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* kbuild: allow archs to select link dead code/data eliminationNicholas Piggin2016-09-091-0/+13
| | | | | | | | | | | | | | | | | | | | | Introduce LD_DEAD_CODE_DATA_ELIMINATION option for architectures to select to build with -ffunction-sections, -fdata-sections, and link with --gc-sections. It requires some work (documented) to ensure all unreferenced entrypoints are live, and requires toolchain and build verification, so it is made a per-arch option for now. On a random powerpc64le build, this yelds a significant size saving, it boots and runs fine, but there is a lot I haven't tested as yet, so these savings may be reduced if there are bugs in the link. text data bss dec filename 11169741 1180744 1923176 14273661 vmlinux 10445269 1004127 1919707 13369103 vmlinux.dce ~700K text, ~170K data, 6% removed from kernel image size. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.com>
* kbuild: allow architectures to use thin archives instead of ld -rStephen Rothwell2016-09-091-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ld -r is an incremental link used to create built-in.o files in build subdirectories. It produces relocatable object files containing all its input files, and these are are then pulled together and relocated in the final link. Aside from the bloat, this constrains the final link relocations, which has bitten large powerpc builds with unresolvable relocations in the final link. Alan Modra has recommended the kernel use thin archives for linking. This is an alternative and means that the linker has more information available to it when it links the kernel. This patch enables a config option architectures can select, which causes all built-in.o files to be built as thin archives. built-in.o files in subdirectories do not get symbol table or index attached, which improves speed and size. The final link pass creates a built-in.o archive in the root output directory which includes the symbol table and index. The linker then uses takes this file to link. The --whole-archive linker option is required, because the linker now has visibility to every individual object file, and it will otherwise just completely avoid including those without external references (consider a file with EXPORT_SYMBOL or initcall or hardware exceptions as its only entry points). The traditional built works "by luck" as built-in.o files are large enough that they're going to get external references. However this optimisation is unpredictable for the kernel (due to above external references), ineffective at culling unused, and costly because the .o files have to be searched for references. Superior alternatives for link-time culling should be used instead. Build characteristics for inclink vs thinarc, on a small powerpc64le pseries VM with a modest .config: inclink thinarc sizes vmlinux 15 618 680 15 625 028 sum of all built-in.o 56 091 808 1 054 334 sum excluding root built-in.o 151 430 find -name built-in.o | xargs rm ; time make vmlinux real 22.772s 21.143s user 13.280s 13.430s sys 4.310s 2.750s - Final kernel pulled in only about 6K more, which shows how ineffective the object file culling is. - Build performance looks improved due to less pagecache activity. On IO constrained systems it could be a bigger win. - Build size saving is significant. Side note, the toochain understands archives, so there's some tricks, $ ar t built-in.o # list all files you linked with $ size built-in.o # and their sizes $ objdump -d built-in.o # disassembly (unrelocated) with filenames Implementation by sfr, minor tweaks by npiggin. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.com>
* ia64: move exports to definitionsAl Viro2016-08-0825-92/+64
| | | | | | | | | | | | | | Here we have another kind of deviation from the default case - a difference between exporting functions and non-functions. EXPORT_DATA_SYMBOL... is really different from EXPORT_SYMBOL... on ia64, and we need to use the right one when moving exports from *.c where C compiler has the required information to *.S, where we need to supply it manually. parisc64 will be another one like that. Tested-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sparc32: debride memcpy.S a bitAl Viro2016-08-081-79/+0
| | | | | | | unreachable code, unused macros... Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [sparc] unify 32bit and 64bit string.hAl Viro2016-08-084-105/+34
| | | | | Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sparc: move exports to definitionsAl Viro2016-08-0845-265/+141
| | | | | Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ppc: move exports to definitionsAl Viro2016-08-0837-131/+98
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* arm: move exports to definitionsAl Viro2016-08-0847-208/+131
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* s390: move exports to definitionsAl Viro2016-08-086-16/+14
| | | | | Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* m68k: move exports to definitionsAl Viro2016-08-0812-39/+32
| | | | | Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* alpha: move exports to actual definitionsAl Viro2016-08-0841-131/+99
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* x86: move exports to actual definitionsAl Viro2016-08-0827-150/+68
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [kbuild] handle exports in lib-y objects reliablyAl Viro2016-08-082-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Collect the symbols exported by anything that goes into lib.a and add an empty object (lib-exports.o) with explicit undefs for each of those to obj-y. That allows to relax the rules regarding the use of exports in lib-* objects - right now an object with export can be in lib-* only if we are guaranteed that there always will be users in built-in parts of the tree, otherwise it needs to be in obj-*. As the result, we have an unholy mix of lib- and obj- in lib/Makefile and (especially) in arch/*/lib/Makefile. Moreover, a change in generic part of the kernel can lead to mysteriously missing exports on some configs. With this change we don't have to worry about that anymore. One side effect is that built-in.o now pulls everything with exports from the corresponding lib.a (if such exists). That's exactly what we want for linking vmlinux and fortunately it's almost the only thing built-in.o is used in. arch/ia64/hp/sim/boot/bootloader is the only exception and it's easy to get rid of now - just turn everything in arch/ia64/lib into lib-* and don't bother with arch/ia64/lib/built-in.o anymore. [AV: stylistic fix from Michal folded in] Acked-by: Michal Marek <mmarek@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2016-08-0613-62/+96
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull more KVM updates from Paolo Bonzini: - ARM bugfix and MSI injection support - x86 nested virt tweak and OOPS fix - Simplify pvclock code (vdso bits acked by Andy Lutomirski). * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: nvmx: mark ept single context invalidation as supported nvmx: remove comment about missing nested vpid support KVM: lapic: fix access preemption timer stuff even if kernel_irqchip=off KVM: documentation: fix KVM_CAP_X2APIC_API information x86: vdso: use __pvclock_read_cycles pvclock: introduce seqcount-like API arm64: KVM: Set cpsr before spsr on fault injection KVM: arm: vgic-irqfd: Workaround changing kvm_set_routing_entry prototype KVM: arm/arm64: Enable MSI routing KVM: arm/arm64: Enable irqchip routing KVM: Move kvm_setup_default/empty_irq_routing declaration in arch specific header KVM: irqchip: Convey devid to kvm_set_msi KVM: Add devid in kvm_kernel_irq_routing_entry KVM: api: Pass the devid in the msi routing entry
| * nvmx: mark ept single context invalidation as supportedBandan Das2016-08-041-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | Commit 4b855078601f ("KVM: nVMX: Don't advertise single context invalidation for invept") removed advertising single context invalidation since the spec does not mandate it. However, some hypervisors (such as ESX) require it to be present before willing to use ept in a nested environment. Advertise it and fallback to the global case. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * nvmx: remove comment about missing nested vpid supportBandan Das2016-08-041-1/+0
| | | | | | | | | | | | | | | | Nested vpid is already supported and both single/global modes are advertised to the guest Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * KVM: lapic: fix access preemption timer stuff even if kernel_irqchip=offWanpeng Li2016-08-041-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BUG: unable to handle kernel NULL pointer dereference at 000000000000008c IP: [<ffffffffc04e0180>] kvm_lapic_hv_timer_in_use+0x10/0x20 [kvm] PGD 0 Oops: 0000 [#1] SMP Call Trace: kvm_arch_vcpu_load+0x86/0x260 [kvm] vcpu_load+0x46/0x60 [kvm] kvm_vcpu_ioctl+0x79/0x7c0 [kvm] ? __lock_is_held+0x54/0x70 do_vfs_ioctl+0x96/0x6a0 ? __fget_light+0x2a/0x90 SyS_ioctl+0x79/0x90 do_syscall_64+0x7c/0x1e0 entry_SYSCALL64_slow_path+0x25/0x25 RIP [<ffffffffc04e0180>] kvm_lapic_hv_timer_in_use+0x10/0x20 [kvm] RSP <ffff8800db1f3d70> CR2: 000000000000008c ---[ end trace a55fb79d2b3b4ee8 ]--- This can be reproduced steadily by kernel_irqchip=off. We should not access preemption timer stuff if lapic is emulated in userspace. This patch fix it by avoiding access preemption timer stuff when kernel_irqchip=off. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Yunhong Jiang <yunhong.jiang@intel.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * Merge tag 'kvm-arm-for-4.8-take2' of ↵Paolo Bonzini2016-08-048-7/+52
| |\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/ARM Changes for v4.8 - Take 2 Includes GSI routing support to go along with the new VGIC and a small fix that has been cooking in -next for a while.
| | * arm64: KVM: Set cpsr before spsr on fault injectionAndrew Jones2016-08-011-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to set cpsr before determining the spsr bank, as the bank depends on the target exception level of the injection, not the current mode of the vcpu. Normally this is one in the same (EL1), but not when we manage to trap an EL0 fault. It still doesn't really matter for the 64-bit EL0 case though, as vcpu_spsr() unconditionally uses the EL1 bank for that. However the 32-bit EL0 case gets fun, as that path will lead to the BUG() in vcpu_spsr32(). This patch fixes the assignment order and also modifies some white space in order to better group pairs of lines that have strict order. Cc: stable@vger.kernel.org # v4.5 Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * KVM: arm/arm64: Enable irqchip routingEric Auger2016-07-226-0/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds compilation and link against irqchip. Main motivation behind using irqchip code is to enable MSI routing code. In the future irqchip routing may also be useful when targeting multiple irqchips. Routing standard callbacks now are implemented in vgic-irqfd: - kvm_set_routing_entry - kvm_set_irq - kvm_set_msi They only are supported with new_vgic code. Both HAVE_KVM_IRQCHIP and HAVE_KVM_IRQ_ROUTING are defined. KVM_CAP_IRQ_ROUTING is advertised and KVM_SET_GSI_ROUTING is allowed. So from now on IRQCHIP routing is enabled and a routing table entry must exist for irqfd injection to succeed for a given SPI. This patch builds a default flat irqchip routing table (gsi=irqchip.pin) covering all the VGIC SPI indexes. This routing table is overwritten by the first first user-space call to KVM_SET_GSI_ROUTING ioctl. MSI routing setup is not yet allowed. Signed-off-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * KVM: Move kvm_setup_default/empty_irq_routing declaration in arch specific ↵Eric Auger2016-07-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | header kvm_setup_default_irq_routing and kvm_setup_empty_irq_routing are not used by generic code. So let's move the declarations in x86 irq.h header instead of kvm_host.h. Signed-off-by: Eric Auger <eric.auger@redhat.com> Suggested-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| * | x86: vdso: use __pvclock_read_cyclesPaolo Bonzini2016-08-041-13/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new simplified __pvclock_read_cycles does the same computation as vread_pvclock, except that (because it takes the pvclock_vcpu_time_info pointer) it has to be moved inside the loop. Since the loop is expected to never roll, this makes no difference. Acked-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | pvclock: introduce seqcount-like APIPaolo Bonzini2016-08-043-34/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The version field in struct pvclock_vcpu_time_info basically implements a seqcount. Wrap it with the usual read_begin and read_retry functions, and use these APIs instead of peppering the code with smp_rmb()s. While at it, change it to the more pedantically correct virt_rmb(). With this change, __pvclock_read_cycles can be simplified noticeably. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds2016-08-0667-795/+1397
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS for 4.8. Also includes is a minor SSB cleanup as SSB code traditionally is merged through the MIPS tree: ATH25: - MIPS: Add default configuration for ath25 Boot: - For zboot, copy appended dtb to the end of the kernel - store the appended dtb address in a variable BPF: - Fix off by one error in offset allocation Cobalt code: - Fix typos Core code: - debugfs_create_file returns NULL on error, so don't use IS_ERR for testing for errors. - Fix double locking issue in RM7000 S-cache code. This would only affect RM7000 ARC systems on reboot. - Fix page table corruption on THP permission changes. - Use compat_sys_keyctl for 32 bit userspace on 64 bit kernels. David says, there are no compatibility issues raised by this fix. - Move some signal code around. - Rewrite r4k count/compare clockevent device registration such that min_delta_ticks/max_delta_ticks files are guaranteed to be initialized. - Only register r4k count/compare as clockevent device if we can assume the clock to be constant. - Fix MSA asm warnings in control reg accessors - uasm and tlbex fixes and tweaking. - Print segment physical address when EU=1. - Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO. - CP: Allow booting by VP other than VP 0 - Cache handling fixes and optimizations for r4k class caches - Add hotplug support for R6 processors - Cleanup hotplug bits in kconfig - traps: return correct si code for accessing nonmapped addresses - Remove cpu_has_safe_index_cacheops Lantiq: - Register IRQ handler for virtual IRQ number - Fix EIU interrupt loading code - Use the real EXIN count - Fix build error. Loongson 3: - Increase HPET_MIN_PROG_DELTA and decrease HPET_MIN_CYCLES Octeon: - Delete built-in DTB pruning code for D-Link DSR-1000N. - Clean up GPIO definitions in dlink_dsr-1000n.dts. - Add more LEDs to the DSR-100n DTS - Fix off by one in octeon_irq_gpio_map() - Typo fixes - Enable SATA by default in cavium_octeon_defconfig - Support readq/writeq() - Remove forced mappings of USB interrupts. - Ensure DMA descriptors are always in the low 4GB - Improve USB reset code for OCTEON II. Pistachio: - Add maintainers entry for pistachio SoC Support - Remove plat_setup_iocoherency Ralink: - Fix pwm UART in spis group pinmux. SSB: - Change bare unsigned to unsigned int to suit coding style Tools: - Fix reloc tool compiler warnings. Other: - Delete use of ARCH_WANT_OPTIONAL_GPIOLIB" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (61 commits) MIPS: mm: Fix definition of R6 cache instruction MIPS: tools: Fix relocs tool compiler warnings MIPS: Cobalt: Fix typo MIPS: Octeon: Fix typo MIPS: Lantiq: Fix build failure MIPS: Use CPHYSADDR to implement mips32 __pa MIPS: Octeon: Dlink_dsr-1000n.dts: add more leds. MIPS: Octeon: Clean up GPIO definitions in dlink_dsr-1000n.dts. MIPS: Octeon: Delete built-in DTB pruning code for D-Link DSR-1000N. MIPS: store the appended dtb address in a variable MIPS: ZBOOT: copy appended dtb to the end of the kernel MIPS: ralink: fix spis group pinmux MIPS: Factor o32 specific code into signal_o32.c MIPS: non-exec stack & heap when non-exec PT_GNU_STACK is present MIPS: Use per-mm page to execute branch delay slot instructions MIPS: Modify error handling MIPS: c-r4k: Use SMP calls for CM indexed cache ops MIPS: c-r4k: Avoid small flush_icache_range SMP calls MIPS: c-r4k: Local flush_icache_range cache op override MIPS: c-r4k: Split r4k_flush_kernel_vmap_range() ...
| * \ \ Merge branch '4.7-fixes' into mips-for-linux-nextRalf Baechle2016-08-0322-74/+199
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| | * | | MIPS: Fix MSA asm warnings in control reg accessorsJames Hogan2016-07-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Building an MSA capable kernel with a toolchain that supports MSA produces warnings such as this: CC arch/mips/kernel/cpu-probe.o {standard input}: Assembler messages: {standard input}:4786: Warning: the `msa' extension requires 64-bit FPRs This is due to ".set msa" without ".set fp=64" in the inline assembly of control register accessors, since MSA requires the 64-bit FPU registers (FR=1). Add the missing fp=64 in these functions to silence the warnings. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13554/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | MIPS: Lantiq: Register IRQ handler for virtual IRQ numberHauke Mehrtens2016-07-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We used the hardware IRQ number to register the IRQ handler and not the virtual one. This probably caused some problems because the hardware IRQ numbers are only unique for each IRQ controller and not in the system. The virtual IRQ number is managed by Linux and unique in the system. This was probably the reason there was a gab of 8 IRQ numbers added before the numbers used for the lantiq IRQ controller. With the current setup the hardware and the virtual IRQ numbers are the same. Reported-by: Thomas Langer <thomas.langer@intel.com> Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> Acked-by: John Crispin <john@phrozen.org> Cc: thomas.langer@intel.com Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13539/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | MIPS: Lantiq: Fix eiu interrupt loading codeJohn Crispin2016-07-241-9/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using of_irq_count to load the irq index from the devicetree is incorrect. This will cause the kernel to map them regardless, even if they dont actually get used. Change the code to use of_property_count_u32_elems() instead which is the correct API to use in this case. Signed-off-by: John Crispin <john@phrozen.org> Cc: Linux-MIPS <linux-mips@linux-mips.org> Patchwork: https://patchwork.linux-mips.org/patch/13601/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | MIPS: hpet: Increase HPET_MIN_PROG_DELTA and decrease HPET_MIN_CYCLESHuacai Chen2016-07-241-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At first, we prefer to use mips clockevent device, so we decrease the rating of hpet clockevent device. For hpet, if HPET_MIN_PROG_DELTA (minimum delta of hpet programming) is too small and HPET_MIN_CYCLES (threshold of -ETIME checking) is too large, then hpet_next_event() can easily return -ETIME. After commit c6eb3f70d44828 ("hrtimer: Get rid of hrtimer softirq") this will cause a RCU stall. So, HPET_MIN_PROG_DELTA must be sufficient that we don't re-trip the -ETIME check -- if we do, we will return -ETIME, forward the next event time, try to set it, return -ETIME again, and basically lock the system up. Meanwhile, HPET_MIN_CYCLES doesn't need to be too large, 16 cycles is enough. This solution is similar to commit f9eccf24615672 ("clocksource/drivers /vt8500: Increase the minimum delta"). By the way, this patch ensures hpet count/compare to be 32-bit long. Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: John Crispin <john@phrozen.org> Cc: Steven J . Hill <Steven.Hill@imgtec.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13819/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | MIPS: Don't register r4k sched clock when CPUFREQ enabledHuacai Chen2016-07-241-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't register r4k sched clock when CPUFREQ enabled because sched clock need a constant frequency. Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: John Crispin <john@phrozen.org> Cc: Steven J . Hill <Steven.Hill@caviumnetworks.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13820/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | MIPS: Fix r4k clockevents registrationHuacai Chen2016-07-241-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPUFreq need min_delta_ticks/max_delta_ticks to be initialized, and this can be done by clockevents_config_and_register(). Cc: stable@vger.kernel.org Signed-off-by: Heiher <r@hev.cc> Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: John Crispin <john@phrozen.org> Cc: Steven J . Hill <Steven.Hill@imgtec.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: stable@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13817/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | MIPS: traps: return correct si code for accessing nonmapped addressesPetar Jovanovic2016-07-211-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | find_vma() returns the first VMA which satisfies fault_addr < vm_end, but it does not guarantee fault_addr is actually within VMA. Therefore, kernel has to check that before it chooses correct si code on return. Signed-off-by: Petar Jovanovic <petar.jovanovic@rt-rk.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13808/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | MIPS: Octeon: Off by one in octeon_irq_gpio_map()Dan Carpenter2016-07-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It should be >= ARRAY_SIZE() instead of > ARRAY_SIZE(). Fixes: 64b139f97c01 ('MIPS: OCTEON: irq: add CIB and other fixes') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: David Daney <david.daney@cavium.com> Cc: Rob Herring <robh@kernel.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-mips@linux-mips.org Cc: kernel-janitors@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13813/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | bpf, mips: fix off-by-one in ctx offset allocationDaniel Borkmann2016-07-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dan Carpenter reported [1] a static checker warning that ctx->offsets[] may be accessed off by one from build_body(), since it's allocated with fp->len * sizeof(*ctx.offsets) as length. The cBPF arm and ppc code doesn't have this issue as claimed, so only mips seems to be affected and should like most other JITs allocate with fp->len + 1. A few number of JITs (x86, sparc, arm64) handle this differently, where they only require fp->len array elements. [1] http://www.spinics.net/lists/mips/msg64193.html Fixes: c6610de353da ("MIPS: net: Add BPF JIT") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: ast@kernel.org Cc: linux-mips@linux-mips.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13814/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | MIPS: RM7000: Double locking bug in rm7k_tc_disable()Dan Carpenter2016-07-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We obviously intended to enable IRQs again at the end. Fixes: 745aef5df1e2 ('MIPS: RM7000: Add support for tertiary cache') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: kernel-janitors@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13815/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: mm: Fix definition of R6 cache instructionMatt Redfearn2016-08-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a168b8f1cde6 ("MIPS: mm: Add MIPS R6 instruction encodings") added an incorrect definition of the redefined MIPSr6 cache instruction. Executing any kernel code including this instuction results in a reserved instruction exception and kernel panic. Fix the instruction definition. Fixes: a168b8f1cde6588ff7a67699fa11e01bc77a5ddd Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: <stable@vger.kernel.org> # 4.x- Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13663/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: tools: Fix relocs tool compiler warningsHarvey Hunt2016-08-031-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using clang as HOSTCC, the following warnings appear: In file included from arch/mips/boot/tools/relocs_64.c:27:0: arch/mips/boot/tools/relocs.c: In function ‘read_relocs’: arch/mips/boot/tools/relocs.c:397:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] ELF_R_SYM(rel->r_info) = elf32_to_cpu(ELF_R_SYM(rel->r_info)); ^~~~~~~~~ arch/mips/boot/tools/relocs.c:397:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] arch/mips/boot/tools/relocs.c: In function ‘walk_relocs’: arch/mips/boot/tools/relocs.c:491:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; ^~~~~~~ arch/mips/boot/tools/relocs.c: In function ‘do_reloc’: arch/mips/boot/tools/relocs.c:502:2: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] unsigned r_type = ELF_R_TYPE(rel->r_info); ^~~~~~~~ arch/mips/boot/tools/relocs.c: In function ‘do_reloc_info’: arch/mips/boot/tools/relocs.c:641:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] rel_type(ELF_R_TYPE(rel->r_info)), ^~~~~~~~ Fix them by making Elf64_Mips_Rela a union Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com> Acked-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13683/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: Cobalt: Fix typoAndrea Gelmini2016-08-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13316/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: Octeon: Fix typoAndrea Gelmini2016-08-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13315/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: Lantiq: Fix build failureSudip Mukherjee2016-08-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some configs of mips like xway_defconffig are failing with the error: arch/mips/lantiq/irq.c:209:2: error: initialization from incompatible pointer type [-Werror] "icu", ^ arch/mips/lantiq/irq.c:209:2: error: (near initialization for 'ltq_irq_type.parent_device') [-Werror] arch/mips/lantiq/irq.c:219:2: error: initialization from incompatible pointer type [-Werror] "eiu", ^ arch/mips/lantiq/irq.c:219:2: error: (near initialization for 'ltq_eiu_type.parent_device') [-Werror] The first member of the "struct irq" is no longer a pointer for the name. Fixes: be45beb2df69 ("genirq: Add runtime power management support for IRQ chips") Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Acked-by: John Crispin <john@phrozen.org> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13684/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: Use CPHYSADDR to implement mips32 __paPaul Burton2016-08-021-10/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use CPHYSADDR to implement the __pa macro converting from a virtual to a physical address for MIPS32, much as is already done for MIPS64 (though without the complication of having both compatibility & XKPHYS segments). This allows for __pa to work regardless of whether the address being translated is in kseg0 or kseg1, unlike the previous subtraction based approach which only worked for addresses in kseg0. Working for kseg1 addresses is important if __pa is used on addresses allocated by dma_alloc_coherent, where on systems with non-coherent I/O we provide addresses in kseg1. If this address is then used with dma_map_single_attrs then it is provided to virt_to_page, which in turn calls virt_to_phys which is a wrapper around __pa. The result is that we end up with a physical address 0x20000000 bytes (ie. the size of kseg0) too high. In addition to providing consistency with MIPS64 & fixing the kseg1 case above this has the added bonus of generating smaller code for systems implementing MIPS32r2 & beyond, where a single ext instruction can extract the physical address rather than needing to load an immediate into a temp register & subtract it. This results in ~1.3KB savings for a boston_defconfig kernel adjusted to set CONFIG_32BIT=y. This patch does not change the EVA case, which may or may not have similar issues around handling both cached & uncached addresses but is beyond the scope of this patch. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13836/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: Octeon: Dlink_dsr-1000n.dts: add more leds.Aaro Koskinen2016-08-021-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add more leds discovered by reverse engineering. Labels are according to markings in the mechanics. Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: linux-mips@linux-mips.org Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13466/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: Octeon: Clean up GPIO definitions in dlink_dsr-1000n.dts.Aaro Koskinen2016-08-021-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clean up GPIO definitions in dlink_dsr-1000n.dts. Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: linux-mips@linux-mips.org Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13465/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: Octeon: Delete built-in DTB pruning code for D-Link DSR-1000N.Aaro Koskinen2016-08-023-41/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Users will get more complete functionality by using the appended DTB, so delete the legacy booting support for this board. Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: linux-mips@linux-mips.org Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13464/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: store the appended dtb address in a variableJonas Gorski2016-08-027-15/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of rewriting the arguments to match the UHI spec, store the address of a appended or UHI supplied dtb in fw_supplied_dtb. That way the original bootloader arugments are kept intact while still making the use of an appended dtb invisible for mach code. Mach code can still find out if it is an appended dtb by comparing fw_arg1 with fw_supplied_dtb. Signed-off-by: Jonas Gorski <jogo@openwrt.org> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: John Crispin <john@phrozen.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Alban Bedel <albeu@free.fr> Cc: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us> Cc: Antony Pavlov <antonynpavlov@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13699/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: ZBOOT: copy appended dtb to the end of the kernelJonas Gorski2016-08-023-36/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of rewriting the arguments, just move the appended dtb to where the decompressed kernel expects it. This eliminates the need for special casing vmlinuz.bin appended dtb files. Signed-off-by: Jonas Gorski <jogo@openwrt.org> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: John Crispin <john@phrozen.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Alban Bedel <albeu@free.fr> Cc: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us> Cc: Antony Pavlov <antonynpavlov@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13698/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: ralink: fix spis group pinmuxÁlvaro Fernández Rojas2016-08-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pwm function for spis conflicts with uart2 and uart1, fix this by changing it to pwm_uart2, which reflects the real use of these pins with these pinmux (2 for pwm and 2 for uart). Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> Cc: john@phrozen.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13369/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: Factor o32 specific code into signal_o32.cHarvey Hunt2016-08-024-284/+293
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") caused building a 64 bit kernel with support for n32 and not o32 to produce a build error: arch/mips/kernel/signal32.c:415:11: error: ‘vdso_image_o32’ undeclared here (not in a function) .vdso = &vdso_image_o32, Fix this by moving the o32 specific code into signal_o32.c and updating the Makefile accordingly. Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13690/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: non-exec stack & heap when non-exec PT_GNU_STACK is presentPaul Burton2016-08-023-2/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The stack and heap have both been executable by default on MIPS until now. This patch changes the default to be non-executable, but only for ELF binaries with a non-executable PT_GNU_STACK header present. This does apply to both the heap & the stack, despite the name PT_GNU_STACK, and this matches the behaviour of other architectures like ARM & x86. Current MIPS toolchains do not produce the PT_GNU_STACK header, which means that we can rely upon this patch not changing the behaviour of existing binaries. The new default will only take effect for newly compiled binaries once toolchains are updated to support PT_GNU_STACK, and since those binaries are newly compiled they can be compiled expecting the change in default behaviour. Again this matches the way in which the ARM & x86 architectures handled their implementations of non-executable memory. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: Maciej Rozycki <maciej.rozycki@imgtec.com> Cc: Faraz Shahbazker <faraz.shahbazker@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13765/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | MIPS: Use per-mm page to execute branch delay slot instructionsPaul Burton2016-08-0212-133/+391
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In some cases the kernel needs to execute an instruction from the delay slot of an emulated branch instruction. These cases include: - Emulated floating point branch instructions (bc1[ft]l?) for systems which don't include an FPU, or upon which the kernel is run with the "nofpu" parameter. - MIPSr6 systems running binaries targeting older revisions of the architecture, which may include branch instructions whose encodings are no longer valid in MIPSr6. Executing instructions from such delay slots is done by writing the instruction to memory followed by a trap, as part of an "emuframe", and executing it. This avoids the requirement of an emulator for the entire MIPS instruction set. Prior to this patch such emuframes are written to the user stack and executed from there. This patch moves FP branch delay emuframes off of the user stack and into a per-mm page. Allocating a page per-mm leaves userland with access to only what it had access to previously, and compared to other solutions is relatively simple. When a thread requires a delay slot emulation, it is allocated a frame. A thread may only have one frame allocated at any one time, since it may only ever be executing one instruction at any one time. In order to ensure that we can free up allocated frame later, its index is recorded in struct thread_struct. In the typical case, after executing the delay slot instruction we'll execute a break instruction with the BRK_MEMU code. This traps back to the kernel & leads to a call to do_dsemulret which frees the allocated frame & moves the user PC back to the instruction that would have executed following the emulated branch. In some cases the delay slot instruction may be invalid, such as a branch, or may trigger an exception. In these cases the BRK_MEMU break instruction will not be hit. In order to ensure that frames are freed this patch introduces dsemul_thread_cleanup() and calls it to free any allocated frame upon thread exit. If the instruction generated an exception & leads to a signal being delivered to the thread, or indeed if a signal simply happens to be delivered to the thread whilst it is executing from the struct emuframe, then we need to take care to exit the frame appropriately. This is done by either rolling back the user PC to the branch or advancing it to the continuation PC prior to signal delivery, using dsemul_thread_rollback(). If this were not done then a sigreturn would return to the struct emuframe, and if that frame had meanwhile been used in response to an emulated branch instruction within the signal handler then we would execute the wrong user code. Whilst a user could theoretically place something like a compact branch to self in a delay slot and cause their thread to become stuck in an infinite loop with the frame never being deallocated, this would: - Only affect the users single process. - Be architecturally invalid since there would be a branch in the delay slot, which is forbidden. - Be extremely unlikely to happen by mistake, and provide a program with no more ability to harm the system than a simple infinite loop would. If a thread requires a delay slot emulation & no frame is available to it (ie. the process has enough other threads that all frames are currently in use) then the thread joins a waitqueue. It will sleep until a frame is freed by another thread in the process. Since we now know whether a thread has an allocated frame due to our tracking of its index, the cookie field of struct emuframe is removed as we can be more certain whether we have a valid frame. Since a thread may only ever have a single frame at any given time, the epc field of struct emuframe is also removed & the PC to continue from is instead stored in struct thread_struct. Together these changes simplify & shrink struct emuframe somewhat, allowing twice as many frames to fit into the page allocated for them. The primary benefit of this patch is that we are now free to mark the user stack non-executable where that is possible. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: Maciej Rozycki <maciej.rozycki@imgtec.com> Cc: Faraz Shahbazker <faraz.shahbazker@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13764/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>