kernel.git/arch/powerpc, branch linux-4.18.y

Revert "powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP"

2018-11-21T08:22:04Z

commit cc4ebf5c0a3440ed0a32d25c55ebdb6ce5f3c0bc upstream. This reverts commit 4f94b2c7462d9720b2afa7e8e8d4c19446bb31ce. That commit was buggy, as it used rlwinm instead of rlwimi. Instead of fixing that bug, we revert the previous commit in order to reduce the dependency between L1 entries and L2 entries Fixes: 4f94b2c7462d9 ("powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/memtrace: Remove memory in chunks

2018-11-21T08:21:57Z

[ Upstream commit 3f7daf3d7582dc6628ac40a9045dd1bbd80c5f35 ] When hot-removing memory release_mem_region_adjustable() splits iomem resources if they are not the exact size of the memory being hot-deleted. Adding this memory back to the kernel adds a new resource. Eg a node has memory 0x0 - 0xfffffffff. Hot-removing 1GB from 0xf40000000 results in the single resource 0x0-0xfffffffff being split into two resources: 0x0-0xf3fffffff and 0xf80000000-0xfffffffff. When we hot-add the memory back we now have three resources: 0x0-0xf3fffffff, 0xf40000000-0xf7fffffff, and 0xf80000000-0xfffffffff. This is an issue if we try to remove some memory that overlaps resources. Eg when trying to remove 2GB at address 0xf40000000, release_mem_region_adjustable() fails as it expects the chunk of memory to be within the boundaries of a single resource. We then get the warning: "Unable to release resource" and attempting to use memtrace again gives us this error: "bash: echo: write error: Resource temporarily unavailable" This patch makes memtrace remove memory in chunks that are always the same size from an address that is always equal to end_of_memory - n*size, for some n. So hotremoving and hotadding memory of different sizes will now not attempt to remove memory that spans multiple resources. Signed-off-by: Rashmica Gupta Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/boot: Ensure _zimage_start is a weak symbol

2018-11-21T08:21:57Z

[ Upstream commit ee9d21b3b3583712029a0db65a4b7c081d08d3b3 ] When building with clang crt0's _zimage_start is not marked weak, which breaks the build when linking the kernel image: $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$ 0000000000000058 g .text 0000000000000000 _zimage_start ld: arch/powerpc/boot/wrapper.a(crt0.o): in function '_zimage_start': (.text+0x58): multiple definition of '_zimage_start'; arch/powerpc/boot/pseries-head.o:(.text+0x0): first defined here Clang requires the .weak directive to appear after the symbol is declared. The binutils manual says: This directive sets the weak attribute on the comma separated list of symbol names. If the symbols do not already exist, they will be created. So it appears this is different with clang. The only reference I could see for this was an OpenBSD mailing list post[1]. Changing it to be after the declaration fixes building with Clang, and still works with GCC. $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$ 0000000000000058 w .text 0000000000000000 _zimage_start Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38921 [1] https://groups.google.com/forum/#!topic/fa.openbsd.tech/PAgKKen2YCY Signed-off-by: Joel Stanley Reviewed-by: Nick Desaulniers Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/mm: Don't report hugepage tables as memory leaks when using kmemleak

2018-11-21T08:21:57Z

[ Upstream commit 803d690e68f0c5230183f1a42c7d50a41d16e380 ] When a process allocates a hugepage, the following leak is reported by kmemleak. This is a false positive which is due to the pointer to the table being stored in the PGD as physical memory address and not virtual memory pointer. unreferenced object 0xc30f8200 (size 512): comm "mmap", pid 374, jiffies 4872494 (age 627.630s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] huge_pte_alloc+0xdc/0x1f8 [<9e0df1e1>] hugetlb_fault+0x560/0x8f8 [<7938ec6c>] follow_hugetlb_page+0x14c/0x44c [] __get_user_pages+0x1c4/0x3dc [] __mm_populate+0xac/0x140 [<3215421e>] vm_mmap_pgoff+0xb4/0xb8 [] ksys_mmap_pgoff+0xcc/0x1fc [<4fcd760f>] ret_from_syscall+0x0/0x38 See commit a984506c542e2 ("powerpc/mm: Don't report PUDs as memory leaks when using kmemleak") for detailed explanation. To fix that, this patch tells kmemleak to ignore the allocated hugepage table. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/nohash: fix undefined behaviour when testing page size support

2018-11-21T08:21:56Z

[ Upstream commit f5e284803a7206d43e26f9ffcae5de9626d95e37 ] When enumerating page size definitions to check hardware support, we construct a constant which is (1U << (def->shift - 10)). However, the array of page size definitions is only initalised for various MMU_PAGE_* constants, so it contains a number of 0-initialised elements with def->shift == 0. This means we end up shifting by a very large number, which gives the following UBSan splat: ================================================================================ UBSAN: Undefined behaviour in /home/dja/dev/linux/linux/arch/powerpc/mm/tlb_nohash.c:506:21 shift exponent 4294967286 is too large for 32-bit type 'unsigned int' CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-00045-ga604f927b012-dirty #6 Call Trace: [c00000000101bc20] [c000000000a13d54] .dump_stack+0xa8/0xec (unreliable) [c00000000101bcb0] [c0000000004f20a8] .ubsan_epilogue+0x18/0x64 [c00000000101bd30] [c0000000004f2b10] .__ubsan_handle_shift_out_of_bounds+0x110/0x1a4 [c00000000101be20] [c000000000d21760] .early_init_mmu+0x1b4/0x5a0 [c00000000101bf10] [c000000000d1ba28] .early_setup+0x100/0x130 [c00000000101bf90] [c000000000000528] start_here_multiplatform+0x68/0x80 ================================================================================ Fix this by first checking if the element exists (shift != 0) before constructing the constant. Signed-off-by: Daniel Axtens Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/eeh: Fix possible null deref in eeh_dump_dev_log()

2018-11-21T08:21:56Z

[ Upstream commit f9bc28aedfb5bbd572d2d365f3095c1becd7209b ] If an error occurs during an unplug operation, it's possible for eeh_dump_dev_log() to be called when edev->pdn is null, which currently leads to dereferencing a null pointer. Handle this by skipping the error log for those devices. Signed-off-by: Sam Bobroff Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/Makefile: Fix PPC_BOOK3S_64 ASFLAGS

2018-11-21T08:21:56Z

[ Upstream commit 960e30029863db95ec79a71009272d4661db5991 ] Ever since commit 15a3204d24a3 ("powerpc/64s: Set assembler machine type to POWER4") we force -mpower4 to be passed to the assembler irrespective of the CFLAGS used (for Book3s 64). When building a powerpc64 kernel with clang, clang will not add -many to the assembler flags, so any instructions that the compiler has generated that are not available on power4 will cause an error: /usr/bin/as -a64 -mppc64 -mlittle-endian -mpower8 \ -I ./arch/powerpc/include -I ./arch/powerpc/include/generated \ -I ./include -I ./arch/powerpc/include/uapi \ -I ./arch/powerpc/include/generated/uapi -I ./include/uapi \ -I ./include/generated/uapi -I arch/powerpc -I arch/powerpc \ -maltivec -mpower4 -o init/do_mounts.o /tmp/do_mounts-3b0a3d.s /tmp/do_mounts-51ce54.s:748: Error: unrecognized opcode: `isel' GCC does include -many, so the GCC driven gas call will succeed: as -v -I ./arch/powerpc/include -I ./arch/powerpc/include/generated -I ./include -I ./arch/powerpc/include/uapi -I ./arch/powerpc/include/generated/uapi -I ./include/uapi -I ./include/generated/uapi -I arch/powerpc -I arch/powerpc -a64 -mpower8 -many -mlittle -maltivec -mpower4 -o init/do_mounts.o Note that isel is power7 and above for IBM CPUs. GCC only generates it for Power9 and above, but the above test was run against the clang generated assembly. Peter Bergner explains: When using -many -mpower4, gas will first try and find a matching power4 mnemonic and failing that, it will then allow any valid mnemonic that gas knows about. GCC's use of -many predates me though. IIRC, Alan looked at trying to remove it, but I forget why he didn't. Could be either a gcc or gas issue at the time. I'm not sure whether issue still exists or not. He and I have modified how gas works internally a fair amount since he tried removing gcc use of -many. I will also note that when using -many, gas will choose the first mnemonic that matches in the mnemonic table and we have (mostly) sorted the table so that server mnemonics show up earlier in the table than other mnemonics, so they'll be seen/chosen first. By explicitly setting -many we can build with Clang and GCC while retaining the -mpower4 option. Signed-off-by: Joel Stanley Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/mm: fix always true/false warning in slice.c

2018-11-21T08:21:56Z

[ Upstream commit 37e9c674e7e6f445e12cb1151017bd4bacdd1e2d ] This patch fixes the following warnings (obtained with make W=1). arch/powerpc/mm/slice.c: In function 'slice_range_to_mask': arch/powerpc/mm/slice.c:73:12: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (start < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c:81:20: error: comparison is always false due to limited range of data type [-Werror=type-limits] if ((start + len) > SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c: In function 'slice_mask_for_free': arch/powerpc/mm/slice.c:136:17: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (high_limit <= SLICE_LOW_TOP) ^ arch/powerpc/mm/slice.c: In function 'slice_check_range_fits': arch/powerpc/mm/slice.c:185:12: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (start < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c:195:39: error: comparison is always false due to limited range of data type [-Werror=type-limits] if (SLICE_NUM_HIGH && ((start + len) > SLICE_LOW_TOP)) { ^ arch/powerpc/mm/slice.c: In function 'slice_scan_available': arch/powerpc/mm/slice.c:306:11: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (addr < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c: In function 'get_slice_psize': arch/powerpc/mm/slice.c:709:11: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (addr < SLICE_LOW_TOP) { ^ Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/mm: Fix page table dump to work on Radix

2018-11-21T08:21:56Z

[ Upstream commit 0d923962ab69c27cca664a2d535e90ef655110ca ] When we're running on Book3S with the Radix MMU enabled the page table dump currently prints the wrong addresses because it uses the wrong start address. Fix it to use PAGE_OFFSET rather than KERN_VIRT_START. Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/64/module: REL32 relocation range check

2018-11-21T08:21:55Z

[ Upstream commit b851ba02a6f3075f0f99c60c4bc30a4af80cf428 ] The recent module relocation overflow crash demonstrated that we have no range checking on REL32 relative relocations. This patch implements a basic check, the same kernel that previously oopsed and rebooted now continues with some of these errors when loading the module: module_64: x_tables: REL32 527703503449812 out of range! Possibly other relocations (ADDR32, REL16, TOC16, etc.) should also have overflow checks. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman