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2020-09-21Merge tag 'v5.2.60' into v5.2/standard/baseBruce Ashfield
This is the 5.2.60 stable release
2020-09-17powerpc: Allow 4224 bytes of stack expansion for the signal frameMichael Ellerman
commit 63dee5df43a31f3844efabc58972f0a206ca4534 upstream. We have powerpc specific logic in our page fault handling to decide if an access to an unmapped address below the stack pointer should expand the stack VMA. The code was originally added in 2004 "ported from 2.4". The rough logic is that the stack is allowed to grow to 1MB with no extra checking. Over 1MB the access must be within 2048 bytes of the stack pointer, or be from a user instruction that updates the stack pointer. The 2048 byte allowance below the stack pointer is there to cover the 288 byte "red zone" as well as the "about 1.5kB" needed by the signal delivery code. Unfortunately since then the signal frame has expanded, and is now 4224 bytes on 64-bit kernels with transactional memory enabled. This means if a process has consumed more than 1MB of stack, and its stack pointer lies less than 4224 bytes from the next page boundary, signal delivery will fault when trying to expand the stack and the process will see a SEGV. The total size of the signal frame is the size of struct rt_sigframe (which includes the red zone) plus __SIGNAL_FRAMESIZE (128 bytes on 64-bit). The 2048 byte allowance was correct until 2008 as the signal frame was: struct rt_sigframe { struct ucontext uc; /* 0 1440 */ /* --- cacheline 11 boundary (1408 bytes) was 32 bytes ago --- */ long unsigned int _unused[2]; /* 1440 16 */ unsigned int tramp[6]; /* 1456 24 */ struct siginfo * pinfo; /* 1480 8 */ void * puc; /* 1488 8 */ struct siginfo info; /* 1496 128 */ /* --- cacheline 12 boundary (1536 bytes) was 88 bytes ago --- */ char abigap[288]; /* 1624 288 */ /* size: 1920, cachelines: 15, members: 7 */ /* padding: 8 */ }; 1920 + 128 = 2048 Then in commit ce48b2100785 ("powerpc: Add VSX context save/restore, ptrace and signal support") (Jul 2008) the signal frame expanded to 2304 bytes: struct rt_sigframe { struct ucontext uc; /* 0 1696 */ <-- /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ long unsigned int _unused[2]; /* 1696 16 */ unsigned int tramp[6]; /* 1712 24 */ struct siginfo * pinfo; /* 1736 8 */ void * puc; /* 1744 8 */ struct siginfo info; /* 1752 128 */ /* --- cacheline 14 boundary (1792 bytes) was 88 bytes ago --- */ char abigap[288]; /* 1880 288 */ /* size: 2176, cachelines: 17, members: 7 */ /* padding: 8 */ }; 2176 + 128 = 2304 At this point we should have been exposed to the bug, though as far as I know it was never reported. I no longer have a system old enough to easily test on. Then in 2010 commit 320b2b8de126 ("mm: keep a guard page below a grow-down stack segment") caused our stack expansion code to never trigger, as there was always a VMA found for a write up to PAGE_SIZE below r1. That meant the bug was hidden as we continued to expand the signal frame in commit 2b0a576d15e0 ("powerpc: Add new transactional memory state to the signal context") (Feb 2013): struct rt_sigframe { struct ucontext uc; /* 0 1696 */ /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ struct ucontext uc_transact; /* 1696 1696 */ <-- /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */ long unsigned int _unused[2]; /* 3392 16 */ unsigned int tramp[6]; /* 3408 24 */ struct siginfo * pinfo; /* 3432 8 */ void * puc; /* 3440 8 */ struct siginfo info; /* 3448 128 */ /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */ char abigap[288]; /* 3576 288 */ /* size: 3872, cachelines: 31, members: 8 */ /* padding: 8 */ /* last cacheline: 32 bytes */ }; 3872 + 128 = 4000 And commit 573ebfa6601f ("powerpc: Increase stack redzone for 64-bit userspace to 512 bytes") (Feb 2014): struct rt_sigframe { struct ucontext uc; /* 0 1696 */ /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ struct ucontext uc_transact; /* 1696 1696 */ /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */ long unsigned int _unused[2]; /* 3392 16 */ unsigned int tramp[6]; /* 3408 24 */ struct siginfo * pinfo; /* 3432 8 */ void * puc; /* 3440 8 */ struct siginfo info; /* 3448 128 */ /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */ char abigap[512]; /* 3576 512 */ <-- /* size: 4096, cachelines: 32, members: 8 */ /* padding: 8 */ }; 4096 + 128 = 4224 Then finally in 2017, commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") exposed us to the existing bug, because it changed the stack VMA to be the correct/real size, meaning our stack expansion code is now triggered. Fix it by increasing the allowance to 4224 bytes. Hard-coding 4224 is obviously unsafe against future expansions of the signal frame in the same way as the existing code. We can't easily use sizeof() because the signal frame structure is not in a header. We will either fix that, or rip out all the custom stack expansion checking logic entirely. Fixes: ce48b2100785 ("powerpc: Add VSX context save/restore, ptrace and signal support") Cc: stable@vger.kernel.org # v2.6.27+ Reported-by: Tom Lane <tgl@sss.pgh.pa.us> Tested-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724092528.1578671-2-mpe@ellerman.id.au Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-09-07Merge tag 'v5.2.59' into v5.2/standard/baseBruce Ashfield
This is the 5.2.59 stable release
2020-09-04powerpc/book3s64/pkeys: Use PVR check instead of cpu featureAneesh Kumar K.V
commit d79e7a5f26f1d179cbb915a8bf2469b6d7431c29 upstream. We are wrongly using CPU_FTRS_POWER8 to check for P8 support. Instead, we should use PVR value. Now considering we are using CPU_FTRS_POWER8, that implies we returned true for P9 with older firmware. Keep the same behavior by checking for P9 PVR value. Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-2-aneesh.kumar@linux.ibm.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-08-16Merge tag 'v5.2.53' into v5.2/standard/baseBruce Ashfield
This is the 5.2.53 stable release
2020-08-13powerpc/book3s64/pkeys: Fix pkey_access_permitted() for execute disable pkeyAneesh Kumar K.V
commit 192b6a780598976feb7321ff007754f8511a4129 upstream. Even if the IAMR value denies execute access, the current code returns true from pkey_access_permitted() for an execute permission check, if the AMR read pkey bit is cleared. This results in repeated page fault loop with a test like below: #define _GNU_SOURCE #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <signal.h> #include <inttypes.h> #include <assert.h> #include <malloc.h> #include <unistd.h> #include <pthread.h> #include <sys/mman.h> #ifdef SYS_pkey_mprotect #undef SYS_pkey_mprotect #endif #ifdef SYS_pkey_alloc #undef SYS_pkey_alloc #endif #ifdef SYS_pkey_free #undef SYS_pkey_free #endif #undef PKEY_DISABLE_EXECUTE #define PKEY_DISABLE_EXECUTE 0x4 #define SYS_pkey_mprotect 386 #define SYS_pkey_alloc 384 #define SYS_pkey_free 385 #define PPC_INST_NOP 0x60000000 #define PPC_INST_BLR 0x4e800020 #define PROT_RWX (PROT_READ | PROT_WRITE | PROT_EXEC) static int sys_pkey_mprotect(void *addr, size_t len, int prot, int pkey) { return syscall(SYS_pkey_mprotect, addr, len, prot, pkey); } static int sys_pkey_alloc(unsigned long flags, unsigned long access_rights) { return syscall(SYS_pkey_alloc, flags, access_rights); } static int sys_pkey_free(int pkey) { return syscall(SYS_pkey_free, pkey); } static void do_execute(void *region) { /* jump to region */ asm volatile( "mtctr %0;" "bctrl" : : "r"(region) : "ctr", "lr"); } static void do_protect(void *region) { size_t pgsize; int i, pkey; pgsize = getpagesize(); pkey = sys_pkey_alloc(0, PKEY_DISABLE_EXECUTE); assert (pkey > 0); /* perform mprotect */ assert(!sys_pkey_mprotect(region, pgsize, PROT_RWX, pkey)); do_execute(region); /* free pkey */ assert(!sys_pkey_free(pkey)); } int main(int argc, char **argv) { size_t pgsize, numinsns; unsigned int *region; int i; /* allocate memory region to protect */ pgsize = getpagesize(); region = memalign(pgsize, pgsize); assert(region != NULL); assert(!mprotect(region, pgsize, PROT_RWX)); /* fill page with NOPs with a BLR at the end */ numinsns = pgsize / sizeof(region[0]); for (i = 0; i < numinsns - 1; i++) region[i] = PPC_INST_NOP; region[i] = PPC_INST_BLR; do_protect(region); return EXIT_SUCCESS; } The fix is to only check the IAMR for an execute check, the AMR value is not relevant. Fixes: f2407ef3ba22 ("powerpc: helper to validate key-access permissions of a pte") Cc: stable@vger.kernel.org # v4.16+ Reported-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Add detail to change log, tweak wording & formatting] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200712132047.1038594-1-aneesh.kumar@linux.ibm.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-08-13Revert "powerpc/kasan: Fix shadow pages allocation failure"Christophe Leroy
commit b506923ee44ae87fc9f4de16b53feb313623e146 upstream. This reverts commit d2a91cef9bbdeb87b7449fdab1a6be6000930210. This commit moved too much work in kasan_init(). The allocation of shadow pages has to be moved for the reason explained in that patch, but the allocation of page tables still need to be done before switching to the final hash table. First revert the incorrect commit, following patch redoes it properly. Fixes: d2a91cef9bbd ("powerpc/kasan: Fix shadow pages allocation failure") Cc: stable@vger.kernel.org Reported-by: Erhard F. <erhard_f@mailbox.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://bugzilla.kernel.org/show_bug.cgi?id=208181 Link: https://lore.kernel.org/r/3667deb0911affbf999b99f87c31c77d5e870cd2.1593690707.git.christophe.leroy@csgroup.eu Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-07-20Merge tag 'v5.2.49' into v5.2/standard/baseBruce Ashfield
This is the 5.2.49 stable release
2020-07-13powerpc/32s: Don't warn when mapping RO data ROX.Christophe Leroy
commit 4b19f96a81bceaf0bcf44d79c0855c61158065ec upstream. Mapping RO data as ROX is not an issue since that data cannot be modified to introduce an exploit. PPC64 accepts to have RO data mapped ROX, as a trade off between kernel size and strictness of protection. On PPC32, kernel size is even more critical as amount of memory is usually small. Depending on the number of available IBATs, the last IBATs might overflow the end of text. Only warn if it crosses the end of RO data. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6499f8eeb2a36330e5c9fc1cee9a79374875bd54.1589866984.git.christophe.leroy@csgroup.eu Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-07-13powerpc/ptdump: Add _PAGE_COHERENT flagChristophe Leroy
commit 3af4786eb429b2df76cbd7ce3bae21467ac3e4fb upstream. For platforms using shared.c (4xx, Book3e, Book3s/32), also handle the _PAGE_COHERENT flag which corresponds to the M bit of the WIMG flags. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Make it more verbose, use "coherent" rather than "m"] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/324c3d860717e8e91fca3bb6c0f8b23e1644a404.1589866984.git.christophe.leroy@csgroup.eu Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-07-12Merge tag 'v5.2.48' into v5.2/standard/baseBruce Ashfield
This is the 5.2.48 stable release
2020-07-12Merge tag 'v5.2.47' into v5.2/standard/baseBruce Ashfield
This is the 5.2.47 stable release
2020-07-11powerpc/kasan: Fix shadow pages allocation failureChristophe Leroy
commit d2a91cef9bbdeb87b7449fdab1a6be6000930210 upstream. Doing kasan pages allocation in MMU_init is too early, kernel doesn't have access yet to the entire memory space and memblock_alloc() fails when the kernel is a bit big. Do it from kasan_init() instead. Fixes: 2edb16efc899 ("powerpc/32: Add KASAN support") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c24163ee5d5f8cdf52fefa45055ceb35435b8f15.1589866984.git.christophe.leroy@csgroup.eu Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-07-11powerpc/mm: Fix conditions to perform MMU specific management by blocks on ↵Christophe Leroy
PPC32. commit 4e3319c23a66dabfd6c35f4d2633d64d99b68096 upstream. Setting init mem to NX shall depend on sinittext being mapped by block, not on stext being mapped by block. Setting text and rodata to RO shall depend on stext being mapped by block, not on sinittext being mapped by block. Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7d565fb8f51b18a3d98445a830b2f6548cb2da2a.1589866984.git.christophe.leroy@csgroup.eu Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-07-07mm: move the powerpc hugepd code to mm/gup.cChristoph Hellwig
commit cbd34da7dc9afd521e0bea5e7d12701f4a9da7c7 upstream. While only powerpc supports the hugepd case, the code is pretty generic and I'd like to keep all GUP internals in one place. Link: http://lkml.kernel.org/r/20190625143715.1689-15-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-07-07powerpc/ptdump: Properly handle non standard page sizeChristophe Leroy
commit b00ff6d8c1c3898b0f768cbb38ef722d25bd2f39 upstream. In order to properly display information regardless of the page size, it is necessary to take into account real page size. Fixes: cabe8138b23c ("powerpc: dump as a single line areas mapping a single physical page.") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a53b2a0ffd042a8d85464bf90d55bc5b970e00a1.1589866984.git.christophe.leroy@csgroup.eu Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-06-05Merge tag 'v5.2.42' into v5.2/standard/baseBruce Ashfield
This is the 5.2.42 stable release
2020-06-01powerpc/fsl_booke: Avoid creating duplicate tlb1 entryLaurentiu Tudor
commit aa4113340ae6c2811e046f08c2bc21011d20a072 upstream. In the current implementation, the call to loadcam_multi() is wrapped between switch_to_as1() and restore_to_as0() calls so, when it tries to create its own temporary AS=1 TLB1 entry, it ends up duplicating the existing one created by switch_to_as1(). Add a check to skip creating the temporary entry if already running in AS=1. Fixes: d9e1831a4202 ("powerpc/85xx: Load all early TLB entries at once") Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com> Acked-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200123111914.2565-1-laurentiu.tudor@nxp.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-19Merge tag 'v5.2.40' into v5.2/standard/baseBruce Ashfield
This is the 5.2.40 stable release
2020-05-15powerpc/hugetlb: Fix 512k hugepages on 8xx with 16k page sizeChristophe Leroy
commit f2b67ef90b0d5eca0f2255e02cf2f620bc0ddcdb upstream. Commit 55c8fc3f4930 ("powerpc/8xx: reintroduce 16K pages with HW assistance") redefined pte_t as a struct of 4 pte_basic_t, because in 16K pages mode there are four identical entries in the page table. But the size of hugepage tables is calculated based of the size of (void *). Therefore, we end up with page tables of size 1k instead of 4k for 512k pages. As 512k hugepage tables are the same size as standard page tables, ie 4k, use the standard page tables instead of PGT_CACHE tables. Fixes: 3fb69c6a1a13 ("powerpc/8xx: Enable 512k hugepage support with HW assistance") Cc: stable@vger.kernel.org # v5.0+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/90ec56a2315be602494619ed0223bba3b0b8d619.1580997007.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-15powerpc/mm/hugetlb: Fix kernel crash if we fail to allocate page table cachesAneesh Kumar K.V
commit 5d49275a27310233964fc3edc8dd097a094ce338 upstream. We only check for hugetlb allocations, because with hugetlb we do conditional registration. For PGD/PUD/PMD levels we register them always in pgtable_cache_init. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-15powerpc/mm/hugetlb: Don't enable HugeTLB if we don't have a page table cacheAneesh Kumar K.V
commit ac25ba68fa4001c85395f0488b1c7a2421c5aada upstream. This makes sure we don't enable HugeTLB if the cache is not configured. I am still not sure about this. IMHO hugetlb support should be a hardware support derivative and any cache allocation failure should be handled as I did in the earlier patch. But then if we were not able to create hugetlb page table cache, we can as well declare hugetlb support disabled thereby avoiding calling into allocation routines. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-15powerpc/mm: Don't log user reads to 0xffffffffChristophe Leroy
commit 0f9aee0cb9da7db7d96f63cfa2dc5e4f1bffeb87 upstream. Running vdsotest leaves many times the following log: [ 79.629901] vdsotest[396]: User access of kernel address (ffffffff) - exploit attempt? (uid: 0) A pointer set to (-1) is likely a programming error similar to a NULL pointer and is not worth logging as an exploit attempt. Don't log user accesses to 0xffffffff. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0728849e826ba16f1fbd6fa7f5c6cc87bd64e097.1577087627.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-05Merge branch 'linux-5.2.y' into v5.2/standard/baseBruce Ashfield
2020-05-04powerpc/ptdump: Fix W+X verification call in mark_rodata_ro()Christophe Leroy
commit e26ad936dd89d79f66c2b567f700e0c2a7103070 upstream. ptdump_check_wx() also have to be called when pages are mapped by blocks. Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/37517da8310f4457f28921a4edb88fb21d27b62a.1578989531.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-04powerpc/32s: Fix bad_kuap_fault()Christophe Leroy
commit 6ec20aa2e510b6297906c45f009aa08b2d97269a upstream. At the moment, bad_kuap_fault() reports a fault only if a bad access to userspace occurred while access to userspace was not granted. But if a fault occurs for a write outside the allowed userspace segment(s) that have been unlocked, bad_kuap_fault() fails to detect it and the kernel loops forever in do_page_fault(). Fix it by checking that the accessed address is within the allowed range. Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f48244e9485ada0a304ed33ccbb8da271180c80d.1579866752.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-04powerpc/ptdump: Fix W+X verificationChristophe Leroy
commit d80ae83f1f932ab7af47b54d0d3bef4f4dba489f upstream. Verification cannot rely on simple bit checking because on some platforms PAGE_RW is 0, checking that a page is not W means checking that PAGE_RO is set instead of checking that PAGE_RW is not set. Use pte helpers instead of checking bits. Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0d894839fdbb19070f0e1e4140363be4f2bb62fc.1578989540.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-05-04powerpc/mmu_gather: enable RCU_TABLE_FREE even for !SMP caseAneesh Kumar K.V
commit 12e4d53f3f04e81f9e83d6fc10edc7314ab9f6b9 upstream. Patch series "Fixup page directory freeing", v4. This is a repost of patch series from Peter with the arch specific changes except ppc64 dropped. ppc64 changes are added here because we are redoing the patch series on top of ppc64 changes. This makes it easy to backport these changes. Only the first 2 patches need to be backported to stable. The thing is, on anything SMP, freeing page directories should observe the exact same order as normal page freeing: 1) unhook page/directory 2) TLB invalidate 3) free page/directory Without this, any concurrent page-table walk could end up with a Use-after-Free. This is esp. trivial for anything that has software page-table walkers (HAVE_FAST_GUP / software TLB fill) or the hardware caches partial page-walks (ie. caches page directories). Even on UP this might give issues since mmu_gather is preemptible these days. An interrupt or preempted task accessing user pages might stumble into the free page if the hardware caches page directories. This patch series fixes ppc64 and add generic MMU_GATHER changes to support the conversion of other architectures. I haven't added patches w.r.t other architecture because they are yet to be acked. This patch (of 9): A followup patch is going to make sure we correctly invalidate page walk cache before we free page table pages. In order to keep things simple enable RCU_TABLE_FREE even for !SMP so that we don't have to fixup the !SMP case differently in the followup patch !SMP case is right now broken for radix translation w.r.t page walk cache flush. We can get interrupted in between page table free and that would imply we have page walk cache entries pointing to tables which got freed already. Michael said "both our platforms that run on Power9 force SMP on in Kconfig, so the !SMP case is unlikely to be a problem for anyone in practice, unless they've hacked their kernel to build it !SMP." Link: http://lkml.kernel.org/r/20200116064531.483522-2-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-04-19Merge branch 'linux-5.2.y' into v5.2/standard/baseBruce Ashfield
2020-04-16powerpc/kasan: Fix kasan_remap_early_shadow_ro()Christophe Leroy
commit af92bad615be75c6c0d1b1c5b48178360250a187 upstream. At the moment kasan_remap_early_shadow_ro() does nothing, because k_end is 0 and k_cur < 0 is always true. Change the test to k_cur != k_end, as done in kasan_init_shadow_page_tables() Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Fixes: cbd18991e24f ("powerpc/mm: Fix an Oops in kasan_mmu_init()") Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4e7b56865e01569058914c991143f5961b5d4719.1583507333.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-03-21Merge branch 'linux-5.2.y' into v5.2/standard/baseBruce Ashfield
2020-03-20powerpc: Ensure that swiotlb buffer is allocated from low memoryMike Rapoport
commit 8fabc623238e68b3ac63c0dd1657bf86c1fa33af upstream. Some powerpc platforms (e.g. 85xx) limit DMA-able memory way below 4G. If a system has more physical memory than this limit, the swiotlb buffer is not addressable because it is allocated from memblock using top-down mode. Force memblock to bottom-up mode before calling swiotlb_init() to ensure that the swiotlb buffer is DMA-able. Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191204123524.22919-1-rppt@kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-03-20powerpc/mm: Mark get_slice_psize() & slice_addr_is_low() as notraceMichael Ellerman
commit 91a063c956084fb21cf2523bce6892514e3f1799 upstream. These slice routines are called from the SLB miss handler, which can lead to warnings from the IRQ code, because we have not reconciled the IRQ state properly: WARNING: CPU: 72 PID: 30150 at arch/powerpc/kernel/irq.c:258 arch_local_irq_restore.part.0+0xcc/0x100 Modules linked in: CPU: 72 PID: 30150 Comm: ftracetest Not tainted 5.5.0-rc2-gcc9x-g7e0165b2f1a9 #1 NIP: c00000000001d83c LR: c00000000029ab90 CTR: c00000000026cf90 REGS: c0000007eee3b960 TRAP: 0700 Not tainted (5.5.0-rc2-gcc9x-g7e0165b2f1a9) MSR: 8000000000021033 <SF,ME,IR,DR,RI,LE> CR: 22242844 XER: 20000000 CFAR: c00000000001d780 IRQMASK: 0 ... NIP arch_local_irq_restore.part.0+0xcc/0x100 LR trace_graph_entry+0x270/0x340 Call Trace: trace_graph_entry+0x254/0x340 (unreliable) function_graph_enter+0xe4/0x1a0 prepare_ftrace_return+0xa0/0x130 ftrace_graph_caller+0x44/0x94 # (get_slice_psize()) slb_allocate_user+0x7c/0x100 do_slb_fault+0xf8/0x300 instruction_access_slb_common+0x140/0x180 Fixes: 48e7b7695745 ("powerpc/64s/hash: Convert SLB miss handlers to C") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191221121337.4894-1-mpe@ellerman.id.au Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-03-11Merge tag 'v5.2.34' into v5.2/standard/baseBruce Ashfield
This is the 5.2.34 stable release # gpg: Signature made Sat 07 Mar 2020 07:25:00 PM EST # gpg: using RSA key EBCE84042C07D1D6 # gpg: Can't check signature: No public key
2020-03-07powerpc/book3s64/hash: Add cond_resched to avoid soft lockup warningAneesh Kumar K.V
commit 16f6b67cf03cb43db7104acb2ca877bdc2606c92 upstream. With large memory (8TB and more) hotplug, we can get soft lockup warnings as below. These were caused by a long loop without any explicit cond_resched which is a problem for !PREEMPT kernels. Avoid this using cond_resched() while inserting hash page table entries. We already do similar cond_resched() in __add_pages(), see commit f64ac5e6e306 ("mm, memory_hotplug: add scheduling point to __add_pages"). rcu: 3-....: (24002 ticks this GP) idle=13e/1/0x4000000000000002 softirq=722/722 fqs=12001 (t=24003 jiffies g=4285 q=2002) NMI backtrace for cpu 3 CPU: 3 PID: 3870 Comm: ndctl Not tainted 5.3.0-197.18-default+ #2 Call Trace: dump_stack+0xb0/0xf4 (unreliable) nmi_cpu_backtrace+0x124/0x130 nmi_trigger_cpumask_backtrace+0x1ac/0x1f0 arch_trigger_cpumask_backtrace+0x28/0x3c rcu_dump_cpu_stacks+0xf8/0x154 rcu_sched_clock_irq+0x878/0xb40 update_process_times+0x48/0x90 tick_sched_handle.isra.16+0x4c/0x80 tick_sched_timer+0x68/0xe0 __hrtimer_run_queues+0x180/0x430 hrtimer_interrupt+0x110/0x300 timer_interrupt+0x108/0x2f0 decrementer_common+0x114/0x120 --- interrupt: 901 at arch_add_memory+0xc0/0x130 LR = arch_add_memory+0x74/0x130 memremap_pages+0x494/0x650 devm_memremap_pages+0x3c/0xa0 pmem_attach_disk+0x188/0x750 nvdimm_bus_probe+0xac/0x2c0 really_probe+0x148/0x570 driver_probe_device+0x19c/0x1d0 device_driver_attach+0xcc/0x100 bind_store+0x134/0x1c0 drv_attr_store+0x44/0x60 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1a0/0x270 __vfs_write+0x3c/0x70 vfs_write+0xd0/0x260 ksys_write+0xdc/0x130 system_call+0x5c/0x68 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191001084656.31277-1-aneesh.kumar@linux.ibm.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-03-07powerpc/pseries: Don't fail hash page table insert for bolted mappingAneesh Kumar K.V
commit 75838a3290cd4ebbd1f567f310ba04b6ef017ce4 upstream. If the hypervisor returned H_PTEG_FULL for H_ENTER hcall, retry a hash page table insert by removing a random entry from the group. After some runtime, it is very well possible to find all the 8 hash page table entry slot in the hpte group used for mapping. Don't fail a bolted entry insert in that case. With Storage class memory a user can find this error easily since a namespace enable/disable is equivalent to memory add/remove. This results in failures as reported below: $ ndctl create-namespace -r region1 -t pmem -m devdax -a 65536 -s 100M libndctl: ndctl_dax_enable: dax1.3: failed to enable Error: namespace1.2: failed to enable failed to create namespace: No such device or address In kernel log we find the details as below: Unable to create mapping for hot added memory 0xc000042006000000..0xc00004200d000000: -1 dax_pmem: probe of dax1.3 failed with error -14 This indicates that we failed to create a bolted hash table entry for direct-map address backing the namespace. We also observe failures such that not all namespaces will be enabled with ndctl enable-namespace all command. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191024093542.29777-2-aneesh.kumar@linux.ibm.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-10Merge tag 'v5.2.22' into v5.2/standard/baseBruce Ashfield
This is the 5.2.22 stable release # gpg: Signature made Sat 09 Nov 2019 08:56:23 PM EST # gpg: using RSA key EBCE84042C07D1D6 # gpg: Can't check signature: No public key
2019-11-09libnvdimm/altmap: Track namespace boundaries in altmapAneesh Kumar K.V
commit cf387d9644d8c78721cf9b77af9f67bb5b04da16 upstream. With PFN_MODE_PMEM namespace, the memmap area is allocated from the device area. Some architectures map the memmap area with large page size. On architectures like ppc64, 16MB page for memap mapping can map 262144 pfns. This maps a namespace size of 16G. When populating memmap region with 16MB page from the device area, make sure the allocated space is not used to map resources outside this namespace. Such usage of device area will prevent a namespace destroy. Add resource end pnf in altmap and use that to check if the memmap area allocation can map pfn outside the namespace. On ppc64 in such case we fallback to allocation from memory. This fix kernel crash reported below: [ 132.034989] WARNING: CPU: 13 PID: 13719 at mm/memremap.c:133 devm_memremap_pages_release+0x2d8/0x2e0 [ 133.464754] BUG: Unable to handle kernel data access at 0xc00c00010b204000 [ 133.464760] Faulting instruction address: 0xc00000000007580c [ 133.464766] Oops: Kernel access of bad area, sig: 11 [#1] [ 133.464771] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries ..... [ 133.464901] NIP [c00000000007580c] vmemmap_free+0x2ac/0x3d0 [ 133.464906] LR [c0000000000757f8] vmemmap_free+0x298/0x3d0 [ 133.464910] Call Trace: [ 133.464914] [c000007cbfd0f7b0] [c0000000000757f8] vmemmap_free+0x298/0x3d0 (unreliable) [ 133.464921] [c000007cbfd0f8d0] [c000000000370a44] section_deactivate+0x1a4/0x240 [ 133.464928] [c000007cbfd0f980] [c000000000386270] __remove_pages+0x3a0/0x590 [ 133.464935] [c000007cbfd0fa50] [c000000000074158] arch_remove_memory+0x88/0x160 [ 133.464942] [c000007cbfd0fae0] [c0000000003be8c0] devm_memremap_pages_release+0x150/0x2e0 [ 133.464949] [c000007cbfd0fb70] [c000000000738ea0] devm_action_release+0x30/0x50 [ 133.464955] [c000007cbfd0fb90] [c00000000073a5a4] release_nodes+0x344/0x400 [ 133.464961] [c000007cbfd0fc40] [c00000000073378c] device_release_driver_internal+0x15c/0x250 [ 133.464968] [c000007cbfd0fc80] [c00000000072fd14] unbind_store+0x104/0x110 [ 133.464973] [c000007cbfd0fcd0] [c00000000072ee24] drv_attr_store+0x44/0x70 [ 133.464981] [c000007cbfd0fcf0] [c0000000004a32bc] sysfs_kf_write+0x6c/0xa0 [ 133.464987] [c000007cbfd0fd10] [c0000000004a1dfc] kernfs_fop_write+0x17c/0x250 [ 133.464993] [c000007cbfd0fd60] [c0000000003c348c] __vfs_write+0x3c/0x70 [ 133.464999] [c000007cbfd0fd80] [c0000000003c75d0] vfs_write+0xd0/0x250 djbw: Aneesh notes that this crash can likely be triggered in any kernel that supports 'papr_scm', so flagging that commit for -stable consideration. Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") Cc: <stable@vger.kernel.org> Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Pankaj Gupta <pagupta@redhat.com> Tested-by: Santosh Sivaraj <santosh@fossix.org> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Link: https://lore.kernel.org/r/20190910062826.10041-1-aneesh.kumar@linux.ibm.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9Aneesh Kumar K.V
commit 047e6575aec71d75b765c22111820c4776cd1c43 upstream. On POWER9, under some circumstances, a broadcast TLB invalidation will fail to invalidate the ERAT cache on some threads when there are parallel mtpidr/mtlpidr happening on other threads of the same core. This can cause stores to continue to go to a page after it's unmapped. The workaround is to force an ERAT flush using PID=0 or LPID=0 tlbie flush. This additional TLB flush will cause the ERAT cache invalidation. Since we are using PID=0 or LPID=0, we don't get filtered out by the TLB snoop filtering logic. We need to still follow this up with another tlbie to take care of store vs tlbie ordering issue explained in commit: a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9"). The presence of ERAT cache implies we can still get new stores and they may miss store queue marking flush. Cc: stable@vger.kernel.org Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190924035254.24612-3-aneesh.kumar@linux.ibm.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/mm: Fix an Oops in kasan_mmu_init()Christophe Leroy
commit cbd18991e24fea2c31da3bb117c83e4a3538cd11 upstream. Uncompressing Kernel Image ... OK Loading Device Tree to 01ff7000, end 01fff74f ... OK [ 0.000000] printk: bootconsole [udbg0] enabled [ 0.000000] BUG: Unable to handle kernel data access at 0xf818c000 [ 0.000000] Faulting instruction address: 0xc0013c7c [ 0.000000] Thread overran stack, or stack corrupted [ 0.000000] Oops: Kernel access of bad area, sig: 11 [#1] [ 0.000000] BE PAGE_SIZE=16K PREEMPT [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.3.0-rc4-s3k-dev-00743-g5abe4a3e8fd3-dirty #2080 [ 0.000000] NIP: c0013c7c LR: c0013310 CTR: 00000000 [ 0.000000] REGS: c0c5ff38 TRAP: 0300 Not tainted (5.3.0-rc4-s3k-dev-00743-g5abe4a3e8fd3-dirty) [ 0.000000] MSR: 00001032 <ME,IR,DR,RI> CR: 99033955 XER: 80002100 [ 0.000000] DAR: f818c000 DSISR: 82000000 [ 0.000000] GPR00: c0013310 c0c5fff0 c0ad6ac0 c0c600c0 f818c031 82000000 00000000 ffffffff [ 0.000000] GPR08: 00000000 f1f1f1f1 c0013c2c c0013304 99033955 00400008 00000000 07ff9598 [ 0.000000] GPR16: 00000000 07ffb94c 00000000 00000000 00000000 00000000 00000000 f818cfb2 [ 0.000000] GPR24: 00000000 00000000 00001000 ffffffff 00000000 c07dbf80 00000000 f818c000 [ 0.000000] NIP [c0013c7c] do_page_fault+0x50/0x904 [ 0.000000] LR [c0013310] handle_page_fault+0xc/0x38 [ 0.000000] Call Trace: [ 0.000000] Instruction dump: [ 0.000000] be010080 91410014 553fe8fe 3d40c001 3d20f1f1 7d800026 394a3c2c 3fffe000 [ 0.000000] 6129f1f1 900100c4 9181007c 91410018 <913f0000> 3d2001f4 6129f4f4 913f0004 Don't map the early shadow page read-only yet when creating the new page tables for the real shadow memory, otherwise the memblock allocations that immediately follows to create the real shadow pages that are about to replace the early shadow page trigger a page fault if they fall into the region being worked on at the moment. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Fixes: 2edb16efc899 ("powerpc/32: Add KASAN support") Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/fe86886fb8db44360417cee0dc515ad47ca6ef72.1566382750.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/mm: Add a helper to select PAGE_KERNEL_RO or PAGE_READONLYChristophe Leroy
commit 4c0f5d1eb4072871c34530358df45f05ab80edd6 upstream. In a couple of places there is a need to select whether read-only protection of shadow pages is performed with PAGE_KERNEL_RO or with PAGE_READONLY. Add a helper to avoid duplicating the choice. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9f33f44b9cd741c4a02b3dce7b8ef9438fe2cd2a.1566382750.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/book3s64/radix: Rename CPU_FTR_P9_TLBIE_BUG feature flagAneesh Kumar K.V
commit 09ce98cacd51fcd0fa0af2f79d1e1d3192f4cbb0 upstream. Rename the #define to indicate this is related to store vs tlbie ordering issue. In the next patch, we will be adding another feature flag that is used to handles ERAT flush vs tlbie ordering issue. Fixes: a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190924035254.24612-2-aneesh.kumar@linux.ibm.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/kasan: Fix shadow area set up for modules.Christophe Leroy
commit 663c0c9496a69f80011205ba3194049bcafd681d upstream. When loading modules, from time to time an Oops is encountered during the init of shadow area for globals. This is due to the last page not always being mapped depending on the exact distance between the start and the end of the shadow area and the alignment with the page addresses. Fix this by aligning the starting address with the page address. Fixes: 2edb16efc899 ("powerpc/32: Add KASAN support") Cc: stable@vger.kernel.org # v5.2+ Reported-by: Erhard F. <erhard_f@mailbox.org> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4f887e9b77d0d725cbb52035c7ece485c1c5fc14.1565361881.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/kasan: Fix parallel loading of modules.Christophe Leroy
commit 45ff3c55958542c3b76075d59741297b8cb31cbb upstream. Parallel loading of modules may lead to bad setup of shadow page table entries. First, lets align modules so that two modules never share the same shadow page. Second, ensure that two modules cannot allocate two page tables for the same PMD entry at the same time. This is done by using init_mm.page_table_lock in the same way as __pte_alloc_kernel() Fixes: 2edb16efc899 ("powerpc/32: Add KASAN support") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c97284f912128cbc3f2fe09d68e90e65fb3e6026.1565361876.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/pseries: Fix cpu_hotplug_lock acquisition in resize_hpt()Gautham R. Shenoy
commit c784be435d5dae28d3b03db31753dd7a18733f0c upstream. The calls to arch_add_memory()/arch_remove_memory() are always made with the read-side cpu_hotplug_lock acquired via memory_hotplug_begin(). On pSeries, arch_add_memory()/arch_remove_memory() eventually call resize_hpt() which in turn calls stop_machine() which acquires the read-side cpu_hotplug_lock again, thereby resulting in the recursive acquisition of this lock. In the absence of CONFIG_PROVE_LOCKING, we hadn't observed a system lockup during a memory hotplug operation because cpus_read_lock() is a per-cpu rwsem read, which, in the fast-path (in the absence of the writer, which in our case is a CPU-hotplug operation) simply increments the read_count on the semaphore. Thus a recursive read in the fast-path doesn't cause any problems. However, we can hit this problem in practice if there is a concurrent CPU-Hotplug operation in progress which is waiting to acquire the write-side of the lock. This will cause the second recursive read to block until the writer finishes. While the writer is blocked since the first read holds the lock. Thus both the reader as well as the writers fail to make any progress thereby blocking both CPU-Hotplug as well as Memory Hotplug operations. Memory-Hotplug CPU-Hotplug CPU 0 CPU 1 ------ ------ 1. down_read(cpu_hotplug_lock.rw_sem) [memory_hotplug_begin] 2. down_write(cpu_hotplug_lock.rw_sem) [cpu_up/cpu_down] 3. down_read(cpu_hotplug_lock.rw_sem) [stop_machine()] Lockdep complains as follows in these code-paths. swapper/0/1 is trying to acquire lock: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: stop_machine+0x2c/0x60 but task is already holding lock: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: mem_hotplug_begin+0x20/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(cpu_hotplug_lock.rw_sem); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by swapper/0/1: #0: (____ptrval____) (&dev->mutex){....}, at: __driver_attach+0x12c/0x1b0 #1: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: mem_hotplug_begin+0x20/0x50 #2: (____ptrval____) (mem_hotplug_lock.rw_sem){++++}, at: percpu_down_write+0x54/0x1a0 stack backtrace: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc5-58373-gbc99402235f3-dirty #166 Call Trace: dump_stack+0xe8/0x164 (unreliable) __lock_acquire+0x1110/0x1c70 lock_acquire+0x240/0x290 cpus_read_lock+0x64/0xf0 stop_machine+0x2c/0x60 pseries_lpar_resize_hpt+0x19c/0x2c0 resize_hpt_for_hotplug+0x70/0xd0 arch_add_memory+0x58/0xfc devm_memremap_pages+0x5e8/0x8f0 pmem_attach_disk+0x764/0x830 nvdimm_bus_probe+0x118/0x240 really_probe+0x230/0x4b0 driver_probe_device+0x16c/0x1e0 __driver_attach+0x148/0x1b0 bus_for_each_dev+0x90/0x130 driver_attach+0x34/0x50 bus_add_driver+0x1a8/0x360 driver_register+0x108/0x170 __nd_driver_register+0xd0/0xf0 nd_pmem_driver_init+0x34/0x48 do_one_initcall+0x1e0/0x45c kernel_init_freeable+0x540/0x64c kernel_init+0x2c/0x160 ret_from_kernel_thread+0x5c/0x68 Fix this issue by 1) Requiring all the calls to pseries_lpar_resize_hpt() be made with cpu_hotplug_lock held. 2) In pseries_lpar_resize_hpt() invoke stop_machine_cpuslocked() as a consequence of 1) 3) To satisfy 1), in hpt_order_set(), call mmu_hash_ops.resize_hpt() with cpu_hotplug_lock held. Fixes: dbcf929c0062 ("powerpc/pseries: Add support for hash table resizing") Cc: stable@vger.kernel.org # v4.11+ Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1557906352-29048-1-git-send-email-ego@linux.vnet.ibm.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/ptdump: Fix addresses display on PPC32Christophe Leroy
commit 7c7a532ba3fc51bf9527d191fb410786c1fdc73c upstream. Commit 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot") wrongly changed KERN_VIRT_START from 0 to PAGE_OFFSET, leading to a shift in the displayed addresses. Lets revert that change to resync walk_pagetables()'s addr val and pgd_t pointer for PPC32. Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/eb4d626514e22f85814830012642329018ef6af9.1565786091.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09powerpc/32s: Fix boot failure with DEBUG_PAGEALLOC without KASAN.Christophe Leroy
commit 9d6d712fbf7766f21c838940eebcd7b4d476c5e6 upstream. When KASAN is selected, the definitive hash table has to be set up later, but there is already an early temporary one. When KASAN is not selected, there is no early hash table, so the setup of the definitive hash table cannot be delayed. Fixes: 72f208c6a8f7 ("powerpc/32s: move hash code patching out of MMU_init_hw()") Cc: stable@vger.kernel.org # v5.2+ Reported-by: Jonathan Neuschafer <j.neuschaefer@gmx.net> Tested-by: Jonathan Neuschafer <j.neuschaefer@gmx.net> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b7860c5e1e784d6b96ba67edf47dd6cbc2e78ab6.1565776892.git.christophe.leroy@c-s.fr Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-10-10Merge tag 'v5.2.20' into v5.2/standard/baseBruce Ashfield
This is the 5.2.20 stable release # gpg: Signature made Mon 07 Oct 2019 12:59:42 PM EDT # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key
2019-10-07powerpc/64s/radix: Fix memory hotplug section page table creationNicholas Piggin
[ Upstream commit 8f51e3929470942e6a8744061254fdeef646cd36 ] create_physical_mapping expects physical addresses, but creating and splitting these mappings after boot is supplying virtual (effective) addresses. This can be irritated by booting with mem= to limit memory then probing an unused physical memory range: echo <addr> > /sys/devices/system/memory/probe This mostly works by accident, firstly because __va(__va(x)) == __va(x) so the virtual address does not get corrupted. Secondly because pfn_pte masks out the upper bits of the pfn beyond the physical address limit, so a pfn constructed with a 0xc000000000000000 virtual linear address will be masked back to the correct physical address in the pte. Fixes: 6cc27341b21a8 ("powerpc/mm: add radix__create_section_mapping()") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190724084638.24982-1-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-24Merge tag 'v5.2.17' into v5.2/standard/baseBruce Ashfield
This is the 5.2.17 stable release # gpg: Signature made Sat 21 Sep 2019 01:18:51 AM EDT # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key