- 24 Feb, 2022 1 commit
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Nicholas Piggin authored
Hash faults are not resoved in NMI context, instead causing the access to fail. This is done because perf interrupts can get backtraces including walking the user stack, and taking a hash fault on those could deadlock on the HPTE lock if the perf interrupt hits while the same HPTE lock is being held by the hash fault code. The user-access for the stack walking will notice the access failed and deal with that in the perf code. The reason to allow perf interrupts in is to better profile hash faults. The problem with this is any hash fault on a kernel access that happens in NMI context will crash, because kernel accesses must not fail. Hard lockups, system reset, machine checks that access vmalloc space including modules and including stack backtracing and symbol lookup in modules, per-cpu data, etc could all run into this problem. Fix this by disallowing perf interrupts in the hash fault code (the direct hash fault is covered by MSR[EE]=0 so the PMI disable just needs to extend to the preload case). This simplifies the tricky logic in hash faults and perf, at the cost of reduced profiling of hash faults. perf can still latch addresses when interrupts are disabled, it just won't get the stack trace at that point, so it would still find hot spots, just sometimes with confusing stack chains. An alternative could be to allow perf interrupts here but always do the slowpath stack walk if we are in nmi context, but that slows down all perf interrupt stack walking on hash though and it does not remove as much tricky code. Reported-by:
Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Tested-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/20220204035348.545435-1-npiggin@gmail.com
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- 23 Feb, 2022 1 commit
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Christophe Leroy authored
Following commit 12318163 ("powerpc/32: Remove remaining .stabs annotations"), stabs code are not used anymore. Remove them. Signed-off-by:
Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by:
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- 16 Feb, 2022 5 commits
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Vaibhav Jain authored
Presently PAPR doesn't support injecting smart errors on an NVDIMM. This makes testing the NVDIMM health reporting functionality difficult as simulating NVDIMM health related events need a hacked up qemu version. To solve this problem this patch proposes simulating certain set of NVDIMM health related events in papr_scm. Specifically 'fatal' health state and 'dirty' shutdown state. These error can be injected via the user-space 'ndctl-inject-smart(1)' command. With the proposed patch and corresponding ndctl patches following command flow is expected: $ sudo ndctl list -DH -d nmem0 ... "health_state":"ok", "shutdown_state":"clean", ... # inject unsafe shutdown and fatal health error $ sudo ndctl inject-smart nmem0 -Uf ... "health_state":"fatal", "shutdown_state":"dirty", ... # uninject all errors $ sudo ndctl inject-smart nmem0 -N ... "health_state":"ok", "shutdown_state":"clean", ... The patch adds a new member 'health_bitmap_inject_mask' inside struct papr_scm_priv which is then bitwise ANDed to the health bitmap fetched from the hypervisor. The value for 'health_bitmap_inject_mask' is accessible from sysfs at nmemX/papr/health_bitmap_inject. A new PDSM named 'SMART_INJECT' is proposed that accepts newly introduced 'struct nd_papr_pdsm_smart_inject' as payload thats exchanged between libndctl and papr_scm to indicate the requested smart-error states. When the processing the PDSM 'SMART_INJECT', papr_pdsm_smart_inject() constructs a pair or 'inject_mask' and 'clear_mask' bitmaps from the payload and bit-blt it to the 'health_bitmap_inject_mask'. This ensures the after being fetched from the hypervisor, the health_bitmap reflects requested smart-error states. Signed-off-by:Vaibhav Jain <vaibhav@linux.ibm.com> Signed-off-by:
Shivaprasad G Bhat <sbhat@linux.ibm.com> Signed-off-by:
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Christophe Leroy authored
Add some line breaks to better match the file's style, add some space after comma and fix a couple of misplaced blanks. Suggested-by:
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by:
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Christophe Leroy authored
When FL_SAVE_REGS is not set we get here via ftrace_caller() which doesn't save all registers. ftrace_caller() explicitely clears regs.msr, so we can rely on it to know where we come from. We don't expect MSR register to be 0 at all when involving ftrace. Fixes: 40b035ef ("powerpc/ftrace: Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS") Reported-by:
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Christophe Leroy authored
The function_graph_enter() does not provide any recursion protection. Add a protection in prepare_ftrace_return() in case function_graph_enter() calls something that gets function graph traced. Fixes: 83021378 ("powerpc/ftrace: directly call of function graph tracer by ftrace caller") Reported-by:
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Christophe Leroy authored
Also save r1 in ftrace_caller() r1 is needed during unwinding when the function_graph tracer is active. Fixes: 83021378 ("powerpc/ftrace: directly call of function graph tracer by ftrace caller") Reported-by:
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- 15 Feb, 2022 1 commit
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Paul Menzel authored
Currently, `git status` lists the file as untracked by git, so tell git to ignore it. Fixes: aa3bc365 ("powerpc/ps3: Add check for otheros image size") Signed-off-by:
Paul Menzel <pmenzel@molgen.mpg.de> Acked-by:
Geoff Levand <geoff@infradead.org> Signed-off-by:
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- 14 Feb, 2022 1 commit
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Christophe Leroy authored
Warnings in assembly must use EMIT_WARN_ENTRY in order to generate the necessary entry in exception table. Check in EMIT_BUG_ENTRY that flags don't include BUGFLAG_WARNING. This change avoids problems like the one fixed by commit fd1eaaaa ("powerpc/64s: Use EMIT_WARN_ENTRY for SRR debug warnings"). Signed-off-by:
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- 12 Feb, 2022 18 commits
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Michael Ellerman authored
Our skiroot_defconfig doesn't enable FTRACE, and so doesn't get STACKTRACE enabled either. That leads to a build failure since commit 1614b2b1 ("arch: Make ARCH_STACKWALK independent of STACKTRACE") made stacktrace.c build even when STACKTRACE=n. arch/powerpc/kernel/stacktrace.c: In function ‘handle_backtrace_ipi’: arch/powerpc/kernel/stacktrace.c:171:2: error: implicit declaration of function ‘nmi_cpu_backtrace’ 171 | nmi_cpu_backtrace(regs); | ^~~~~~~~~~~~~~~~~ arch/powerpc/kernel/stacktrace.c: In function ‘arch_trigger_cpumask_backtrace’: arch/powerpc/kernel/stacktrace.c:226:2: error: implicit declaration of function ‘nmi_trigger_cpumask_backtrace’ 226 | nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace_ipi); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This happens because our headers haven't defined arch_trigger_cpumask_backtrace, which causes lib/nmi_backtrace.c not to build nmi_cpu_backtrace(). The code in question doesn't actually depend on STACKTRACE=y, that was just added because arch_trigger_cpumask_backtrace() lived in stacktrace.c for convenience. So drop the dependency on CONFIG_STACKTRACE, that causes lib/nmi_backtrace.c to build nmi_cpu_backtrace() etc. and fixes the build. Fixes: 1614b2b1 ("arch: Make ARCH_STACKWALK independent of STACKTRACE") Signed-off-by:
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Aneesh Kumar K.V authored
commit: d9c23400 ("Do not depend on MAX_ORDER when grouping pages by mobility") introduced pageblock_order which will be used to group pages better. The kernel now groups pages based on the value of HPAGE_SHIFT. Hence HPAGE_SHIFT should be set before we call set_pageblock_order. set_pageblock_order happens early in the boot and default hugetlb page size should be initialized before that to compute the right pageblock_order value. Currently, default hugetlbe page size is set via arch_initcalls which happens late in the boot as shown via the below callstack: [c000000007383b10] [c000000001289328] hugetlbpage_init+0x2b8/0x2f8 [c000000007383bc0] [c0000000012749e4] do_one_initcall+0x14c/0x320 [c000000007383c90] [c00000000127505c] kernel_init_freeable+0x410/0x4e8 [c000000007383da0] [c000000000012664] kernel_init+0x30/0x15c [c000000007383e10] [c00000000000cf14] ret_from_kernel_thread+0x5c/0x64 and the pageblock_order initialization is done early during the boot. [c0000000018bfc80] [c0000000012ae120] set_pageblock_order+0x50/0x64 [c0000000018bfca0] [c0000000012b3d94] sparse_init+0x188/0x268 [c0000000018bfd60] [c000000001288bfc] initmem_init+0x28c/0x328 [c0000000018bfe50] [c00000000127b370] setup_arch+0x410/0x480 [c0000000018bfed0] [c00000000127401c] start_kernel+0xb8/0x934 [c0000000018bff90] [c00000000000d984] start_here_common+0x1c/0x98 delaying default hugetlb page size initialization implies the kernel will initialize pageblock_order to (MAX_ORDER - 1) which is not an optimal value for mobility grouping. IIUC we always had this issue. But it was not a problem for hash translation mode because (MAX_ORDER - 1) is the same as HUGETLB_PAGE_ORDER (8) in the case of hash (16MB). With radix, HUGETLB_PAGE_ORDER will be 5 (2M size) and hence pageblock_order should be 5 instead of 8. Signed-off-by:
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Ritesh Harjani authored
While debugging an issue, we wanted to check whether the arch specific kernel memmove implementation is correct. This selftest could help test that. Suggested-by:
Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by:
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Nathan Lynch authored
pseries_devicetree_update() has only one call site, in the same file in which it is defined. Make it static. Signed-off-by:
Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by:
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Christophe Leroy authored
Now that gettimeofday.S is unique, move cvdso_call macro into that file which is the only user. Signed-off-by:
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Christophe Leroy authored
cvdso_call_time macro is very similar to cvdso_call macro. Add a call_time argument to cvdso_call which is 0 by default and set to 1 when using cvdso_call to call __c_kernel_time(). Return returned value as is with CR[SO] cleared when it is used for time(). Signed-off-by:
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Christophe Leroy authored
merge vdso64 into vdso32 and rename it vdso. Reported-by:
kernel test robot <lkp@intel.com> Signed-off-by:
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Christophe Leroy authored
In order to merge vdso32 and vdso64 build in following patch, rework Makefile is order to add -32 suffix to VDSO32 object files. Also change sigtramp.S to sigtramp32.S as VDSO64 sigtramp.S is too different to be squashed into VDSO32 sigtramp.S at the first place. gen_vdso_offsets.sh also becomes gen_vdso32_offsets.sh Signed-off-by:
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Christophe Leroy authored
VDSO64 cacheflush.S datapage.S gettimeofday.S and vgettimeofday.c are very similar to their VDSO32 counterpart. VDSO32 counterpart is already more complete than the VDSO64 version as it supports both PPC32 vdso and 32 bits VDSO for PPC64. Use compat macros wherever necessary in PPC32 files so that they can also be used to build VDSO64. vdso64/note.S is already a link to vdso32/note.S so no change is required. Signed-off-by:
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Christophe Leroy authored
Use truncate_if_32bit() when possible instead of open coding. truncate_if_32bit() returns an unsigned long, so don't use it when a signed value is expected. Signed-off-by:
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Christophe Leroy authored
MSR_64BIT is always defined, no need to hide code using MSR_64BIT inside an #ifdef __powerpc64__ Signed-off-by:
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Christophe Leroy authored
Don't opencode dcache size retrieval based on whether that's ppc32 or ppc64. Use l1_dcache_bytes() Signed-off-by:
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Christophe Leroy authored
Two places deserve using the macro is_tsk_32bit_task() added by commit 25274524 ("powerpc/audit: Fix syscall_get_arch()") Signed-off-by:
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Christophe Leroy authored
The book3s/32 MMU doesn't support per page execution protection and doesn't support RO protection for kernel pages. However, on the 603 which implements software loaded TLBs, execution protection is honored by the TLB Miss handler which doesn't load Instruction TLB for non executable pages. And RO protection is honored by clearing the C bit for RO pages, leading to DSI. So on the 603, STRICT_MODULE_RWX is possible without much effort. Don't disable STRICT_MODULE_RWX on book3s/32 and print a warning in case STRICT_MODULE_RWX has been selected and the platform has a Hardware HASH MMU. Signed-off-by:
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Christophe Leroy authored
BPF_REG_5, BPF_REG_AX and TMP_REG are mapped on non volatile registers because there are not enough volatile registers, but they don't need to be preserved on function calls. So when some volatile registers become available, those registers can always be reallocated regardless of whether SEEN_FUNC is set or not. Suggested-by:
Naveen N. Rao <naveen.n.rao@linux.ibm.com> Signed-off-by:
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Christophe Leroy authored
set_memory_attr() was implemented by commit 4d1755b6 ("powerpc/mm: implement set_memory_attr()") because the set_memory_xx() couldn't be used at that time to modify memory "on the fly" as explained it the commit. But set_memory_attr() uses set_pte_at() which leads to warnings when CONFIG_DEBUG_VM is selected, because set_pte_at() is unexpected for updating existing page table entries. The check could be bypassed by using __set_pte_at() instead, as it was the case before commit c988cfd3 ("powerpc/32: use set_memory_attr()") but since commit 9f7853d7 ("powerpc/mm: Fix set_memory_*() against concurrent accesses") it is now possible to use set_memory_xx() functions to update page table entries "on the fly" because the update is now atomic. For DEBUG_PAGEALLOC we need to clear and set back _PAGE_PRESENT. Add set_memory_np() and set_memory_p() for that. Replace all uses of set_memory_attr() by the relevant set_memory_xx() and remove set_memory_attr(). Fixes: c988cfd3 ("powerpc/32: use set_memory_attr()") Cc: stable@vger.kernel.org Reported-by:
Maxime Bizon <mbizon@freebox.fr> Signed-off-by:
Russell Currey <ruscur@russell.cc> Depends-on: 9f7853d7 ("powerpc/mm: Fix set_memory_*() against concurrent accesses") Signed-off-by:
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Christophe Leroy authored
Commit 1f9ad21c ("powerpc/mm: Implement set_memory() routines") included a spin_lock() to change_page_attr() in order to safely perform the three step operations. But then commit 9f7853d7 ("powerpc/mm: Fix set_memory_*() against concurrent accesses") modify it to use pte_update() and do the operation safely against concurrent access. In the meantime, Maxime reported some spinlock recursion. [ 15.351649] BUG: spinlock recursion on CPU#0, kworker/0:2/217 [ 15.357540] lock: init_mm+0x3c/0x420, .magic: dead4ead, .owner: kworker/0:2/217, .owner_cpu: 0 [ 15.366563] CPU: 0 PID: 217 Comm: kworker/0:2 Not tainted 5.15.0+ #523 [ 15.373350] Workqueue: events do_free_init [ 15.377615] Call Trace: [ 15.380232] [e4105ac0] [800946a4] do_raw_spin_lock+0xf8/0x120 (unreliable) [ 15.387340] [e4105ae0] [8001f4ec] change_page_attr+0x40/0x1d4 [ 15.393413] [e4105b10] [801424e0] __apply_to_page_range+0x164/0x310 [ 15.400009] [e4105b60] [80169620] free_pcp_prepare+0x1e4/0x4a0 [ 15.406045] [e4105ba0] [8016c5a0] free_unref_page+0x40/0x2b8 [ 15.411979] [e4105be0] [8018724c] kasan_depopulate_vmalloc_pte+0x6c/0x94 [ 15.418989] [e4105c00] [801424e0] __apply_to_page_range+0x164/0x310 [ 15.425451] [e4105c50] [80187834] kasan_release_vmalloc+0xbc/0x134 [ 15.431898] [e4105c70] [8015f7a8] __purge_vmap_area_lazy+0x4e4/0xdd8 [ 15.438560] [e4105d30] [80160d10] _vm_unmap_aliases.part.0+0x17c/0x24c [ 15.445283] [e4105d60] [801642d0] __vunmap+0x2f0/0x5c8 [ 15.450684] [e4105db0] [800e32d0] do_free_init+0x68/0x94 [ 15.456181] [e4105dd0] [8005d094] process_one_work+0x4bc/0x7b8 [ 15.462283] [e4105e90] [8005d614] worker_thread+0x284/0x6e8 [ 15.468227] [e4105f00] [8006aaec] kthread+0x1f0/0x210 [ 15.473489] [e4105f40] [80017148] ret_from_kernel_thread+0x14/0x1c Remove the read / modify / write sequence to make the operation atomic and remove the spin_lock() in change_page_attr(). To do the operation atomically, we can't use pte modification helpers anymore. Because all platforms have different combination of bits, it is not easy to use those bits directly. But all have the _PAGE_KERNEL_{RO/ROX/RW/RWX} set of flags. All we need it to compare two sets to know which bits are set or cleared. For instance, by comparing _PAGE_KERNEL_ROX and _PAGE_KERNEL_RO you know which bit gets cleared and which bit get set when changing exec permission. Reported-by:
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Christophe Leroy authored
Functions in ftrace_32.S are common with PPC64. Reuse the ones defined for PPC64 with slight modification when required. Signed-off-by:
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- 07 Feb, 2022 13 commits
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Christophe Leroy authored
PPC64 mprofile versions and PPC32 are very similar. Modify PPC64 version so that if can be reused for PPC32. Signed-off-by:
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Christophe Leroy authored
Modify function graph tracer to be handled directly by the standard ftrace caller. This is made possible as powerpc now supports CONFIG_DYNAMIC_FTRACE_WITH_ARGS. This change simplifies the call of function graph ftrace. Signed-off-by:
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Christophe Leroy authored
ftrace_enable_ftrace_graph_caller() and ftrace_disable_ftrace_graph_caller() have common code. They will have even more common code after following patch. Refactor into a single ftrace_modify_ftrace_graph_caller() function. Signed-off-by:
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Christophe Leroy authored
Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS. It accelerates the call of livepatching. Also note that powerpc being the last one to convert to CONFIG_DYNAMIC_FTRACE_WITH_ARGS, it will now be possible to remove klp_arch_set_pc() on all architectures. Signed-off-by:
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Christophe Leroy authored
In order to implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS, change ftrace_caller() to handle LIVEPATCH the same way as frace_caller_regs(). Signed-off-by:
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Christophe Leroy authored
In order to implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS, change ftrace_caller() stack layout to match struct pt_regs. Signed-off-by:
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Christophe Leroy authored
return_to_handler() was copied from PPC64. For PPC32 it just needs to save r3 and r4, and doesn't require any nop after the bl. Signed-off-by:
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Christophe Leroy authored
PPC32 mcount() caller already saves LR on stack, no need to save it again. Signed-off-by:
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Christophe Leroy authored
PPC64 needs some special logic to properly set up the TOC. See commit 85baa095 ("powerpc/livepatch: Add live patching support on ppc64le") for details. PPC32 doesn't have TOC so it doesn't need that logic, so adding LIVEPATCH support is straight forward. Add CONFIG_LIVEPATCH_64 and move livepatch stack logic into that item. Livepatch sample modules all work. Signed-off-by:
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Christophe Leroy authored
Livepatching a loaded module involves applying relocations through apply_relocate_add(), which attempts to write to read-only memory when CONFIG_STRICT_MODULE_RWX=y. R_PPC_ADDR16_LO, R_PPC_ADDR16_HI, R_PPC_ADDR16_HA and R_PPC_REL24 are the types generated by the kpatch-build userspace tool or klp-convert kernel tree observed applying a relocation to a post-init module. Use patch_instruction() to patch those relocations. Commit 8734b41b ("powerpc/module_64: Fix livepatching for RO modules") did similar change in module_64. Signed-off-by:
Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by:
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Christophe Leroy authored
Trying to build livepatch on powerpc/32 results in: kernel/livepatch/core.c: In function 'klp_resolve_symbols': kernel/livepatch/core.c:221:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] 221 | sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info); | ^ kernel/livepatch/core.c:221:21: error: assignment to 'Elf32_Sym *' {aka 'struct elf32_sym *'} from incompatible pointer type 'Elf64_Sym *' {aka 'struct elf64_sym *'} [-Werror=incompatible-pointer-types] 221 | sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info); | ^ kernel/livepatch/core.c: In function 'klp_apply_section_relocs': kernel/livepatch/core.c:312:35: error: passing argument 1 of 'klp_resolve_symbols' from incompatible pointer type [-Werror=incompatible-pointer-types] 312 | ret = klp_resolve_symbols(sechdrs, strtab, symndx, sec, sec_objname); | ^~~~~~~ | | | Elf32_Shdr * {aka struct elf32_shdr *} kernel/livepatch/core.c:193:44: note: expected 'Elf64_Shdr *' {aka 'struct elf64_shdr *'} but argument is of type 'Elf32_Shdr *' {aka 'struct elf32_shdr *'} 193 | static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab, | ~~~~~~~~~~~~^~~~~~~ Fix it by using the right types instead of forcing 64 bits types. Fixes: 7c8e2bdd ("livepatch: Apply vmlinux-specific KLP relocations early") Signed-off-by:Petr Mladek <pmladek@suse.com> Acked-by:
Miroslav Benes <mbenes@suse.cz> Signed-off-by:
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Christophe Leroy authored
_ENTRY() is now redundant with _GLOBAL(). Remove it. Signed-off-by:
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Christophe Leroy authored
STABS debug format has been superseded long time ago by DWARF. Remove the few remaining .stabs annotations from old 32 bits code. Reported-by:
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