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* powerpc/64: Fix stack trace not displaying final frameMichael Ellerman2021-03-172-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit e3de1e291fa58a1ab0f471a4b458eff2514e4b5f ] In commit bf13718bc57a ("powerpc: show registers when unwinding interrupt frames") we changed our stack dumping logic to show the full registers whenever we find an interrupt frame on the stack. However we didn't notice that on 64-bit this doesn't show the final frame, ie. the interrupt that brought us in from userspace, whereas on 32-bit it does. That is due to confusion about the size of that last frame. The code in show_stack() calls validate_sp(), passing it STACK_INT_FRAME_SIZE to check the sp is at least that far below the top of the stack. However on 64-bit that size is too large for the final frame, because it includes the red zone, but we don't allocate a red zone for the first frame. So add a new define that encodes the correct size for 32-bit and 64-bit, and use it in show_stack(). This results in the full trace being shown on 64-bit, eg: sysrq: Trigger a crash Kernel panic - not syncing: sysrq triggered crash CPU: 0 PID: 83 Comm: sh Not tainted 5.11.0-rc2-gcc-8.2.0-00188-g571abcb96b10-dirty #649 Call Trace: [c00000000a1c3ac0] [c000000000897b70] dump_stack+0xc4/0x114 (unreliable) [c00000000a1c3b00] [c00000000014334c] panic+0x178/0x41c [c00000000a1c3ba0] [c00000000094e600] sysrq_handle_crash+0x40/0x50 [c00000000a1c3c00] [c00000000094ef98] __handle_sysrq+0xd8/0x210 [c00000000a1c3ca0] [c00000000094f820] write_sysrq_trigger+0x100/0x188 [c00000000a1c3ce0] [c0000000005559dc] proc_reg_write+0x10c/0x1b0 [c00000000a1c3d10] [c000000000479950] vfs_write+0xf0/0x360 [c00000000a1c3d60] [c000000000479d9c] ksys_write+0x7c/0x140 [c00000000a1c3db0] [c00000000002bf5c] system_call_exception+0x19c/0x2c0 [c00000000a1c3e10] [c00000000000d35c] system_call_common+0xec/0x278 --- interrupt: c00 at 0x7fff9fbab428 NIP: 00007fff9fbab428 LR: 000000001000b724 CTR: 0000000000000000 REGS: c00000000a1c3e80 TRAP: 0c00 Not tainted (5.11.0-rc2-gcc-8.2.0-00188-g571abcb96b10-dirty) MSR: 900000000280f033 <SF,HV,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: 22002884 XER: 00000000 IRQMASK: 0 GPR00: 0000000000000004 00007fffc3cb8960 00007fff9fc59900 0000000000000001 GPR04: 000000002a4b32d0 0000000000000002 0000000000000063 0000000000000063 GPR08: 000000002a4b32d0 0000000000000000 0000000000000000 0000000000000000 GPR12: 0000000000000000 00007fff9fcca9a0 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 00000000100b8fd0 GPR20: 000000002a4b3485 00000000100b8f90 0000000000000000 0000000000000000 GPR24: 000000002a4b0440 00000000100e77b8 0000000000000020 000000002a4b32d0 GPR28: 0000000000000001 0000000000000002 000000002a4b32d0 0000000000000001 NIP [00007fff9fbab428] 0x7fff9fbab428 LR [000000001000b724] 0x1000b724 --- interrupt: c00 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210209141627.2898485-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc: improve handling of unrecoverable system resetNicholas Piggin2021-03-171-1/+4
| | | | | | | | | | | | | [ Upstream commit 11cb0a25f71818ca7ab4856548ecfd83c169aa4d ] If an unrecoverable system reset hits in process context, the system does not have to panic. Similar to machine check, call nmi_exit() before die(). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-26-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/pci: Add ppc_md.discover_phbs()Oliver O'Halloran2021-03-171-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 5537fcb319d016ce387f818dd774179bc03217f5 ] On many powerpc platforms the discovery and initalisation of pci_controllers (PHBs) happens inside of setup_arch(). This is very early in boot (pre-initcalls) and means that we're initialising the PHB long before many basic kernel services (slab allocator, debugfs, a real ioremap) are available. On PowerNV this causes an additional problem since we map the PHB registers with ioremap(). As of commit d538aadc2718 ("powerpc/ioremap: warn on early use of ioremap()") a warning is printed because we're using the "incorrect" API to setup and MMIO mapping in searly boot. The kernel does provide early_ioremap(), but that is not intended to create long-lived MMIO mappings and a seperate warning is printed by generic code if early_ioremap() mappings are "leaked." This is all fixable with dumb hacks like using early_ioremap() to setup the initial mapping then replacing it with a real ioremap later on in boot, but it does raise the question: Why the hell are we setting up the PHB's this early in boot? The old and wise claim it's due to "hysterical rasins." Aside from amused grapes there doesn't appear to be any real reason to maintain the current behaviour. Already most of the newer embedded platforms perform PHB discovery in an arch_initcall and between the end of setup_arch() and the start of initcalls none of the generic kernel code does anything PCI related. On powerpc scanning PHBs occurs in a subsys_initcall so it should be possible to move the PHB discovery to a core, postcore or arch initcall. This patch adds the ppc_md.discover_phbs hook and a core_initcall stub that calls it. The core_initcalls are the earliest to be called so this will any possibly issues with dependency between initcalls. This isn't just an academic issue either since on pseries and PowerNV EEH init occurs in an arch_initcall and depends on the pci_controllers being available, similarly the creation of pci_dns occurs at core_initcall_sync (i.e. between core and postcore initcalls). These problems need to be addressed seperately. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Oliver O'Halloran <oohall@gmail.com> [mpe: Make discover_phbs() static] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201103043523.916109-1-oohall@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/603: Fix protection of user pages mapped with PROT_NONEChristophe Leroy2021-03-171-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c119565a15a628efdfa51352f9f6c5186e506a1c upstream. On book3s/32, page protection is defined by the PP bits in the PTE which provide the following protection depending on the access keys defined in the matching segment register: - PP 00 means RW with key 0 and N/A with key 1. - PP 01 means RW with key 0 and RO with key 1. - PP 10 means RW with both key 0 and key 1. - PP 11 means RO with both key 0 and key 1. Since the implementation of kernel userspace access protection, PP bits have been set as follows: - PP00 for pages without _PAGE_USER - PP01 for pages with _PAGE_USER and _PAGE_RW - PP11 for pages with _PAGE_USER and without _PAGE_RW For kernelspace segments, kernel accesses are performed with key 0 and user accesses are performed with key 1. As PP00 is used for non _PAGE_USER pages, user can't access kernel pages not flagged _PAGE_USER while kernel can. For userspace segments, both kernel and user accesses are performed with key 0, therefore pages not flagged _PAGE_USER are still accessible to the user. This shouldn't be an issue, because userspace is expected to be accessible to the user. But unlike most other architectures, powerpc implements PROT_NONE protection by removing _PAGE_USER flag instead of flagging the page as not valid. This means that pages in userspace that are not flagged _PAGE_USER shall remain inaccessible. To get the expected behaviour, just mimic other architectures in the TLB miss handler by checking _PAGE_USER permission on userspace accesses as if it was the _PAGE_PRESENT bit. Note that this problem only is only for 603 cores. The 604+ have an hash table, and hash_page() function already implement the verification of _PAGE_USER permission on userspace pages. Fixes: f342adca3afc ("powerpc/32s: Prepare Kernel Userspace Access Protection") Cc: stable@vger.kernel.org # v5.2+ Reported-by: Christoph Plattner <christoph.plattner@thalesgroup.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4a0c6e3bb8f0c162457bf54d9bc6fd8d7b55129f.1612160907.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/32s: Add missing call to kuep_lock on syscall entryChristophe Leroy2021-03-041-0/+3
| | | | | | | | | | | | | | | | | | commit 57fdfbce89137ae85cd5cef48be168040a47dd13 upstream. Userspace Execution protection and fast syscall entry were implemented independently from each other and were both merged in kernel 5.2, leading to syscall entry missing userspace execution protection. On syscall entry, execution of user space memory must be locked in the same way as on exception entry. Fixes: b86fb88855ea ("powerpc/32: implement fast entry for syscalls on non BOOKE") 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/c65e105b63aaf74f91a14f845bc77192350b84a6.1612796617.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/prom: Fix "ibm,arch-vec-5-platform-support" scanCédric Le Goater2021-03-041-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit ed5b00a05c2ae95b59adc3442f45944ec632e794 upstream. The "ibm,arch-vec-5-platform-support" property is a list of pairs of bytes representing the options and values supported by the platform firmware. At boot time, Linux scans this list and activates the available features it recognizes : Radix and XIVE. A recent change modified the number of entries to loop on and 8 bytes, 4 pairs of { options, values } entries are always scanned. This is fine on KVM but not on PowerVM which can advertises less. As a consequence on this platform, Linux reads extra entries pointing to random data, interprets these as available features and tries to activate them, leading to a firmware crash in ibm,client-architecture-support. Fix that by using the property length of "ibm,arch-vec-5-platform-support". Fixes: ab91239942a9 ("powerpc/prom: Remove VLA in prom_check_platform_support()") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210122075029.797013-1-clg@kaod.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/8xx: Fix software emulation interruptChristophe Leroy2021-03-041-1/+1
| | | | | | | | | | | | | | | | [ Upstream commit 903178d0ce6bb30ef80a3604ab9ee2b57869fbc9 ] For unimplemented instructions or unimplemented SPRs, the 8xx triggers a "Software Emulation Exception" (0x1000). That interrupt doesn't set reason bits in SRR1 as the "Program Check Exception" does. Go through emulation_assist_interrupt() to set REASON_ILLEGAL. Fixes: fbbcc3bb139e ("powerpc/8xx: Remove SoftwareEmulation()") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ad782af87a222efc79cfb06079b0fd23d4224eaf.1612515180.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
* vmlinux.lds.h: Create section for protection against instrumentationThomas Gleixner2021-02-171-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 6553896666433e7efec589838b400a2a652b3ffa ] Some code pathes, especially the low level entry code, must be protected against instrumentation for various reasons: - Low level entry code can be a fragile beast, especially on x86. - With NO_HZ_FULL RCU state needs to be established before using it. Having a dedicated section for such code allows to validate with tooling that no unsafe functions are invoked. Add the .noinstr.text section and the noinstr attribute to mark functions. noinstr implies notrace. Kprobes will gain a section check later. Provide also a set of markers: instrumentation_begin()/end() These are used to mark code inside a noinstr function which calls into regular instrumentable text section as safe. The instrumentation markers are only active when CONFIG_DEBUG_ENTRY is enabled as the end marker emits a NOP to prevent the compiler from merging the annotation points. This means the objtool verification requires a kernel compiled with this option. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134100.075416272@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc: Fix alignment bug within the init sectionsAriel Marcovitch2021-01-271-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 2225a8dda263edc35a0e8b858fe2945cf6240fde ] This is a bug that causes early crashes in builds with an .exit.text section smaller than a page and an .init.text section that ends in the beginning of a physical page (this is kinda random, which might explain why this wasn't really encountered before). The init sections are ordered like this: .init.text .exit.text .init.data Currently, these sections aren't page aligned. Because the init code might become read-only at runtime and because the .init.text section can potentially reside on the same physical page as .init.data, the beginning of .init.data might be mapped read-only along with .init.text. Then when the kernel tries to modify a variable in .init.data (like kthreadd_done, used in kernel_init()) the kernel panics. To avoid this, make _einittext page aligned and also align .exit.text to make sure .init.data is always seperated from the text segments. Fixes: 060ef9d89d18 ("powerpc32: PAGE_EXEC required for inittext") Signed-off-by: Ariel Marcovitch <ariel.marcovitch@gmail.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210102201156.10805-1-ariel.marcovitch@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc: Use the common INIT_DATA_SECTION macro in vmlinux.lds.SYouling Tang2021-01-271-18/+1
| | | | | | | | | | | | [ Upstream commit fdcfeaba38e5b183045f5b079af94f97658eabe6 ] Use the common INIT_DATA_SECTION rule for the linker script in an effort to regularize the linker script. Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1604487550-20040-1-git-send-email-tangyouling@loongson.cn Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc: Handle .text.{hot,unlikely}.* in linker scriptNathan Chancellor2021-01-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3ce47d95b7346dcafd9bed3556a8d072cb2b8571 upstream. Commit eff8728fe698 ("vmlinux.lds.h: Add PGO and AutoFDO input sections") added ".text.unlikely.*" and ".text.hot.*" due to an LLVM change [1]. After another LLVM change [2], these sections are seen in some PowerPC builds, where there is a orphan section warning then build failure: $ make -skj"$(nproc)" \ ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- LLVM=1 O=out \ distclean powernv_defconfig zImage.epapr ld.lld: warning: kernel/built-in.a(panic.o):(.text.unlikely.) is being placed in '.text.unlikely.' ... ld.lld: warning: address (0xc000000000009314) of section .text is not a multiple of alignment (256) ... ERROR: start_text address is c000000000009400, should be c000000000008000 ERROR: try to enable LD_HEAD_STUB_CATCH config option ERROR: see comments in arch/powerpc/tools/head_check.sh ... Explicitly handle these sections like in the main linker script so there is no more build failure. [1]: https://reviews.llvm.org/D79600 [2]: https://reviews.llvm.org/D92493 Fixes: 83a092cf95f2 ("powerpc: Link warning for orphan sections") Cc: stable@vger.kernel.org Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://github.com/ClangBuiltLinux/linux/issues/1218 Link: https://lore.kernel.org/r/20210104205952.1399409-1-natechancellor@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/rtas: Fix typo of ibm,open-errinjct in RTAS filterTyrel Datwyler2020-12-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f10881a46f8914428110d110140a455c66bdf27b upstream. Commit bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") introduced the following error when invoking the errinjct userspace tool: [root@ltcalpine2-lp5 librtas]# errinjct open [327884.071171] sys_rtas: RTAS call blocked - exploit attempt? [327884.071186] sys_rtas: token=0x26, nargs=0 (called by errinjct) errinjct: Could not open RTAS error injection facility errinjct: librtas: open: Unexpected I/O error The entry for ibm,open-errinjct in rtas_filter array has a typo where the "j" is omitted in the rtas call name. After fixing this typo the errinjct tool functions again as expected. [root@ltcalpine2-lp5 linux]# errinjct open RTAS error injection facility open, token = 1 Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201208195434.8289-1-tyreld@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/64: Fix an EMIT_BUG_ENTRY in head_64.SJordan Niethe2020-12-301-1/+1
| | | | | | | | | | | | | | | | | [ Upstream commit fe18a35e685c9bdabc8b11b3e19deb85a068b75d ] Commit 63ce271b5e37 ("powerpc/prom: convert PROM_BUG() to standard trap") added an EMIT_BUG_ENTRY for the trap after the branch to start_kernel(). The EMIT_BUG_ENTRY was for the address "0b", however the trap was not labeled with "0". Hence the address used for bug is in relative_toc() where the previous "0" label is. Label the trap as "0" so the correct address is used. Fixes: 63ce271b5e37 ("powerpc/prom: convert PROM_BUG() to standard trap") Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201130004404.30953-1-jniethe5@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc: Avoid broken GCC __attribute__((optimize))Ard Biesheuvel2020-12-304-9/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit a7223f5bfcaeade4a86d35263493bcda6c940891 ] Commit 7053f80d9696 ("powerpc/64: Prevent stack protection in early boot") introduced a couple of uses of __attribute__((optimize)) with function scope, to disable the stack protector in some early boot code. Unfortunately, and this is documented in the GCC man pages [0], overriding function attributes for optimization is broken, and is only supported for debug scenarios, not for production: the problem appears to be that setting GCC -f flags using this method will cause it to forget about some or all other optimization settings that have been applied. So the only safe way to disable the stack protector is to disable it for the entire source file. [0] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html Fixes: 7053f80d9696 ("powerpc/64: Prevent stack protection in early boot") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> [mpe: Drop one remaining use of __nostackprotector, reported by snowpatch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201028080433.26799-1-ardb@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/64: Set up a kernel stack for secondaries before cpu_restore()Jordan Niethe2020-12-302-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 3c0b976bf20d236c57adcefa80f86a0a1d737727 ] Currently in generic_secondary_smp_init(), cur_cpu_spec->cpu_restore() is called before a stack has been set up in r1. This was previously fine as the cpu_restore() functions were implemented in assembly and did not use a stack. However commit 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features") used __restore_cpu_cpufeatures() as the cpu_restore() function for a device-tree features based cputable entry. This is a C function and hence uses a stack in r1. generic_secondary_smp_init() is entered on the secondary cpus via the primary cpu using the OPAL call opal_start_cpu(). In OPAL, each hardware thread has its own stack. The OPAL call is ran in the primary's hardware thread. During the call, a job is scheduled on a secondary cpu that will start executing at the address of generic_secondary_smp_init(). Hence the value that will be left in r1 when the secondary cpu enters the kernel is part of that secondary cpu's individual OPAL stack. This means that __restore_cpu_cpufeatures() will write to that OPAL stack. This is not horribly bad as each hardware thread has its own stack and the call that enters the kernel from OPAL never returns, but it is still wrong and should be corrected. Create the temp kernel stack before calling cpu_restore(). As noted by mpe, for a kexec boot, the secondary CPUs are released from the spin loop at address 0x60 by smp_release_cpus() and then jump to generic_secondary_smp_init(). The call to smp_release_cpus() is in setup_arch(), and it comes before the call to emergency_stack_init(). emergency_stack_init() allocates an emergency stack in the PACA for each CPU. This address in the PACA is what is used to set up the temp kernel stack in generic_secondary_smp_init(). Move releasing the secondary CPUs to after the PACAs have been allocated an emergency stack, otherwise the PACA stack pointer will contain garbage and hence the temp kernel stack created from it will be broken. Fixes: 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features") Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201014072837.24539-1-jniethe5@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/8xx: Always fault when _PAGE_ACCESSED is not setChristophe Leroy2020-11-221-12/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 29daf869cbab69088fe1755d9dd224e99ba78b56 upstream. The kernel expects pte_young() to work regardless of CONFIG_SWAP. Make sure a minor fault is taken to set _PAGE_ACCESSED when it is not already set, regardless of the selection of CONFIG_SWAP. This adds at least 3 instructions to the TLB miss exception handlers fast path. Following patch will reduce this overhead. Also update the rotation instruction to the correct number of bits to reflect all changes done to _PAGE_ACCESSED over time. Fixes: d069cb4373fe ("powerpc/8xx: Don't touch ACCESSED when no SWAP.") Fixes: 5f356497c384 ("powerpc/8xx: remove unused _PAGE_WRITETHRU") Fixes: e0a8e0d90a9f ("powerpc/8xx: Handle PAGE_USER via APG bits") Fixes: 5b2753fc3e8a ("powerpc/8xx: Implementation of PAGE_EXEC") Fixes: a891c43b97d3 ("powerpc/8xx: Prepare handlers for _PAGE_HUGE for 512k pages.") 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/af834e8a0f1fa97bfae65664950f0984a70c4750.1602492856.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* selftests/powerpc: entry flush testDaniel Axtens2020-11-221-1/+1
| | | | | | | | | | | | | | commit 89a83a0c69c81a25ce91002b90ca27ed86132a0a upstream. Add a test modelled on the RFI flush test which counts the number of L1D misses doing a simple syscall with the entry flush on and off. For simplicity of backporting, this test duplicates a lot of code from the upstream rfi_flush. This is cleaned up upstream, but we don't clean it up here because it would involve bringing in even more commits. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/64s: flush L1D after user accessesNicholas Piggin2020-11-223-57/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9a32a7e78bd0cd9a9b6332cbdc345ee5ffd0c5de upstream. IBM Power9 processors can speculatively operate on data in the L1 cache before it has been completely validated, via a way-prediction mechanism. It is not possible for an attacker to determine the contents of impermissible memory using this method, since these systems implement a combination of hardware and software security measures to prevent scenarios where protected data could be leaked. However these measures don't address the scenario where an attacker induces the operating system to speculatively execute instructions using data that the attacker controls. This can be used for example to speculatively bypass "kernel user access prevention" techniques, as discovered by Anthony Steinhauser of Google's Safeside Project. This is not an attack by itself, but there is a possibility it could be used in conjunction with side-channels or other weaknesses in the privileged code to construct an attack. This issue can be mitigated by flushing the L1 cache between privilege boundaries of concern. This patch flushes the L1 cache after user accesses. This is part of the fix for CVE-2020-4788. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/64s: flush L1D on kernel entryNicholas Piggin2020-11-223-7/+109
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f79643787e0a0762d2409b7b8334e83f22d85695 upstream. [backporting note: we need to mark some exception handlers as out-of-line because the flushing makes them take too much space -- dja] IBM Power9 processors can speculatively operate on data in the L1 cache before it has been completely validated, via a way-prediction mechanism. It is not possible for an attacker to determine the contents of impermissible memory using this method, since these systems implement a combination of hardware and software security measures to prevent scenarios where protected data could be leaked. However these measures don't address the scenario where an attacker induces the operating system to speculatively execute instructions using data that the attacker controls. This can be used for example to speculatively bypass "kernel user access prevention" techniques, as discovered by Anthony Steinhauser of Google's Safeside Project. This is not an attack by itself, but there is a possibility it could be used in conjunction with side-channels or other weaknesses in the privileged code to construct an attack. This issue can be mitigated by flushing the L1 cache between privilege boundaries of concern. This patch flushes the L1 cache on kernel entry. This is part of the fix for CVE-2020-4788. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/603: Always fault when _PAGE_ACCESSED is not setChristophe Leroy2020-11-181-12/+0
| | | | | | | | | | | | | | | | | | commit 11522448e641e8f1690c9db06e01985e8e19b401 upstream. The kernel expects pte_young() to work regardless of CONFIG_SWAP. Make sure a minor fault is taken to set _PAGE_ACCESSED when it is not already set, regardless of the selection of CONFIG_SWAP. Fixes: 84de6ab0e904 ("powerpc/603: don't handle PAGE_ACCESSED in TLB miss handlers.") 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/a44367744de54e2315b2f1a8cbbd7f88488072e0.1602342806.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/eeh_cache: Fix a possible debugfs deadlockQian Cai2020-11-181-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit fd552e0542b4532483289cce48fdbd27b692984b ] Lockdep complains that a possible deadlock below in eeh_addr_cache_show() because it is acquiring a lock with IRQ enabled, but eeh_addr_cache_insert_dev() needs to acquire the same lock with IRQ disabled. Let's just make eeh_addr_cache_show() acquire the lock with IRQ disabled as well. CPU0 CPU1 ---- ---- lock(&pci_io_addr_cache_root.piar_lock); local_irq_disable(); lock(&tp->lock); lock(&pci_io_addr_cache_root.piar_lock); <Interrupt> lock(&tp->lock); *** DEADLOCK *** lock_acquire+0x140/0x5f0 _raw_spin_lock_irqsave+0x64/0xb0 eeh_addr_cache_insert_dev+0x48/0x390 eeh_probe_device+0xb8/0x1a0 pnv_pcibios_bus_add_device+0x3c/0x80 pcibios_bus_add_device+0x118/0x290 pci_bus_add_device+0x28/0xe0 pci_bus_add_devices+0x54/0xb0 pcibios_init+0xc4/0x124 do_one_initcall+0xac/0x528 kernel_init_freeable+0x35c/0x3fc kernel_init+0x24/0x148 ret_from_kernel_thread+0x5c/0x80 lock_acquire+0x140/0x5f0 _raw_spin_lock+0x4c/0x70 eeh_addr_cache_show+0x38/0x110 seq_read+0x1a0/0x660 vfs_read+0xc8/0x1f0 ksys_read+0x74/0x130 system_call_exception+0xf8/0x1d0 system_call_common+0xe8/0x218 Fixes: 5ca85ae6318d ("powerpc/eeh_cache: Add a way to dump the EEH address cache") Signed-off-by: Qian Cai <cai@redhat.com> Reviewed-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201028152717.8967-1-cai@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc: Fix undetected data corruption with P9N DD2.1 VSX CI load emulationMichael Neuling2020-11-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1da4a0272c5469169f78cd76cf175ff984f52f06 upstream. __get_user_atomic_128_aligned() stores to kaddr using stvx which is a VMX store instruction, hence kaddr must be 16 byte aligned otherwise the store won't occur as expected. Unfortunately when we call __get_user_atomic_128_aligned() in p9_hmi_special_emu(), the buffer we pass as kaddr (ie. vbuf) isn't guaranteed to be 16B aligned. This means that the write to vbuf in __get_user_atomic_128_aligned() has the bottom bits of the address truncated. This results in other local variables being overwritten. Also vbuf will not contain the correct data which results in the userspace emulation being wrong and hence undetected user data corruption. In the past we've been mostly lucky as vbuf has ended up aligned but this is fragile and isn't always true. CONFIG_STACKPROTECTOR in particular can change the stack arrangement enough that our luck runs out. This issue only occurs on POWER9 Nimbus <= DD2.1 bare metal. The fix is to align vbuf to a 16 byte boundary. Fixes: 5080332c2c89 ("powerpc/64s: Add workaround for P9 vector CI load issue") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201013043741.743413-1-mikey@neuling.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/powermac: Fix low_sleep_handler with KUAP and KUEPChristophe Leroy2020-11-051-1/+1
| | | | | | | | | | | | | | | | | | commit 2c637d2df4ee4830e9d3eb2bd5412250522ce96e upstream. low_sleep_handler() has an hardcoded restore of segment registers that doesn't take KUAP and KUEP into account. Use head_32's load_segment_registers() routine instead. Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection") Fixes: 31ed2b13c48d ("powerpc/32s: Implement Kernel Userspace Execution Prevention.") 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/21b05f7298c1b18f73e6e5b4cd5005aafa24b6da.1599820109.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc: Warn about use of smt_snooze_delayJoel Stanley2020-11-051-25/+17
| | | | | | | | | | | | | | | | | | | | commit a02f6d42357acf6e5de6ffc728e6e77faf3ad217 upstream. It's not done anything for a long time. Save the percpu variable, and emit a warning to remind users to not expect it to do anything. This uses pr_warn_once instead of pr_warn_ratelimit as testing 'ppc64_cpu --smt=off' on a 24 core / 4 SMT system showed the warning to be noisy, as the online/offline loop is slow. Fixes: 3fa8cad82b94 ("powerpc/pseries/cpuidle: smt-snooze-delay cleanup.") Cc: stable@vger.kernel.org # v3.14 Signed-off-by: Joel Stanley <joel@jms.id.au> Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200902000012.3440389-1-joel@jms.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/rtas: Restrict RTAS requests from userspaceAndrew Donnellan2020-11-051-0/+153
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit bd59380c5ba4147dcbaad3e582b55ccfd120b764 upstream. A number of userspace utilities depend on making calls to RTAS to retrieve information and update various things. The existing API through which we expose RTAS to userspace exposes more RTAS functionality than we actually need, through the sys_rtas syscall, which allows root (or anyone with CAP_SYS_ADMIN) to make any RTAS call they want with arbitrary arguments. Many RTAS calls take the address of a buffer as an argument, and it's up to the caller to specify the physical address of the buffer as an argument. We allocate a buffer (the "RMO buffer") in the Real Memory Area that RTAS can access, and then expose the physical address and size of this buffer in /proc/powerpc/rtas/rmo_buffer. Userspace is expected to read this address, poke at the buffer using /dev/mem, and pass an address in the RMO buffer to the RTAS call. However, there's nothing stopping the caller from specifying whatever address they want in the RTAS call, and it's easy to construct a series of RTAS calls that can overwrite arbitrary bytes (even without /dev/mem access). Additionally, there are some RTAS calls that do potentially dangerous things and for which there are no legitimate userspace use cases. In the past, this would not have been a particularly big deal as it was assumed that root could modify all system state freely, but with Secure Boot and lockdown we need to care about this. We can't fundamentally change the ABI at this point, however we can address this by implementing a filter that checks RTAS calls against a list of permitted calls and forces the caller to use addresses within the RMO buffer. The list is based off the list of calls that are used by the librtas userspace library, and has been tested with a number of existing userspace RTAS utilities. For compatibility with any applications we are not aware of that require other calls, the filter can be turned off at build time. Cc: stable@vger.kernel.org Reported-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200820044512.7543-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/tau: Disable TAU between measurementsFinn Thain2020-10-291-41/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit e63d6fb5637e92725cf143559672a34b706bca4f ] Enabling CONFIG_TAU_INT causes random crashes: Unrecoverable exception 1700 at c0009414 (msr=1000) Oops: Unrecoverable exception, sig: 6 [#1] BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-pmac-00043-gd5f545e1a8593 #5 NIP: c0009414 LR: c0009414 CTR: c00116fc REGS: c0799eb8 TRAP: 1700 Not tainted (5.7.0-pmac-00043-gd5f545e1a8593) MSR: 00001000 <ME> CR: 22000228 XER: 00000100 GPR00: 00000000 c0799f70 c076e300 00800000 0291c0ac 00e00000 c076e300 00049032 GPR08: 00000001 c00116fc 00000000 dfbd3200 ffffffff 007f80a8 00000000 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 c075ce04 GPR24: c075ce04 dfff8880 c07b0000 c075ce04 00080000 00000001 c079ef98 c079ef5c NIP [c0009414] arch_cpu_idle+0x24/0x6c LR [c0009414] arch_cpu_idle+0x24/0x6c Call Trace: [c0799f70] [00000001] 0x1 (unreliable) [c0799f80] [c0060990] do_idle+0xd8/0x17c [c0799fa0] [c0060ba4] cpu_startup_entry+0x20/0x28 [c0799fb0] [c072d220] start_kernel+0x434/0x44c [c0799ff0] [00003860] 0x3860 Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX 3d20c07b XXXXXXXX XXXXXXXX XXXXXXXX 7c0802a6 XXXXXXXX XXXXXXXX XXXXXXXX 4e800421 XXXXXXXX XXXXXXXX XXXXXXXX 7d2000a6 ---[ end trace 3a0c9b5cb216db6b ]--- Resolve this problem by disabling each THRMn comparator when handling the associated THRMn interrupt and by disabling the TAU entirely when updating THRMn thresholds. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5a0ba3dc5612c7aac596727331284a3676c08472.1599260540.git.fthain@telegraphics.com.au Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/tau: Check processor type before enabling TAU interruptFinn Thain2020-10-291-19/+14
| | | | | | | | | | | | | | | [ Upstream commit 5e3119e15fed5b9a9a7e528665ff098a4a8dbdbc ] According to Freescale's documentation, MPC74XX processors have an erratum that prevents the TAU interrupt from working, so don't try to use it when running on those processors. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c281611544768e758bd58fe812cf702a5bd2d042.1599260540.git.fthain@telegraphics.com.au Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/tau: Remove duplicated set_thresholds() callFinn Thain2020-10-291-5/+0
| | | | | | | | | | | | | | | | | [ Upstream commit 420ab2bc7544d978a5d0762ee736412fe9c796ab ] The commentary at the call site seems to disagree with the code. The conditional prevents calling set_thresholds() via the exception handler, which appears to crash. Perhaps that's because it immediately triggers another TAU exception. Anyway, calling set_thresholds() from TAUupdate() is redundant because tau_timeout() does so. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d7c7ee33232cf72a6a6bbb6ef05838b2e2b113c0.1599260540.git.fthain@telegraphics.com.au Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/tau: Convert from timer to workqueueFinn Thain2020-10-291-20/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b1c6a0a10bfaf36ec82fde6f621da72407fa60a1 ] Since commit 19dbdcb8039cf ("smp: Warn on function calls from softirq context") the Thermal Assist Unit driver causes a warning like the following when CONFIG_SMP is enabled. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/smp.c:428 smp_call_function_many_cond+0xf4/0x38c Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-pmac #3 NIP: c00b37a8 LR: c00b3abc CTR: c001218c REGS: c0799c60 TRAP: 0700 Not tainted (5.7.0-pmac) MSR: 00029032 <EE,ME,IR,DR,RI> CR: 42000224 XER: 00000000 GPR00: c00b3abc c0799d18 c076e300 c079ef5c c0011fec 00000000 00000000 00000000 GPR08: 00000100 00000100 00008000 ffffffff 42000224 00000000 c079d040 c079d044 GPR16: 00000001 00000000 00000004 c0799da0 c079f054 c07a0000 c07a0000 00000000 GPR24: c0011fec 00000000 c079ef5c c079ef5c 00000000 00000000 00000000 00000000 NIP [c00b37a8] smp_call_function_many_cond+0xf4/0x38c LR [c00b3abc] on_each_cpu+0x38/0x68 Call Trace: [c0799d18] [ffffffff] 0xffffffff (unreliable) [c0799d68] [c00b3abc] on_each_cpu+0x38/0x68 [c0799d88] [c0096704] call_timer_fn.isra.26+0x20/0x7c [c0799d98] [c0096b40] run_timer_softirq+0x1d4/0x3fc [c0799df8] [c05b4368] __do_softirq+0x118/0x240 [c0799e58] [c0039c44] irq_exit+0xc4/0xcc [c0799e68] [c000ade8] timer_interrupt+0x1b0/0x230 [c0799ea8] [c0013520] ret_from_except+0x0/0x14 --- interrupt: 901 at arch_cpu_idle+0x24/0x6c LR = arch_cpu_idle+0x24/0x6c [c0799f70] [00000001] 0x1 (unreliable) [c0799f80] [c0060990] do_idle+0xd8/0x17c [c0799fa0] [c0060ba8] cpu_startup_entry+0x24/0x28 [c0799fb0] [c072d220] start_kernel+0x434/0x44c [c0799ff0] [00003860] 0x3860 Instruction dump: 8129f204 2f890000 40beff98 3d20c07a 8929eec4 2f890000 40beff88 0fe00000 81220000 552805de 550802ef 4182ff84 <0fe00000> 3860ffff 7f65db78 7f44d378 ---[ end trace 34a886e47819c2eb ]--- Don't call on_each_cpu() from a timer callback, call it from a worker thread instead. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bb61650bea4f4c91fb8e24b9a6f130a1438651a7.1599260540.git.fthain@telegraphics.com.au Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/tau: Use appropriate temperature sample intervalFinn Thain2020-10-291-8/+4
| | | | | | | | | | | | | | | | | | | [ Upstream commit 66943005cc41f48e4d05614e8f76c0ca1812f0fd ] According to the MPC750 Users Manual, the SITV value in Thermal Management Register 3 is 13 bits long. The present code calculates the SITV value as 60 * 500 cycles. This would overflow to give 10 us on a 500 MHz CPU rather than the intended 60 us. (But according to the Microprocessor Datasheet, there is also a factor of 266 that has to be applied to this value on certain parts i.e. speed sort above 266 MHz.) Always use the maximum cycle count, as recommended by the Datasheet. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/896f542e5f0f1d6cf8218524c2b67d79f3d69b3c.1599260540.git.fthain@telegraphics.com.au Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/traps: Make unrecoverable NMIs die instead of panicNicholas Piggin2020-10-011-3/+3
| | | | | | | | | | | | | | [ Upstream commit 265d6e588d87194c2fe2d6c240247f0264e0c19b ] System Reset and Machine Check interrupts that are not recoverable due to being nested or interrupting when RI=0 currently panic. This is not necessary, and can often just kill the current context and recover. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Link: https://lore.kernel.org/r/20200508043408.886394-16-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/eeh: Only dump stack once if an MMIO loop is detectedOliver O'Halloran2020-10-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 4e0942c0302b5ad76b228b1a7b8c09f658a1d58a ] Many drivers don't check for errors when they get a 0xFFs response from an MMIO load. As a result after an EEH event occurs a driver can get stuck in a polling loop unless it some kind of internal timeout logic. Currently EEH tries to detect and report stuck drivers by dumping a stack trace after eeh_dev_check_failure() is called EEH_MAX_FAILS times on an already frozen PE. The value of EEH_MAX_FAILS was chosen so that a dump would occur every few seconds if the driver was spinning in a loop. This results in a lot of spurious stack traces in the kernel log. Fix this by limiting it to printing one stack trace for each PE freeze. If the driver is truely stuck the kernel's hung task detector is better suited to reporting the probelm anyway. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com> Tested-by: Sam Bobroff <sbobroff@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191016012536.22588-1-oohall@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/64s: Always disable branch profiling for prom_init.oMichael Ellerman2020-10-011-1/+1
| | | | | | | | | | | | | | [ Upstream commit 6266a4dadb1d0976490fdf5af4f7941e36f64e80 ] Otherwise the build fails because prom_init is calling symbols it's not allowed to, eg: Error: External symbol 'ftrace_likely_update' referenced from prom_init.c make[3]: *** [arch/powerpc/kernel/Makefile:197: arch/powerpc/kernel/prom_init_check] Error 1 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191106051129.7626-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/dma: Fix dma_map_ops::get_required_maskAlexey Kardashevskiy2020-09-231-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 437ef802e0adc9f162a95213a3488e8646e5fc03 upstream. There are 2 problems with it: 1. "<" vs expected "<<" 2. the shift number is an IOMMU page number mask, not an address mask as the IOMMU page shift is missing. This did not hit us before f1565c24b596 ("powerpc: use the generic dma_ops_bypass mode") because we had additional code to handle bypass mask so this chunk (almost?) never executed.However there were reports that aacraid does not work with "iommu=nobypass". After f1565c24b596, aacraid (and probably others which call dma_get_required_mask() before setting the mask) was unable to enable 64bit DMA and fall back to using IOMMU which was known not to work, one of the problems is double free of an IOMMU page. This fixes DMA for aacraid, both with and without "iommu=nobypass" in the kernel command line. Verified with "stress-ng -d 4". Fixes: 6a5c7be5e484 ("powerpc: Override dma_get_required_mask by platform hook and ops") Cc: stable@vger.kernel.org # v3.2+ Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200908015106.79661-1-aik@ozlabs.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/64s: Don't init FSCR_DSCR in __init_FSCR()Michael Ellerman2020-09-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 0828137e8f16721842468e33df0460044a0c588b upstream. __init_FSCR() was added originally in commit 2468dcf641e4 ("powerpc: Add support for context switching the TAR register") (Feb 2013), and only set FSCR_TAR. At that point FSCR (Facility Status and Control Register) was not context switched, so the setting was permanent after boot. Later we added initialisation of FSCR_DSCR to __init_FSCR(), in commit 54c9b2253d34 ("powerpc: Set DSCR bit in FSCR setup") (Mar 2013), again that was permanent after boot. Then commit 2517617e0de6 ("powerpc: Fix context switch DSCR on POWER8") (Aug 2013) added a limited context switch of FSCR, just the FSCR_DSCR bit was context switched based on thread.dscr_inherit. That commit said "This clears the H/FSCR DSCR bit initially", but it didn't, it left the initialisation of FSCR_DSCR in __init_FSCR(). However the initial context switch from init_task to pid 1 would clear FSCR_DSCR because thread.dscr_inherit was 0. That commit also introduced the requirement that FSCR_DSCR be clear for user processes, so that we can take the facility unavailable interrupt in order to manage dscr_inherit. Then in commit 152d523e6307 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") (Dec 2015) FSCR was added to thread_struct. However it still wasn't fully context switched, we just took the existing value and set FSCR_DSCR if the new thread had dscr_inherit set. FSCR was still initialised at boot to FSCR_DSCR | FSCR_TAR, but that value was not propagated into the thread_struct, so the initial context switch set FSCR_DSCR back to 0. Finally commit b57bd2de8c6c ("powerpc: Improve FSCR init and context switching") (Jun 2016) added a full context switch of the FSCR, and added an initialisation of init_task.thread.fscr to FSCR_TAR | FSCR_EBB, but omitted FSCR_DSCR. The end result is that swapper runs with FSCR_DSCR set because of the initialisation in __init_FSCR(), but no other processes do, they use the value from init_task.thread.fscr. Having FSCR_DSCR set for swapper allows it to access SPR 3 from userspace, but swapper never runs userspace, so it has no useful effect. It's also confusing to have the value initialised in two places to two different values. So remove FSCR_DSCR from __init_FSCR(), this at least gets us to the point where there's a single value of FSCR, even if it's still set in two places. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200527145843.2761782-1-mpe@ellerman.id.au Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/vdso: Fix vdso cpu truncationMilton Miller2020-08-191-1/+1
| | | | | | | | | | | | | | | | | | | | | [ Upstream commit a9f675f950a07d5c1dbcbb97aabac56f5ed085e3 ] The code in vdso_cpu_init that exposes the cpu and numa node to userspace via SPRG_VDSO incorrctly masks the cpu to 12 bits. This means that any kernel running on a box with more than 4096 threads (NR_CPUS advertises a limit of of 8192 cpus) would expose userspace to two cpu contexts running at the same time with the same cpu number. Note: I'm not aware of any distro shipping a kernel with support for more than 4096 threads today, nor of any system image that currently exceeds 4096 threads. Found via code browsing. Fixes: 18ad51dd342a7eb09dbcd059d0b451b616d4dafc ("powerpc: Add VDSO version of getcpu") Signed-off-by: Milton Miller <miltonm@us.ibm.com> Signed-off-by: Anton Blanchard <anton@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200715233704.1352257-1-anton@ozlabs.org Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/rtas: don't online CPUs for partition suspendNathan Lynch2020-08-191-120/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ec2fc2a9e9bbad9023aab65bc472ce7a3ca8608f ] Partition suspension, used for hibernation and migration, requires that the OS place all but one of the LPAR's processor threads into one of two states prior to calling the ibm,suspend-me RTAS function: * the architected offline state (via RTAS stop-self); or * the H_JOIN hcall, which does not return until the partition resumes execution Using H_CEDE as the offline mode, introduced by commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state"), means that any threads which are offline from Linux's point of view must be moved to one of those two states before a partition suspension can proceed. This was eventually addressed in commit 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation"), which added code to temporarily bring up any offline processor threads so they can call H_JOIN. Conceptually this is fine, but the implementation has had multiple races with cpu hotplug operations initiated from user space[1][2][3], the error handling is fragile, and it generates user-visible cpu hotplug events which is a lot of noise for a platform feature that's supposed to minimize disruption to workloads. With commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state") reverted, this code becomes unnecessary, so remove it. Since any offline CPUs now are truly offline from the platform's point of view, it is no longer necessary to bring up CPUs only to have them call H_JOIN and then go offline again upon resuming. Only active threads are required to call H_JOIN; stopped threads can be left alone. [1] commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and serialization during LPM") [2] commit 9fb603050ffd ("powerpc/rtas: retry when cpu offline races with suspend/migration") [3] commit dfd718a2ed1f ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration") Fixes: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-3-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/pseries/svm: Fix incorrect check for shared_lppaca_sizeSatheesh Rajendran2020-07-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b710d27bf72068b15b2f0305d825988183e2ff28 upstream. Early secure guest boot hits the below crash while booting with vcpus numbers aligned with page boundary for PAGE size of 64k and LPPACA size of 1k i.e 64, 128 etc. Partition configured for 64 cpus. CPU maps initialized for 1 thread per core ------------[ cut here ]------------ kernel BUG at arch/powerpc/kernel/paca.c:89! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries This is due to the BUG_ON() for shared_lppaca_total_size equal to shared_lppaca_size. Instead the code should only BUG_ON() if we have exceeded the total_size, which indicates we've overflowed the array. Fixes: bd104e6db6f0 ("powerpc/pseries/svm: Use shared memory for LPPACA structures") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> [mpe: Reword change log to clarify we're fixing not removing the check] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200619070113.16696-1-sathnaga@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc: Fix kernel crash in show_instructions() w/DEBUG_VIRTUALAneesh Kumar K.V2020-06-241-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit a6e2c226c3d51fd93636320e47cabc8a8f0824c5 ] With CONFIG_DEBUG_VIRTUAL=y, we can hit a BUG() if we take a hard lockup watchdog interrupt when in OPAL mode. This happens in show_instructions() if the kernel takes the watchdog NMI IPI, or any other interrupt, with MSR_IR == 0. show_instructions() updates the variable pc in the loop and the second iteration will result in BUG(). We hit the BUG_ON due the below check in __va() #define __va(x) ({ VIRTUAL_BUG_ON((unsigned long)(x) >= PAGE_OFFSET); (void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET); }) Fix it by moving the check out of the loop. Also update nip so that the nip == pc check still matches. Fixes: 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va and __pa addresses") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Use IS_ENABLED(), massage change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200524093822.423487-1-aneesh.kumar@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/64s/exception: Fix machine check no-loss idle wakeupNicholas Piggin2020-06-241-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 8a5054d8cbbe03c68dcb0957c291c942132e4101 ] The architecture allows for machine check exceptions to cause idle wakeups which resume at the 0x200 address which has to return via the idle wakeup code, but the early machine check handler is run first. The case of a no state-loss sleep is broken because the early handler uses non-volatile register r1 , which is needed for the wakeup protocol, but it is not restored. Fix this by loading r1 from the MCE exception frame before returning to the idle wakeup code. Also update the comment which has become stale since the idle rewrite in C. This crash was found and fix confirmed with a machine check injection test in qemu powernv model (which is not upstream in qemu yet). Fixes: 10d91611f426d ("powerpc/64s: Reimplement book3s idle code in C") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200508043408.886394-2-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/64: Don't initialise init_task->thread.regsMichael Ellerman2020-06-241-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 7ffa8b7dc11752827329e4e84a574ea6aaf24716 ] Aneesh increased the size of struct pt_regs by 16 bytes and started seeing this WARN_ON: smp: Bringing up secondary CPUs ... ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at arch/powerpc/kernel/process.c:455 giveup_all+0xb4/0x110 Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc2-gcc-8.2.0-1.g8f6a41f-default+ #318 NIP: c00000000001a2b4 LR: c00000000001a29c CTR: c0000000031d0000 REGS: c0000000026d3980 TRAP: 0700 Not tainted (5.7.0-rc2-gcc-8.2.0-1.g8f6a41f-default+) MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 48048224 XER: 00000000 CFAR: c000000000019cc8 IRQMASK: 1 GPR00: c00000000001a264 c0000000026d3c20 c0000000026d7200 800000000280b033 GPR04: 0000000000000001 0000000000000000 0000000000000077 30206d7372203164 GPR08: 0000000000002000 0000000002002000 800000000280b033 3230303030303030 GPR12: 0000000000008800 c0000000031d0000 0000000000800050 0000000002000066 GPR16: 000000000309a1a0 000000000309a4b0 000000000309a2d8 000000000309a890 GPR20: 00000000030d0098 c00000000264da40 00000000fd620000 c0000000ff798080 GPR24: c00000000264edf0 c0000001007469f0 00000000fd620000 c0000000020e5e90 GPR28: c00000000264edf0 c00000000264d200 000000001db60000 c00000000264d200 NIP [c00000000001a2b4] giveup_all+0xb4/0x110 LR [c00000000001a29c] giveup_all+0x9c/0x110 Call Trace: [c0000000026d3c20] [c00000000001a264] giveup_all+0x64/0x110 (unreliable) [c0000000026d3c90] [c00000000001ae34] __switch_to+0x104/0x480 [c0000000026d3cf0] [c000000000e0b8a0] __schedule+0x320/0x970 [c0000000026d3dd0] [c000000000e0c518] schedule_idle+0x38/0x70 [c0000000026d3df0] [c00000000019c7c8] do_idle+0x248/0x3f0 [c0000000026d3e70] [c00000000019cbb8] cpu_startup_entry+0x38/0x40 [c0000000026d3ea0] [c000000000011bb0] rest_init+0xe0/0xf8 [c0000000026d3ed0] [c000000002004820] start_kernel+0x990/0x9e0 [c0000000026d3f90] [c00000000000c49c] start_here_common+0x1c/0x400 Which was unexpected. The warning is checking the thread.regs->msr value of the task we are switching from: usermsr = tsk->thread.regs->msr; ... WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC))); ie. if MSR_VSX is set then both of MSR_FP and MSR_VEC are also set. Dumping tsk->thread.regs->msr we see that it's: 0x1db60000 Which is not a normal looking MSR, in fact the only valid bit is MSR_VSX, all the other bits are reserved in the current definition of the MSR. We can see from the oops that it was swapper/0 that we were switching from when we hit the warning, ie. init_task. So its thread.regs points to the base (high addresses) in init_stack. Dumping the content of init_task->thread.regs, with the members of pt_regs annotated (the 16 bytes larger version), we see: 0000000000000000 c000000002780080 gpr[0] gpr[1] 0000000000000000 c000000002666008 gpr[2] gpr[3] c0000000026d3ed0 0000000000000078 gpr[4] gpr[5] c000000000011b68 c000000002780080 gpr[6] gpr[7] 0000000000000000 0000000000000000 gpr[8] gpr[9] c0000000026d3f90 0000800000002200 gpr[10] gpr[11] c000000002004820 c0000000026d7200 gpr[12] gpr[13] 000000001db60000 c0000000010aabe8 gpr[14] gpr[15] c0000000010aabe8 c0000000010aabe8 gpr[16] gpr[17] c00000000294d598 0000000000000000 gpr[18] gpr[19] 0000000000000000 0000000000001ff8 gpr[20] gpr[21] 0000000000000000 c00000000206d608 gpr[22] gpr[23] c00000000278e0cc 0000000000000000 gpr[24] gpr[25] 000000002fff0000 c000000000000000 gpr[26] gpr[27] 0000000002000000 0000000000000028 gpr[28] gpr[29] 000000001db60000 0000000004750000 gpr[30] gpr[31] 0000000002000000 000000001db60000 nip msr 0000000000000000 0000000000000000 orig_r3 ctr c00000000000c49c 0000000000000000 link xer 0000000000000000 0000000000000000 ccr softe 0000000000000000 0000000000000000 trap dar 0000000000000000 0000000000000000 dsisr result 0000000000000000 0000000000000000 ppr kuap 0000000000000000 0000000000000000 pad[2] pad[3] This looks suspiciously like stack frames, not a pt_regs. If we look closely we can see return addresses from the stack trace above, c000000002004820 (start_kernel) and c00000000000c49c (start_here_common). init_task->thread.regs is setup at build time in processor.h: #define INIT_THREAD { \ .ksp = INIT_SP, \ .regs = (struct pt_regs *)INIT_SP - 1, /* XXX bogus, I think */ \ The early boot code where we setup the initial stack is: LOAD_REG_ADDR(r3,init_thread_union) /* set up a stack pointer */ LOAD_REG_IMMEDIATE(r1,THREAD_SIZE) add r1,r3,r1 li r0,0 stdu r0,-STACK_FRAME_OVERHEAD(r1) Which creates a stack frame of size 112 bytes (STACK_FRAME_OVERHEAD). Which is far too small to contain a pt_regs. So the result is init_task->thread.regs is pointing at some stack frames on the init stack, not at a pt_regs. We have gotten away with this for so long because with pt_regs at its current size the MSR happens to point into the first frame, at a location that is not written to by the early asm. With the 16 byte expansion the MSR falls into the second frame, which is used by the compiler, and collides with a saved register that tends to be non-zero. As far as I can see this has been wrong since the original merge of 64-bit ppc support, back in 2002. Conceptually swapper should have no regs, it never entered from userspace, and in fact that's what we do on 32-bit. It's also presumably what the "bogus" comment is referring to. So I think the right fix is to just not-initialise regs at all. I'm slightly worried this will break some code that isn't prepared for a NULL regs, but we'll have to see. Remove the comment in head_64.S which refers to us setting up the regs (even though we never did), and is otherwise not really accurate any more. Reported-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/20200428123130.73078-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/crashkernel: Take "mem=" option into accountPingfan Liu2020-06-241-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit be5470e0c285a68dc3afdea965032f5ddc8269d7 ] 'mem=" option is an easy way to put high pressure on memory during some test. Hence after applying the memory limit, instead of total mem, the actual usable memory should be considered when reserving mem for crashkernel. Otherwise the boot up may experience OOM issue. E.g. it would reserve 4G prior to the change and 512M afterward, if passing crashkernel="2G-4G:384M,4G-16G:512M,16G-64G:1G,64G-128G:2G,128G-:4G", and mem=5G on a 256G machine. This issue is powerpc specific because it puts higher priority on fadump and kdump reservation than on "mem=". Referring the following code: if (fadump_reserve_mem() == 0) reserve_crashkernel(); ... /* Ensure that total memory size is page-aligned. */ limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE); memblock_enforce_memory_limit(limit); While on other arches, the effect of "mem=" takes a higher priority and pass through memblock_phys_mem_size() before calling reserve_crashkernel(). Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Reviewed-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1585749644-4148-1-git-send-email-kernelfans@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* powerpc/64s: Save FSCR to init_task.thread.fscr after feature initMichael Ellerman2020-06-221-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 912c0a7f2b5daa3cbb2bc10f303981e493de73bd upstream. At boot the FSCR is initialised via one of two paths. On most systems it's set to a hard coded value in __init_FSCR(). On newer skiboot systems we use the device tree CPU features binding, where firmware can tell Linux what bits to set in FSCR (and HFSCR). In both cases the value that's configured at boot is not propagated into the init_task.thread.fscr value prior to the initial fork of init (pid 1), which means the value is not used by any processes other than swapper (the idle task). For the __init_FSCR() case this is OK, because the value in init_task.thread.fscr is initialised to something sensible. However it does mean that the value set in __init_FSCR() is not used other than for swapper, which is odd and confusing. The bigger problem is for the device tree CPU features case it prevents firmware from setting (or clearing) FSCR bits for use by user space. This means all existing kernels can not have features enabled/disabled by firmware if those features require setting/clearing FSCR bits. We can handle both cases by saving the FSCR value into init_task.thread.fscr after we have initialised it at boot. This fixes the bug for device tree CPU features, and will allow us to simplify the initialisation for the __init_FSCR() case in a future patch. Fixes: 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200527145843.2761782-3-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/64s: Don't let DT CPU features set FSCR_DSCRMichael Ellerman2020-06-221-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 993e3d96fd08c3ebf7566e43be9b8cd622063e6d upstream. The device tree CPU features binding includes FSCR bit numbers which Linux is instructed to set by firmware. Whether that's a good idea or not, in the case of the DSCR the Linux implementation has a hard requirement that the FSCR_DSCR bit not be set by default. We use it to track when a process reads/writes to DSCR, so it must be clear to begin with. So if firmware tells us to set FSCR_DSCR we must ignore it. Currently this does not cause a bug in our DSCR handling because the value of FSCR that the device tree CPU features code establishes is only used by swapper. All other tasks use the value hard coded in init_task.thread.fscr. However we'd like to fix that in a future commit, at which point this will become necessary. Fixes: 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200527145843.2761782-2-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/fadump: Account for memory_limit while reserving memoryHari Bathini2020-06-221-1/+1
| | | | | | | | | | | | | | | | | | commit 9a2921e5baca1d25eb8d21f21d1e90581a6d0f68 upstream. If the memory chunk found for reserving memory overshoots the memory limit imposed, do not proceed with reserving memory. Default behavior was this until commit 140777a3d8df ("powerpc/fadump: consider reserved ranges while reserving memory") changed it unwittingly. Fixes: 140777a3d8df ("powerpc/fadump: consider reserved ranges while reserving memory") Cc: stable@vger.kernel.org Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/159057266320.22331.6571453892066907320.stgit@hbathini.in.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/fadump: consider reserved ranges while reserving memoryHari Bathini2020-06-221-9/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 140777a3d8dfdb3d3f20ea7707c0f1c0ce1b0aa5 upstream. Commit 0962e8004e97 ("powerpc/prom: Scan reserved-ranges node for memory reservations") enabled support to parse reserved-ranges DT node and reserve kernel memory falling in these ranges for F/W purposes. Memory reserved for FADump should not overlap with these ranges as it could corrupt memory meant for F/W or crash'ed kernel memory to be exported as vmcore. But since commit 579ca1a27675 ("powerpc/fadump: make use of memblock's bottom up allocation mode"), memblock_find_in_range() is being used to find the appropriate area to reserve memory for FADump, which can't account for reserved-ranges as these ranges are reserved only after FADump memory reservation. With reserved-ranges now being populated during early boot, look out for these memory ranges while reserving memory for FADump. Without this change, MPIPL on PowerNV systems aborts with hostboot failure, when memory reserved for FADump is less than 4096MB. Fixes: 579ca1a27675 ("powerpc/fadump: make use of memblock's bottom up allocation mode") Cc: stable@vger.kernel.org Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/158737297693.26700.16193820746269425424.stgit@hbathini.in.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/fadump: use static allocation for reserved memory rangesHari Bathini2020-06-221-32/+45
| | | | | | | | | | | | | | | | | | | | | commit 02c04e374e176ae3a3f64a682f80702f8d2fb65d upstream. At times, memory ranges have to be looked up during early boot, when kernel couldn't be initialized for dynamic memory allocation. In fact, reserved-ranges look up is needed during FADump memory reservation. Without accounting for reserved-ranges in reserving memory for FADump, MPIPL boot fails with memory corruption issues. So, extend memory ranges handling to support static allocation and populate reserved memory ranges during early boot. Fixes: dda9dbfeeb7a ("powerpc/fadump: consider reserved ranges while releasing memory") Cc: stable@vger.kernel.org Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/158737294432.26700.4830263187856221314.stgit@hbathini.in.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bpf: Support llvm-objcopy for vmlinux BTFFangrui Song2020-06-171-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 90ceddcb495008ac8ba7a3dce297841efcd7d584 upstream. Simplify gen_btf logic to make it work with llvm-objcopy. The existing 'file format' and 'architecture' parsing logic is brittle and does not work with llvm-objcopy/llvm-objdump. 'file format' output of llvm-objdump>=11 will match GNU objdump, but 'architecture' (bfdarch) may not. .BTF in .tmp_vmlinux.btf is non-SHF_ALLOC. Add the SHF_ALLOC flag because it is part of vmlinux image used for introspection. C code can reference the section via linker script defined __start_BTF and __stop_BTF. This fixes a small problem that previous .BTF had the SHF_WRITE flag (objcopy -I binary -O elf* synthesized .data). Additionally, `objcopy -I binary` synthesized symbols _binary__btf_vmlinux_bin_start and _binary__btf_vmlinux_bin_stop (not used elsewhere) are replaced with more commonplace __start_BTF and __stop_BTF. Add 2>/dev/null because GNU objcopy (but not llvm-objcopy) warns "empty loadable segment detected at vaddr=0xffffffff81000000, is this intentional?" We use a dd command to change the e_type field in the ELF header from ET_EXEC to ET_REL so that lld will accept .btf.vmlinux.bin.o. Accepting ET_EXEC as an input file is an extremely rare GNU ld feature that lld does not intend to support, because this is error-prone. The output section description .BTF in include/asm-generic/vmlinux.lds.h avoids potential subtle orphan section placement issues and suppresses --orphan-handling=warn warnings. Fixes: df786c9b9476 ("bpf: Force .BTF section start to zero when dumping from vmlinux") Fixes: cb0cc635c7a9 ("powerpc: Include .BTF section") Reported-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Stanislav Fomichev <sdf@google.com> Tested-by: Andrii Nakryiko <andriin@fb.com> Reviewed-by: Stanislav Fomichev <sdf@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Link: https://github.com/ClangBuiltLinux/linux/issues/871 Link: https://lore.kernel.org/bpf/20200318222746.173648-1-maskray@google.com Signed-off-by: Maria Teguiani <teguiani@google.com> Tested-by: Matthias Maennich <maennich@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/mm: Fix CONFIG_PPC_KUAP_DEBUG on PPC32Christophe Leroy2020-04-291-1/+1
| | | | | | | | | | | | | | | | | | | | commit feb8e960d780e170e992a70491eec9dd68f4dbf2 upstream. CONFIG_PPC_KUAP_DEBUG is not selectable because it depends on PPC_32 which doesn't exists. Fixing it leads to a deadlock due to a vital register getting clobbered in _switch(). Change dependency to PPC32 and use r0 instead of r4 in _switch() Fixes: e2fb9f544431 ("powerpc/32: Prepare for 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/540242f7d4573f7cdf1b3bf46bb35f743b2cd68f.1587124651.git.christophe.leroy@c-s.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/setup_64: Set cache-line-size based on cache-block-sizeChris Packham2020-04-291-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 94c0b013c98583614e1ad911e8795ca36da34a85 upstream. If {i,d}-cache-block-size is set and {i,d}-cache-line-size is not, use the block-size value for both. Per the devicetree spec cache-line-size is only needed if it differs from the block size. Originally the code would fallback from block size to line size. An error message was printed if both properties were missing. Later the code was refactored to use clearer names and logic but it inadvertently made line size a required property, meaning on systems without a line size property we fall back to the default from the cputable. On powernv (OPAL) platforms, since the introduction of device tree CPU features (5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features")), that has led to the wrong value being used, as the fallback value is incorrect for Power8/Power9 CPUs. The incorrect values flow through to the VDSO and also to the sysconf values, SC_LEVEL1_ICACHE_LINESIZE etc. Fixes: bd067f83b084 ("powerpc/64: Fix naming of cache block vs. cache line") Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Reported-by: Qian Cai <cai@lca.pw> [mpe: Add even more detail to change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200416221908.7886-1-chris.packham@alliedtelesis.co.nz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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