kernel/arch/powerpc/include/uapi/asm, branch linux-4.1.y

KVM: PPC: Book3S HV: Save/restore XER in checkpointed register state

2017-01-13T01:56:54Z

[ Upstream commit 0d808df06a44200f52262b6eb72bcb6042f5a7c5 ] When switching from/to a guest that has a transaction in progress, we need to save/restore the checkpointed register state. Although XER is part of the CPU state that gets checkpointed, the code that does this saving and restoring doesn't save/restore XER. This fixes it by saving and restoring the XER. To allow userspace to read/write the checkpointed XER value, we also add a new ONE_REG specifier. The visible effect of this bug is that the guest may see its XER value being corrupted when it uses transactions. Fixes: e4e38121507a ("KVM: PPC: Book3S HV: Add transactional memory support") Fixes: 0a8eccefcb34 ("KVM: PPC: Book3S HV: Add missing code for transaction reclaim on guest exit") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Paul Mackerras Reviewed-by: Thomas Huth Signed-off-by: Paul Mackerras Signed-off-by: Sasha Levin

powerpc: scan_features() updates incorrect bits for REAL_LE

2016-05-08T12:09:03Z

[ Upstream commit 6997e57d693b07289694239e52a10d2f02c3a46f ] The REAL_LE feature entry in the ibm_pa_feature struct is missing an MMU feature value, meaning all the remaining elements initialise the wrong values. This means instead of checking for byte 5, bit 0, we check for byte 0, bit 0, and then we incorrectly set the CPU feature bit as well as MMU feature bit 1 and CPU user feature bits 0 and 2 (5). Checking byte 0 bit 0 (IBM numbering), means we're looking at the "Memory Management Unit (MMU)" feature - ie. does the CPU have an MMU. In practice that bit is set on all platforms which have the property. This means we set CPU_FTR_REAL_LE always. In practice that seems not to matter because all the modern cpus which have this property also implement REAL_LE, and we've never needed to disable it. We're also incorrectly setting MMU feature bit 1, which is: #define MMU_FTR_TYPE_8xx 0x00000002 Luckily the only place that looks for MMU_FTR_TYPE_8xx is in Book3E code, which can't run on the same cpus as scan_features(). So this also doesn't matter in practice. Finally in the CPU user feature mask, we're setting bits 0 and 2. Bit 2 is not currently used, and bit 0 is: #define PPC_FEATURE_PPC_LE 0x00000001 Which says the CPU supports the old style "PPC Little Endian" mode. Again this should be harmless in practice as no 64-bit CPUs implement that mode. Fix the code by adding the missing initialisation of the MMU feature. Also add a comment marking CPU user feature bit 2 (0x4) as reserved. It would be unsafe to start using it as old kernels incorrectly set it. Fixes: 44ae3ab3358e ("powerpc: Free up some CPU feature bits by moving out MMU-related features") Signed-off-by: Anton Blanchard Cc: stable@vger.kernel.org [mpe: Flesh out changelog, add comment reserving 0x4] Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/module: Handle R_PPC64_ENTRY relocations

2016-01-31T19:23:39Z

commit a61674bdfc7c2bf909c4010699607b62b69b7bec upstream. GCC 6 will include changes to generated code with -mcmodel=large, which is used to build kernel modules on powerpc64le. This was necessary because the large model is supposed to allow arbitrary sizes and locations of the code and data sections, but the ELFv2 global entry point prolog still made the unconditional assumption that the TOC associated with any particular function can be found within 2 GB of the function entry point: func: addis r2,r12,(.TOC.-func)@ha addi r2,r2,(.TOC.-func)@l .localentry func, .-func To remove this assumption, GCC will now generate instead this global entry point prolog sequence when using -mcmodel=large: .quad .TOC.-func func: .reloc ., R_PPC64_ENTRY ld r2, -8(r12) add r2, r2, r12 .localentry func, .-func The new .reloc triggers an optimization in the linker that will replace this new prolog with the original code (see above) if the linker determines that the distance between .TOC. and func is in range after all. Since this new relocation is now present in module object files, the kernel module loader is required to handle them too. This patch adds support for the new relocation and implements the same optimization done by the GNU linker. Signed-off-by: Ulrich Weigand Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

Revert "powerpc/tm: Abort syscalls in active transactions"

2015-04-30T05:24:58Z

This reverts commit feba40362b11341bee6d8ed58d54b896abbd9f84. Although the principle of this change is good, the implementation has a few issues. Firstly we can sometimes fail to abort a syscall because r12 may have been clobbered by C code if we went down the virtual CPU accounting path, or if syscall tracing was enabled. Secondly we have decided that it is safer to abort the syscall even earlier in the syscall entry path, so that we avoid the syscall tracing path when we are transactional. So that we have time to thoroughly test those changes we have decided to revert this for this merge window and will merge the fixed version in the next window. NB. Rather than reverting the selftest we just drop tm-syscall from TEST_PROGS so that it's not run by default. Fixes: feba40362b11 ("powerpc/tm: Abort syscalls in active transactions") Signed-off-by: Michael Ellerman

Merge branch 'akpm' (patches from Andrew)

2015-04-17T13:04:38Z

Merge third patchbomb from Andrew Morton: - various misc things - a couple of lib/ optimisations - provide DIV_ROUND_CLOSEST_ULL() - checkpatch updates - rtc tree - befs, nilfs2, hfs, hfsplus, fatfs, adfs, affs, bfs - ptrace fixes - fork() fixes - seccomp cleanups - more mmap_sem hold time reductions from Davidlohr * emailed patches from Andrew Morton : (138 commits) proc: show locks in /proc/pid/fdinfo/X docs: add missing and new /proc/PID/status file entries, fix typos drivers/rtc/rtc-at91rm9200.c: make IO endian agnostic Documentation/spi/spidev_test.c: fix warning drivers/rtc/rtc-s5m.c: allow usage on device type different than main MFD type .gitignore: ignore *.tar MAINTAINERS: add Mediatek SoC mailing list tomoyo: reduce mmap_sem hold for mm->exe_file powerpc/oprofile: reduce mmap_sem hold for exe_file oprofile: reduce mmap_sem hold for mm->exe_file mips: ip32: add platform data hooks to use DS1685 driver lib/Kconfig: fix up HAVE_ARCH_BITREVERSE help text x86: switch to using asm-generic for seccomp.h sparc: switch to using asm-generic for seccomp.h powerpc: switch to using asm-generic for seccomp.h parisc: switch to using asm-generic for seccomp.h mips: switch to using asm-generic for seccomp.h microblaze: use asm-generic for seccomp.h arm: use asm-generic for seccomp.h seccomp: allow COMPAT sigreturn overrides ...

powerpc: switch to using asm-generic for seccomp.h

2015-04-17T13:04:10Z

Switch to using the newly created asm-generic/seccomp.h for the seccomp strict mode syscall definitions. The obsolete sigreturn in COMPAT mode is retained as an override. Remaining definitions are identical, though they incorrectly appeared in uapi, which has been corrected. Signed-off-by: Kees Cook Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

powerpc/tm: Abort syscalls in active transactions

2015-04-11T10:49:19Z

This patch changes the syscall handler to doom (tabort) active transactions when a syscall is made and return immediately without performing the syscall. Currently, the system call instruction automatically suspends an active transaction which causes side effects to persist when an active transaction fails. This does change the kernel's behaviour, but in a way that was documented as unsupported. It doesn't reduce functionality because syscalls will still be performed after tsuspend. It also provides a consistent interface and makes the behaviour of user code substantially the same across powerpc and platforms that do not support suspended transactions (e.g. x86 and s390). Performance measurements using http://ozlabs.org/~anton/junkcode/null_syscall.c indicate the cost of a system call increases by about 0.5%. Signed-off-by: Sam Bobroff Acked-By: Michael Neuling Signed-off-by: Michael Ellerman

powerpc: Add a proper syscall for switching endianness

2015-03-28T11:03:40Z

We currently have a "special" syscall for switching endianness. This is syscall number 0x1ebe, which is handled explicitly in the 64-bit syscall exception entry. That has a few problems, firstly the syscall number is outside of the usual range, which confuses various tools. For example strace doesn't recognise the syscall at all. Secondly it's handled explicitly as a special case in the syscall exception entry, which is complicated enough without it. As a first step toward removing the special syscall, we need to add a regular syscall that implements the same functionality. The logic is simple, it simply toggles the MSR_LE bit in the userspace MSR. This is the same as the special syscall, with the caveat that the special syscall clobbers fewer registers. This version clobbers r9-r12, XER, CTR, and CR0-1,5-7. Signed-off-by: Michael Ellerman

powerpc: Change vrX register defines to vX to match gcc and glibc

2015-03-16T07:32:11Z

As our various loops (copy, string, crypto etc) get more complicated, we want to share implementations between userspace (eg glibc) and the kernel. We also want to write userspace test harnesses to put in tools/testing/selftest. One gratuitous difference between userspace and the kernel is the VMX register definitions - the kernel uses vrX whereas both gcc and glibc use vX. Change the kernel to match userspace. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman

powerpc: Wire up sys_execveat() syscall

2014-12-29T04:44:53Z

Wire up sys_execveat(). This passes the selftests for the system call. Check success of execveat(3, '../execveat', 0)... [OK] Check success of execveat(5, 'execveat', 0)... [OK] Check success of execveat(6, 'execveat', 0)... [OK] Check success of execveat(-100, '/home/pranith/linux/...ftests/exec/execveat', 0)... [OK] Check success of execveat(99, '/home/pranith/linux/...ftests/exec/execveat', 0)... [OK] Check success of execveat(8, '', 4096)... [OK] Check success of execveat(17, '', 4096)... [OK] Check success of execveat(9, '', 4096)... [OK] Check success of execveat(14, '', 4096)... [OK] Check success of execveat(14, '', 4096)... [OK] Check success of execveat(15, '', 4096)... [OK] Check failure of execveat(8, '', 0) with ENOENT... [OK] Check failure of execveat(8, '(null)', 4096) with EFAULT... [OK] Check success of execveat(5, 'execveat.symlink', 0)... [OK] Check success of execveat(6, 'execveat.symlink', 0)... [OK] Check success of execveat(-100, '/home/pranith/linux/...xec/execveat.symlink', 0)... [OK] Check success of execveat(10, '', 4096)... [OK] Check success of execveat(10, '', 4352)... [OK] Check failure of execveat(5, 'execveat.symlink', 256) with ELOOP... [OK] Check failure of execveat(6, 'execveat.symlink', 256) with ELOOP... [OK] Check failure of execveat(-100, '/home/pranith/linux/tools/testing/selftests/exec/execveat.symlink', 256) with ELOOP... [OK] Check success of execveat(3, '../script', 0)... [OK] Check success of execveat(5, 'script', 0)... [OK] Check success of execveat(6, 'script', 0)... [OK] Check success of execveat(-100, '/home/pranith/linux/...elftests/exec/script', 0)... [OK] Check success of execveat(13, '', 4096)... [OK] Check success of execveat(13, '', 4352)... [OK] Check failure of execveat(18, '', 4096) with ENOENT... [OK] Check failure of execveat(7, 'script', 0) with ENOENT... [OK] Check success of execveat(16, '', 4096)... [OK] Check success of execveat(16, '', 4096)... [OK] Check success of execveat(4, '../script', 0)... [OK] Check success of execveat(4, 'script', 0)... [OK] Check success of execveat(4, '../script', 0)... [OK] Check failure of execveat(4, 'script', 0) with ENOENT... [OK] Check failure of execveat(5, 'execveat', 65535) with EINVAL... [OK] Check failure of execveat(5, 'no-such-file', 0) with ENOENT... [OK] Check failure of execveat(6, 'no-such-file', 0) with ENOENT... [OK] Check failure of execveat(-100, 'no-such-file', 0) with ENOENT... [OK] Check failure of execveat(5, '', 4096) with EACCES... [OK] Check failure of execveat(5, 'Makefile', 0) with EACCES... [OK] Check failure of execveat(11, '', 4096) with EACCES... [OK] Check failure of execveat(12, '', 4096) with EACCES... [OK] Check failure of execveat(99, '', 4096) with EBADF... [OK] Check failure of execveat(99, 'execveat', 0) with EBADF... [OK] Check failure of execveat(8, 'execveat', 0) with ENOTDIR... [OK] Invoke copy of 'execveat' via filename of length 4093: Check success of execveat(19, '', 4096)... [OK] Check success of execveat(5, 'xxxxxxxxxxxxxxxxxxxx...yyyyyyyyyyyyyyyyyyyy', 0)... [OK] Invoke copy of 'script' via filename of length 4093: Check success of execveat(20, '', 4096)... [OK] /bin/sh: 0: Can't open /dev/fd/5/xxxxxxx(... a long line of x's and y's, 0)... [OK] Check success of execveat(5, 'xxxxxxxxxxxxxxxxxxxx...yyyyyyyyyyyyyyyyyyyy', 0)... [OK] Tested on a 32-bit powerpc system. Signed-off-by: Pranith Kumar Signed-off-by: Michael Ellerman