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2021-06-24powerpc/64: allow alternate return locations for soft-masked interruptsNicholas Piggin3-2/+86
The exception table fixup adjusts a failed page fault's interrupt return location if it was taken at an address specified in the exception table, to a corresponding fixup handler address. Introduce a variation of that idea which adds a fixup table for NMIs and soft-masked asynchronous interrupts. This will be used to protect certain critical sections that are sensitive to being clobbered by interrupts coming in (due to using the same SPRs and/or irq soft-mask state). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-10-npiggin@gmail.com
2021-06-24powerpc/64s: save one more register in the masked interrupt handlerNicholas Piggin1-14/+20
This frees up one more register (and takes advantage of that to clean things up a little bit). This register will be used in the following patch. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-9-npiggin@gmail.com
2021-06-24powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE]Nicholas Piggin2-4/+2
This extends the MSR[RI]=0 window a little further into the system call in order to pair RI and EE enabling with a single mtmsrd. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-8-npiggin@gmail.com
2021-06-24powerpc/64: move interrupt return asm to interrupt_64.SNicholas Piggin3-624/+639
The next patch would like to move interrupt return assembly code to a low location before general text, so move it into its own file and include via head_64.S Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-7-npiggin@gmail.com
2021-06-24powerpc/64s: avoid reloading (H)SRR registers if they are still validNicholas Piggin23-134/+273
When an interrupt is taken, the SRR registers are set to return to where it left off. Unless they are modified in the meantime, or the return address or MSR are modified, there is no need to reload these registers when returning from interrupt. Introduce per-CPU flags that track the validity of SRR and HSRR registers. These are cleared when returning from interrupt, when using the registers for something else (e.g., OPAL calls), when adjusting the return address or MSR of a context, and when context switching (which changes the return address and MSR). This improves the performance of interrupt returns. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fold in fixup patch from Nick] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com
2021-06-24powerpc/64s: introduce different functions to return from SRR vs HSRR interruptsNicholas Piggin4-55/+92
This makes no real difference yet except that HSRR type interrupts will use hrfid to return. This is important for the next patch. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-4-npiggin@gmail.com
2021-06-24powerpc: remove interrupt exit helpers unused argumentNicholas Piggin1-2/+2
The msr argument is not used, remove it. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-3-npiggin@gmail.com
2021-06-24powerpc/interrupt: Fix CONFIG ifdef typoChristophe Leroy1-1/+1
CONFIG_PPC_BOOK3S should be CONFIG_PPC_BOOK3S_64. restore_math is a no-op for other configurations. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [np: split from another patch] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-2-npiggin@gmail.com
2021-06-24powerpc/prom_init: Pass linux_banner to firmware via option vector 7Michael Ellerman1-0/+13
Pass the value of linux_banner to firmware via option vector 7. Option vector 7 is described in "LoPAR" Linux on Power Architecture Reference v2.9, in table B.7 on page 824: An ASCII character formatted null terminated string that describes the client operating system. The string shall be human readable and may be displayed on the console. The string can be up to 256 bytes total, including the nul terminator. linux_banner contains lots of information, and should make it possible to identify the exact kernel version that is running: const char linux_banner[] = "Linux version " UTS_RELEASE " (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION "\n"; For example: Linux version 4.15.0-144-generic (buildd@bos02-ppc64el-018) (gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)) #148-Ubuntu SMP Sat May 8 02:32:13 UTC 2021 (Ubuntu 4.15.0-144.148-generic 4.15.18) It's also printed at boot to the console/dmesg, which should make it possible to correlate what firmware receives with the console/dmesg on the machine. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210621064938.2021419-2-mpe@ellerman.id.au
2021-06-24powerpc/prom_init: Convert prom_strcpy() into prom_strscpy_pad()Michael Ellerman1-6/+24
In a subsequent patch we'd like to have something like a strscpy_pad() implementation usable in prom_init.c. Currently we have a strcpy() implementation with only one caller, so convert it into strscpy_pad() and update the caller. Reviewed-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210621064938.2021419-1-mpe@ellerman.id.au
2021-06-21powerpc/microwatt: Use standard 16550 UART for consoleBenjamin Herrenschmidt1-0/+39
This adds support to the Microwatt platform to use the standard 16550-style UART which available in the standalone Microwatt FPGA. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/YMwXGCTzedpQje7r@thinks.paulus.ozlabs.org
2021-06-21powerpc/kprobes: Mark newly allocated probes as ROXRussell Currey1-0/+17
Add the arch specific insn page allocator for powerpc. This allocates ROX pages if STRICT_KERNEL_RWX is enabled. These pages are only written to with patch_instruction() which is able to write RO pages. Signed-off-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [jpn: Reword commit message, switch to __vmalloc_node_range()] Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210609013431.9805-5-jniethe5@gmail.com
2021-06-21powerpc/modules: Make module_alloc() Strict Module RWX awareJordan Niethe1-1/+3
Make module_alloc() use PAGE_KERNEL protections instead of PAGE_KERNEL_EXEX if Strict Module RWX is enabled. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210609013431.9805-4-jniethe5@gmail.com
2021-06-21powerpc/security: Add a security feature for STF barrierNicholas Piggin1-5/+2
Rather than tying this mitigation to RFI L1D flush requirement, add a new bit for it. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210503130243.891868-3-npiggin@gmail.com
2021-06-21powerpc/powernv: Fix machine check reporting of async store errorsNicholas Piggin1-8/+40
POWER9 and POWER10 asynchronous machine checks due to stores have their cause reported in SRR1 but SRR1[42] is set, which in other cases indicates DSISR cause. Check for these cases and clear SRR1[42], so the cause matching uses the i-side (SRR1) table. Fixes: 7b9f71f974a1 ("powerpc/64s: POWER9 machine check handler") Fixes: 201220bb0e8c ("powerpc/powernv: Machine check handler for POWER10") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210517140355.2325406-1-npiggin@gmail.com
2021-06-20Merge tag 'powerpc-5.13-6' of ↵Linus Torvalds1-5/+4
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Fix initrd corruption caused by our recent change to use relative jump labels. Fix a crash using perf record on systems without a hardware PMU backend. Rework our 64-bit signal handling slighty to make it more closely match the old behaviour, after the recent change to use unsafe user accessors. Thanks to Anastasia Kovaleva, Athira Rajeev, Christophe Leroy, Daniel Axtens, Greg Kurz, and Roman Bolshakov" * tag 'powerpc-5.13-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/perf: Fix crash in perf_instruction_pointer() when ppmu is not set powerpc: Fix initrd corruption with relative jump labels powerpc/signal64: Copy siginfo before changing regs->nip powerpc/mem: Add back missing header to fix 'no previous prototype' error
2021-06-18sched: Introduce task_is_running()Peter Zijlstra1-2/+2
Replace a bunch of 'p->state == TASK_RUNNING' with a new helper: task_is_running(p). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210611082838.222401495@infradead.org
2021-06-18Merge branch 'sched/urgent' into sched/core, to resolve conflictsIngo Molnar4-43/+11
This commit in sched/urgent moved the cfs_rq_is_decayed() function: a7b359fc6a37: ("sched/fair: Correctly insert cfs_rq's to list on unthrottle") and this fresh commit in sched/core modified it in the old location: 9e077b52d86a: ("sched/pelt: Check that *_avg are null when *_sum are") Merge the two variants. Conflicts: kernel/sched/fair.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-06-17Merge branch 'topic/ppc-kvm' into nextMichael Ellerman4-223/+43
Merge some powerpc KVM patches from our topic branch. In particular this brings in Nick's big series rewriting parts of the guest entry/exit path in C. Conflicts: arch/powerpc/kernel/security.c arch/powerpc/kvm/book3s_hv_rmhandlers.S
2021-06-17powerpc/signal64: Don't read sigaction arguments back from user memoryMichael Ellerman1-2/+2
When delivering a signal to a sigaction style handler (SA_SIGINFO), we pass pointers to the siginfo and ucontext via r4 and r5. Currently we populate the values in those registers by reading the pointers out of the sigframe in user memory, even though the values in user memory were written by the kernel just prior: unsafe_put_user(&frame->info, &frame->pinfo, badframe_block); unsafe_put_user(&frame->uc, &frame->puc, badframe_block); ... if (ksig->ka.sa.sa_flags & SA_SIGINFO) { err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); ie. we write &frame->info into frame->pinfo, and then read frame->pinfo back into r4, and similarly for &frame->uc. The code has always been like this, since linux-fullhistory commit d4f2d95eca2c ("Forward port of 2.4 ppc64 signal changes."). There's no reason for us to read the values back from user memory, rather than just setting the value in the gpr[4/5] directly. In fact reading the value back from user memory opens up the possibility of another user thread changing the values before we read them back. Although any process doing that would be racing against the kernel delivering the signal, and would risk corrupting the stack, so that would be a userspace bug. Note that this is 64-bit only code, so there's no subtlety with the size of pointers differing between kernel and user. Also the frame variable is not modified to point elsewhere during the function. In the past reading the values back from user memory was not costly, but now that we have KUAP on some CPUs it is, so we'd rather avoid it for that reason too. So change the code to just set the values directly, using the same values we have written to the sigframe previously in the function. Note also that this matches what our 32-bit signal code does. Using a version of will-it-scale's signal1_threads that sets SA_SIGINFO, this results in a ~4% increase in signals per second on a Power9, from 229,777 to 239,766. Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210610072949.3198522-1-mpe@ellerman.id.au
2021-06-16powerpc/watchdog: include linux/processor.h for spin_until_condSudeep Holla1-0/+1
This implementation uses spin_until_cond in wd_smp_lock including neither linux/processor.h nor asm/processor.h This patch includes linux/processor.h here for spin_until_cond usage. Signed-off-by: Sudeep Holla <sudeep.holla@arm.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/5e8d2d50f301a346040362028c2ecba40685de9e.1623438544.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/signal32: Remove impossible #ifdef combinationsChristophe Leroy1-55/+0
PPC_TRANSACTIONAL_MEM is only on book3s/64 SPE is only on booke PPC_TRANSACTIONAL_MEM selects ALTIVEC and VSX Therefore, within PPC_TRANSACTIONAL_MEM sections, ALTIVEC and VSX are always defined while SPE never is. Remove all SPE code and all #ifdef ALTIVEC and VSX in tm functions. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a069a348ee3c2fe3123a5a93695c2b35dc42cb40.1623340691.git.christophe.leroy@csgroup.eu
2021-06-16powerpc: make stack walking KASAN-safeDaniel Axtens2-6/+7
Make our stack-walking code KASAN-safe by using __no_sanitize_address. Generic code, arm64, s390 and x86 all make accesses unchecked for similar sorts of reasons: when unwinding a stack, we might touch memory that KASAN has marked as being out-of-bounds. In ppc64 KASAN development, I hit this sometimes when checking for an exception frame - because we're checking an arbitrary offset into the stack frame. See commit 20955746320e ("s390/kasan: avoid false positives during stack unwind"), commit bcaf669b4bdb ("arm64: disable kasan when accessing frame->fp in unwind_frame"), commit 91e08ab0c851 ("x86/dumpstack: Prevent KASAN false positive warnings") and commit 6e22c8366416 ("tracing, kasan: Silence Kasan warning in check_stack of stack_tracer"). Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210614120907.1952321-1-dja@axtens.net
2021-06-16powerpc/32: Remove __main()Christophe Leroy1-6/+0
Comment says that __main() is there to make GCC happy. It's been there since the implementation of ppc arch in Linux 1.3.45. ppc32 is the only architecture having that. Even ppc64 doesn't have it. Seems like GCC is still happy without it. Drop it for good. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d01028f8166b98584eec536b52f14c5e3f98ff6b.1623172922.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/32s: Rename PTE_SIZE to PTE_T_SIZEChristophe Leroy1-2/+0
PTE_SIZE means PTE page table size in most placed, whereas in hash_low.S in means size of one entry in the table. Rename it PTE_T_SIZE, and define it directly in hash_low.S instead of going through asm-offsets. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/83a008a9fd6cc3f2bbcb470f592555d260ed7a3d.1623063174.git.christophe.leroy@csgroup.eu
2021-06-16powerpc: Define swapper_pg_dir[] in CChristophe Leroy7-81/+1
Don't duplicate swapper_pg_dir[] in each platform's head.S Define it in mm/pgtable.c Define MAX_PTRS_PER_PGD because on book3s/64 PTRS_PER_PGD is not a constant. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5e3f1b8a4695c33ccc80aa3870e016bef32b85e1.1623063174.git.christophe.leroy@csgroup.eu
2021-06-16powerpc: Define empty_zero_page[] in CChristophe Leroy6-28/+0
At the time being, empty_zero_page[] is defined in each platform head.S. Define it in mm/mem.c instead, and put it in BSS section instead of the DATA section. Commit 5227cfa71f9e ("arm64: mm: place empty_zero_page in bss") explains why it is interesting to have it in BSS. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5838caffa269e0957c5a50cc85477876220298b0.1623063174.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/nohash: Convert set_context() to CChristophe Leroy3-17/+0
ppc8xx already has set_context() in C. Other ones have it in assembly. The only thing it does is to write the context id into SPRN_PID. Do it in C. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a5d0759064f3831c6b88af49ef5d3b05ba1c4dad.1622712515.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/nohash: Refactor update of BDI2000 pointers in switch_mmu_context()Christophe Leroy4-53/+0
Instead of duplicating the update of BDI2000 pointers in set_context(), do it directly from switch_mmu_context(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4c54997edd3548fa54717915e7c6ebaf60f208c0.1622712515.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/32s: Rework Kernel Userspace Access ProtectionChristophe Leroy1-0/+3
On book3s/32, KUAP is provided by toggling Ks bit in segment registers. One segment register addresses 256M of virtual memory. At the time being, KUAP implements a complex logic to apply the unlock/lock on the exact number of segments covering the user range to access, with saving the boundaries of the range of segments in a member of thread struct. But most if not all user accesses are within a single segment. Rework KUAP with a different approach: - Open only one segment, the one corresponding to the starting address of the range to be accessed. - If a second segment is involved, it will generate a page fault. The segment will then be open by the page fault handler. The kuap member of thread struct will now contain: - The start address of the current on going user access, that will be used to know which segment to lock at the end of the user access. - ~0 when no user access is open - ~1 when additionnal segments are opened by a page fault. Then, at lock time - When only one segment is open, close it. - When several segments are open, close all user segments. Almost 100% of the time, only one segment will be involved. In interrupts, inline the function that unlock/lock all segments, because not inlining them implies a lot of register save/restore. With the patch, writing value 128 in userspace in perf_copy_attr() is done with 16 instructions: 3890: 93 82 04 dc stw r28,1244(r2) 3894: 7d 20 e5 26 mfsrin r9,r28 3898: 55 29 00 80 rlwinm r9,r9,0,2,0 389c: 7d 20 e1 e4 mtsrin r9,r28 38a0: 4c 00 01 2c isync 38a4: 39 20 00 80 li r9,128 38a8: 91 3c 00 00 stw r9,0(r28) 38ac: 81 42 04 dc lwz r10,1244(r2) 38b0: 39 00 ff ff li r8,-1 38b4: 91 02 04 dc stw r8,1244(r2) 38b8: 2c 0a ff fe cmpwi r10,-2 38bc: 41 82 00 88 beq 3944 <perf_copy_attr+0x36c> 38c0: 7d 20 55 26 mfsrin r9,r10 38c4: 65 29 40 00 oris r9,r9,16384 38c8: 7d 20 51 e4 mtsrin r9,r10 38cc: 4c 00 01 2c isync ... 3944: 48 00 00 01 bl 3944 <perf_copy_attr+0x36c> 3944: R_PPC_REL24 kuap_lock_all_ool Before the patch it was 118 instructions. In reality only 42 are executed in most cases, but GCC is not able to see that a properly aligned user access cannot involve more than one segment. 5060: 39 1d 00 04 addi r8,r29,4 5064: 3d 20 b0 00 lis r9,-20480 5068: 7c 08 48 40 cmplw r8,r9 506c: 40 81 00 08 ble 5074 <perf_copy_attr+0x2cc> 5070: 3d 00 b0 00 lis r8,-20480 5074: 39 28 ff ff addi r9,r8,-1 5078: 57 aa 00 06 rlwinm r10,r29,0,0,3 507c: 55 29 27 3e rlwinm r9,r9,4,28,31 5080: 39 29 00 01 addi r9,r9,1 5084: 7d 29 53 78 or r9,r9,r10 5088: 91 22 04 dc stw r9,1244(r2) 508c: 7d 20 ed 26 mfsrin r9,r29 5090: 55 29 00 80 rlwinm r9,r9,0,2,0 5094: 7c 08 50 40 cmplw r8,r10 5098: 40 81 00 c0 ble 5158 <perf_copy_attr+0x3b0> 509c: 7d 46 50 f8 not r6,r10 50a0: 7c c6 42 14 add r6,r6,r8 50a4: 54 c6 27 be rlwinm r6,r6,4,30,31 50a8: 7d 20 51 e4 mtsrin r9,r10 50ac: 3c ea 10 00 addis r7,r10,4096 50b0: 39 29 01 11 addi r9,r9,273 50b4: 7f 88 38 40 cmplw cr7,r8,r7 50b8: 55 29 02 06 rlwinm r9,r9,0,8,3 50bc: 40 9d 00 9c ble cr7,5158 <perf_copy_attr+0x3b0> 50c0: 2f 86 00 00 cmpwi cr7,r6,0 50c4: 41 9e 00 4c beq cr7,5110 <perf_copy_attr+0x368> 50c8: 2f 86 00 01 cmpwi cr7,r6,1 50cc: 41 9e 00 2c beq cr7,50f8 <perf_copy_attr+0x350> 50d0: 2f 86 00 02 cmpwi cr7,r6,2 50d4: 41 9e 00 14 beq cr7,50e8 <perf_copy_attr+0x340> 50d8: 7d 20 39 e4 mtsrin r9,r7 50dc: 39 29 01 11 addi r9,r9,273 50e0: 3c e7 10 00 addis r7,r7,4096 50e4: 55 29 02 06 rlwinm r9,r9,0,8,3 50e8: 7d 20 39 e4 mtsrin r9,r7 50ec: 39 29 01 11 addi r9,r9,273 50f0: 3c e7 10 00 addis r7,r7,4096 50f4: 55 29 02 06 rlwinm r9,r9,0,8,3 50f8: 7d 20 39 e4 mtsrin r9,r7 50fc: 3c e7 10 00 addis r7,r7,4096 5100: 39 29 01 11 addi r9,r9,273 5104: 7f 88 38 40 cmplw cr7,r8,r7 5108: 55 29 02 06 rlwinm r9,r9,0,8,3 510c: 40 9d 00 4c ble cr7,5158 <perf_copy_attr+0x3b0> 5110: 7d 20 39 e4 mtsrin r9,r7 5114: 39 29 01 11 addi r9,r9,273 5118: 3c c7 10 00 addis r6,r7,4096 511c: 55 29 02 06 rlwinm r9,r9,0,8,3 5120: 7d 20 31 e4 mtsrin r9,r6 5124: 39 29 01 11 addi r9,r9,273 5128: 3c c6 10 00 addis r6,r6,4096 512c: 55 29 02 06 rlwinm r9,r9,0,8,3 5130: 7d 20 31 e4 mtsrin r9,r6 5134: 39 29 01 11 addi r9,r9,273 5138: 3c c7 30 00 addis r6,r7,12288 513c: 55 29 02 06 rlwinm r9,r9,0,8,3 5140: 7d 20 31 e4 mtsrin r9,r6 5144: 3c e7 40 00 addis r7,r7,16384 5148: 39 29 01 11 addi r9,r9,273 514c: 7f 88 38 40 cmplw cr7,r8,r7 5150: 55 29 02 06 rlwinm r9,r9,0,8,3 5154: 41 9d ff bc bgt cr7,5110 <perf_copy_attr+0x368> 5158: 4c 00 01 2c isync 515c: 39 20 00 80 li r9,128 5160: 91 3d 00 00 stw r9,0(r29) 5164: 38 e0 00 00 li r7,0 5168: 90 e2 04 dc stw r7,1244(r2) 516c: 7d 20 ed 26 mfsrin r9,r29 5170: 65 29 40 00 oris r9,r9,16384 5174: 40 81 00 c0 ble 5234 <perf_copy_attr+0x48c> 5178: 7d 47 50 f8 not r7,r10 517c: 7c e7 42 14 add r7,r7,r8 5180: 54 e7 27 be rlwinm r7,r7,4,30,31 5184: 7d 20 51 e4 mtsrin r9,r10 5188: 3d 4a 10 00 addis r10,r10,4096 518c: 39 29 01 11 addi r9,r9,273 5190: 7c 08 50 40 cmplw r8,r10 5194: 55 29 02 06 rlwinm r9,r9,0,8,3 5198: 40 81 00 9c ble 5234 <perf_copy_attr+0x48c> 519c: 2c 07 00 00 cmpwi r7,0 51a0: 41 82 00 4c beq 51ec <perf_copy_attr+0x444> 51a4: 2c 07 00 01 cmpwi r7,1 51a8: 41 82 00 2c beq 51d4 <perf_copy_attr+0x42c> 51ac: 2c 07 00 02 cmpwi r7,2 51b0: 41 82 00 14 beq 51c4 <perf_copy_attr+0x41c> 51b4: 7d 20 51 e4 mtsrin r9,r10 51b8: 39 29 01 11 addi r9,r9,273 51bc: 3d 4a 10 00 addis r10,r10,4096 51c0: 55 29 02 06 rlwinm r9,r9,0,8,3 51c4: 7d 20 51 e4 mtsrin r9,r10 51c8: 39 29 01 11 addi r9,r9,273 51cc: 3d 4a 10 00 addis r10,r10,4096 51d0: 55 29 02 06 rlwinm r9,r9,0,8,3 51d4: 7d 20 51 e4 mtsrin r9,r10 51d8: 3d 4a 10 00 addis r10,r10,4096 51dc: 39 29 01 11 addi r9,r9,273 51e0: 7c 08 50 40 cmplw r8,r10 51e4: 55 29 02 06 rlwinm r9,r9,0,8,3 51e8: 40 81 00 4c ble 5234 <perf_copy_attr+0x48c> 51ec: 7d 20 51 e4 mtsrin r9,r10 51f0: 39 29 01 11 addi r9,r9,273 51f4: 3c ea 10 00 addis r7,r10,4096 51f8: 55 29 02 06 rlwinm r9,r9,0,8,3 51fc: 7d 20 39 e4 mtsrin r9,r7 5200: 39 29 01 11 addi r9,r9,273 5204: 3c e7 10 00 addis r7,r7,4096 5208: 55 29 02 06 rlwinm r9,r9,0,8,3 520c: 7d 20 39 e4 mtsrin r9,r7 5210: 39 29 01 11 addi r9,r9,273 5214: 3c ea 30 00 addis r7,r10,12288 5218: 55 29 02 06 rlwinm r9,r9,0,8,3 521c: 7d 20 39 e4 mtsrin r9,r7 5220: 3d 4a 40 00 addis r10,r10,16384 5224: 39 29 01 11 addi r9,r9,273 5228: 7c 08 50 40 cmplw r8,r10 522c: 55 29 02 06 rlwinm r9,r9,0,8,3 5230: 41 81 ff bc bgt 51ec <perf_copy_attr+0x444> 5234: 4c 00 01 2c isync Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Export the ool handlers to fix build errors] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d9121f96a7c4302946839a0771f5d1daeeb6968c.1622708530.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/32s: Initialise KUAP and KUEP in CChristophe Leroy2-6/+4
In order to selectively activate KUAP and KUEP in a following patch, perform KUAP and KUEP initialisation in C. Unlike PPC64, PPC32 doesn't have an early_setup_secondary(), so do it in start_secondary(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/87be72023448dd4e476744ed279b8c04b8d08a1c.1622708530.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/32s: Convert switch_mmu_context() to CChristophe Leroy2-63/+0
switch_mmu_context() does things that can easily be done in C. For updating user segments, we have update_user_segments(). As mentionned in commit b5efec00b671 ("powerpc/32s: Move KUEP locking/unlocking in C"), update_user_segments() has the loop unrolled which is a significant performance gain. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/05c0875ad8220c03452c3a334946e207c6ca04d6.1622708530.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/44x: Implement Kernel Userspace Exec Protection (KUEP)Christophe Leroy1-0/+8
Powerpc 44x has two bits for exec protection in TLBs: one for user (UX) and one for superviser (SX). Clear SX on user pages in TLB miss handlers to provide KUEP. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/169310e08152aa1d96c979770291d165ec6896ae.1622616032.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/optprobes: use PPC_RAW_ macrosChristophe Leroy1-32/+7
Use PPC_RAW_ macros to simplify the code. And use PPC_LO/PPC_HI instead of IMM_L/IMM_H which are for internal use inside ppc-opcode.h Those macros are self explanatory, comments can go as well. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5a167b8ba4d33a5c09cd504f0c862e25ffe85459.1621516826.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/optprobes: Compact code source a bit.Christophe Leroy1-22/+11
Now that lines can be up to 100 chars long, minimise the amount of split lines to increase readability. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8ebbd977ea8cf8d706d82458f2a21acd44562a99.1621516826.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/optprobes: Minimise castsChristophe Leroy1-12/+11
nip is already an unsigned long, no cast needed. op_callback_addr and emulate_step_addr are kprobe_opcode_t *. There value is obtained with ppc_kallsyms_lookup_name() which returns 'unsigned long', and there values are used create_branch() which expects 'unsigned long'. So change them to 'unsigned long' to avoid casting them back and forth. can_optimize() used p->addr several times as 'unsigned long'. Use a local 'unsigned long' variable and avoid casting multiple times. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e03192a6d4123242a275e71ce2ba0bb4d90700c1.1621516826.git.christophe.leroy@csgroup.eu
2021-06-16powerpc: Don't use 'struct ppc_inst' to reference instruction locationChristophe Leroy10-68/+56
'struct ppc_inst' is an internal representation of an instruction, but in-memory instructions are and will remain a table of 'u32' forever. Replace all 'struct ppc_inst *' used for locating an instruction in memory by 'u32 *'. This removes a lot of undue casts to 'struct ppc_inst *'. It also helps locating ab-use of 'struct ppc_inst' dereference. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Fix ppc_inst_next(), use u32 instead of unsigned int] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7062722b087228e42cbd896e39bfdf526d6a340a.1621516826.git.christophe.leroy@csgroup.eu
2021-06-16powerpc: Do not dereference code as 'struct ppc_inst' (uprobe, ↵Christophe Leroy1-1/+1
code-patching, feature-fixups) 'struct ppc_inst' is an internal structure to represent an instruction, it is not directly the representation of that instruction in text code. It is not meant to map and dereference code. Dereferencing code directly through 'struct ppc_inst' has two main issues: - On powerpc, structs are expected to be 8 bytes aligned while code is spread every 4 byte. - Should a non prefixed instruction lie at the end of the page and the following page not be mapped, it would generate a page fault. In-memory code must be accessed with ppc_inst_read(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c9a1201dd0a66b4a0f91f0fb46d9385cbf030feb.1621516826.git.christophe.leroy@csgroup.eu
2021-06-15powerpc: Replace PPC_INST_NOP by PPC_RAW_NOP()Christophe Leroy3-3/+3
On the road to removing all PPC_INST_xx defines in asm/ppc-opcodes.h, change PPC_INST_NOP to PPC_RAW_NOP(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ad46c195ca1b8572629ef07ba6bfe247585239a6.1621506159.git.christophe.leroy@csgroup.eu
2021-06-15powerpc/traps: Start using PPC_RAW_xx() macrosChristophe Leroy1-3/+4
Start using PPC_RAW_xx() macros where relevant. PPC_INST_SYNC is used to both represent the 'sync' instruction and the family of synchronisation instructions. Keep it for the later, maybe we'll change the name in the future to avoid confusion. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0945c155d6cb113431185fc1296ac127359fe29b.1621506159.git.christophe.leroy@csgroup.eu
2021-06-15powerpc/ftrace: Use PPC_RAW_MFLR() and PPC_RAW_NOP()Christophe Leroy1-9/+9
Use PPC_RAW_MFLR() instead of open coding with PPC_INST_MFLR. Same for PPC_INST_NOP. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/98fd4d717810b7c4032a1edf62dd6fe638e64329.1621506159.git.christophe.leroy@csgroup.eu
2021-06-15powerpc/security: Use PPC_RAW_BLR() and PPC_RAW_NOP()Christophe Leroy1-6/+6
On the road to remove all use of PPC_INST_xxx, replace PPC_INST_BLR by PPC_RAW_BLR(). Same for PPC_INST_NOP. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c04f88d0e53d2122fbbe92226892a01ebc668b6a.1621506159.git.christophe.leroy@csgroup.eu
2021-06-15powerpc/modules: Use PPC_RAW_xx() macrosChristophe Leroy2-51/+23
To improve readability, use PPC_RAW_xx() macros instead of open coding. Those macros are self-explanatory so the comments can go as well. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/99d9ee8849d3992beeadb310a665aae01c3abfb1.1621506159.git.christophe.leroy@csgroup.eu
2021-06-15powerpc/signal: Use PPC_RAW_xx() macrosChristophe Leroy2-16/+10
To improve readability, use PPC_RAW_xx() macros instead of open coding. Those macros are self-explanatory so the comments can go as well. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4ca2bfdca2f47a293d05f61eb3c4e487ee170f1f.1621506159.git.christophe.leroy@csgroup.eu
2021-06-15powerpc/lib/code-patching: Use PPC_RAW_() macrosChristophe Leroy1-1/+1
Instead of open coding with PPC_INST_ defines, use PPC_RAW_() macros. It improves readability. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8c92f1d9e825ee47c6f88fe43ad42d2a8cc2ab4a.1621506159.git.christophe.leroy@csgroup.eu
2021-06-15powerpc: Don't handle ALTIVEC/SPE in ASM in _switch(). Do it in C.Christophe Leroy3-37/+9
_switch() saves and restores ALTIVEC and SPE status. For altivec this is redundant with what __switch_to() does with save_sprs() and restore_sprs() and giveup_all() before calling _switch(). Add support for SPI in save_sprs() and restore_sprs() and remove things from _switch(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8ab21fd93d6e0047aa71e6509e5e312f14b2991b.1620998075.git.christophe.leroy@csgroup.eu
2021-06-15Merge branch 'fixes' into nextMichael Ellerman6-50/+17
Merge our fixes branch which has a number of important fixes, notably the fix for initrd corruption, as well as the fixes for scv vs ptrace.
2021-06-15powerpc/tau: Remove superfluous parameter in alloc_workqueue() callFinn Thain1-1/+1
This avoids an (optional) compiler warning: arch/powerpc/kernel/tau_6xx.c: In function 'TAU_init': arch/powerpc/kernel/tau_6xx.c:204:30: error: too many arguments for format [-Werror=format-extra-args] tau_workq = alloc_workqueue("tau", WQ_UNBOUND, 1, 0); Fixes: b1c6a0a10bfa ("powerpc/tau: Convert from timer to workqueue") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Finn Thain <fthain@linux-m68k.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a1456e8bbd33ef702e3ff6f14b1bf3919241c62b.1623398307.git.fthain@linux-m68k.org
2021-06-15powerpc/prom_init: Move custom isspace() to its own namespaceAndy Shevchenko1-9/+8
If by some reason any of the headers will include ctype.h we will have a name collision. Avoid this by moving isspace() to the dedicate namespace. First appearance of the code is in the commit cf68787b68a2 ("powerpc/prom_init: Evaluate mem kernel parameter for early allocation"). Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> [mpe: Reformat prom_isxdigit() now that we allow longer lines] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210510144925.58195-1-andriy.shevchenko@linux.intel.com
2021-06-14powerpc/signal64: Copy siginfo before changing regs->nipMichael Ellerman1-5/+4
In commit 96d7a4e06fab ("powerpc/signal64: Rewrite handle_rt_signal64() to minimise uaccess switches") the 64-bit signal code was rearranged to use user_write_access_begin/end(). As part of that change the call to copy_siginfo_to_user() was moved later in the function, so that it could be done after the user_write_access_end(). In particular it was moved after we modify regs->nip to point to the signal trampoline. That means if copy_siginfo_to_user() fails we exit handle_rt_signal64() with an error but with regs->nip modified, whereas previously we would not modify regs->nip until the copy succeeded. Returning an error from signal delivery but with regs->nip updated leaves the process in a sort of half-delivered state. We do immediately force a SEGV in signal_setup_done(), called from do_signal(), so the process should never run in the half-delivered state. However that SEGV is not delivered until we've gone around to do_notify_resume() again, so it's possible some tracing could observe the half-delivered state. There are other cases where we fail signal delivery with regs partly updated, eg. the write to newsp and SA_SIGINFO, but the latter at least is very unlikely to fail as it reads back from the frame we just wrote to. Looking at other arches they seem to be more careful about leaving regs unchanged until the copy operations have succeeded, and in general that seems like good hygenie. So although the current behaviour is not cleary buggy, it's also not clearly correct. So move the call to copy_siginfo_to_user() up prior to the modification of regs->nip, which is closer to the old behaviour, and easier to reason about. Fixes: 96d7a4e06fab ("powerpc/signal64: Rewrite handle_rt_signal64() to minimise uaccess switches") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210608134605.2783677-1-mpe@ellerman.id.au
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