reference state for the returned pointer. Similar to unreferenced pointer case, return value for this case will also be PTR_TO_BTF_ID_OR_NULL. The reference for the returned pointer must either be eventually released by calling the corresponding release function, otherwise it must be transferred into another map. It is also allowed to call bpf_kptr_xchg with a NULL pointer, to clear the value, and obtain the old value if any. BPF_LDX, BPF_STX, and BPF_ST cannot access referenced kptr. A future commit will permit using BPF_LDX for such pointers, but attempt at making it safe, since the lifetime of object won't be guaranteed. There are valid reasons to enforce the restriction of permitting only bpf_kptr_xchg to operate on referenced kptr. The pointer value must be consistent in face of concurrent modification, and any prior values contained in the map must also be released before a new one is moved into the map. To ensure proper transfer of this ownership, bpf_kptr_xchg returns the old value, which the verifier would require the user to either free or move into another map, and releases the reference held for the pointer being moved in. In the future, direct BPF_XCHG instruction may also be permitted to work like bpf_kptr_xchg helper. Note that process_kptr_func doesn't have to call check_helper_mem_access, since we already disallow rdonly/wronly flags for map, which is what check_map_access_type checks, and we already ensure the PTR_TO_MAP_VALUE refers to kptr by obtaining its off_desc, so check_map_access is also not required. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-04-25scsi: sd: sd_zbc: Hide gap zonesDamien Le Moal1-1/+8
ZBC-2 allows host-managed disks to report gap zones. This allow zoned disks to report an offset between data zone starts that is a power of two even if the number of logical blocks with data per zone is not a power of two. Another new feature in ZBC-2 is support for constant zone starting LBA offsets. For zoned disks that report a constant zone starting LBA offset, hide the gap zones from the block layer. Report the offset between data zone starts as zone size and report the number of logical blocks with data per zone as the zone capacity. Link: https://lore.kernel.org/r/[email protected] Acked-by: Douglas Gilbert <[email protected]> Signed-off-by: Damien Le Moal <[email protected]> [ bvanassche: Reworked this patch ] Signed-off-by: Bart Van Assche <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]>
2022-04-25scsi: iscsi: Fix harmless double shift bugDan Carpenter1-3/+3
These flags are supposed to be bit numbers. Right now they cause a double shift bug where we use BIT(BIT(2)) instead of BIT(2). Fortunately, the bit numbers are small and it's done consistently so it does not cause an issue at run time. Link: https://lore.kernel.org/r/YmFyWHf8nrrx+SHa@kili Fixes: 5bd856256f8c ("scsi: iscsi: Merge suspend fields") Reviewed-by: Mike Christie <[email protected]> Reviewed-by: Lee Duncan <[email protected]> Signed-off-by: Dan Carpenter <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]>
2022-04-25bpf: Tag argument to be released in bpf_func_protoKumar Kartikeya Dwivedi2-3/+5
Add a new type flag for bpf_arg_type that when set tells verifier that for a release function, that argument's register will be the one for which meta.ref_obj_id will be set, and which will then be released using release_reference. To capture the regno, introduce a new field release_regno in bpf_call_arg_meta. This would be required in the next patch, where we may either pass NULL or a refcounted pointer as an argument to the release function bpf_kptr_xchg. Just releasing only when meta.ref_obj_id is set is not enough, as there is a case where the type of argument needed matches, but the ref_obj_id is set to 0. Hence, we must enforce that whenever meta.ref_obj_id is zero, the register that is to be released can only be NULL for a release function. Since we now indicate whether an argument is to be released in bpf_func_proto itself, is_release_function helper has lost its utitlity, hence refactor code to work without it, and just rely on meta.release_regno to know when to release state for a ref_obj_id. Still, the restriction of one release argument and only one ref_obj_id passed to BPF helper or kfunc remains. This may be lifted in the future. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-04-25bpf: Allow storing unreferenced kptr in mapKumar Kartikeya Dwivedi2-1/+32
This commit introduces a new pointer type 'kptr' which can be embedded in a map value to hold a PTR_TO_BTF_ID stored by a BPF program during its invocation. When storing such a kptr, BPF program's PTR_TO_BTF_ID register must have the same type as in the map value's BTF, and loading a kptr marks the destination register as PTR_TO_BTF_ID with the correct kernel BTF and BTF ID. Such kptr are unreferenced, i.e. by the time another invocation of the BPF program loads this pointer, the object which the pointer points to may not longer exist. Since PTR_TO_BTF_ID loads (using BPF_LDX) are patched to PROBE_MEM loads by the verifier, it would safe to allow user to still access such invalid pointer, but passing such pointers into BPF helpers and kfuncs should not be permitted. A future patch in this series will close this gap. The flexibility offered by allowing programs to dereference such invalid pointers while being safe at runtime frees the verifier from doing complex lifetime tracking. As long as the user may ensure that the object remains valid, it can ensure data read by it from the kernel object is valid. The user indicates that a certain pointer must be treated as kptr capable of accepting stores of PTR_TO_BTF_ID of a certain type, by using a BTF type tag 'kptr' on the pointed to type of the pointer. Then, this information is recorded in the object BTF which will be passed into the kernel by way of map's BTF information. The name and kind from the map value BTF is used to look up the in-kernel type, and the actual BTF and BTF ID is recorded in the map struct in a new kptr_off_tab member. For now, only storing pointers to structs is permitted. An example of this specification is shown below: #define __kptr __attribute__((btf_type_tag("kptr"))) struct map_value { ... struct task_struct __kptr *task; ... }; Then, in a BPF program, user may store PTR_TO_BTF_ID with the type task_struct into the map, and then load it later. Note that the destination register is marked PTR_TO_BTF_ID_OR_NULL, as the verifier cannot know whether the value is NULL or not statically, it must treat all potential loads at that map value offset as loading a possibly NULL pointer. Only BPF_LDX, BPF_STX, and BPF_ST (with insn->imm = 0 to denote NULL) are allowed instructions that can access such a pointer. On BPF_LDX, the destination register is updated to be a PTR_TO_BTF_ID, and on BPF_STX, it is checked whether the source register type is a PTR_TO_BTF_ID with same BTF type as specified in the map BTF. The access size must always be BPF_DW. For the map in map support, the kptr_off_tab for outer map is copied from the inner map's kptr_off_tab. It was chosen to do a deep copy instead of introducing a refcount to kptr_off_tab, because the copy only needs to be done when paramterizing using inner_map_fd in the map in map case, hence would be unnecessary for all other users. It is not permitted to use MAP_FREEZE command and mmap for BPF map having kptrs, similar to the bpf_timer case. A kptr also requires that BPF program has both read and write access to the map (hence both BPF_F_RDONLY_PROG and BPF_F_WRONLY_PROG are disallowed). Note that check_map_access must be called from both check_helper_mem_access and for the BPF instructions, hence the kptr check must distinguish between ACCESS_DIRECT and ACCESS_HELPER, and reject ACCESS_HELPER cases. We rename stack_access_src to bpf_access_src and reuse it for this purpose. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-04-25bpf: Use bpf_prog_run_array_cg_flags everywhereStanislav Fomichev1-6/+2
Rename bpf_prog_run_array_cg_flags to bpf_prog_run_array_cg and use it everywhere. check_return_code already enforces sane return ranges for all cgroup types. (only egress and bind hooks have uncanonical return ranges, the rest is using [0, 1]) No functional changes. v2: - 'func_ret & 1' under explicit test (Andrii & Martin) Suggested-by: Alexei Starovoitov <[email protected]> Signed-off-by: Stanislav Fomichev <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-04-25dt-bindings: ARM: MediaTek: Add new document bindings of MT8186 clockChun-Jie Chen1-0/+445
This patch adds the new binding documentation for system clock and functional clock on MediaTek MT8186. Signed-off-by: Chun-Jie Chen <[email protected]> Reviewed-by: Rob Herring <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Stephen Boyd <[email protected]>
2022-04-25dt-bindings: clock: u8500: Add clkout clock bindingsLinus Walleij1-0/+17
This adds device tree bindings for the externally routed clocks CLKOUT1 and CLKOUT2 clocks found in the DB8500. Cc: [email protected] Reviewed-by: Ulf Hansson <[email protected]> Signed-off-by: Linus Walleij <[email protected]> Link: https://lore.kernel.org/r/[email protected] Reviewed-by: Rob Herring <[email protected]> Signed-off-by: Stephen Boyd <[email protected]>
2022-04-25f2fs: introduce data read/write showing path infoJaegeuk Kim1-0/+94
This was used in Android for a long time. Let's upstream it. Reviewed-by: Chao Yu <[email protected]> Signed-off-by: Jaegeuk Kim <[email protected]>
2022-04-26drm/msm/dsi: Pass DSC params to drm_panelVinod Koul1-0/+7
When DSC is enabled, we need to get the DSC parameters from the panel driver, so add a dsc parameter in panel to fetch and pass DSC configuration for DSI panels to DPU encoder, which will enable and then configure DSC hardware blocks accordingly. Signed-off-by: Dmitry Baryshkov <[email protected]> Reviewed-by: Abhinav Kumar <[email protected]> Signed-off-by: Vinod Koul <[email protected]> Patchwork: https://patchwork.freedesktop.org/patch/480910/ Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Dmitry Baryshkov <[email protected]>
2022-04-25gpio: pcf857x: Make teardown callback return voidUwe Kleine-König1-1/+1
All teardown functions return 0. Also there is little sense in returning a negative error code from an i2c remove function as this only results in emitting an error message but the device is removed nevertheless. This patch is a preparation for making i2c remove callbacks return void. Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Bartosz Golaszewski <[email protected]>
2022-04-25irq/gpio: ixp4xx: Drop boardfile probe pathLinus Walleij1-12/+0
The boardfiles for IXP4xx have been deleted. Delete all the quirks and code dealing with that boot path and rely solely on device tree boot. Fix some missing static keywords that the kernel test robot was complaining about while we're at it. Cc: Bartosz Golaszewski <[email protected]> Acked-by: Marc Zyngier <[email protected]> Signed-off-by: Linus Walleij <[email protected]> Signed-off-by: Bartosz Golaszewski <[email protected]>
2022-04-25net: mac802154: Create an error helper for asynchronous offloading errorsMiquel Raynal1-0/+9
A few drivers do the full transmit operation asynchronously, which means that a bus error that happens when forwarding the packet to the transmitter or a timeout happening when offloading the request to the transmitter will not be reported immediately. The solution in this case is to call this new helper to free the necessary resources, restart the queue and always return the same generic TRAC error code: IEEE802154_SYSTEM_ERROR. Suggested-by: Alexander Aring <[email protected]> Signed-off-by: Miquel Raynal <[email protected]> Acked-by: Alexander Aring <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Stefan Schmidt <[email protected]>
2022-04-25net: mac802154: Create an offloaded transmission error helperMiquel Raynal1-0/+10
So far there is only a helper for successful transmissions, which led device drivers to implement their own handling in case of error. Unfortunately, we really need all the drivers to give the hand back to the core once they are done in order to be able to build a proper synchronous API. So let's create a _xmit_error() helper and take this opportunity to fill the new device-global field storing Tx statuses. Suggested-by: Alexander Aring <[email protected]> Signed-off-by: Miquel Raynal <[email protected]> Acked-by: Alexander Aring <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Stefan Schmidt <[email protected]>
2022-04-25net: ieee802154: Fill the list of MLME return codesMiquel Raynal1-1/+66
There are more codes than already listed, let's be a bit more exhaustive. This will allow to drop device drivers local definitions of these codes. Signed-off-by: Miquel Raynal <[email protected]> Acked-by: Alexander Aring <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Stefan Schmidt <[email protected]>
2022-04-25net: ieee802154: Enhance/fix the names of the MLME return codesMiquel Raynal1-7/+7
Let's keep these definitions as close to the specification as possible while they are not yet in use. The names get slightly longer, but we gain the minor cost of being able to search the spec more easily. Signed-off-by: Miquel Raynal <[email protected]> Acked-by: Alexander Aring <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Stefan Schmidt <[email protected]>
2022-04-25ASoC: Add macros for signed TLV controls with callbacksMark Brown1-0/+17
Merge series from Richard Fitzgerald <[email protected]>: This adds SOC_DOUBLE_R_S_EXT_TLV and SOC_SINGLE_S_EXT_TLV macros for signed TLV controls that need custom get/put callbacks. These will be needed by future Cirrus codec drivers, but are not particularly exotic so could be useful for others.
2022-04-25of: overlay: rework overlay apply and remove kfree()sFrank Rowand1-1/+2
Fix various kfree() issues related to of_overlay_apply(). - Double kfree() of fdt and tree when init_overlay_changeset() returns an error. - free_overlay_changeset() free the root of the unflattened overlay (variable tree) instead of the memory that contains the unflattened overlay. - For the case of a failure during applying an overlay, move kfree() of new_fdt and overlay_mem into free_overlay_changeset(), which is called by the function that allocated them. - For the case of removing an overlay, the kfree() of new_fdt and overlay_mem remains in free_overlay_changeset(). - Check return value of of_fdt_unflatten_tree() for error instead of checking the returned value of overlay_root. - When storing pointers to allocated objects in ovcs, do so as near to the allocation as possible instead of in deeply layered function. More clearly document policy related to lifetime of pointers into overlay memory. Double kfree() Reported-by: Slawomir Stepien <[email protected]> Signed-off-by: Frank Rowand <[email protected]> Signed-off-by: Rob Herring <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-25Drivers: hv: vmbus: Introduce {lock,unlock}_requestor()Andrea Parri (Microsoft)1-0/+15
To abtract the lock and unlock operations on the requestor spin lock. The helpers will come in handy in hv_pci. No functional change. Suggested-by: Michael Kelley <[email protected]> Signed-off-by: Andrea Parri (Microsoft) <[email protected]> Reviewed-by: Michael Kelley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Wei Liu <[email protected]>
2022-04-25Drivers: hv: vmbus: Introduce vmbus_request_addr_match()Andrea Parri (Microsoft)1-0/+5
The function can be used to retrieve and clear/remove a transation ID from a channel requestor, provided the memory address corresponding to the ID equals a specified address. The function, and its 'lockless' variant __vmbus_request_addr_match(), will be used by hv_pci. Refactor vmbus_request_addr() to reuse the 'newly' introduced code. No functional change. Suggested-by: Michael Kelley <[email protected]> Signed-off-by: Andrea Parri (Microsoft) <[email protected]> Reviewed-by: Michael Kelley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Wei Liu <[email protected]>
2022-04-25Drivers: hv: vmbus: Introduce vmbus_sendpacket_getid()Andrea Parri (Microsoft)1-0/+7
The function can be used to send a VMbus packet and retrieve the corresponding transaction ID. It will be used by hv_pci. No functional change. Suggested-by: Michael Kelley <[email protected]> Signed-off-by: Andrea Parri (Microsoft) <[email protected]> Reviewed-by: Michael Kelley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Wei Liu <[email protected]>
2022-04-25Drivers: hv: vmbus: Add VMbus IMC device to unsupported listMichael Kelley1-3/+9
Hyper-V may offer an Initial Machine Configuration (IMC) synthetic device to guest VMs. The device may be used by Windows guests to get specialization information, such as the hostname. But the device is not used in Linux and there is no Linux driver, so it is unsupported. Currently, the IMC device GUID is not recognized by the VMbus driver, which results in an "Unknown GUID" error message during boot. Add the GUID to the list of known but unsupported devices so that the error message is not generated. Other than avoiding the error message, there is no change in guest behavior. Signed-off-by: Michael Kelley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Wei Liu <[email protected]>
2022-04-25firmware: cirrus: cs_dsp: Avoid padding bytes in cs_dsp_coeff_ctlRichard Fitzgerald1-14/+14
Change the order of members in struct cs_dsp_coeff_ctl to avoid the compiler having to insert alignment padding bytes. On a x86_64 build this saves 16 bytes per control. - Pointers are collected to the top of the struct (with the exception of priv, as noted below), so that they are inherently aligned. - The set and enable bitflags are placed together so they can be merged. - priv is placed at the end of the struct - it is for use by the client so it is helpful to make it stand out, and since the compiler will always pad the struct size to an alignment multiple putting a pointer last won't introduce any more padding. - struct cs_dsp_alg_region is placed at the end, right before priv, for the same reasoning as priv. Signed-off-by: Richard Fitzgerald <[email protected]> Reviewed-by: Charles Keepax <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Mark Brown <[email protected]>
2022-04-25ASoC: soc.h: Add SOC_SINGLE_S_EXT_TLV macroRichard Fitzgerald1-0/+6
Add a SOC_SINGLE_S_EXT_TLV macro as a convenience wrapper around SOC_DOUBLE_R_S_EXT_TLV for mono volume controls. Signed-off-by: Richard Fitzgerald <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Mark Brown <[email protected]>
2022-04-25ASoC: soc.h: Introduce SOC_DOUBLE_R_S_EXT_TLV() macroSimon Trimmer1-0/+11
A straightforward extension of the SOC_DOUBLE_R_S_TLV() macro that allows the get and put functions to be customised. Signed-off-by: Simon Trimmer <[email protected]> Signed-off-by: Richard Fitzgerald <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Mark Brown <[email protected]>
2022-04-25fanotify: enable "evictable" inode marksAmir Goldstein1-0/+1
Now that the direct reclaim path is handled we can enable evictable inode marks. Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Amir Goldstein <[email protected]> Signed-off-by: Jan Kara <[email protected]>
2022-04-25fanotify: implement "evictable" inode marksAmir Goldstein1-0/+1
When an inode mark is created with flag FAN_MARK_EVICTABLE, it will not pin the marked inode to inode cache, so when inode is evicted from cache due to memory pressure, the mark will be lost. When an inode mark with flag FAN_MARK_EVICATBLE is updated without using this flag, the marked inode is pinned to inode cache. When an inode mark is updated with flag FAN_MARK_EVICTABLE but an existing mark already has the inode pinned, the mark update fails with error EEXIST. Evictable inode marks can be used to setup inode marks with ignored mask to suppress events from uninteresting files or directories in a lazy manner, upon receiving the first event, without having to iterate all the uninteresting files or directories before hand. The evictbale inode mark feature allows performing this lazy marks setup without exhausting the system memory with pinned inodes. This change does not enable the feature yet. Link: https://lore.kernel.org/linux-fsdevel/CAOQ4uxiRDpuS=2uA6+ZUM7yG9vVU-u212tkunBmSnP_u=mkv=Q@mail.gmail.com/ Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Amir Goldstein <[email protected]> Signed-off-by: Jan Kara <[email protected]>
2022-04-25fsnotify: allow adding an inode mark without pinning inodeAmir Goldstein1-0/+2
fsnotify_add_mark() and variants implicitly take a reference on inode when attaching a mark to an inode. Make that behavior opt-out with the mark flag FSNOTIFY_MARK_FLAG_NO_IREF. Instead of taking the inode reference when attaching connector to inode and dropping the inode reference when detaching connector from inode, take the inode reference on attach of the first mark that wants to hold an inode reference and drop the inode reference on detach of the last mark that wants to hold an inode reference. Backends can "upgrade" an existing mark to take an inode reference, but cannot "downgrade" a mark with inode reference to release the refernce. This leaves the choice to the backend whether or not to pin the inode when adding an inode mark. This is intended to be used when adding a mark with ignored mask that is used for optimization in cases where group can afford getting unneeded events and reinstate the mark with ignored mask when inode is accessed again after being evicted. Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Amir Goldstein <[email protected]> Signed-off-by: Jan Kara <[email protected]>
2022-04-25fsnotify: create helpers for group mark_mutex lockAmir Goldstein1-0/+28
Create helpers to take and release the group mark_mutex lock. Define a flag FSNOTIFY_GROUP_NOFS in fsnotify_group that determines if the mark_mutex lock is fs reclaim safe or not. If not safe, the lock helpers take the lock and disable direct fs reclaim. In that case we annotate the mutex with a different lockdep class to express to lockdep that an allocation of mark of an fs reclaim safe group may take the group lock of another "NOFS" group to evict inodes. For now, converted only the callers in common code and no backend defines the NOFS flag. It is intended to be set by fanotify for evictable marks support. Link: https://lore.kernel.org/r/[email protected] Suggested-by: Jan Kara <[email protected]> Link: https://lore.kernel.org/r/[email protected]/ Signed-off-by: Amir Goldstein <[email protected]> Signed-off-by: Jan Kara <[email protected]>
2022-04-25fsnotify: make allow_dups a property of the groupAmir Goldstein1-6/+7
Instead of passing the allow_dups argument to fsnotify_add_mark() as an argument, define the group flag FSNOTIFY_GROUP_DUPS to express the allow_dups behavior and set this behavior at group creation time for all calls of fsnotify_add_mark(). Rename the allow_dups argument to generic add_flags argument for future use. Link: https://lore.kernel.org/r/[email protected] Suggested-by: Jan Kara <[email protected]> Signed-off-by: Amir Goldstein <[email protected]> Signed-off-by: Jan Kara <[email protected]>
2022-04-25fsnotify: pass flags argument to fsnotify_alloc_group()Amir Goldstein1-2/+6
Add flags argument to fsnotify_alloc_group(), define and use the flag FSNOTIFY_GROUP_USER in inotify and fanotify instead of the helper fsnotify_alloc_user_group() to indicate user allocation. Although the flag FSNOTIFY_GROUP_USER is currently not used after group allocation, we store the flags argument in the group struct for future use of other group flags. Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Amir Goldstein <[email protected]> Signed-off-by: Jan Kara <[email protected]>
2022-04-25inotify: move control flags from mask to mark flagsAmir Goldstein1-7/+9
The inotify control flags in the mark mask (e.g. FS_IN_ONE_SHOT) are not relevant to object interest mask, so move them to the mark flags. This frees up some bits in the object interest mask. Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Amir Goldstein <[email protected]> Signed-off-by: Jan Kara <[email protected]>
2022-04-25tcp: make sure treq->af_specific is initializedEric Dumazet1-0/+1
syzbot complained about a recent change in TCP stack, hitting a NULL pointer [1] tcp request sockets have an af_specific pointer, which was used before the blamed change only for SYNACK generation in non SYNCOOKIE mode. tcp requests sockets momentarily created when third packet coming from client in SYNCOOKIE mode were not using treq->af_specific. Make sure this field is populated, in the same way normal TCP requests sockets do in tcp_conn_request(). [1] TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 PID: 3695 Comm: syz-executor864 Not tainted 5.18.0-rc3-syzkaller-00224-g5fd1fe4807f9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:tcp_create_openreq_child+0xe16/0x16b0 net/ipv4/tcp_minisocks.c:534 Code: 48 c1 ea 03 80 3c 02 00 0f 85 e5 07 00 00 4c 8b b3 28 01 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7e 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c9 07 00 00 48 8b 3c 24 48 89 de 41 ff 56 08 48 RSP: 0018:ffffc90000de0588 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff888076490330 RCX: 0000000000000100 RDX: 0000000000000001 RSI: ffffffff87d67ff0 RDI: 0000000000000008 RBP: ffff88806ee1c7f8 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87d67f00 R11: 0000000000000000 R12: ffff88806ee1bfc0 R13: ffff88801b0e0368 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f517fe58700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcead76960 CR3: 000000006f97b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> tcp_v6_syn_recv_sock+0x199/0x23b0 net/ipv6/tcp_ipv6.c:1267 tcp_get_cookie_sock+0xc9/0x850 net/ipv4/syncookies.c:207 cookie_v6_check+0x15c3/0x2340 net/ipv6/syncookies.c:258 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1131 [inline] tcp_v6_do_rcv+0x1148/0x13b0 net/ipv6/tcp_ipv6.c:1486 tcp_v6_rcv+0x3305/0x3840 net/ipv6/tcp_ipv6.c:1725 ip6_protocol_deliver_rcu+0x2e9/0x1900 net/ipv6/ip6_input.c:422 ip6_input_finish+0x14c/0x2c0 net/ipv6/ip6_input.c:464 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:473 dst_input include/net/dst.h:461 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0x27f/0x3b0 net/ipv6/ip6_input.c:297 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5405 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5519 process_backlog+0x3a0/0x7c0 net/core/dev.c:5847 __napi_poll+0xb3/0x6e0 net/core/dev.c:6413 napi_poll net/core/dev.c:6480 [inline] net_rx_action+0x8ec/0xc60 net/core/dev.c:6567 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 Fixes: 5b0b9e4c2c89 ("tcp: md5: incorrect tcp_header_len for incoming connections") Signed-off-by: Eric Dumazet <[email protected]> Cc: Francesco Ruggeri <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2022-04-25tcp: fix potential xmit stalls caused by TCP_NOTSENT_LOWATEric Dumazet1-0/+1
I had this bug sitting for too long in my pile, it is time to fix it. Thanks to Doug Porter for reminding me of it! We had various attempts in the past, including commit 0cbe6a8f089e ("tcp: remove SOCK_QUEUE_SHRUNK"), but the issue is that TCP stack currently only generates EPOLLOUT from input path, when tp->snd_una has advanced and skb(s) cleaned from rtx queue. If a flow has a big RTT, and/or receives SACKs, it is possible that the notsent part (tp->write_seq - tp->snd_nxt) reaches 0 and no more data can be sent until tp->snd_una finally advances. What is needed is to also check if POLLOUT needs to be generated whenever tp->snd_nxt is advanced, from output path. This bug triggers more often after an idle period, as we do not receive ACK for at least one RTT. tcp_notsent_lowat could be a fraction of what CWND and pacing rate would allow to send during this RTT. In a followup patch, I will remove the bogus call to tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED) from tcp_check_space(). Fact that we have decided to generate an EPOLLOUT does not mean the application has immediately refilled the transmit queue. This optimistic call might have been the reason the bug seemed not too serious. Tested: 200 ms rtt, 1% packet loss, 32 MB tcp_rmem[2] and tcp_wmem[2] $ echo 500000 >/proc/sys/net/ipv4/tcp_notsent_lowat $ cat bench_rr.sh SUM=0 for i in {1..10} do V=`netperf -H remote_host -l30 -t TCP_RR -- -r 10000000,10000 -o LOCAL_BYTES_SENT | egrep -v "MIGRATED|Bytes"` echo $V SUM=$(($SUM + $V)) done echo SUM=$SUM Before patch: $ bench_rr.sh 130000000 80000000 140000000 140000000 140000000 140000000 130000000 40000000 90000000 110000000 SUM=1140000000 After patch: $ bench_rr.sh 430000000 590000000 530000000 450000000 450000000 350000000 450000000 490000000 480000000 460000000 SUM=4680000000 # This is 410 % of the value before patch. Fixes: c9bee3b7fdec ("tcp: TCP_NOTSENT_LOWAT socket option") Signed-off-by: Eric Dumazet <[email protected]> Reported-by: Doug Porter <[email protected]> Cc: Soheil Hassas Yeganeh <[email protected]> Cc: Neal Cardwell <[email protected]> Acked-by: Soheil Hassas Yeganeh <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2022-04-25ip_gre, ip6_gre: Fix race condition on o_seqno in collect_md modePeilin Ye2-2/+2
As pointed out by Jakub Kicinski, currently using TUNNEL_SEQ in collect_md mode is racy for [IP6]GRE[TAP] devices. Consider the following sequence of events: 1. An [IP6]GRE[TAP] device is created in collect_md mode using "ip link add ... external". "ip" ignores "[o]seq" if "external" is specified, so TUNNEL_SEQ is off, and the device is marked as NETIF_F_LLTX (i.e. it uses lockless TX); 2. Someone sets TUNNEL_SEQ on outgoing skb's, using e.g. bpf_skb_set_tunnel_key() in an eBPF program attached to this device; 3. gre_fb_xmit() or __gre6_xmit() processes these skb's: gre_build_header(skb, tun_hlen, flags, protocol, tunnel_id_to_key32(tun_info->key.tun_id), (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0); ^^^^^^^^^^^^^^^^^ Since we are not using the TX lock (&txq->_xmit_lock), multiple CPUs may try to do this tunnel->o_seqno++ in parallel, which is racy. Fix it by making o_seqno atomic_t. As mentioned by Eric Dumazet in commit b790e01aee74 ("ip_gre: lockless xmit"), making o_seqno atomic_t increases "chance for packets being out of order at receiver" when NETIF_F_LLTX is on. Maybe a better fix would be: 1. Do not ignore "oseq" in external mode. Users MUST specify "oseq" if they want the kernel to allow sequencing of outgoing packets; 2. Reject all outgoing TUNNEL_SEQ packets if the device was not created with "oseq". Unfortunately, that would break userspace. We could now make [IP6]GRE[TAP] devices always NETIF_F_LLTX, but let us do it in separate patches to keep this fix minimal. Suggested-by: Jakub Kicinski <[email protected]> Fixes: 77a5196a804e ("gre: add sequence number for collect md mode.") Signed-off-by: Peilin Ye <[email protected]> Acked-by: William Tu <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2022-04-25gpio: use raw spinlock for gpio chip shadowed dataSchspa Shi1-1/+1
In case of PREEMPT_RT, there is a raw_spinlock -> spinlock dependency as the lockdep report shows. __irq_set_handler irq_get_desc_buslock __irq_get_desc_lock raw_spin_lock_irqsave(&desc->lock, *flags); // raw spinlock get here __irq_do_set_handler mask_ack_irq dwapb_irq_ack spin_lock_irqsave(&gc->bgpio_lock, flags); // sleep able spinlock irq_put_desc_busunlock Replace with a raw lock to avoid BUGs. This lock is only used to access registers, and It's safe to replace with the raw lock without bad influence. [ 15.090359][ T1] ============================= [ 15.090365][ T1] [ BUG: Invalid wait context ] [ 15.090373][ T1] 5.10.59-rt52-00983-g186a6841c682-dirty #3 Not tainted [ 15.090386][ T1] ----------------------------- [ 15.090392][ T1] swapper/0/1 is trying to lock: [ 15.090402][ T1] 70ff00018507c188 (&gc->bgpio_lock){....}-{3:3}, at: _raw_spin_lock_irqsave+0x1c/0x28 [ 15.090470][ T1] other info that might help us debug this: [ 15.090477][ T1] context-{5:5} [ 15.090485][ T1] 3 locks held by swapper/0/1: [ 15.090497][ T1] #0: c2ff0001816de1a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock+0x98/0x104 [ 15.090553][ T1] #1: ffff90001485b4b8 (irq_domain_mutex){+.+.}-{4:4}, at: irq_domain_associate+0xbc/0x6d4 [ 15.090606][ T1] #2: 4bff000185d7a8e0 (lock_class){....}-{2:2}, at: _raw_spin_lock_irqsave+0x1c/0x28 [ 15.090654][ T1] stack backtrace: [ 15.090661][ T1] CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.10.59-rt52-00983-g186a6841c682-dirty #3 [ 15.090682][ T1] Hardware name: Horizon Robotics Journey 5 DVB (DT) [ 15.090692][ T1] Call trace: ...... [ 15.090811][ T1] _raw_spin_lock_irqsave+0x1c/0x28 [ 15.090828][ T1] dwapb_irq_ack+0xb4/0x300 [ 15.090846][ T1] __irq_do_set_handler+0x494/0xb2c [ 15.090864][ T1] __irq_set_handler+0x74/0x114 [ 15.090881][ T1] irq_set_chip_and_handler_name+0x44/0x58 [ 15.090900][ T1] gpiochip_irq_map+0x210/0x644 Signed-off-by: Schspa Shi <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Acked-by: Linus Walleij <[email protected]> Acked-by: Doug Berger <[email protected]> Acked-by: Serge Semin <[email protected]> Signed-off-by: Bartosz Golaszewski <[email protected]>
2022-04-25PCI: Add PCI_EXP_SLTCTL_ASPL_DISABLE macroPali Rohár1-0/+1
Add macro defining Auto Slot Power Limit Disable bit in Slot Control Register. Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Pali Rohár <[email protected]> Signed-off-by: Marek Behún <[email protected]> Signed-off-by: Lorenzo Pieralisi <[email protected]> Acked-by: Bjorn Helgaas <[email protected]>
2022-04-25devlink: introduce line card device info infrastructureJiri Pirko1-2/+6
Extend the line card info message with information (e.g., FW version) about devices found on the line card. Example: $ devlink lc info pci/0000:01:00.0 lc 8 pci/0000:01:00.0: lc 8 versions: fixed: hw.revision 0 running: ini.version 4 devices: device 0 versions: running: fw 19.2010.1310 device 1 versions: running: fw 19.2010.1310 device 2 versions: running: fw 19.2010.1310 device 3 versions: running: fw 19.2010.1310 Signed-off-by: Jiri Pirko <[email protected]> Signed-off-by: Ido Schimmel <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2022-04-25devlink: introduce line card info get messageJiri Pirko2-1/+8
Allow the driver to provide per line card info get op to fill-up info, similar to the "devlink dev info". Example: $ devlink lc info pci/0000:01:00.0 lc 8 pci/0000:01:00.0: lc 8 versions: fixed: hw.revision 0 running: ini.version 4 Signed-off-by: Jiri Pirko <[email protected]> Signed-off-by: Ido Schimmel <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2022-04-25devlink: introduce line card devices supportJiri Pirko2-0/+10
Line card can contain one or more devices that makes sense to make visible to the user. For example, this can be a gearbox with flash memory, which could be updated. Provide the driver possibility to attach such devices to a line card and expose those to user. Example: $ devlink lc show pci/0000:01:00.0 lc 8 pci/0000:01:00.0: lc 8 state active type 16x100G supported_types: 16x100G devices: device 0 device 1 device 2 device 3 Signed-off-by: Jiri Pirko <[email protected]> Signed-off-by: Ido Schimmel <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2022-04-25mm: Add fault_in_subpage_writeable() to probe at sub-page granularityCatalin Marinas2-0/+23
On hardware with features like arm64 MTE or SPARC ADI, an access fault can be triggered at sub-page granularity. Depending on how the fault_in_writeable() function is used, the caller can get into a live-lock by continuously retrying the fault-in on an address different from the one where the uaccess failed. In the majority of cases progress is ensured by the following conditions: 1. copy_to_user_nofault() guarantees at least one byte access if the user address is not faulting. 2. The fault_in_writeable() loop is resumed from the first address that could not be accessed by copy_to_user_nofault(). If the loop iteration is restarted from an earlier (initial) point, the loop is repeated with the same conditions and it would live-lock. Introduce an arch-specific probe_subpage_writeable() and call it from the newly added fault_in_subpage_writeable() function. The arch code with sub-page faults will have to implement the specific probing functionality. Note that no other fault_in_subpage_*() functions are added since they have no callers currently susceptible to a live-lock. Signed-off-by: Catalin Marinas <[email protected]> Cc: Andrew Morton <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Catalin Marinas <[email protected]>