kernel/git/stable/linux.git/drivers/of/fdt.c, branch linux-5.17.y

of/fdt: Ignore disabled memory nodes

2022-06-09T08:25:29+00:00

[ Upstream commit df5cd369876114f91f9ae60658fea80acfb15890 ] When we boot a machine using a devicetree, the generic DT code goes through all nodes with a 'device_type = "memory"' property, and collects all memory banks mentioned there. However it does not check for the status property, so any nodes which are explicitly "disabled" will still be added as a memblock. This ends up badly for QEMU, when booting with secure firmware on arm/arm64 machines, because QEMU adds a node describing secure-only memory: =================== secram@e000000 { secure-status = "okay"; status = "disabled"; reg = <0x00 0xe000000 0x00 0x1000000>; device_type = "memory"; }; =================== The kernel will eventually use that memory block (which is located below the main DRAM bank), but accesses to that will be answered with an SError: =================== [ 0.000000] Internal error: synchronous external abort: 96000050 [#1] PREEMPT SMP [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.18.0-rc6-00014-g10c8acb8b679 #524 [ 0.000000] Hardware name: linux,dummy-virt (DT) [ 0.000000] pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 0.000000] pc : new_slab+0x190/0x340 [ 0.000000] lr : new_slab+0x184/0x340 [ 0.000000] sp : ffff80000a4b3d10 .... ================== The actual crash location and call stack will be somewhat random, and depend on the specific allocation of that physical memory range. As the DT spec[1] explicitly mentions standard properties, add a simple check to skip over disabled memory nodes, so that we only use memory that is meant for non-secure code to use. That fixes booting a QEMU arm64 VM with EL3 enabled ("secure=on"), when not using UEFI. In this case the QEMU generated DT will be handed on to the kernel, which will see the secram node. This issue is reproducible when using TF-A together with U-Boot as firmware, then booting with the "booti" command. When using U-Boot as an UEFI provider, the code there [2] explicitly filters for disabled nodes when generating the UEFI memory map, so we are safe. EDK/2 only reads the first bank of the first DT memory node [3] to learn about memory, so we got lucky there. [1] https://github.com/devicetree-org/devicetree-specification/blob/main/source/chapter3-devicenodes.rst#memory-node (after the table) [2] https://source.denx.de/u-boot/u-boot/-/blob/master/lib/fdtdec.c#L1061-1063 [3] https://github.com/tianocore/edk2/blob/master/ArmVirtPkg/PrePi/FdtParser.c Reported-by: Ross Burton Signed-off-by: Andre Przywara Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20220517101410.3493781-1-andre.przywara@arm.com Signed-off-by: Sasha Levin

of/fdt: move elfcorehdr reservation early for crash dump kernel

2022-02-17T23:13:52+00:00

elfcorehdr_addr is fixed address passed to Second kernel which may be conflicted with potential reserved memory in Second kernel,so fdt_reserve_elfcorehdr() ahead of fdt_init_reserved_mem() can relieve this situation. Signed-off-by: Nikhil Gupta Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20220128042321.15228-1-nikhil.gupta@nxp.com

Merge branch 'akpm' (patches from Andrew)

2022-01-15T18:37:06+00:00

Merge misc updates from Andrew Morton: "146 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak, dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap, memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb, userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp, ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and damon)" * emailed patches from Andrew Morton : (146 commits) mm/damon: hide kernel pointer from tracepoint event mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging mm/damon/dbgfs: remove an unnecessary variable mm/damon: move the implementation of damon_insert_region to damon.h mm/damon: add access checking for hugetlb pages Docs/admin-guide/mm/damon/usage: update for schemes statistics mm/damon/dbgfs: support all DAMOS stats Docs/admin-guide/mm/damon/reclaim: document statistics parameters mm/damon/reclaim: provide reclamation statistics mm/damon/schemes: account how many times quota limit has exceeded mm/damon/schemes: account scheme actions that successfully applied mm/damon: remove a mistakenly added comment for a future feature Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning Docs/admin-guide/mm/damon/usage: remove redundant information Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks mm/damon: convert macro functions to static inline functions mm/damon: modify damon_rand() macro to static inline function mm/damon: move damon_rand() definition into damon.h ...

mm: kmemleak: alloc gray object for reserved region with direct map

2022-01-15T14:30:25+00:00

Reserved regions with direct mapping may contain references to other regions. CMA region with fixed location is reserved without creating kmemleak_object for it. So add them as gray kmemleak objects. Link: https://lkml.kernel.org/r/20211123090641.3654006-1-calvinzhang.cool@gmail.com Signed-off-by: Calvin Zhang Cc: Rob Herring Cc: Frank Rowand Cc: Catalin Marinas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'dt/linus' into dt/next

2022-01-12T16:14:09+00:00

Pick a fix which didn't make it into v5.16.

of/fdt: Don't worry about non-memory region overlap for no-map

2022-01-08T14:50:39+00:00

In commit 8a5a75e5e9e5 ("of/fdt: Make sure no-map does not remove already reserved regions") we returned -EBUSY when trying to mark regions as no-map when they intersect with reserved memory. The goal was to find bad no-map reserved memory DT nodes that would unmap the kernel text/data sections. The problem is the reserved memory check will still trigger if the DT has a /memreserve/ that completely subsumes the no-map memory carveouts in the reserved memory node _and_ that region is also not part of the memory reg property. For example in sc7180.dtsi we have the following reserved-memory and memory node: memory@80000000 { /* We expect the bootloader to fill in the size */ reg = <0 0x80000000 0 0>; }; smem_mem: memory@80900000 { reg = <0x0 0x80900000 0x0 0x200000>; no-map; }; and the memreserve filled in by the bootloader is /memreserve/ 0x80800000 0x400000; while the /memory node is transformed into memory@80000000 { /* The bootloader fills in the size, and adds another region */ reg = <0 0x80000000 0 0x00800000>, <0 0x80c00000 0 0x7f200000>; }; The smem region is doubly reserved via /memreserve/ and by not being part of the /memory reg property. This leads to the following warning printed at boot. OF: fdt: Reserved memory: failed to reserve memory for node 'memory@80900000': base 0x0000000080900000, size 2 MiB Otherwise nothing really goes wrong because the smem region is not going to be mapped by the kernel's direct linear mapping given that it isn't part of the memory node. Therefore, let's only consider this to be a problem if we're trying to mark a region as no-map and it is actually memory that we're intending to keep out of the kernel's direct mapping but it's already been reserved. Acked-by: Mike Rapoport Cc: Douglas Anderson Cc: Nicolas Boichat Cc: Quentin Perret Cc: Jan Kiszka Fixes: 8a5a75e5e9e5 ("of/fdt: Make sure no-map does not remove already reserved regions") Signed-off-by: Stephen Boyd Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20220107194233.2793146-1-swboyd@chromium.org

efi: apply memblock cap after memblock_add()

2021-12-22T13:28:26+00:00

On arm64, during kdump kernel saves vmcore, it runs into the following bug: ... [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! [ 15.159707] ------------[ cut here ]------------ [ 15.164311] kernel BUG at mm/usercopy.c:99! [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 15.228073] pc : usercopy_abort+0x9c/0xa0 [ 15.232074] lr : usercopy_abort+0x9c/0xa0 [ 15.236070] sp : ffff8000121abba0 [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b [ 15.310593] Call trace: [ 15.313027] usercopy_abort+0x9c/0xa0 [ 15.316677] __check_heap_object+0xd4/0xf0 [ 15.320762] __check_object_size.part.0+0x160/0x1e0 [ 15.325628] __check_object_size+0x2c/0x40 [ 15.329711] copy_oldmem_page+0x7c/0x140 [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 [ 15.342920] read_vmcore+0x28/0x34 [ 15.346309] proc_reg_read+0xb4/0xf0 [ 15.349871] vfs_read+0xb8/0x1f0 [ 15.353088] ksys_read+0x74/0x100 [ 15.356390] __arm64_sys_read+0x28/0x34 ... This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling"), which moves memblock_cap_memory_range() to fdt, but it breaches the rules that memblock_cap_memory_range() should come after memblock_add() etc as said in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). As a consequence, the virtual address set up by copy_oldmem_page() does not bail out from the test of virt_addr_valid() in check_heap_object(), and finally hits the BUG_ON(). Since memblock allocator has no idea about when the memblock is fully populated, while efi_init() is aware, so tackling this issue by calling the interface early_init_dt_check_for_usable_mem_range() exposed by of/fdt. Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") Signed-off-by: Pingfan Liu Cc: Rob Herring Cc: Zhen Lei Cc: Catalin Marinas Cc: Will Deacon Cc: Andrew Morton Cc: Mike Rapoport Cc: Geert Uytterhoeven Cc: Frank Rowand Cc: Ard Biesheuvel Cc: Nick Terrell Cc: linux-arm-kernel@lists.infradead.org To: devicetree@vger.kernel.org To: linux-efi@vger.kernel.org Acked-by: Ard Biesheuvel Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20211215021348.8766-1-kernelfans@gmail.com

of: fdt: Aggregate the processing of "linux,usable-memory-range"

2021-12-22T13:28:26+00:00

Currently, we parse the "linux,usable-memory-range" property in early_init_dt_scan_chosen(), to obtain the specified memory range of the crash kernel. We then reserve the required memory after early_init_dt_scan_memory() has identified all available physical memory. Because the two pieces of code are separated far, the readability and maintainability are reduced. So bring them together. Suggested-by: Rob Herring Signed-off-by: Zhen Lei (change the prototype of early_init_dt_check_for_usable_mem_range(), in order to use it outside) Signed-off-by: Pingfan Liu Tested-by: Dave Kleikamp Acked-by: John Donnelly Reviewed-by: Rob Herring Cc: Catalin Marinas Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org To: devicetree@vger.kernel.org To: linux-efi@vger.kernel.org Signed-off-by: Rob Herring

of/fdt: Rework early_init_dt_scan_memory() to call directly

2021-12-16T22:07:52+00:00

Use of the of_scan_flat_dt() function predates libfdt and is discouraged as libfdt provides a nicer set of APIs. Rework early_init_dt_scan_memory() to be called directly and use libfdt. Cc: John Crispin Cc: Thomas Bogendoerfer Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Frank Rowand Cc: linux-mips@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Reviewed-by: Frank Rowand Signed-off-by: Rob Herring Tested-by: Michael Ellerman Link: https://lore.kernel.org/r/20211215150102.1303588-1-robh@kernel.org

of/fdt: Rework early_init_dt_scan_root() to call directly

2021-12-16T22:07:48+00:00

Use of the of_scan_flat_dt() function predates libfdt and is discouraged as libfdt provides a nicer set of APIs. Rework early_init_dt_scan_root() to be called directly and use libfdt. Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Frank Rowand Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Rob Herring Reviewed-by: Frank Rowand Link: https://lore.kernel.org/r/20211118181213.1433346-3-robh@kernel.org