Using ".arm .inst" for the arm signature introduces build issues for
programs compiled in Thumb mode because the assembler stays in the
arm mode for the rest of the inline assembly. Revert to using a ".word"
to express the signature as data instead.
The choice of signature is a valid trap instruction on arm32 little
endian, where both code and data are little endian.
ARMv6+ big endian (BE8) generates mixed endianness code vs data:
little-endian code and big-endian data. The data value of the signature
needs to have its byte order reversed to generate the trap instruction.
Prior to ARMv6, -mbig-endian generates big-endian code and data
(which match), so the endianness of the data representation of the
signature should not be reversed. However, the choice between BE32
and BE8 is done by the linker, so we cannot know whether code and
data endianness will be mixed before the linker is invoked. So rather
than try to play tricks with the linker, the rseq signature is simply
data (not a trap instruction) prior to ARMv6 on big endian. This is
why the signature is expressed as data (.word) rather than as
instruction (.inst) in assembler.
Because a ".word" is used to emit the signature, it will be interpreted
as a literal pool by a disassembler, not as an actual instruction.
Considering that the signature is not meant to be executed except in
scenarios where the program execution is completely bogus, this should
not be an issue.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Will Deacon <will.deacon@arm.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Andi Kleen <andi@firstfloor.org>
CC: linux-kselftest@vger.kernel.org
CC: "H . Peter Anvin" <hpa@zytor.com>
CC: Chris Lameter <cl@linux.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
CC: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
CC: Paul Turner <pjt@google.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ben Maurer <bmaurer@fb.com>
CC: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Carlos O'Donell <carlos@redhat.com>
CC: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Pull more kselftest updates from Shuah Khan:
- kselftest framework bpf build/test workflow regression fix
- Fix to kselftest install to use default install path
- Fix to kselftest KBUILD_OUTPUT builds to not clutter main
KBUILD_OUTPUT directory with selftest objects
- .gitignore fixes (Kelsey Skunberg)
- rseq selftests updates (Mathieu Desnoyers and Martin Schwidefsky)
They change the per-architecture pre-abort signatures to ensure those
are valid trap instructions.
The way exit points are presented to debuggers is enhanced, ensuring
all exit points are present, so debuggers don't have to disassemble
rseq critical section to properly skip over them.
Discussions with the glibc community is reaching a consensus of
exposing a __rseq_handled symbol from glibc to coexist with rseq
early adopters. Update the rseq selftest code to expose and use this
symbol.
Support for compiling asm goto with clang is added with the
"-no-integrated-as" compiler switch, similarly to the top level
kernel Makefile.
- kselftest Makefile test run output refactoring and making test output
TAP13 compliant from Kees Cook:
This re-factors the selftest Makefiles to extract the test running
logic to be reused between "run_tests" and "emit_tests", while also
fixing up the test output to be TAP version 13 compliant:
- added "plan" line
- fixed result line syntax
- moved all test output to be "# "-prefixed as TAP "diagnostic"
lines
The prefixing code includes a fallback mode for limited execution
environments.
Additionally, the plan lines are fixed for all callers of
kselftest.h.
* tag 'linux-kselftest-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (25 commits)
selftests: avoid KBUILD_OUTPUT dir cluttering with selftest objects
selftests: drivers: Create .gitignore to include /dma-buf/udmabuf
selftests: pidfd: Create .gitignore to include pidfd_test
selftests: fix bpf build/test workflow regression when KBUILD_OUTPUT is set
selftests: fix install target to use default install path
rseq/selftests: add -no-integrated-as for clang
rseq/selftests: mips: use break instruction for RSEQ_SIG
rseq/selftests: powerpc code signature: generate valid instructions
rseq/selftests: aarch64 code signature: handle big-endian environment
rseq/selftests: arm: use udf instruction for RSEQ_SIG
rseq/selftests: s390: use trap4 for RSEQ_SIG
rseq/selftests: x86: use ud1 instruction as RSEQ_SIG opcode
rseq/selftests: s390: use jg instruction for jumps outside of the asm
rseq/selftests: Use __rseq_handled symbol to coexist with glibc
rseq/selftests: Introduce __rseq_cs_ptr_array, rename __rseq_table to __rseq_cs
rseq/selftests: Add __rseq_exit_point_array section for debuggers
rseq/selftests: x86: Work-around bogus gcc-8 optimisation
selftests: Add test plan API to kselftest.h and adjust callers
selftests: Remove KSFT_TAP_LEVEL
selftests: Move test output to diagnostic lines
...
Pull Kselftest updates from Shuah Khan:
- fixes to seccomp test, and kselftest framework
- cleanups to remove duplicate header defines
- fixes to efivarfs "make clean" target
- cgroup cleanup path
- Moving the IMA kexec_load selftest to selftests/kexec work from Mimi
Johar and Petr Vorel
- A framework to kselftest for writing kernel test modules addition
from Tobin C. Harding
* tag 'linux-kselftest-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits)
selftests: build and run gpio when output directory is the src dir
selftests/ipc: Fix msgque compiler warnings
selftests/efivarfs: clean up test files from test_create*()
selftests: fix headers_install circular dependency
selftests/kexec: update get_secureboot_mode
selftests/kexec: make kexec_load test independent of IMA being enabled
selftests/kexec: check kexec_load and kexec_file_load are enabled
selftests/kexec: Add missing '=y' to config options
selftests/kexec: kexec_file_load syscall test
selftests/kexec: define "require_root_privileges"
selftests/kexec: define common logging functions
selftests/kexec: define a set of common functions
selftests/kexec: cleanup the kexec selftest
selftests/kexec: move the IMA kexec_load selftest to selftests/kexec
selftests/harness: Add 30 second timeout per test
selftests/seccomp: Handle namespace failures gracefully
selftests: cgroup: fix cleanup path in test_memcg_subtree_control()
selftests: efivarfs: remove the test_create_read file if it was exist
rseq/selftests: Adapt number of threads to the number of detected cpus
lib: Add test module for strscpy_pad
...
Pull arm64 updates from Will Deacon:
"A bunch of good stuff in here. Worth noting is that we've pulled in
the x86/mm branch from -tip so that we can make use of the core
ioremap changes which allow us to put down huge mappings in the
vmalloc area without screwing up the TLB. Much of the positive
diffstat is because of the rseq selftest for arm64.
Summary:
- Wire up support for qspinlock, replacing our trusty ticket lock
code
- Add an IPI to flush_icache_range() to ensure that stale
instructions fetched into the pipeline are discarded along with the
I-cache lines
- Support for the GCC "stackleak" plugin
- Support for restartable sequences, plus an arm64 port for the
selftest
- Kexec/kdump support on systems booting with ACPI
- Rewrite of our syscall entry code in C, which allows us to zero the
GPRs on entry from userspace
- Support for chained PMU counters, allowing 64-bit event counters to
be constructed on current CPUs
- Ensure scheduler topology information is kept up-to-date with CPU
hotplug events
- Re-enable support for huge vmalloc/IO mappings now that the core
code has the correct hooks to use break-before-make sequences
- Miscellaneous, non-critical fixes and cleanups"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (90 commits)
arm64: alternative: Use true and false for boolean values
arm64: kexec: Add comment to explain use of __flush_icache_range()
arm64: sdei: Mark sdei stack helper functions as static
arm64, kaslr: export offset in VMCOREINFO ELF notes
arm64: perf: Add cap_user_time aarch64
efi/libstub: Only disable stackleak plugin for arm64
arm64: drop unused kernel_neon_begin_partial() macro
arm64: kexec: machine_kexec should call __flush_icache_range
arm64: svc: Ensure hardirq tracing is updated before return
arm64: mm: Export __sync_icache_dcache() for xen-privcmd
drivers/perf: arm-ccn: Use devm_ioremap_resource() to map memory
arm64: Add support for STACKLEAK gcc plugin
arm64: Add stack information to on_accessible_stack
drivers/perf: hisi: update the sccl_id/ccl_id when MT is supported
arm64: fix ACPI dependencies
rseq/selftests: Add support for arm64
arm64: acpi: fix alignment fault in accessing ACPI
efi/arm: map UEFI memory map even w/o runtime services enabled
efi/arm: preserve early mapping of UEFI memory map longer for BGRT
drivers: acpi: add dependency of EFI for arm64
...
Pull s390 updates from Heiko Carstens:
"Since Martin is on vacation you get the s390 pull request from me:
- Host large page support for KVM guests. As the patches have large
impact on arch/s390/mm/ this series goes out via both the KVM and
the s390 tree.
- Add an option for no compression to the "Kernel compression mode"
menu, this will come in handy with the rework of the early boot
code.
- A large rework of the early boot code that will make life easier
for KASAN and KASLR. With the rework the bootable uncompressed
image is not generated anymore, only the bzImage is available. For
debuggung purposes the new "no compression" option is used.
- Re-enable the gcc plugins as the issue with the latent entropy
plugin is solved with the early boot code rework.
- More spectre relates changes:
+ Detect the etoken facility and remove expolines automatically.
+ Add expolines to a few more indirect branches.
- A rewrite of the common I/O layer trace points to make them
consumable by 'perf stat'.
- Add support for format-3 PCI function measurement blocks.
- Changes for the zcrypt driver:
+ Add attributes to indicate the load of cards and queues.
+ Restructure some code for the upcoming AP device support in KVM.
- Build flags improvements in various Makefiles.
- A few fixes for the kdump support.
- A couple of patches for gcc 8 compile warning cleanup.
- Cleanup s390 specific proc handlers.
- Add s390 support to the restartable sequence self tests.
- Some PTR_RET vs PTR_ERR_OR_ZERO cleanup.
- Lots of bug fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (107 commits)
s390/dasd: fix hanging offline processing due to canceled worker
s390/dasd: fix panic for failed online processing
s390/mm: fix addressing exception after suspend/resume
rseq/selftests: add s390 support
s390: fix br_r1_trampoline for machines without exrl
s390/lib: use expoline for all bcr instructions
s390/numa: move initial setup of node_to_cpumask_map
s390/kdump: Fix elfcorehdr size calculation
s390/cpum_sf: save TOD clock base in SDBs for time conversion
KVM: s390: Add huge page enablement control
s390/mm: Add huge page gmap linking support
s390/mm: hugetlb pages within a gmap can not be freed
KVM: s390: Add skey emulation fault handling
s390/mm: Add huge pmd storage key handling
s390/mm: Clear skeys for newly mapped huge guest pmds
s390/mm: Clear huge page storage keys on enable_skey
s390/mm: Add huge page dirty sync support
s390/mm: Add gmap pmd invalidation and clearing
s390/mm: Add gmap pmd notification bit setting
s390/mm: Add gmap pmd linking
...
Implement support for s390 in the rseq selftests, in order to sanity
check the recently enabled rseq syscall. The Implementation covers both
64-bit and 31-bit mode.
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull rseq fixes from Thomas Gleixer:
"A pile of rseq related fixups:
- Prevent infinite recursion when delivering SIGSEGV
- Remove the abort of rseq critical section on fork() as syscalls
inside rseq critical sections are explicitely forbidden. So no
point in doing the abort on the child.
- Align the rseq structure on 32 bytes in the ARM selftest code.
- Fix file permissions of the test script"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq: Avoid infinite recursion when delivering SIGSEGV
rseq/cleanup: Do not abort rseq c.s. in child on fork()
rseq/selftests/arm: Align 'struct rseq_cs' on 32 bytes
rseq/selftests: Make run_param_test.sh executable
