wireguard-linux/arch/powerpc/kernel/asm-offsets.c, branch jd/unified-crypt-queue

powerpc/32s: Fix DSI and ISI exceptions for CONFIG_VMAP_STACK

2020-02-18T10:31:11Z

hash_page() needs to read page tables from kernel memory. When entire kernel memory is mapped by BATs, which is normally the case when CONFIG_STRICT_KERNEL_RWX is not set, it works even if the page hosting the page table is not referenced in the MMU hash table. However, if the page where the page table resides is not covered by a BAT, a DSI fault can be encountered from hash_page(), and it loops forever. This can happen when CONFIG_STRICT_KERNEL_RWX is selected and the alignment of the different regions is too small to allow covering the entire memory with BATs. This also happens when CONFIG_DEBUG_PAGEALLOC is selected or when booting with 'nobats' flag. Also, if the page containing the kernel stack is not present in the MMU hash table, registers cannot be saved and a recursive DSI fault is encountered. To allow hash_page() to properly do its job at all time and load the MMU hash table whenever needed, it must run with data MMU disabled. This means it must be called before re-enabling data MMU. To allow this, registers clobbered by hash_page() and create_hpte() have to be saved in the thread struct together with SRR0, SSR1, DAR and DSISR. It is also necessary to ensure that DSI prolog doesn't overwrite regs saved by prolog of the current running exception. That means: - DSI can only use SPRN_SPRG_SCRATCH0 - Exceptions must free SPRN_SPRG_SCRATCH0 before writing to the stack. This also fixes the Oops reported by Erhard when create_hpte() is called by add_hash_page(). Due to prolog size increase, a few more exceptions had to get split in two parts. Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK") Reported-by: Erhard F. Signed-off-by: Christophe Leroy Tested-by: Erhard F. Tested-by: Larry Finger Signed-off-by: Michael Ellerman Link: https://bugzilla.kernel.org/show_bug.cgi?id=206501 Link: https://lore.kernel.org/r/64a4aa44686e9fd4b01333401367029771d9b231.1581761633.git.christophe.leroy@c-s.fr

powerpc/32: prepare for CONFIG_VMAP_STACK

2020-01-26T11:15:09Z

To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr

powerpc/vdso32: implement clock_getres entirely

2020-01-23T10:31:15Z

clock_getres returns hrtimer_res for all clocks but coarse ones for which it returns KTIME_LOW_RES. return EINVAL for unknown clocks. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/37f94e47c91070b7606fb3ec3fe6fd2302a475a0.1575273217.git.christophe.leroy@c-s.fr

powerpc/vdso32: Don't read cache line size from the datapage on PPC32.

2020-01-23T10:31:15Z

On PPC32, the cache lines have a fixed size known at build time. Don't read it from the datapage. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/dfa7b35e27e01964fcda84bf1ed8b2b31cf93826.1575273217.git.christophe.leroy@c-s.fr

powerpc: Fix vDSO clock_getres()

2019-12-04T13:13:55Z

clock_getres in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time. Fix the powerpc vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly. Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel") Cc: stable@vger.kernel.org Signed-off-by: Vincenzo Frascino Reviewed-by: Christophe Leroy Acked-by: Shuah Khan [chleroy: changed CLOCK_REALTIME_RES to CLOCK_HRTIMER_RES] Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/a55eca3a5e85233838c2349783bcb5164dae1d09.1575273217.git.christophe.leroy@c-s.fr

y2038: vdso: powerpc: avoid timespec references

2019-11-15T13:38:28Z

As a preparation to stop using 'struct timespec' in the kernel, change the powerpc vdso implementation: - split up the vdso data definition to have equivalent members for seconds and nanoseconds instead of an xtime structure - use timespec64 as an intermediate for the xtime update - change the asm-offsets definition to be based the appropriate fixed-length types This is only a temporary fix for changing the types, in order to actually support a 64-bit safe vdso32 version of clock_gettime(), the entire powerpc vdso should be replaced with the generic lib/vdso/ implementation. If that happens first, this patch becomes obsolete. Signed-off-by: Arnd Bergmann

y2038: vdso: change timeval to __kernel_old_timeval

2019-11-15T13:38:27Z

The gettimeofday() function in vdso uses the traditional 'timeval' structure layout, which will be incompatible with future versions of glibc on 32-bit architectures that use a 64-bit time_t. This interface is problematic for y2038, when time_t overflows on 32-bit architectures, but the plan so far is that a libc with 64-bit time_t will not call into the gettimeofday() vdso helper at all, and only have a method for entering clock_gettime(). This means we don't have to fix it here, though we probably want to add a new clock_gettime() entry point using a 64-bit version of 'struct timespec' at some point. Changing the vdso code to use __kernel_old_timeval helps isolate this usage from the other ones that still need to be fixed properly, and it gets us closer to removing the 'timeval' definition from the kernel sources. Reviewed-by: Thomas Gleixner Signed-off-by: Arnd Bergmann

powerpc/kvm: Use UV_RETURN ucall to return to ultravisor

2019-08-29T23:40:16Z

When an SVM makes an hypercall or incurs some other exception, the Ultravisor usually forwards (a.k.a. reflects) the exceptions to the Hypervisor. After processing the exception, Hypervisor uses the UV_RETURN ultracall to return control back to the SVM. The expected register state on entry to this ultracall is: * Non-volatile registers are restored to their original values. * If returning from an hypercall, register R0 contains the return value (unlike other ultracalls) and, registers R4 through R12 contain any output values of the hypercall. * R3 contains the ultracall number, i.e UV_RETURN. * If returning with a synthesized interrupt, R2 contains the synthesized interrupt number. Thanks to input from Paul Mackerras, Ram Pai and Mike Anderson. Signed-off-by: Sukadev Bhattiprolu Signed-off-by: Claudio Carvalho Acked-by: Paul Mackerras Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190822034838.27876-8-cclaudio@linux.ibm.com

Merge tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2019-07-13T23:08:36Z

Pull powerpc updates from Michael Ellerman: "Notable changes: - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver, as well as some other functions only used by drivers that haven't (yet?) made it upstream. - A fix for a bug in our handling of hardware watchpoints (eg. perf record -e mem: ...) which could lead to register corruption and kernel crashes. - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for vmalloc when using the Radix MMU. - A large but incremental rewrite of our exception handling code to use gas macros rather than multiple levels of nested CPP macros. And the usual small fixes, cleanups and improvements. Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz, Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj Jitindar Singh, Thiago Jung Bauermann, YueHaibing" * tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits) powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state. powerpc/eeh: Handle hugepages in ioremap space ocxl: Update for AFU descriptor template version 1.1 powerpc/boot: pass CONFIG options in a simpler and more robust way powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h powerpc/irq: Don't WARN continuously in arch_local_irq_restore() powerpc/module64: Use symbolic instructions names. powerpc/module32: Use symbolic instructions names. powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h powerpc/module64: Fix comment in R_PPC64_ENTRY handling powerpc/boot: Add lzo support for uImage powerpc/boot: Add lzma support for uImage powerpc/boot: don't force gzipped uImage powerpc/8xx: Add microcode patch to move SMC parameter RAM. powerpc/8xx: Use IO accessors in microcode programming. powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c powerpc/8xx: refactor programming of microcode CPM params. powerpc/8xx: refactor printing of microcode patch name. powerpc/8xx: Refactor microcode write powerpc/8xx: refactor writing of CPM microcode arrays ...

powerpc/64s/exception: remove bad stack branch

2019-07-02T11:39:49Z

The bad stack test in interrupt handlers has a few problems. For performance it is taken in the common case, which is a fetch bubble and a waste of i-cache. For code development and maintainence, it requires yet another stack frame setup routine, and that constrains all exception handlers to follow the same register save pattern which inhibits future optimisation. Remove the test/branch and replace it with a trap. Teach the program check handler to use the emergency stack for this case. This does not result in quite so nice a message, however the SRR0 and SRR1 of the crashed interrupt can be seen in r11 and r12, as is the original r1 (adjusted by INT_FRAME_SIZE). These are the most important parts to debugging the issue. The original r9-12 and cr0 is lost, which is the main downside. kernel BUG at linux/arch/powerpc/kernel/exceptions-64s.S:847! Oops: Exception in kernel mode, sig: 5 [#1] BE SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted NIP: c000000000009108 LR: c000000000cadbcc CTR: c0000000000090f0 REGS: c0000000fffcbd70 TRAP: 0700 Not tainted MSR: 9000000000021032 CR: 28222448 XER: 20040000 CFAR: c000000000009100 IRQMASK: 0 GPR00: 000000000000003d fffffffffffffd00 c0000000018cfb00 c0000000f02b3166 GPR04: fffffffffffffffd 0000000000000007 fffffffffffffffb 0000000000000030 GPR08: 0000000000000037 0000000028222448 0000000000000000 c000000000ca8de0 GPR12: 9000000002009032 c000000001ae0000 c000000000010a00 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: c0000000f00322c0 c000000000f85200 0000000000000004 ffffffffffffffff GPR24: fffffffffffffffe 0000000000000000 0000000000000000 000000000000000a GPR28: 0000000000000000 0000000000000000 c0000000f02b391c c0000000f02b3167 NIP [c000000000009108] decrementer_common+0x18/0x160 LR [c000000000cadbcc] .vsnprintf+0x3ec/0x4f0 Call Trace: Instruction dump: 996d098a 994d098b 38610070 480246ed 48005518 60000000 38200000 718a4000 7c2a0b78 3821fd00 41c20008 e82d0970 <0981fd00> f92101a0 f9610170 f9810178 Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman