kernel.git/arch/arm/mm, branch linux-5.4.y

ARM: 9447/1: arm/memremap: fix arch_memremap_can_ram_remap()

2025-06-27T10:02:51Z

commit 96e0b355883006554a0bee3697da475971d6bba8 upstream. arm/memremap: fix arch_memremap_can_ram_remap() commit 260364d112bc ("arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map") added the definition of arch_memremap_can_ram_remap() for arm[64] specific filtering of what pages can be used from the linear mapping. memblock_is_map_memory() was called with the pfn of the address given to arch_memremap_can_ram_remap(); however, memblock_is_map_memory() expects to be given an address for arm, not a pfn. This results in calls to memremap() returning a newly mapped area when it should return an address in the existing linear mapping. Fix this by removing the address to pfn translation and pass the address directly. Fixes: 260364d112bc ("arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map") Signed-off-by: Ross Stutterheim Cc: Mike Rapoport Cc: stable@vger.kernel.org Reviewed-by: Catalin Marinas Reviewed-by: Linus Walleij Signed-off-by: Russell King (Oracle) Signed-off-by: Greg Kroah-Hartman

ARM: Remove address checking for MMUless devices

2025-04-10T12:29:39Z

commit 3ccea4784fddd96fbd6c4497eb28b45dab638c2a upstream. Commit 169f9102f9198b ("ARM: 9350/1: fault: Implement copy_from_kernel_nofault_allowed()") added the function to check address before use. However, for devices without MMU, addr > TASK_SIZE will always fail. This patch move this function after the #ifdef CONFIG_MMU statement. Signed-off-by: Yanjun Yang Acked-by: Ard Biesheuvel Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218953 Fixes: 169f9102f9198b ("ARM: 9350/1: fault: Implement copy_from_kernel_nofault_allowed()") Link: https://lore.kernel.org/r/20240611100947.32241-1-yangyj.ee@gmail.com Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

ARM: 9351/1: fault: Add "cut here" line for prefetch aborts

2025-04-10T12:29:38Z

commit 8f09b8b4fa58e99cbfd9a650b31d65cdbd8e4276 upstream. The common pattern in arm is to emit a "8<--- cut here ---" line for faults, but it was missing for do_PrefetchAbort(). Add it. Cc: Wang Kefeng Cc: Ben Hutchings Cc: linux-arm-kernel@lists.infradead.org Acked-by: Ard Biesheuvel Signed-off-by: Kees Cook Signed-off-by: Russell King (Oracle) Signed-off-by: Greg Kroah-Hartman

ARM: 9350/1: fault: Implement copy_from_kernel_nofault_allowed()

2025-04-10T12:29:38Z

commit 169f9102f9198b04afffa6164372a4ba4070f412 upstream. Under PAN emulation when dumping backtraces from things like the LKDTM EXEC_USERSPACE test[1], a double fault (which would hang a CPU) would happen because of dump_instr() attempting to read a userspace address. Make sure copy_from_kernel_nofault() does not attempt this any more. Closes: https://lava.sirena.org.uk/scheduler/job/497571 Link: https://lore.kernel.org/all/202401181125.D48DCB4C@keescook/ [1] Reported-by: Mark Brown Suggested-by: Russell King (Oracle) Reviewed-by: Ard Biesheuvel Tested-by: Mark Brown Cc: Wang Kefeng Cc: Andrew Morton Cc: Ben Hutchings Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Kees Cook Signed-off-by: Russell King (Oracle) Signed-off-by: Greg Kroah-Hartman

treewide: Remove uninitialized_var() usage

2023-06-09T08:29:01Z

commit 3f649ab728cda8038259d8f14492fe400fbab911 upstream. Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var$([^$]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe # IB Acked-by: Kalle Valo # wireless drivers Reviewed-by: Chao Yu # erofs Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

dma-mapping: drop the dev argument to arch_sync_dma_for_*

2023-04-05T09:16:43Z

[ Upstream commit 56e35f9c5b87ec1ae93e483284e189c84388de16 ] These are pure cache maintainance routines, so drop the unused struct device argument. Signed-off-by: Christoph Hellwig Suggested-by: Daniel Vetter Stable-dep-of: ab327f8acdf8 ("mips: bmips: BCM6358: disable RAC flush for TP1") Signed-off-by: Sasha Levin

exit: Add and use make_task_dead.

2023-02-06T06:52:49Z

commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream. There are two big uses of do_exit. The first is it's design use to be the guts of the exit(2) system call. The second use is to terminate a task after something catastrophic has happened like a NULL pointer in kernel code. Add a function make_task_dead that is initialy exactly the same as do_exit to cover the cases where do_exit is called to handle catastrophic failure. In time this can probably be reduced to just a light wrapper around do_task_dead. For now keep it exactly the same so that there will be no behavioral differences introducing this new concept. Replace all of the uses of do_exit that use it for catastraphic task cleanup with make_task_dead to make it clear what the code is doing. As part of this rename rewind_stack_do_exit rewind_stack_and_make_dead. Signed-off-by: "Eric W. Biederman" Signed-off-by: Eric Biggers Signed-off-by: Sasha Levin

ARM: 9280/1: mm: fix warning on phys_addr_t to void pointer assignment

2023-02-06T06:52:44Z

commit a4e03921c1bb118e6718e0a3b0322a2c13ed172b upstream. zero_page is a void* pointer but memblock_alloc() returns phys_addr_t type so this generates a warning while using clang and with -Wint-error enabled that becomes and error. So let's cast the return of memblock_alloc() to (void *). Cc: # 4.14.x + Fixes: 340a982825f7 ("ARM: 9266/1: mm: fix no-MMU ZERO_PAGE() implementation") Signed-off-by: Giulio Benetti Signed-off-by: Russell King (Oracle) Signed-off-by: Greg Kroah-Hartman

ARM: 9266/1: mm: fix no-MMU ZERO_PAGE() implementation

2022-12-14T10:30:40Z

[ Upstream commit 340a982825f76f1cff0daa605970fe47321b5ee7 ] Actually in no-MMU SoCs(i.e. i.MXRT) ZERO_PAGE(vaddr) expands to ``` virt_to_page(0) ``` that in order expands to: ``` pfn_to_page(virt_to_pfn(0)) ``` and then virt_to_pfn(0) to: ``` ((((unsigned long)(0) - PAGE_OFFSET) >> PAGE_SHIFT) + PHYS_PFN_OFFSET) ``` where PAGE_OFFSET and PHYS_PFN_OFFSET are the DRAM offset(0x80000000) and PAGE_SHIFT is 12. This way we obtain 16MB(0x01000000) summed to the base of DRAM(0x80000000). When ZERO_PAGE(0) is then used, for example in bio_add_page(), the page gets an address that is out of DRAM bounds. So instead of using fake virtual page 0 let's allocate a dedicated zero_page during paging_init() and assign it to a global 'struct page * empty_zero_page' the same way mmu.c does and it's the same approach used in m68k with commit dc068f462179 as discussed here[0]. Then let's move ZERO_PAGE() definition to the top of pgtable.h to be in common between mmu.c and nommu.c. [0]: https://lore.kernel.org/linux-m68k/2a462b23-5b8e-bbf4-ec7d-778434a3b9d7@google.com/T/#m1266ceb63 ad140743174d6b3070364d3c9a5179b Signed-off-by: Giulio Benetti Reviewed-by: Arnd Bergmann Signed-off-by: Russell King (Oracle) Signed-off-by: Sasha Levin

ARM: 9247/1: mm: set readonly for MT_MEMORY_RO with ARM_LPAE

2022-10-26T11:22:22Z

[ Upstream commit 14ca1a4690750bb54e1049e49f3140ef48958a6e ] MT_MEMORY_RO is introduced by commit 598f0a99fa8a ("ARM: 9210/1: Mark the FDT_FIXED sections as shareable"), which is a readonly memory type for FDT area, but there are some different between ARM_LPAE and non-ARM_LPAE, we need to setup PMD_SECT_AP2 and L_PMD_SECT_RDONLY for MT_MEMORY_RO when ARM_LAPE enabled. non-ARM_LPAE 0xff800000-0xffa00000 2M PGD KERNEL ro NX SHD ARM_LPAE 0xff800000-0xffc00000 4M PMD RW NX SHD ARM_LPAE+fix 0xff800000-0xffc00000 4M PMD ro NX SHD Fixes: 598f0a99fa8a ("ARM: 9210/1: Mark the FDT_FIXED sections as shareable") Signed-off-by: Kefeng Wang Signed-off-by: Russell King (Oracle) Signed-off-by: Sasha Levin