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2023-06-09powerpc/signal32: Force inlining of __unsafe_save_user_regs() and ↵Christophe Leroy
save_tm_user_regs_unsafe() Looking at generated code for handle_signal32() shows calls to a function called __unsafe_save_user_regs.constprop.0 while user access is open. And that __unsafe_save_user_regs.constprop.0 function has two nops at the begining, allowing it to be traced, which is unexpected during user access open window. The solution could be to mark __unsafe_save_user_regs() no trace, but to be on the safe side the most efficient is to flag it __always_inline as already done for function __unsafe_restore_general_regs(). The function is relatively small and only called twice, so the size increase will remain in the noise. Do the same with save_tm_user_regs_unsafe() as it may suffer the same issue. Fixes: ef75e7318294 ("powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/7e469c8f01860a69c1ada3ca6a5e2aa65f0f74b2.1685955220.git.christophe.leroy@csgroup.eu
2022-09-28powerpc: Include all arch-specific syscall prototypesRohan McLure
Forward declare all syscall handler prototypes where a generic prototype is not provided in either linux/syscalls.h or linux/compat.h in asm/syscalls.h. This is required for compile-time type-checking for syscall handlers, which is implemented later in this series. 32-bit compatibility syscall handlers are expressed in terms of types in ppc32.h. Expose this header globally. Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Acked-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Use standard include guard naming for syscalls_32.h] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220921065605.1051927-17-rmclure@linux.ibm.com
2022-05-19powerpc/signal: Report minimum signal frame size to userspace via AT_MINSIGSTKSZNicholas Piggin
Implement the AT_MINSIGSTKSZ AUXV entry, allowing userspace to dynamically size stack allocations in a manner forward-compatible with new processor state saved in the signal frame For now these statically find the maximum signal frame size rather than doing any runtime testing of features to minimise the size. glibc 2.34 will take advantage of this, as will applications that use use _SC_MINSIGSTKSZ and _SC_SIGSTKSZ. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> References: 94b07c1f8c39 ("arm64: signal: Report signal frame size to userspace via auxv") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220307182734.289289-2-npiggin@gmail.com
2021-12-02powerpc/signal32: Use struct_group() to zero spe regsKees Cook
In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Add a struct_group() for the spe registers so that memset() can correctly reason about the size: In function 'fortify_memset_chk', inlined from 'restore_user_regs.part.0' at arch/powerpc/kernel/signal_32.c:539:3: >> include/linux/fortify-string.h:195:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 195 | __write_overflow_field(); | ^~~~~~~~~~~~~~~~~~~~~~~~ Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211118203604.1288379-1-keescook@chromium.org
2021-11-19signal: Replace force_fatal_sig with force_exit_sig when in doubtEric W. Biederman
Recently to prevent issues with SECCOMP_RET_KILL and similar signals being changed before they are delivered SA_IMMUTABLE was added. Unfortunately this broke debuggers[1][2] which reasonably expect to be able to trap synchronous SIGTRAP and SIGSEGV even when the target process is not configured to handle those signals. Add force_exit_sig and use it instead of force_fatal_sig where historically the code has directly called do_exit. This has the implementation benefits of going through the signal exit path (including generating core dumps) without the danger of allowing userspace to ignore or change these signals. This avoids userspace regressions as older kernels exited with do_exit which debuggers also can not intercept. In the future is should be possible to improve the quality of implementation of the kernel by changing some of these force_exit_sig calls to force_fatal_sig. That can be done where it matters on a case-by-case basis with careful analysis. Reported-by: Kyle Huey <me@kylehuey.com> Reported-by: kernel test robot <oliver.sang@intel.com> [1] https://lkml.kernel.org/r/CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com [2] https://lkml.kernel.org/r/20211117150258.GB5403@xsang-OptiPlex-9020 Fixes: 00b06da29cf9 ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed") Fixes: a3616a3c0272 ("signal/m68k: Use force_sigsegv(SIGSEGV) in fpsp040_die") Fixes: 83a1f27ad773 ("signal/powerpc: On swapcontext failure force SIGSEGV") Fixes: 9bc508cf0791 ("signal/s390: Use force_sigsegv in default_trap_handler") Fixes: 086ec444f866 ("signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig") Fixes: c317d306d550 ("signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails") Fixes: 695dd0d634df ("signal/x86: In emulate_vsyscall force a signal instead of calling do_exit") Fixes: 1fbd60df8a85 ("signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved.") Fixes: 941edc5bf174 ("exit/syscall_user_dispatch: Send ordinary signals on failure") Link: https://lkml.kernel.org/r/871r3dqfv8.fsf_-_@email.froward.int.ebiederm.org Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Kyle Huey <khuey@kylehuey.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-11-10Merge branch 'exit-cleanups-for-v5.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull exit cleanups from Eric Biederman: "While looking at some issues related to the exit path in the kernel I found several instances where the code is not using the existing abstractions properly. This set of changes introduces force_fatal_sig a way of sending a signal and not allowing it to be caught, and corrects the misuse of the existing abstractions that I found. A lot of the misuse of the existing abstractions are silly things such as doing something after calling a no return function, rolling BUG by hand, doing more work than necessary to terminate a kernel thread, or calling do_exit(SIGKILL) instead of calling force_sig(SIGKILL). In the review a deficiency in force_fatal_sig and force_sig_seccomp where ptrace or sigaction could prevent the delivery of the signal was found. I have added a change that adds SA_IMMUTABLE to change that makes it impossible to interrupt the delivery of those signals, and allows backporting to fix force_sig_seccomp And Arnd found an issue where a function passed to kthread_run had the wrong prototype, and after my cleanup was failing to build." * 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (23 commits) soc: ti: fix wkup_m3_rproc_boot_thread return type signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed signal: Replace force_sigsegv(SIGSEGV) with force_fatal_sig(SIGSEGV) exit/r8188eu: Replace the macro thread_exit with a simple return 0 exit/rtl8712: Replace the macro thread_exit with a simple return 0 exit/rtl8723bs: Replace the macro thread_exit with a simple return 0 signal/x86: In emulate_vsyscall force a signal instead of calling do_exit signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails exit/syscall_user_dispatch: Send ordinary signals on failure signal: Implement force_fatal_sig exit/kthread: Have kernel threads return instead of calling do_exit signal/s390: Use force_sigsegv in default_trap_handler signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved. signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON signal/sparc: In setup_tsb_params convert open coded BUG into BUG signal/powerpc: On swapcontext failure force SIGSEGV signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL) signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT signal/sparc32: Remove unreachable do_exit in do_sparc_fault ...
2021-10-29signal: Replace force_sigsegv(SIGSEGV) with force_fatal_sig(SIGSEGV)Eric W. Biederman
Now that force_fatal_sig exists it is unnecessary and a bit confusing to use force_sigsegv in cases where the simpler force_fatal_sig is wanted. So change every instance we can to make the code clearer. Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Link: https://lkml.kernel.org/r/877de7jrev.fsf@disp2133 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-10-25signal/powerpc: On swapcontext failure force SIGSEGVEric W. Biederman
If the register state may be partial and corrupted instead of calling do_exit, call force_sigsegv(SIGSEGV). Which properly kills the process with SIGSEGV and does not let any more userspace code execute, instead of just killing one thread of the process and potentially confusing everything. Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linuxppc-dev@lists.ozlabs.org History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Fixes: 756f1ae8a44e ("PPC32: Rework signal code and add a swapcontext system call.") Fixes: 04879b04bf50 ("[PATCH] ppc64: VMX (Altivec) support & signal32 rework, from Ben Herrenschmidt") Link: https://lkml.kernel.org/r/20211020174406.17889-7-ebiederm@xmission.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2021-10-18gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable}Andreas Gruenbacher
Turn fault_in_pages_{readable,writeable} into versions that return the number of bytes not faulted in, similar to copy_to_user, instead of returning a non-zero value when any of the requested pages couldn't be faulted in. This supports the existing users that require all pages to be faulted in as well as new users that are happy if any pages can be faulted in. Rename the functions to fault_in_{readable,writeable} to make sure this change doesn't silently break things. Neither of these functions is entirely trivial and it doesn't seem useful to inline them, so move them to mm/gup.c. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2021-06-25powerpc/64s: avoid reloading (H)SRR registers if they are still validNicholas Piggin
When an interrupt is taken, the SRR registers are set to return to where it left off. Unless they are modified in the meantime, or the return address or MSR are modified, there is no need to reload these registers when returning from interrupt. Introduce per-CPU flags that track the validity of SRR and HSRR registers. These are cleared when returning from interrupt, when using the registers for something else (e.g., OPAL calls), when adjusting the return address or MSR of a context, and when context switching (which changes the return address and MSR). This improves the performance of interrupt returns. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fold in fixup patch from Nick] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com
2021-06-17powerpc/signal32: Remove impossible #ifdef combinationsChristophe Leroy
PPC_TRANSACTIONAL_MEM is only on book3s/64 SPE is only on booke PPC_TRANSACTIONAL_MEM selects ALTIVEC and VSX Therefore, within PPC_TRANSACTIONAL_MEM sections, ALTIVEC and VSX are always defined while SPE never is. Remove all SPE code and all #ifdef ALTIVEC and VSX in tm functions. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a069a348ee3c2fe3123a5a93695c2b35dc42cb40.1623340691.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/signal: Use PPC_RAW_xx() macrosChristophe Leroy
To improve readability, use PPC_RAW_xx() macros instead of open coding. Those macros are self-explanatory so the comments can go as well. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4ca2bfdca2f47a293d05f61eb3c4e487ee170f1f.1621506159.git.christophe.leroy@csgroup.eu
2021-04-30Merge tag 'powerpc-5.13-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Enable KFENCE for 32-bit. - Implement EBPF for 32-bit. - Convert 32-bit to do interrupt entry/exit in C. - Convert 64-bit BookE to do interrupt entry/exit in C. - Changes to our signal handling code to use user_access_begin/end() more extensively. - Add support for time namespaces (CONFIG_TIME_NS) - A series of fixes that allow us to reenable STRICT_KERNEL_RWX. - Other smaller features, fixes & cleanups. Thanks to Alexey Kardashevskiy, Andreas Schwab, Andrew Donnellan, Aneesh Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Bixuan Cui, Cédric Le Goater, Chen Huang, Chris Packham, Christophe Leroy, Christopher M. Riedl, Colin Ian King, Dan Carpenter, Daniel Axtens, Daniel Henrique Barboza, David Gibson, Davidlohr Bueso, Denis Efremov, dingsenjie, Dmitry Safonov, Dominic DeMarco, Fabiano Rosas, Ganesh Goudar, Geert Uytterhoeven, Geetika Moolchandani, Greg Kurz, Guenter Roeck, Haren Myneni, He Ying, Jiapeng Chong, Jordan Niethe, Laurent Dufour, Lee Jones, Leonardo Bras, Li Huafei, Madhavan Srinivasan, Mahesh Salgaonkar, Masahiro Yamada, Nathan Chancellor, Nathan Lynch, Nicholas Piggin, Oliver O'Halloran, Paul Menzel, Pu Lehui, Randy Dunlap, Ravi Bangoria, Rosen Penev, Russell Currey, Santosh Sivaraj, Sebastian Andrzej Siewior, Segher Boessenkool, Shivaprasad G Bhat, Srikar Dronamraju, Stephen Rothwell, Thadeu Lima de Souza Cascardo, Thomas Gleixner, Tony Ambardar, Tyrel Datwyler, Vaibhav Jain, Vincenzo Frascino, Xiongwei Song, Yang Li, Yu Kuai, and Zhang Yunkai. * tag 'powerpc-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (302 commits) powerpc/signal32: Fix erroneous SIGSEGV on RT signal return powerpc: Avoid clang uninitialized warning in __get_user_size_allowed powerpc/papr_scm: Mark nvdimm as unarmed if needed during probe powerpc/kvm: Fix build error when PPC_MEM_KEYS/PPC_PSERIES=n powerpc/kasan: Fix shadow start address with modules powerpc/kernel/iommu: Use largepool as a last resort when !largealloc powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs powerpc/44x: fix spelling mistake in Kconfig "varients" -> "variants" powerpc/iommu: Annotate nested lock for lockdep powerpc/iommu: Do not immediately panic when failed IOMMU table allocation powerpc/iommu: Allocate it_map by vmalloc selftests/powerpc: remove unneeded semicolon powerpc/64s: remove unneeded semicolon powerpc/eeh: remove unneeded semicolon powerpc/selftests: Add selftest to test concurrent perf/ptrace events powerpc/selftests/perf-hwbreak: Add testcases for 2nd DAWR powerpc/selftests/perf-hwbreak: Coalesce event creation code powerpc/selftests/ptrace-hwbreak: Add testcases for 2nd DAWR powerpc/configs: Add IBMVNIC to some 64-bit configs selftests/powerpc: Add uaccess flush test ...
2021-04-28powerpc/signal32: Fix erroneous SIGSEGV on RT signal returnChristophe Leroy
Return of user_read_access_begin() is tested the wrong way, leading to a SIGSEGV when the user address is valid and likely an Oops when the user address is bad. Fix the test. Fixes: 887f3ceb51cd ("powerpc/signal32: Convert do_setcontext[_tm]() to user access block") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a29aadc54c93bcbf069a83615fa102ca0f59c3ae.1619185912.git.christophe.leroy@csgroup.eu
2021-04-14powerpc: remove partial register save logicNicholas Piggin
All subarchitectures always save all GPRs to pt_regs interrupt frames now. Remove FULL_REGS and associated bits. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210316104206.407354-11-npiggin@gmail.com
2021-04-12powerpc/signal32: Fix build failure with CONFIG_SPEChristophe Leroy
Add missing fault exit label in unsafe_copy_from_user() in order to avoid following build failure with CONFIG_SPE CC arch/powerpc/kernel/signal_32.o arch/powerpc/kernel/signal_32.c: In function 'restore_user_regs': arch/powerpc/kernel/signal_32.c:565:36: error: macro "unsafe_copy_from_user" requires 4 arguments, but only 3 given 565 | ELF_NEVRREG * sizeof(u32)); | ^ In file included from ./include/linux/uaccess.h:11, from ./include/linux/sched/task.h:11, from ./include/linux/sched/signal.h:9, from ./include/linux/rcuwait.h:6, from ./include/linux/percpu-rwsem.h:7, from ./include/linux/fs.h:33, from ./include/linux/huge_mm.h:8, from ./include/linux/mm.h:707, from arch/powerpc/kernel/signal_32.c:17: ./arch/powerpc/include/asm/uaccess.h:428: note: macro "unsafe_copy_from_user" defined here 428 | #define unsafe_copy_from_user(d, s, l, e) \ | arch/powerpc/kernel/signal_32.c:564:3: error: 'unsafe_copy_from_user' undeclared (first use in this function); did you mean 'raw_copy_from_user'? 564 | unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs, | ^~~~~~~~~~~~~~~~~~~~~ | raw_copy_from_user arch/powerpc/kernel/signal_32.c:564:3: note: each undeclared identifier is reported only once for each function it appears in make[3]: *** [arch/powerpc/kernel/signal_32.o] Error 1 Fixes: 627b72bee84d ("powerpc/signal32: Convert restore_[tm]_user_regs() to user access block") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/aad2cb1801a3cc99bc27081022925b9fc18a0dfb.1618159169.git.christophe.leroy@csgroup.eu
2021-04-03powerpc/signal32: Simplify logging in sigreturn()Christophe Leroy
Same spirit as commit debf122c777f ("powerpc/signal32: Simplify logging in handle_rt_signal32()"), remove this intermediate 'addr' local var. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/638fa99530beb29f82f94370057d110e91272acc.1616151715.git.christophe.leroy@csgroup.eu
2021-04-03powerpc/signal32: Convert do_setcontext[_tm]() to user access blockChristophe Leroy
Add unsafe_get_user_sigset() and transform PPC32 get_sigset_t() into an unsafe version unsafe_get_sigset_t(). Then convert do_setcontext() and do_setcontext_tm() to use user_read_access_begin/end. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9273ba664db769b8d9c7540ae91395e346e4945e.1616151715.git.christophe.leroy@csgroup.eu
2021-04-03powerpc/signal32: Convert restore_[tm]_user_regs() to user access blockChristophe Leroy
Convert restore_user_regs() and restore_tm_user_regs() to use user_access_read_begin/end blocks. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/181adf15a6f644efcd1aeafb355f3578ff1b6bc5.1616151715.git.christophe.leroy@csgroup.eu
2021-04-03powerpc/signal32: Reorder user reads in restore_tm_user_regs()Christophe Leroy
In restore_tm_user_regs(), regroup the reads from 'sr' and the ones from 'tm_sr' together in order to allow two block user accesses in following patch. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7c518b9a4c8e5ae9a3bfb647bc8b20bf820233af.1616151715.git.christophe.leroy@csgroup.eu
2021-04-03powerpc/signal32: Perform access_ok() inside restore_user_regs()Christophe Leroy
In preparation of using user_access_begin/end in restore_user_regs(), move the access_ok() inside the function. It makes no difference as the behaviour on a failed access_ok() is the same as on failed restore_user_regs(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c106eb2f37c3040f1fd38b40e50c670feb7cb835.1616151715.git.christophe.leroy@csgroup.eu
2021-04-03powerpc/signal32: Remove ifdefery in middle of if/else in sigreturn()Christophe Leroy
In the same spirit as commit f1cf4f93de2f ("powerpc/signal32: Remove ifdefery in middle of if/else") MSR_TM_ACTIVE() is always defined and returns always 0 when CONFIG_PPC_TRANSACTIONAL_MEM is not selected, so the awful ifdefery in the middle of an if/else can be removed. Make 'msr_hi' a 'long long' to avoid build failure on PPC32 due to the 32 bits left shift. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a4b48b2f0be1ef13fc8e57452b7f8350da28d521.1616151715.git.christophe.leroy@csgroup.eu
2021-04-03powerpc/signal32: Rename save_user_regs_unsafe() and save_general_regs_unsafe()Christophe Leroy
Convention is to prefix functions with __unsafe_ instead of suffixing it with _unsafe. Rename save_user_regs_unsafe() and save_general_regs_unsafe() accordingly, that is respectively __unsafe_save_general_regs() and __unsafe_save_user_regs(). Suggested-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8cef43607e5b35a7fd0829dec812d88beb570df2.1616151715.git.christophe.leroy@csgroup.eu
2021-04-02powerpc/signal32: Fix Oops on sigreturn with unmapped VDSOChristophe Leroy
PPC32 encounters a KUAP fault when trying to handle a signal with VDSO unmapped. Kernel attempted to read user page (7fc07ec0) - exploit attempt? (uid: 0) BUG: Unable to handle kernel data access on read at 0x7fc07ec0 Faulting instruction address: 0xc00111d4 Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=16K PREEMPT CMPC885 CPU: 0 PID: 353 Comm: sigreturn_vdso Not tainted 5.12.0-rc4-s3k-dev-01553-gb30c310ea220 #4814 NIP: c00111d4 LR: c0005a28 CTR: 00000000 REGS: cadb3dd0 TRAP: 0300 Not tainted (5.12.0-rc4-s3k-dev-01553-gb30c310ea220) MSR: 00009032 <EE,ME,IR,DR,RI> CR: 48000884 XER: 20000000 DAR: 7fc07ec0 DSISR: 88000000 GPR00: c0007788 cadb3e90 c28d4a40 7fc07ec0 7fc07ed0 000004e0 7fc07ce0 00000000 GPR08: 00000001 00000001 7fc07ec0 00000000 28000282 1001b828 100a0920 00000000 GPR16: 100cac0c 100b0000 105c43a4 105c5685 100d0000 100d0000 100d0000 100b2e9e GPR24: ffffffff 105c43c8 00000000 7fc07ec8 cadb3f40 cadb3ec8 c28d4a40 00000000 NIP [c00111d4] flush_icache_range+0x90/0xb4 LR [c0005a28] handle_signal32+0x1bc/0x1c4 Call Trace: [cadb3e90] [100d0000] 0x100d0000 (unreliable) [cadb3ec0] [c0007788] do_notify_resume+0x260/0x314 [cadb3f20] [c000c764] syscall_exit_prepare+0x120/0x184 [cadb3f30] [c00100b4] ret_from_syscall+0xc/0x28 --- interrupt: c00 at 0xfe807f8 NIP: 0fe807f8 LR: 10001060 CTR: c0139378 REGS: cadb3f40 TRAP: 0c00 Not tainted (5.12.0-rc4-s3k-dev-01553-gb30c310ea220) MSR: 0000d032 <EE,PR,ME,IR,DR,RI> CR: 28000482 XER: 20000000 GPR00: 00000025 7fc081c0 77bb1690 00000000 0000000a 28000482 00000001 0ff03a38 GPR08: 0000d032 00006de5 c28d4a40 00000009 88000482 1001b828 100a0920 00000000 GPR16: 100cac0c 100b0000 105c43a4 105c5685 100d0000 100d0000 100d0000 100b2e9e GPR24: ffffffff 105c43c8 00000000 77ba7628 10002398 10010000 10002124 00024000 NIP [0fe807f8] 0xfe807f8 LR [10001060] 0x10001060 --- interrupt: c00 Instruction dump: 38630010 7c001fac 38630010 4200fff0 7c0004ac 4c00012c 4e800020 7c001fac 2c0a0000 38630010 4082ffcc 4bffffe4 <7c00186c> 2c070000 39430010 4082ff8c ---[ end trace 3973fb72b049cb06 ]--- This is because flush_icache_range() is called on user addresses. The same problem was detected some time ago on PPC64. It was fixed by enabling KUAP in commit 59bee45b9712 ("powerpc/mm: Fix missing KUAP disable in flush_coherent_icache()"). PPC32 doesn't use flush_coherent_icache() and fallbacks on clean_dcache_range() and invalidate_icache_range(). We could fix it similarly by enabling user access in those functions, but this is overkill for just flushing two instructions. The two instructions are 8 bytes aligned, so a single dcbst/icbi is enough to flush them. Do like __patch_instruction() and inline a dcbst followed by an icbi just after the write of the instructions, while user access is still allowed. The isync is not required because rfi will be used to return to user. icbi() is handled as a read so read-write user access is needed. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bde9154e5351a5ac7bca3d59cdb5a5e8edacbb79.1617199569.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/signal: Use __get_user() to copy sigset_tChristopher M. Riedl
Usually sigset_t is exactly 8B which is a "trivial" size and does not warrant using __copy_from_user(). Use __get_user() directly in anticipation of future work to remove the trivial size optimizations from __copy_from_user(). The ppc32 implementation of get_sigset_t() previously called copy_from_user() which, unlike __copy_from_user(), calls access_ok(). Replacing this w/ __get_user() (no access_ok()) is fine here since both callsites in signal_32.c are preceded by an earlier access_ok(). Signed-off-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210227011259.11992-11-cmr@codefail.de
2021-02-11powerpc: use kernel endianness in MSR in 32-bit signal handlerJoseph J Allen
This mirrors the behavior in handle_rt_signal32, to obey kernel endianness rather than assume a 32-bit process is big-endian. Without this change, any 32-bit little-endian process will SIGILL immediately upon handling a signal. Signed-off-by: Joseph J Allen <eerykitty@gmail.com> Signed-off-by: Will Springer <skirmisher@protonmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2058876.irdbgypaU6@sheen
2020-12-04powerpc/vdso: Retrieve sigtramp offsets at buildtimeChristophe Leroy
This is copied from arm64. Instead of using runtime generated signal trampoline offsets, get offsets at buildtime. If the said trampoline doesn't exist, build will fail. So no need to check whether the trampoline exists or not in the VDSO. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f8bfd6812c3e3678b1cdb4d55a52f9eb022b40d3.1601197618.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/vdso: Replace vdso_base by vdsoChristophe Leroy
All other architectures but s390 use a void pointer named 'vdso' to reference the VDSO mapping. In a following patch, the VDSO data page will be put in front of text, vdso_base will then not anymore point to VDSO text. To avoid confusion between vdso_base and VDSO text, rename vdso_base into vdso and make it a void __user *. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8e6cefe474aa4ceba028abb729485cd46c140990.1601197618.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in ↵Christophe Leroy
'unsafe' version Change those two functions to be used within a user access block. For that, change save_general_regs() to and unsafe_save_general_regs(), then replace all user accesses by unsafe_ versions. This series leads to a reduction from 2.55s to 1.73s of the system CPU time with the following microbench app on an mpc832x with KUAP (approx 32%) Without KUAP, the difference is in the noise. void sigusr1(int sig) { } int main(int argc, char **argv) { int i = 100000; signal(SIGUSR1, sigusr1); for (;i--;) raise(SIGUSR1); exit(0); } An additional 0.10s reduction is achieved by removing CONFIG_PPC_FPU, as the mpc832x has no FPU. A bit less spectacular on an 8xx as KUAP is less heavy, prior to the series (with KUAP) it ran in 8.10 ms. Once applies the removal of FPU regs handling, we get 7.05s. With the full series, we get 6.9s. If artificially re-activating FPU regs handling with the full series, we get 7.6s. So for the 8xx, the removal of the FPU regs copy is what makes the difference, but the rework of handle_signal also have a benefit. Same as above, without KUAP the difference is in the noise. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Fixup typo in SPE handling] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c7b37b385ccf9666066452e58f018a86573f83e8.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Isolate non-copy actions in save_user_regs() and ↵Christophe Leroy
save_tm_user_regs() Reorder actions in save_user_regs() and save_tm_user_regs() to regroup copies together in order to switch to user_access_begin() logic in a later patch. Move non-copy actions into new functions called prepare_save_user_regs() and prepare_save_tm_user_regs(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f6eac65781b4a57220477c8864bca2b57f29a5d5.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Switch swap_context() to user_access_begin() logicChristophe Leroy
As this was the last user of put_sigset_t(), remove it as well. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c3ac4f2d134a3391bb51bdaa2d00e9a409aba9f8.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Add and use unsafe_put_sigset_t()Christophe Leroy
put_sigset_t() calls copy_to_user() for copying two words. This is terribly inefficient for copying two words. By switching to unsafe_put_user(), we end up with something as simple as: 3cc: 81 3d 00 00 lwz r9,0(r29) 3d0: 91 26 00 b4 stw r9,180(r6) 3d4: 81 3d 00 04 lwz r9,4(r29) 3d8: 91 26 00 b8 stw r9,184(r6) Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/06def97e87ac1c4ae8e3197e0982e1fab7b3c8ae.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Remove ifdefery in middle of if/elseChristophe Leroy
MSR_TM_ACTIVE() is always defined and returns always 0 when CONFIG_PPC_TRANSACTIONAL_MEM is not selected, so the awful ifdefery in the middle of an if/else can be removed. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f3c36d687e4228f58d5c207a4036aa9ddcc7420a.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Switch handle_rt_signal32() to user_access_begin() logicChristophe Leroy
On the same way as handle_signal32(), replace all user accesses with equivalent unsafe_ versions, and move the trampoline code icache flush outside the user access block. Functions that have no unsafe_ equivalent also remains outside the access block. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2974314226256f958e2984912b48883ef1754185.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Switch handle_signal32() to user_access_begin() logicChristophe Leroy
Replace the access_ok() by user_access_begin() and change all user accesses to unsafe_ version. Move flush_icache_range() outside the user access block. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a27797f781aa00da96f8284c898173d18e952361.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Move signal trampoline setup to handle_[rt_]signal32Christophe Leroy
Move signal trampoline setup into handle_signal32() and handle_rt_signal32(). At the same time, remove the define which hides the mc_pad field used for trampoline. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e439cc0fa35aa45da6776520777a61848b92fd4b.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Misc changes to make handle_[rt_]_signal32() more similarChristophe Leroy
Miscellaneous changes to clean and make handle_signal32() and handle_rt_signal32() even more similar. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/df0bc8c3b8fa96390c46f611df79b2a94ac21844.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Rename local pointers in handle_rt_signal32()Christophe Leroy
Rename pointers in handle_rt_signal32() to make it more similar to handle_signal32() tm_frame becomes tm_mctx frame becomes mctx rt_sf becomes frame Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/be77477b0f05397876015b218e36548ee8f5e10b.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Move handle_signal32() close to handle_rt_signal32()Christophe Leroy
Those two functions are similar and serving the same purpose. To ease refactorisation, move them close to each other. This is pure move, no code change, no cosmetic. Yes, checkpatch is not happy, most will clear 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/dbce67900bf566bcf40179467bf1eb500814c405.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal32: Simplify logging in handle_rt_signal32()Christophe Leroy
If something is bad in the frame, there is no point in knowing which part of the frame exactly is wrong as it got allocated as a single block. Always print the root address of the frame in case of failed user access, just like handle_signal32(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/691895bd31fee89a2d8370befd66ad4eff5b63f2.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal: Refactor bad frame loggingChristophe Leroy
The logging of bad frame appears half a dozen of times and is pretty similar. Create signal_fault() fonction to perform that logging. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/fa094445c119fc00315e1c13783b493346306c6a.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal: Call get_tm_stackpointer() from get_sigframe()Christophe Leroy
Instead of calling get_tm_stackpointer() from the caller, call it directly from get_sigframe(). This avoids a double call and allows get_tm_stackpointer() to become static and be inlined into get_sigframe() by GCC. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/abfdc105b8b28c4eb3ab9a26297d17f302b600ea.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal: Move access_ok() out of get_sigframe()Christophe Leroy
This access_ok() will soon be performed by user_access_begin(). So move it out of get_sigframe(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/900b93744732ed0887f28f5b6a40730fb04a43fa.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal: Remove BUG_ON() in handler_signal functionsChristophe Leroy
There is already the same BUG_ON() check in do_signal() which is the only caller of handle_rt_signal64() handle_rt_signal32() and handle_signal32(). Remove those three redundant BUG_ON(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3582e10a341d523c9c3f1ac925c3aaefc9d9293d.1597770847.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/signal: Don't manage floating point regs when no FPUChristophe Leroy
There is no point in copying floating point regs when there is no FPU and MATH_EMULATION is not selected. Create a new CONFIG_PPC_FPU_REGS bool that is selected by CONFIG_MATH_EMULATION and CONFIG_PPC_FPU, and use it to opt out everything related to fp_state in thread_struct. The asm const used only by fpu.S are opted out with CONFIG_PPC_FPU as fpu.S build is conditionnal to CONFIG_PPC_FPU. The following app spends approx 8.1 seconds system time on an 8xx without the patch, and 7.0 seconds with the patch (13.5% reduction). On an 832x, it spends approx 2.6 seconds system time without the patch and 2.1 seconds with the patch (19% reduction). void sigusr1(int sig) { } int main(int argc, char **argv) { int i = 100000; signal(SIGUSR1, sigusr1); for (;i--;) raise(SIGUSR1); exit(0); } Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7569070083e6cd5b279bb5023da601aba3c06f3c.1597770847.git.christophe.leroy@csgroup.eu
2020-07-15powerpc/signal_32: Simplify loop in PPC64 save_general_regs()Christophe Leroy
save_general_regs() which does special handling when i == PT_SOFTE. Rewrite it to minimise the specific part, especially the __put_user() and associated error handling is the same so make it common. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Use a regular if rather than ternary operator] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/47a38df46cae5a5a88a558a64d71f75e9c4d9950.1594125164.git.christophe.leroy@csgroup.eu
2020-07-15powerpc/signal_32: Remove !FULL_REGS() special handling in PPC64 ↵Christophe Leroy
save_general_regs() Since commit ("1bd79336a426 powerpc: Fix various syscall/signal/swapcontext bugs"), getting save_general_regs() called without FULL_REGS() is very unlikely and generates a warning. The 32-bit version of save_general_regs() doesn't take care of it at all and copies all registers anyway since that commit. Moreover, commit 965dd3ad3076 ("powerpc/64/syscall: Remove non-volatile GPR save optimisation") is another reason why it would never happen. So the same with 64-bit, don't worry about FULL_REGS() and copy all registers all the time. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/173de3b659fa3a5f126a0eb170522cccd909950f.1594125164.git.christophe.leroy@csgroup.eu
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedMike Rapoport
Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done 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: Mike Rapoport <rppt@kernel.org> 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/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-15powerpc: Use trap metadata to prevent double restart rather than zeroing trapNicholas Piggin
It's not very nice to zero trap for this, because then system calls no longer have trap_is_syscall(regs) invariant, and we can't distinguish between sc and scv system calls (in a later patch). Take one last unused bit from the low bits of the pt_regs.trap word for this instead. There is not a really good reason why it should be in trap as opposed to another field, but trap has some concept of flags and it exists. Ideally I think we would move trap to 2-byte field and have 2 more bytes available independently. Add a selftests case for this, which can be seen to fail if trap_norestart() is changed to return false. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Make them static inlines] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200507121332.2233629-4-mpe@ellerman.id.au
2020-04-03powerpc: move common register copy functions from signal_32.c to signal.cMichal Suchanek
These functions are required for 64bit as well. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9fd6d9b7c5e91fab21159fe23534a2f16b4962d3.1584699455.git.msuchanek@suse.de