kernel/arch/powerpc/mm/ptdump, branch linux-6.2.y

powerpc: Remove CONFIG_PPC_BOOK3E_MMU

2022-09-26T13:00:14Z

CONFIG_PPC_BOOK3E_MMU is redundant with CONFIG_PPC_E500. Remove it. Also rename mmu-book3e.h to mmu-e500.h Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/c5549cd59a131204ff94ab909cad2e2dad4ddf2f.1663606876.git.christophe.leroy@csgroup.eu

powerpc/ptdump: Fix display of RW pages on FSL_BOOK3E

2022-06-29T07:03:42Z

On FSL_BOOK3E, _PAGE_RW is defined with two bits, one for user and one for supervisor. As soon as one of the two bits is set, the page has to be display as RW. But the way it is implemented today requires both bits to be set in order to display it as RW. Instead of display RW when _PAGE_RW bits are set and R otherwise, reverse the logic and display R when _PAGE_RW bits are all 0 and RW otherwise. This change has no impact on other platforms as _PAGE_RW is a single bit on all of them. Fixes: 8eb07b187000 ("powerpc/mm: Dump linux pagetables") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/0c33b96317811edf691e81698aaee8fa45ec3449.1656427391.git.christophe.leroy@csgroup.eu

powerpc: Book3S 64-bit outline-only KASAN support

2022-05-22T05:58:29Z

Implement a limited form of KASAN for Book3S 64-bit machines running under the Radix MMU, supporting only outline mode. - Enable the compiler instrumentation to check addresses and maintain the shadow region. (This is the guts of KASAN which we can easily reuse.) - Require kasan-vmalloc support to handle modules and anything else in vmalloc space. - KASAN needs to be able to validate all pointer accesses, but we can't instrument all kernel addresses - only linear map and vmalloc. On boot, set up a single page of read-only shadow that marks all iomap and vmemmap accesses as valid. - Document KASAN in powerpc docs. Background ---------- KASAN support on Book3S is a bit tricky to get right: - It would be good to support inline instrumentation so as to be able to catch stack issues that cannot be caught with outline mode. - Inline instrumentation requires a fixed offset. - Book3S runs code with translations off ("real mode") during boot, including a lot of generic device-tree parsing code which is used to determine MMU features. [ppc64 mm note: The kernel installs a linear mapping at effective address c000...-c008.... This is a one-to-one mapping with physical memory from 0000... onward. Because of how memory accesses work on powerpc 64-bit Book3S, a kernel pointer in the linear map accesses the same memory both with translations on (accessing as an 'effective address'), and with translations off (accessing as a 'real address'). This works in both guests and the hypervisor. For more details, see s5.7 of Book III of version 3 of the ISA, in particular the Storage Control Overview, s5.7.3, and s5.7.5 - noting that this KASAN implementation currently only supports Radix.] - Some code - most notably a lot of KVM code - also runs with translations off after boot. - Therefore any offset has to point to memory that is valid with translations on or off. One approach is just to give up on inline instrumentation. This way boot-time checks can be delayed until after the MMU is set is up, and we can just not instrument any code that runs with translations off after booting. Take this approach for now and require outline instrumentation. Previous attempts allowed inline instrumentation. However, they came with some unfortunate restrictions: only physically contiguous memory could be used and it had to be specified at compile time. Maybe we can do better in the future. [paulus@ozlabs.org - Rebased onto 5.17. Note that a kernel with CONFIG_KASAN=y will crash during boot on a machine using HPT translation because not all the entry points to the generic KASAN code are protected with a call to kasan_arch_is_ready().] Originally-by: Balbir Singh # ppc64 out-of-line radix version Signed-off-by: Daniel Axtens Signed-off-by: Paul Mackerras [mpe: Update copyright year and comment formatting] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/YoTE69OQwiG7z+Gu@cleo

powerpc/ptdump: Fix sparse warning in hashpagetable.c

2022-02-02T09:32:11Z

As reported by sparse: arch/powerpc/mm/ptdump/hashpagetable.c:264:29: warning: restricted __be64 degrades to integer arch/powerpc/mm/ptdump/hashpagetable.c:265:49: warning: restricted __be64 degrades to integer arch/powerpc/mm/ptdump/hashpagetable.c:267:36: warning: incorrect type in assignment (different base types) arch/powerpc/mm/ptdump/hashpagetable.c:267:36: expected unsigned long long [usertype] arch/powerpc/mm/ptdump/hashpagetable.c:267:36: got restricted __be64 [usertype] v arch/powerpc/mm/ptdump/hashpagetable.c:268:36: warning: incorrect type in assignment (different base types) arch/powerpc/mm/ptdump/hashpagetable.c:268:36: expected unsigned long long [usertype] arch/powerpc/mm/ptdump/hashpagetable.c:268:36: got restricted __be64 [usertype] r The values returned by plpar_pte_read_4() are CPU endian, not __be64, so assigning them to struct hash_pte confuses sparse. As a minimal fix open code a struct to hold the values with CPU endian types. Reported-by: kernel test robot Reported-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220202053039.691917-1-mpe@ellerman.id.au

Merge tag 'powerpc-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2022-01-14T14:17:26Z

Pull powerpc updates from Michael Ellerman: - Optimise radix KVM guest entry/exit by 2x on Power9/Power10. - Allow firmware to tell us whether to disable the entry and uaccess flushes on Power10 or later CPUs. - Add BPF_PROBE_MEM support for 32 and 64-bit BPF jits. - Several fixes and improvements to our hard lockup watchdog. - Activate HAVE_DYNAMIC_FTRACE_WITH_REGS on 32-bit. - Allow building the 64-bit Book3S kernel without hash MMU support, ie. Radix only. - Add KUAP (SMAP) support for 40x, 44x, 8xx, Book3E (64-bit). - Add new encodings for perf_mem_data_src.mem_hops field, and use them on Power10. - A series of small performance improvements to 64-bit interrupt entry. - Several commits fixing issues when building with the clang integrated assembler. - Many other small features and fixes. Thanks to Alan Modra, Alexey Kardashevskiy, Ammar Faizi, Anders Roxell, Arnd Bergmann, Athira Rajeev, Cédric Le Goater, Christophe JAILLET, Christophe Leroy, Christoph Hellwig, Daniel Axtens, David Yang, Erhard Furtner, Fabiano Rosas, Greg Kroah-Hartman, Guo Ren, Hari Bathini, Jason Wang, Joel Stanley, Julia Lawall, Kajol Jain, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mark Brown, Minghao Chi, Nageswara R Sastry, Naresh Kamboju, Nathan Chancellor, Nathan Lynch, Nicholas Piggin, Nick Child, Oliver O'Halloran, Peiwei Hu, Randy Dunlap, Ravi Bangoria, Rob Herring, Russell Currey, Sachin Sant, Sean Christopherson, Segher Boessenkool, Thadeu Lima de Souza Cascardo, Tyrel Datwyler, Xiang wangx, and Yang Guang. * tag 'powerpc-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (240 commits) powerpc/xmon: Dump XIVE information for online-only processors. powerpc/opal: use default_groups in kobj_type powerpc/cacheinfo: use default_groups in kobj_type powerpc/sched: Remove unused TASK_SIZE_OF powerpc/xive: Add missing null check after calling kmalloc powerpc/floppy: Remove usage of the deprecated "pci-dma-compat.h" API selftests/powerpc: Add a test of sigreturning to an unaligned address powerpc/64s: Use EMIT_WARN_ENTRY for SRR debug warnings powerpc/64s: Mask NIP before checking against SRR0 powerpc/perf: Fix spelling of "its" powerpc/32: Fix boot failure with GCC latent entropy plugin powerpc/code-patching: Replace patch_instruction() by ppc_inst_write() in selftests powerpc/code-patching: Move code patching selftests in its own file powerpc/code-patching: Move instr_is_branch_{i/b}form() in code-patching.h powerpc/code-patching: Move patch_exception() outside code-patching.c powerpc/code-patching: Use test_trampoline for prefixed patch test powerpc/code-patching: Fix patch_branch() return on out-of-range failure powerpc/code-patching: Reorganise do_patch_instruction() to ease error handling powerpc/code-patching: Fix unmap_patch_area() error handling powerpc/code-patching: Fix error handling in do_patch_instruction() ...

powerpc/mm: Add __init attribute to eligible functions

2021-12-23T11:33:11Z

Some functions defined in 'arch/powerpc/mm' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by: Nick Child Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211216220035.605465-4-nick.child@ibm.com

powerpc/ptdump: Fix DEBUG_WX since generic ptdump conversion

2021-12-21T02:05:59Z

In note_prot_wx() we bail out without reporting anything if CONFIG_PPC_DEBUG_WX is disabled. But CONFIG_PPC_DEBUG_WX was removed in the conversion to generic ptdump, we now need to use CONFIG_DEBUG_WX instead. Fixes: e084728393a5 ("powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP") Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Michael Ellerman Reviewed-by: Christophe Leroy Link: https://lore.kernel.org/r/20211203124112.2912562-1-mpe@ellerman.id.au

powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU

2021-12-09T11:41:13Z

Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves 128kB kernel image size (90kB text) on powernv_defconfig minus KVM, 350kB on pseries_defconfig minus KVM, 40kB on a tiny config. Signed-off-by: Nicholas Piggin [mpe: Fixup defined(ARCH_HAS_MEMREMAP_COMPAT_ALIGN), which needs CONFIG. Fix radix_enabled() use in setup_initial_memory_limit(). Add some stubs to reduce number of ifdefs.] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211201144153.2456614-18-npiggin@gmail.com

powerpc/ptdump: Fix display a BAT's size unit

2021-11-29T11:49:29Z

We have wrong units on BAT's sizes (G instead of M, M instead of ...) ---[ Instruction Block Address Translation ]--- 0: 0xc0000000-0xc03fffff 0x00000000 4G Kernel x m 1: 0xc0400000-0xc05fffff 0x00400000 2G Kernel x m 2: 0xc0600000-0xc06fffff 0x00600000 1G Kernel x m 3: 0xc0700000-0xc077ffff 0x00700000 512M Kernel x m 4: 0xc0780000-0xc079ffff 0x00780000 128M Kernel x m 5: 0xc07a0000-0xc07bffff 0x007a0000 128M Kernel x m 6: - 7: - This is because pt_dump_size() expects a size in Kbytes but bat_show_603() gives the size in bytes. To avoid risk of confusion, change pt_dump_size() to take bytes. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/f16c30f5c9185a63335322cf1a8b22f189d335ef.1637922595.git.christophe.leroy@csgroup.eu

powerpc/ptdump: Fix generic ptdump for 64-bit

2021-09-01T06:52:53Z

Since the conversion to generic ptdump we see crashes on 64-bit: BUG: Unable to handle kernel data access on read at 0xc0eeff7f00000000 Faulting instruction address: 0xc00000000045e5fc Oops: Kernel access of bad area, sig: 11 [#1] ... NIP __walk_page_range+0x2bc/0xce0 LR __walk_page_range+0x240/0xce0 Call Trace: __walk_page_range+0x240/0xce0 (unreliable) walk_page_range_novma+0x74/0xb0 ptdump_walk_pgd+0x98/0x170 ptdump_check_wx+0x88/0xd0 mark_rodata_ro+0x48/0x80 kernel_init+0x74/0x1a0 ret_from_kernel_thread+0x5c/0x64 What's happening is that have walked off the end of the kernel page tables, and started dereferencing junk values. That happens because we initialised the ptdump_range to span all the way up to 0xffffffffffffffff: static struct ptdump_range ptdump_range[] __ro_after_init = { {TASK_SIZE_MAX, ~0UL}, But the kernel page tables don't span that far. So on 64-bit set the end of the range to be the address immediately past the end of the kernel page tables, to limit the page table walk to valid addresses. Fixes: e084728393a5 ("powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP") Reported-by: Nathan Chancellor Tested-by: Nathan Chancellor Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210831135151.886620-1-mpe@ellerman.id.au