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2023-04-20powerpc/64: vmlinux support building with PCREL addresingNicholas Piggin
PC-Relative or PCREL addressing is an extension to the ELF ABI which uses Power ISA v3.1 PC-relative instructions to calculate addresses, rather than the traditional TOC scheme. Add an option to build vmlinux using pcrel addressing. Modules continue to use TOC addressing. - TOC address helpers and r2 are poisoned with -1 when running vmlinux. r2 could be used for something useful once things are ironed out. - Assembly must call C functions with @notoc annotation, or the linker complains aobut a missing nop after the call. This is done with the CFUNC macro introduced earlier. - Boot: with the exception of prom_init, the execution branches to the kernel virtual address early in boot, before any addresses are generated, which ensures 34-bit pcrel addressing does not miss the high PAGE_OFFSET bits. TOC relative addressing has a similar requirement. prom_init does not go to the virtual address and its addresses should not carry over to the post-prom kernel. - Ftrace trampolines are converted from TOC addressing to pcrel addressing, including module ftrace trampolines that currently use the kernel TOC to find ftrace target functions. - BPF function prologue and function calling generation are converted from TOC to pcrel. - copypage_64.S has an interesting problem, prefixed instructions have alignment restrictions so the linker can add padding, which makes the assembler treat the difference between two local labels as non-constant even if alignment is arranged so padding is not required. This may need toolchain help to solve nicely, for now move the prefix instruction out of the alternate patch section to work around it. This reduces kernel text size by about 6%. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230408021752.862660-6-npiggin@gmail.com
2023-01-30powerpc/64: Fix perf profiling asynchronous interrupt handlersNicholas Piggin
Interrupt entry sets the soft mask to IRQS_ALL_DISABLED to match the hard irq disabled state. So when should_hard_irq_enable() returns true because we want PMI interrupts in irq handlers, MSR[EE] is enabled but PMIs just get soft-masked. Fix this by clearing IRQS_PMI_DISABLED before enabling MSR[EE]. This also tidies some of the warnings, no need to duplicate them in both should_hard_irq_enable() and do_hard_irq_enable(). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230121100156.2824054-1-npiggin@gmail.com
2022-12-02powerpc: allow minimum sized kernel stack framesNicholas Piggin
This affects only 64-bit ELFv2 kernels, and reduces the minimum asm-created stack frame size from 112 to 32 byte on those kernels. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221127124942.1665522-16-npiggin@gmail.com
2022-09-05asm-generic: Conditionally enable do_softirq_own_stack() via Kconfig.Sebastian Andrzej Siewior
Remove the CONFIG_PREEMPT_RT symbol from the ifdef around do_softirq_own_stack() and move it to Kconfig instead. Enable softirq stacks based on SOFTIRQ_ON_OWN_STACK which depends on HAVE_SOFTIRQ_ON_OWN_STACK and its default value is set to !PREEMPT_RT. This ensures that softirq stacks are not used on PREEMPT_RT and avoids a 'select' statement on an option which has a 'depends' statement. Link: https://lore.kernel.org/YvN5E%2FPrHfUhggr7@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-08-06Merge tag 'powerpc-6.0-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Add support for syscall stack randomization - Add support for atomic operations to the 32 & 64-bit BPF JIT - Full support for KASAN on 64-bit Book3E - Add a watchdog driver for the new PowerVM hypervisor watchdog - Add a number of new selftests for the Power10 PMU support - Add a driver for the PowerVM Platform KeyStore - Increase the NMI watchdog timeout during live partition migration, to avoid timeouts due to increased memory access latency - Add support for using the 'linux,pci-domain' device tree property for PCI domain assignment - Many other small features and fixes Thanks to Alexey Kardashevskiy, Andy Shevchenko, Arnd Bergmann, Athira Rajeev, Bagas Sanjaya, Christophe Leroy, Erhard Furtner, Fabiano Rosas, Greg Kroah-Hartman, Greg Kurz, Haowen Bai, Hari Bathini, Jason A. Donenfeld, Jason Wang, Jiang Jian, Joel Stanley, Juerg Haefliger, Kajol Jain, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Masahiro Yamada, Maxime Bizon, Miaoqian Lin, Murilo Opsfelder Araújo, Nathan Lynch, Naveen N. Rao, Nayna Jain, Nicholas Piggin, Ning Qiang, Pali Rohár, Petr Mladek, Rashmica Gupta, Sachin Sant, Scott Cheloha, Segher Boessenkool, Stephen Rothwell, Uwe Kleine-König, Wolfram Sang, Xiu Jianfeng, and Zhouyi Zhou. * tag 'powerpc-6.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (191 commits) powerpc/64e: Fix kexec build error EDAC/ppc_4xx: Include required of_irq header directly powerpc/pci: Fix PHB numbering when using opal-phbid powerpc/64: Init jump labels before parse_early_param() selftests/powerpc: Avoid GCC 12 uninitialised variable warning powerpc/cell/axon_msi: Fix refcount leak in setup_msi_msg_address powerpc/xive: Fix refcount leak in xive_get_max_prio powerpc/spufs: Fix refcount leak in spufs_init_isolated_loader powerpc/perf: Include caps feature for power10 DD1 version powerpc: add support for syscall stack randomization powerpc: Move system_call_exception() to syscall.c powerpc/powernv: rename remaining rng powernv_ functions to pnv_ powerpc/powernv/kvm: Use darn for H_RANDOM on Power9 powerpc/powernv: Avoid crashing if rng is NULL selftests/powerpc: Fix matrix multiply assist test powerpc/signal: Update comment for clarity powerpc: make facility_unavailable_exception 64s powerpc/platforms/83xx/suspend: Remove write-only global variable powerpc/platforms/83xx/suspend: Prevent unloading the driver powerpc/platforms/83xx/suspend: Reorder to get rid of a forward declaration ...
2022-06-29powerpc/irq: Simplify __do_irq()Christophe Leroy
Remove duplicated code by implementing a proper if/else. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5a3b21311191f1240850db6ab29b19ac7885fe03.1654769775.git.christophe.leroy@csgroup.eu
2022-06-29powerpc/irq: Perform stack_overflow detection after switching to IRQ stackChristophe Leroy
When KASAN is enabled, as shown by the Oops below, the 2k limit is not enough to allow stack dump after a stack overflow detection when CONFIG_DEBUG_STACKOVERFLOW is selected: do_IRQ: stack overflow: 1984 CPU: 0 PID: 126 Comm: systemd-udevd Not tainted 5.18.0-gentoo-PMacG4 #1 Call Trace: Oops: Kernel stack overflow, sig: 11 [#1] BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac Modules linked in: sr_mod cdrom radeon(+) ohci_pci(+) hwmon i2c_algo_bit drm_ttm_helper ttm drm_dp_helper snd_aoa_i2sbus snd_aoa_soundbus snd_pcm ehci_pci snd_timer ohci_hcd snd ssb ehci_hcd 8250_pci soundcore drm_kms_helper pcmcia 8250 pcmcia_core syscopyarea usbcore sysfillrect 8250_base sysimgblt serial_mctrl_gpio fb_sys_fops usb_common pkcs8_key_parser fuse drm drm_panel_orientation_quirks configfs CPU: 0 PID: 126 Comm: systemd-udevd Not tainted 5.18.0-gentoo-PMacG4 #1 NIP: c02e5558 LR: c07eb3bc CTR: c07f46a8 REGS: e7fe9f50 TRAP: 0000 Not tainted (5.18.0-gentoo-PMacG4) MSR: 00001032 <ME,IR,DR,RI> CR: 44a14824 XER: 20000000 GPR00: c07eb3bc eaa1c000 c26baea0 eaa1c0a0 00000008 00000000 c07eb3bc eaa1c010 GPR08: eaa1c0a8 04f3f3f3 f1f1f1f1 c07f4c84 44a14824 0080f7e4 00000005 00000010 GPR16: 00000025 eaa1c154 eaa1c158 c0dbad64 00000020 fd543810 eaa1c0a0 eaa1c29e GPR24: c0dbad44 c0db8740 05ffffff fd543802 eaa1c150 c0c9a3c0 eaa1c0a0 c0c9a3c0 NIP [c02e5558] kasan_check_range+0xc/0x2b4 LR [c07eb3bc] format_decode+0x80/0x604 Call Trace: [eaa1c000] [c07eb3bc] format_decode+0x80/0x604 (unreliable) [eaa1c070] [c07f4dac] vsnprintf+0x128/0x938 [eaa1c110] [c07f5788] sprintf+0xa0/0xc0 [eaa1c180] [c0154c1c] __sprint_symbol.constprop.0+0x170/0x198 [eaa1c230] [c07ee71c] symbol_string+0xf8/0x260 [eaa1c430] [c07f46d0] pointer+0x15c/0x710 [eaa1c4b0] [c07f4fbc] vsnprintf+0x338/0x938 [eaa1c550] [c00e8fa0] vprintk_store+0x2a8/0x678 [eaa1c690] [c00e94e4] vprintk_emit+0x174/0x378 [eaa1c6d0] [c00ea008] _printk+0x9c/0xc0 [eaa1c750] [c000ca94] show_stack+0x21c/0x260 [eaa1c7a0] [c07d0bd4] dump_stack_lvl+0x60/0x90 [eaa1c7c0] [c0009234] __do_IRQ+0x170/0x174 [eaa1c800] [c0009258] do_IRQ+0x20/0x34 [eaa1c820] [c00045b4] HardwareInterrupt_virt+0x108/0x10c ... As the detection is asynchronously performed at IRQs, we could be long after the limit has been crossed, so increasing the limit would not solve the problem completely. In order to be sure that there is enough stack space for the stack dump, do it after the switch to the IRQ stack. That way it is sure that the stack is large enough, unless the IRQ stack has been overfilled in which case the end of life is close. Reported-by: Erhard Furtner <erhard_f@mailbox.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/c215d714329f475b431a6193369035aadfc0d182.1654769775.git.christophe.leroy@csgroup.eu
2022-06-29powerpc/irq: Make __do_irq() staticChristophe Leroy
Since commit 48cf12d88969 ("powerpc/irq: Inline call_do_irq() and call_do_softirq()"), __do_irq() is not used outside irq.c Reorder functions and make __do_irq() static and drop the declaration in irq.h. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/adbe1c8315ec2d63259f41468e82e51677bb1eda.1654769775.git.christophe.leroy@csgroup.eu
2022-06-29powerpc/irq: Increase stack_overflow detection limit when KASAN is enabledChristophe Leroy
When KASAN is enabled, as shown by the Oops below, the 2k limit is not enough to allow stack dump after a stack overflow detection when CONFIG_DEBUG_STACKOVERFLOW is selected: do_IRQ: stack overflow: 1984 CPU: 0 PID: 126 Comm: systemd-udevd Not tainted 5.18.0-gentoo-PMacG4 #1 Call Trace: Oops: Kernel stack overflow, sig: 11 [#1] BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac Modules linked in: sr_mod cdrom radeon(+) ohci_pci(+) hwmon i2c_algo_bit drm_ttm_helper ttm drm_dp_helper snd_aoa_i2sbus snd_aoa_soundbus snd_pcm ehci_pci snd_timer ohci_hcd snd ssb ehci_hcd 8250_pci soundcore drm_kms_helper pcmcia 8250 pcmcia_core syscopyarea usbcore sysfillrect 8250_base sysimgblt serial_mctrl_gpio fb_sys_fops usb_common pkcs8_key_parser fuse drm drm_panel_orientation_quirks configfs CPU: 0 PID: 126 Comm: systemd-udevd Not tainted 5.18.0-gentoo-PMacG4 #1 NIP: c02e5558 LR: c07eb3bc CTR: c07f46a8 REGS: e7fe9f50 TRAP: 0000 Not tainted (5.18.0-gentoo-PMacG4) MSR: 00001032 <ME,IR,DR,RI> CR: 44a14824 XER: 20000000 GPR00: c07eb3bc eaa1c000 c26baea0 eaa1c0a0 00000008 00000000 c07eb3bc eaa1c010 GPR08: eaa1c0a8 04f3f3f3 f1f1f1f1 c07f4c84 44a14824 0080f7e4 00000005 00000010 GPR16: 00000025 eaa1c154 eaa1c158 c0dbad64 00000020 fd543810 eaa1c0a0 eaa1c29e GPR24: c0dbad44 c0db8740 05ffffff fd543802 eaa1c150 c0c9a3c0 eaa1c0a0 c0c9a3c0 NIP [c02e5558] kasan_check_range+0xc/0x2b4 LR [c07eb3bc] format_decode+0x80/0x604 Call Trace: [eaa1c000] [c07eb3bc] format_decode+0x80/0x604 (unreliable) [eaa1c070] [c07f4dac] vsnprintf+0x128/0x938 [eaa1c110] [c07f5788] sprintf+0xa0/0xc0 [eaa1c180] [c0154c1c] __sprint_symbol.constprop.0+0x170/0x198 [eaa1c230] [c07ee71c] symbol_string+0xf8/0x260 [eaa1c430] [c07f46d0] pointer+0x15c/0x710 [eaa1c4b0] [c07f4fbc] vsnprintf+0x338/0x938 [eaa1c550] [c00e8fa0] vprintk_store+0x2a8/0x678 [eaa1c690] [c00e94e4] vprintk_emit+0x174/0x378 [eaa1c6d0] [c00ea008] _printk+0x9c/0xc0 [eaa1c750] [c000ca94] show_stack+0x21c/0x260 [eaa1c7a0] [c07d0bd4] dump_stack_lvl+0x60/0x90 [eaa1c7c0] [c0009234] __do_IRQ+0x170/0x174 [eaa1c800] [c0009258] do_IRQ+0x20/0x34 [eaa1c820] [c00045b4] HardwareInterrupt_virt+0x108/0x10c ... An investigation shows that on PPC32, calling dump_stack() requires more than 1k when KASAN is not selected and a bit more than 2k bytes when KASAN is selected. On PPC64 the registers are twice the size of PPC32 registers, so the need should be approximately twice the need on PPC32. In the meantime we have THREAD_SIZE which is twice larger on PPC64 than PPC32, and twice larger when KASAN is selected. So we can easily use the value of THREAD_SIZE to set the limit. On PPC32, THREAD_SIZE is 8k without KASAN and 16k with KASAN. On PPC64, THREAD_SIZE is 16k without KASAN. To be on the safe side, leave 2k on PPC32 without KASAN, 4k with KASAN, and 4k on PPC64 without KASAN. It means the limit should be one fourth of THREAD_SIZE. Reported-by: Erhard Furtner <erhard_f@mailbox.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/e8b4eb82a126c3c6c352173a544fe94609ff660b.1654261687.git.christophe.leroy@csgroup.eu
2022-06-29powerpc/irq: Split irq.cChristophe Leroy
More than half of irq.c is dedicated to PPC64. Move PPC64 code out of irq.c into irq_64.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/9f1a47de80f78d3dd270a7a72f69f55f581c4054.1652859593.git.christophe.leroy@csgroup.eu
2022-06-29powerpc: Don't include asm/ppc_asm.h in other headersChristophe Leroy
asm/ppc_asm.h is not needed in any of the header it is included. It is only needed by irq.c. Include it there and remove it from other headers. word-at-a-time.h only need ex_table.h, so include it instead. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e2d7b96547037f852c7ed164e4f79e8918c2607a.1651828453.git.christophe.leroy@csgroup.eu
2022-06-15arch/*: Disable softirq stacks on PREEMPT_RT.Sebastian Andrzej Siewior
PREEMPT_RT preempts softirqs and the current implementation avoids do_softirq_own_stack() and only uses __do_softirq(). Disable the unused softirqs stacks on PREEMPT_RT to save some memory and ensure that do_softirq_own_stack() is not used bwcause it is not expected. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-06-02Merge tag 'livepatching-for-5.19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching Pull livepatching cleanup from Petr Mladek: - Remove duplicated livepatch code [Christophe] * tag 'livepatching-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: livepatch: Remove klp_arch_set_pc() and asm/livepatch.h
2022-05-24livepatch: Remove klp_arch_set_pc() and asm/livepatch.hChristophe Leroy
All three versions of klp_arch_set_pc() do exactly the same: they call ftrace_instruction_pointer_set(). Call ftrace_instruction_pointer_set() directly and remove klp_arch_set_pc(). As klp_arch_set_pc() was the only thing remaining in asm/livepatch.h on x86 and s390, remove asm/livepatch.h livepatch.h remains on powerpc but its content is exclusively used by powerpc specific code. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Petr Mladek <pmladek@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Petr Mladek <pmladek@suse.com>
2022-05-22powerpc/irq: Remove arch_local_irq_restore() for !CONFIG_CC_HAS_ASM_GOTOChristophe Leroy
All supported versions of GCC & clang support asm goto. Remove the !CONFIG_CC_HAS_ASM_GOTO version of arch_local_irq_restore() Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/58df50c9e77e2ed945bacdead30412770578886b.1652715336.git.christophe.leroy@csgroup.eu
2022-05-08powerpc: Use static call for get_irq()Christophe Leroy
__do_irq() inconditionnaly calls ppc_md.get_irq() That's definitely a hot path. At the time being ppc_md.get_irq address is read every time from ppc_md structure. Replace that call by a static call, and initialise that call after ppc_md.init_IRQ() has set ppc_md.get_irq. Emit a warning and don't set the static call if ppc_md.init_IRQ() is still NULL, that way the kernel won't blow up if for some reason ppc_md.get_irq() doesn't get properly set. With the patch: 00000000 <__SCT__ppc_get_irq>: 0: 48 00 00 20 b 20 <__static_call_return0> <== Replaced by 'b <ppc_md.get_irq>' at runtime ... 00000020 <__static_call_return0>: 20: 38 60 00 00 li r3,0 24: 4e 80 00 20 blr ... 00000058 <__do_irq>: ... 64: 48 00 00 01 bl 64 <__do_irq+0xc> 64: R_PPC_REL24 __SCT__ppc_get_irq 68: 2c 03 00 00 cmpwi r3,0 ... Before the patch: 00000038 <__do_irq>: ... 3c: 3d 20 00 00 lis r9,0 3e: R_PPC_ADDR16_HA ppc_md+0x1c ... 44: 81 29 00 00 lwz r9,0(r9) 46: R_PPC_ADDR16_LO ppc_md+0x1c ... 4c: 7d 29 03 a6 mtctr r9 50: 4e 80 04 21 bctrl 54: 2c 03 00 00 cmpwi r3,0 ... On PPC64 which doesn't implement static calls yet we get: 00000000000000d0 <__do_irq>: ... dc: 00 00 22 3d addis r9,r2,0 dc: R_PPC64_TOC16_HA .data+0x8 ... e4: 00 00 89 e9 ld r12,0(r9) e4: R_PPC64_TOC16_LO_DS .data+0x8 ... f0: a6 03 89 7d mtctr r12 f4: 18 00 41 f8 std r2,24(r1) f8: 21 04 80 4e bctrl fc: 18 00 41 e8 ld r2,24(r1) ... So on PPC64 that's similar to what we get without static calls. But at least until ppc_md.get_irq() is set the call is to __static_call_return0. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/afb92085f930651d8b1063e4d4bf0396c80ebc7d.1647002274.git.christophe.leroy@csgroup.eu
2022-05-08powerpc: Remove asm/prom.h from all files that don't need itChristophe Leroy
Several files include asm/prom.h for no reason. Clean it up. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Drop change to prom_parse.c as reported by lkp@intel.com] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7c9b8fda63dcf63e1b28f43e7ebdb95182cbc286.1646767214.git.christophe.leroy@csgroup.eu
2022-03-08powerpc: Move C prototypes out of asm-prototypes.hChristophe Leroy
We originally added asm-prototypes.h in commit 42f5b4cacd78 ("powerpc: Introduce asm-prototypes.h"). It's purpose was for prototypes of C functions that are only called from asm, in order to fix sparse warnings about missing prototypes. A few months later Nick added a different use case in commit 4efca4ed05cb ("kbuild: modversions for EXPORT_SYMBOL() for asm") for C prototypes for exported asm functions. This is basically the inverse of our original usage. Since then we've added various prototypes to asm-prototypes.h for both reasons, meaning we now need to unstitch it all. Dispatch prototypes of C functions into relevant headers and keep only the prototypes for functions defined in assembly. For the time being, leave prom_init() there because moving it into asm/prom.h or asm/setup.h conflicts with drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowrom.o This will be fixed later by untaggling asm/pci.h and asm/prom.h or by renaming the function in shadowrom.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/62d46904eca74042097acf4cb12c175e3067f3d1.1646413435.git.christophe.leroy@csgroup.eu
2021-12-16powerpc/64s/interrupt: Don't enable MSR[EE] in irq handlers unless perf is ↵Nicholas Piggin
in use Enabling MSR[EE] in interrupt handlers while interrupts are still soft masked allows PMIs to profile interrupt handlers to some degree, beyond what SIAR latching allows. When perf is not being used, this is almost useless work. It requires an extra mtmsrd in the irq handler, and it also opens the door to masked interrupts hitting and requiring replay, which is more expensive than just taking them directly. This effect can be noticable in high IRQ workloads. Avoid enabling MSR[EE] unless perf is currently in use. This saves about 60 cycles (or 8%) on a simple decrementer interrupt microbenchmark. Replayed interrupts drop from 1.4% of all interrupts taken, to 0.003%. This does prevent the soft-nmi interrupt being taken in these handlers, but that's not too reliable anyway. The SMP watchdog will continue to be the reliable way to catch lockups. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210922145452.352571-5-npiggin@gmail.com
2021-12-09powerpc/config: Add CONFIG_BOOKE_OR_40xChristophe Leroy
We have many functionnalities common to 40x and BOOKE, it leads to many places with #if defined(CONFIG_BOOKE) || defined(CONFIG_40x). We are going to add a few more with KUAP for booke/40x, so create a new symbol which is defined when either BOOKE or 40x is defined. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9a3dbd60924cb25c9f944d3d8205ac5a0d15e229.1634627931.git.christophe.leroy@csgroup.eu
2021-10-07powerpc/64: warn if local irqs are enabled in NMI or hardirq contextNicholas Piggin
This can help catch bugs such as the one fixed by the previous change to prevent _exception() from enabling irqs. ppc32 could have a similar warning but it has no good config option to debug this stuff (the test may be overkill to add for production kernels). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211004145642.1331214-4-npiggin@gmail.com
2021-08-12powerpc/interrupt: Fix OOPS by not calling do_IRQ() from timer_interrupt()Christophe Leroy
An interrupt handler shall not be called from another interrupt handler otherwise this leads to problems like the following: Kernel attempted to write user page (afd4fa84) - exploit attempt? (uid: 1000) ------------[ cut here ]------------ Bug: Write fault blocked by KUAP! WARNING: CPU: 0 PID: 1617 at arch/powerpc/mm/fault.c:230 do_page_fault+0x484/0x720 Modules linked in: CPU: 0 PID: 1617 Comm: sshd Tainted: G W 5.13.0-pmac-00010-g8393422eb77 #7 NIP: c001b77c LR: c001b77c CTR: 00000000 REGS: cb9e5bc0 TRAP: 0700 Tainted: G W (5.13.0-pmac-00010-g8393422eb77) MSR: 00021032 <ME,IR,DR,RI> CR: 24942424 XER: 00000000 GPR00: c001b77c cb9e5c80 c1582c00 00000021 3ffffbff 085b0000 00000027 c8eb644c GPR08: 00000023 00000000 00000000 00000000 24942424 0063f8c8 00000000 000186a0 GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 c07640c4 cb9e5e98 cb9e5e90 GPR24: 00000040 afd4fa96 00000040 02000000 c1fda6c0 afd4fa84 00000300 cb9e5cc0 NIP [c001b77c] do_page_fault+0x484/0x720 LR [c001b77c] do_page_fault+0x484/0x720 Call Trace: [cb9e5c80] [c001b77c] do_page_fault+0x484/0x720 (unreliable) [cb9e5cb0] [c000424c] DataAccess_virt+0xd4/0xe4 --- interrupt: 300 at __copy_tofrom_user+0x110/0x20c NIP: c001f9b4 LR: c03250a0 CTR: 00000004 REGS: cb9e5cc0 TRAP: 0300 Tainted: G W (5.13.0-pmac-00010-g8393422eb77) MSR: 00009032 <EE,ME,IR,DR,RI> CR: 48028468 XER: 20000000 DAR: afd4fa84 DSISR: 0a000000 GPR00: 20726f6f cb9e5d80 c1582c00 00000004 cb9e5e3a 00000016 afd4fa80 00000000 GPR08: 3835202d 72777872 2d78722d 00000004 28028464 0063f8c8 00000000 000186a0 GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 c07640c4 cb9e5e98 cb9e5e90 GPR24: 00000040 afd4fa96 00000040 cb9e5e0c 00000daa a0000000 cb9e5e98 afd4fa56 NIP [c001f9b4] __copy_tofrom_user+0x110/0x20c LR [c03250a0] _copy_to_iter+0x144/0x990 --- interrupt: 300 [cb9e5d80] [c03e89c0] n_tty_read+0xa4/0x598 (unreliable) [cb9e5df0] [c03e2a0c] tty_read+0xdc/0x2b4 [cb9e5e80] [c0156bf8] vfs_read+0x274/0x340 [cb9e5f00] [c01571ac] ksys_read+0x70/0x118 [cb9e5f30] [c0016048] ret_from_syscall+0x0/0x28 --- interrupt: c00 at 0xa7855c88 NIP: a7855c88 LR: a7855c5c CTR: 00000000 REGS: cb9e5f40 TRAP: 0c00 Tainted: G W (5.13.0-pmac-00010-g8393422eb77) MSR: 0000d032 <EE,PR,ME,IR,DR,RI> CR: 2402446c XER: 00000000 GPR00: 00000003 afd4ec70 a72137d0 0000000b afd4ecac 00004000 0065a990 00000800 GPR08: 00000000 a7947930 00000000 00000004 c15831b0 0063f8c8 00000000 000186a0 GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 0065a9e0 00000001 0065fac0 GPR24: 00000000 00000089 00664050 00000000 00668e30 a720c8dc a7943ff4 0065f9b0 NIP [a7855c88] 0xa7855c88 LR [a7855c5c] 0xa7855c5c --- interrupt: c00 Instruction dump: 3884aa88 38630178 48076861 807f0080 48042e45 2f830000 419e0148 3c80c079 3c60c076 38841be4 386301c0 4801f705 <0fe00000> 3860000b 4bfffe30 3c80c06b ---[ end trace fd69b91a8046c2e5 ]--- Here the problem is that by re-enterring an exception handler, kuap_save_and_lock() is called a second time with this time KUAP access locked, leading to regs->kuap being overwritten hence KUAP not being unlocked at exception exit as expected. Do not call do_IRQ() from timer_interrupt() directly. Instead, redefine do_IRQ() as a standard function named __do_IRQ(), and call it from both do_IRQ() and time_interrupt() handlers. Fixes: 3a96570ffceb ("powerpc: convert interrupt handlers to use wrappers") Cc: stable@vger.kernel.org # v5.12+ Reported-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c17d234f4927d39a1d7100864a8e1145323d33a0.1628611927.git.christophe.leroy@csgroup.eu
2021-06-30powerpc/64: enable MSR[EE] in irq replay pt_regsNicholas Piggin
Similar to commit 2b48e96be2f9f ("powerpc/64: fix irq replay pt_regs->softe value"), enable MSR_EE in pt_regs->msr. This makes the regs look more normal. It also allows some extra debug checks to be added to interrupt handler entry. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210630074621.2109197-7-npiggin@gmail.com
2021-06-25powerpc/64: interrupt soft-enable race fixNicholas Piggin
Prevent interrupt restore from allowing racing hard interrupts going ahead of previous soft-pending ones, by using the soft-masked restart handler to allow a store to clear the soft-mask while knowing nothing is soft-pending. This probably doesn't matter much in practice, but it's a simple demonstrator / test case to exercise the restart table logic. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-11-npiggin@gmail.com
2021-04-21powerpc/irq: Enhance readability of trap typesChristophe Leroy
This patch makes use of trap types in irq.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/f7f8c9f98c33eaea316755c7fef150d1d77e047d.1618847273.git.christophe.leroy@csgroup.eu
2021-04-14powerpc/64e/interrupt: use new interrupt returnNicholas Piggin
Update the new C and asm interrupt return code to account for 64e specifics, switch over to use it. The now-unused old ret_from_except code, that was moved to 64e after the 64s conversion, is removed. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210316104206.407354-5-npiggin@gmail.com
2021-03-29powerpc/irq: Inline call_do_irq() and call_do_softirq()Christophe Leroy
call_do_irq() and call_do_softirq() are simple enough to be worth inlining. Inlining them avoids an mflr/mtlr pair plus a save/reload on stack. This is inspired from S390 arch. Several other arches do more or less the same. The way sparc arch does seems odd thought. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210320122227.345427-1-mpe@ellerman.id.au
2021-03-29powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() genericChristophe Leroy
In preparation of porting powerpc32 to C syscall entry/exit, rename kuap_check_amr() and kuap_get_and_check_amr() as kuap_assert_locked() and kuap_get_and_assert_locked(), and move in the generic asm/kup.h the stub for when CONFIG_PPC_KUAP is not selected. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f82614d9b17b83abd739aa18fc08811815d0c2e3.1615552867.git.christophe.leroy@csgroup.eu
2021-02-24Merge tag 'x86-entry-2021-02-24' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 irq entry updates from Thomas Gleixner: "The irq stack switching was moved out of the ASM entry code in course of the entry code consolidation. It ended up being suboptimal in various ways. This reworks the X86 irq stack handling: - Make the stack switching inline so the stackpointer manipulation is not longer at an easy to find place. - Get rid of the unnecessary indirect call. - Avoid the double stack switching in interrupt return and reuse the interrupt stack for softirq handling. - A objtool fix for CONFIG_FRAME_POINTER=y builds where it got confused about the stack pointer manipulation" * tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Fix stack-swizzle for FRAME_POINTER=y um: Enforce the usage of asm-generic/softirq_stack.h x86/softirq/64: Inline do_softirq_own_stack() softirq: Move do_softirq_own_stack() to generic asm header softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK x86/softirq: Remove indirection in do_softirq_own_stack() x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall x86/entry: Convert device interrupts to inline stack switching x86/entry: Convert system vectors to irq stack macro x86/irq: Provide macro for inlining irq stack switching x86/apic: Split out spurious handling code x86/irq/64: Adjust the per CPU irq stack pointer by 8 x86/irq: Sanitize irq stack tracking x86/entry: Fix instrumentation annotation
2021-02-22Merge tag 'powerpc-5.12-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - A large series adding wrappers for our interrupt handlers, so that irq/nmi/user tracking can be isolated in the wrappers rather than spread in each handler. - Conversion of the 32-bit syscall handling into C. - A series from Nick to streamline our TLB flushing when using the Radix MMU. - Switch to using queued spinlocks by default for 64-bit server CPUs. - A rework of our PCI probing so that it happens later in boot, when more generic infrastructure is available. - Two small fixes to allow 32-bit little-endian processes to run on 64-bit kernels. - Other smaller features, fixes & cleanups. Thanks to: Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang Fan, Christophe Leroy, Christopher M. Riedl, Fabiano Rosas, Florian Fainelli, Frederic Barrat, Ganesh Goudar, Hari Bathini, Jiapeng Chong, Joseph J Allen, Kajol Jain, Markus Elfring, Michal Suchanek, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pingfan Liu, Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan Das, Stephen Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, and Zheng Yongjun. * tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (188 commits) powerpc/perf: Adds support for programming of Thresholding in P10 powerpc/pci: Remove unimplemented prototypes powerpc/uaccess: Merge raw_copy_to_user_allowed() into raw_copy_to_user() powerpc/uaccess: Merge __put_user_size_allowed() into __put_user_size() powerpc/uaccess: get rid of small constant size cases in raw_copy_{to,from}_user() powerpc/64: Fix stack trace not displaying final frame powerpc/time: Remove get_tbl() powerpc/time: Avoid using get_tbl() spi: mpc52xx: Avoid using get_tbl() powerpc/syscall: Avoid storing 'current' in another pointer powerpc/32: Handle bookE debugging in C in syscall entry/exit powerpc/syscall: Do not check unsupported scv vector on PPC32 powerpc/32: Remove the counter in global_dbcr0 powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry powerpc/syscall: implement system call entry/exit logic in C for PPC32 powerpc/32: Always save non volatile GPRs at syscall entry powerpc/syscall: Change condition to check MSR_RI powerpc/syscall: Save r3 in regs->orig_r3 powerpc/syscall: Use is_compat_task() powerpc/syscall: Make interrupt.c buildable on PPC32 ...
2021-02-12Merge branch 'x86/paravirt' into x86/entryIngo Molnar
Merge in the recent paravirt changes to resolve conflicts caused by objtool annotations. Conflicts: arch/x86/xen/xen-asm.S Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-02-11powerpc/kuap: Restore AMR after replaying soft interruptsAlexey Kardashevskiy
Since de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection"), user access helpers call user_{read|write}_access_{begin|end} when user space access is allowed. Commit 890274c2dc4c ("powerpc/64s: Implement KUAP for Radix MMU") made the mentioned helpers program a AMR special register to allow such access for a short period of time, most of the time AMR is expected to block user memory access by the kernel. Since the code accesses the user space memory, unsafe_get_user() calls might_fault() which calls arch_local_irq_restore() if either CONFIG_PROVE_LOCKING or CONFIG_DEBUG_ATOMIC_SLEEP is enabled. arch_local_irq_restore() then attempts to replay pending soft interrupts as KUAP regions have hardware interrupts enabled. If a pending interrupt happens to do user access (performance interrupts do that), it enables access for a short period of time so after returning from the replay, the user access state remains blocked and if a user page fault happens - "Bug: Read fault blocked by AMR!" appears and SIGSEGV is sent. An example trace: Bug: Read fault blocked by AMR! WARNING: CPU: 0 PID: 1603 at /home/aik/p/kernel/arch/powerpc/include/asm/book3s/64/kup-radix.h:145 CPU: 0 PID: 1603 Comm: amr Not tainted 5.10.0-rc6_v5.10-rc6_a+fstn1 #24 NIP: c00000000009ece8 LR: c00000000009ece4 CTR: 0000000000000000 REGS: c00000000dc63560 TRAP: 0700 Not tainted (5.10.0-rc6_v5.10-rc6_a+fstn1) MSR: 8000000000021033 <SF,ME,IR,DR,RI,LE> CR: 28002888 XER: 20040000 CFAR: c0000000001fa928 IRQMASK: 1 GPR00: c00000000009ece4 c00000000dc637f0 c000000002397600 000000000000001f GPR04: c0000000020eb318 0000000000000000 c00000000dc63494 0000000000000027 GPR08: c00000007fe4de68 c00000000dfe9180 0000000000000000 0000000000000001 GPR12: 0000000000002000 c0000000030a0000 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 bfffffffffffffff GPR20: 0000000000000000 c0000000134a4020 c0000000019c2218 0000000000000fe0 GPR24: 0000000000000000 0000000000000000 c00000000d106200 0000000040000000 GPR28: 0000000000000000 0000000000000300 c00000000dc63910 c000000001946730 NIP __do_page_fault+0xb38/0xde0 LR __do_page_fault+0xb34/0xde0 Call Trace: __do_page_fault+0xb34/0xde0 (unreliable) handle_page_fault+0x10/0x2c --- interrupt: 300 at strncpy_from_user+0x290/0x440 LR = strncpy_from_user+0x284/0x440 strncpy_from_user+0x2f0/0x440 (unreliable) getname_flags+0x88/0x2c0 do_sys_openat2+0x2d4/0x5f0 do_sys_open+0xcc/0x140 system_call_exception+0x160/0x240 system_call_common+0xf0/0x27c To fix it save/restore the AMR when replaying interrupts, and also add a check if AMR was not blocked prior to replaying interrupts. Originally found by syzkaller. Fixes: 890274c2dc4c ("powerpc/64s: Implement KUAP for Radix MMU") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Use normal commit citation format and add full oops log to change log, move kuap_check_amr() into the restore routine to avoid warnings about unreconciled IRQ state] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210202091541.36499-1-aik@ozlabs.ru
2021-02-10softirq: Move do_softirq_own_stack() to generic asm headerThomas Gleixner
To avoid include recursion hell move the do_softirq_own_stack() related content into a generic asm header and include it from all places in arch/ which need the prototype. This allows architectures to provide an inline implementation of do_softirq_own_stack() without introducing a lot of #ifdeffery all over the place. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002513.289960691@linutronix.de
2021-02-09powerpc: handle irq_enter/irq_exit in interrupt handler wrappersNicholas Piggin
Move irq_enter/irq_exit into asynchronous interrupt handler wrappers. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-35-npiggin@gmail.com
2021-02-09powerpc: convert interrupt handlers to use wrappersNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-29-npiggin@gmail.com
2021-01-24powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous ↵Nicholas Piggin
interrupt When an asynchronous interrupt calls irq_exit, it checks for softirqs that may have been created, and runs them. Running softirqs enables local irqs, which can replay pending interrupts causing recursion in replay_soft_interrupts. This abridged trace shows how this can occur: ! NIP replay_soft_interrupts LR interrupt_exit_kernel_prepare Call Trace: interrupt_exit_kernel_prepare (unreliable) interrupt_return --- interrupt: ea0 at __rb_reserve_next NIP __rb_reserve_next LR __rb_reserve_next Call Trace: ring_buffer_lock_reserve trace_function function_trace_call ftrace_call __do_softirq irq_exit timer_interrupt ! replay_soft_interrupts interrupt_exit_kernel_prepare interrupt_return --- interrupt: ea0 at arch_local_irq_restore This can not be prevented easily, because softirqs must not block hard irqs, so it has to be dealt with. The recursion is bounded by design in the softirq code because softirq replay disables softirqs and loops around again to check for new softirqs created while it ran, so that's not a problem. However it does mess up interrupt replay state, causing superfluous interrupts when the second replay_soft_interrupts clears a pending interrupt, leaving it still set in the first call in the 'happened' local variable. Fix this by not caching a copy of irqs_happened across interrupt handler calls. Fixes: 3282a3da25bd ("powerpc/64: Implement soft interrupt replay 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/20210123061244.2076145-1-npiggin@gmail.com
2020-12-09powerpc/64: irq replay remove decrementer overflow checkNicholas Piggin
This is way to catch some cases of decrementer overflow, when the decrementer has underflowed an odd number of times, while MSR[EE] was disabled. With a typical small decrementer, a timer that fires when MSR[EE] is disabled will be "lost" if MSR[EE] remains disabled for between 4.3 and 8.6 seconds after the timer expires. In any case, the decrementer interrupt would be taken at 8.6 seconds and the timer would be found at that point. So this check is for catching extreme latency events, and it prevents those latencies from being a further few seconds long. It's not obvious this is a good tradeoff. This is already a watchdog magnitude event and that situation is not improved a significantly with this check. For large decrementers, it's useless. Therefore remove this check, which avoids a mftb when enabling hard disabled interrupts (e.g., when enabling after coming from hardware interrupt handlers). Perhaps more importantly, it also removes the clunky MSR[EE] vs PACA_IRQ_HARD_DIS incoherency in soft-interrupt replay which simplifies the code. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201107014336.2337337-1-npiggin@gmail.com
2020-10-08powerpc: Remove get_tb_or_rtc()Christophe Leroy
601 is gone, get_tb_or_rtc() is equivalent to get_tb(). Replace the former by the later. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3e8a13ee83418630c753c30cb722ae682d5b2d39.1601362098.git.christophe.leroy@csgroup.eu
2020-10-06powerpc/64: make restore_interrupts 64e onlyNicholas Piggin
This is not used by 64s. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200915114650.3980244-5-npiggin@gmail.com
2020-10-06powerpc/64e: remove 64s specific interrupt soft-mask codeNicholas Piggin
Since the assembly soft-masking code was moved to 64e specific, there are some 64s specific interrupt types still there. Remove them. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200915114650.3980244-4-npiggin@gmail.com
2020-10-06powerpc/64e: remove PACA_IRQ_EE_EDGENicholas Piggin
This is not used anywhere. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200915114650.3980244-3-npiggin@gmail.com
2020-10-06powerpc/64: fix irq replay pt_regs->softe valueNicholas Piggin
Replayed interrupts get an "artificial" struct pt_regs constructed to pass to interrupt handler functions. This did not get the softe field set correctly, it's as though the interrupt has hit while irqs are disabled. It should be IRQS_ENABLED. This is possibly harmless, asynchronous handlers should not be testing if irqs were disabled, but it might be possible for example some code is shared with synchronous or NMI handlers, and it makes more sense if debug output looks at this. Fixes: 3282a3da25bd ("powerpc/64: Implement soft interrupt replay 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/20200915114650.3980244-2-npiggin@gmail.com
2020-10-06powerpc/64: fix irq replay missing preemptNicholas Piggin
Prior to commit 3282a3da25bd ("powerpc/64: Implement soft interrupt replay in C"), replayed interrupts returned by the regular interrupt exit code, which performs preemption in case an interrupt had set need_resched. This logic was missed by the conversion. Adding preempt_disable/enable around the interrupt replay and final irq enable will reschedule if needed. Fixes: 3282a3da25bd ("powerpc/64: Implement soft interrupt replay 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/20200915114650.3980244-1-npiggin@gmail.com
2020-07-29powerpc/64s: Move HMI IRQ stat from percpu variable to paca.Mahesh Salgaonkar
With the proposed change in percpu bootmem allocator to use page mapping [1], the percpu first chunk memory area can come from vmalloc ranges. This makes the HMI (Hypervisor Maintenance Interrupt) handler crash the kernel whenever percpu variable is accessed in real mode. This patch fixes this issue by moving the HMI IRQ stat inside paca for safe access in realmode. [1] https://lore.kernel.org/linuxppc-dev/20200608070904.387440-1-aneesh.kumar@linux.ibm.com/ Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/159290806973.3642154.5244613424529764050.stgit@jupiter
2020-06-09mm: reorder includes after introduction of linux/pgtable.hMike Rapoport
The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include of the latter in the middle of asm includes. Fix this up with the aid of the below script and manual adjustments here and there. import sys import re if len(sys.argv) is not 3: print "USAGE: %s <file> <header>" % (sys.argv[0]) sys.exit(1) hdr_to_move="#include <linux/%s>" % sys.argv[2] moved = False in_hdrs = False with open(sys.argv[1], "r") as f: lines = f.readlines() for _line in lines: line = _line.rstrip(' ') if line == hdr_to_move: continue if line.startswith("#include <linux/"): in_hdrs = True elif not moved and in_hdrs: moved = True print hdr_to_move print line Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mm: introduce include/linux/pgtable.hMike Rapoport
The include/linux/pgtable.h is going to be the home of generic page table manipulation functions. Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and make the latter include asm/pgtable.h. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02powerpc: use __vmalloc_node in alloc_vm_stackChristoph Hellwig
alloc_vm_stack can use a slightly higher level vmalloc function. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Gao Xiang <xiang@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Kelley <mikelley@microsoft.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Wei Liu <wei.liu@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/20200414131348.444715-29-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-03powerpc/64s: Fix doorbell wakeup msgclr optimisationNicholas Piggin
Commit 3282a3da25bd ("powerpc/64: Implement soft interrupt replay in C") broke the doorbell wakeup optimisation introduced by commit a9af97aa0a12 ("powerpc/64s: msgclr when handling doorbell exceptions from system reset"). This patch restores the msgclr, in C code. It's now done in the system reset wakeup path rather than doorbell interrupt replay where it used to be, because it is always the right thing to do in the wakeup case, but it may be rarely of use in other interrupt replay situations in which case it's wasted work - we would have to run measurements to see if that was a worthwhile optimisation, and I suspect it would not be. The results are similar to those in the original commit, test on POWER8 of context_switch selftests benchmark with polling idle disabled (e.g., always nap, giving cross-CPU IPIs) gives the following results: broken patched Different threads, same core: 317k/s 375k/s +18.7% Different cores: 280k/s 282k/s +1.0% Fixes: 3282a3da25bd ("powerpc/64: Implement soft interrupt replay 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/20200402121212.1118218-1-npiggin@gmail.com
2020-04-01powerpc/64s: Implement interrupt exit logic in CNicholas Piggin
Implement the bulk of interrupt return logic in C. The asm return code must handle a few cases: restoring full GPRs, and emulating stack store. The stack store emulation is significantly simplfied, rather than creating a new return frame and switching to that before performing the store, it uses the PACA to keep a scratch register around to perform the store. The asm return code is moved into 64e for now. The new logic has made allowance for 64e, but I don't have a full environment that works well to test it, and even booting in emulated qemu is not great for stress testing. 64e shouldn't be too far off working with this, given a bit more testing and auditing of the logic. This is slightly faster on a POWER9 (page fault speed increases about 1.1%), probably due to reduced mtmsrd. mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE handling (including the fast_interrupt_return path), to remove trace_hardirqs_on(), and fixes the interrupt-return part of the MSR_VSX restore bug caught by tm-unavailable selftest. mpe: Incorporate fix from Nick: The return-to-kernel path has to replay any soft-pending interrupts if it is returning to a context that had interrupts soft-enabled. It has to do this carefully and avoid plain enabling interrupts if this is an irq context, which can cause multiple nesting of interrupts on the stack, and other unexpected issues. The code which avoided this case got the soft-mask state wrong, and marked interrupts as enabled before going around again to retry. This seems to be mostly harmless except when PREEMPT=y, this calls preempt_schedule_irq with irqs apparently enabled and runs into a BUG in kernel/sched/core.c Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-04-01powerpc/64: Implement soft interrupt replay in CNicholas Piggin
When local_irq_enable() finds a pending soft-masked interrupt, it "replays" it by setting up registers like the initial interrupt entry, then calls into the low level handler to set up an interrupt stack frame and process the interrupt. This is not necessary, and uses more stack than needed. The high level interrupt handler can be called directly from C, with just pt_regs set up on stack. This should be faster and use less stack. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200225173541.1549955-28-npiggin@gmail.com
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