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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-10-09 09:27:22 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-10-09 09:27:22 -0700 |
commit | e60329c97b9cc07ce15e3c39fc42e57bf14add92 (patch) | |
tree | 292d55061b827e277433c67f6871d1bcd1ff75d2 /Documentation | |
parent | e3280b54afed870d531571212f1fc375df39b7d2 (diff) | |
parent | 3e7c93bd04edfb0cae7dad1215544c9350254b8f (diff) |
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
"A larger-than-usual batch of arm64 fixes for -rc3.
The bulk of the fixes are dealing with a bunch of issues with the
build system from the compat vDSO, which unfortunately led to some
significant Makefile rework to manage the horrible combinations of
toolchains that we can end up needing to drive simultaneously.
We came close to disabling the thing entirely, but Vincenzo was quick
to spin up some patches and I ended up picking up most of the bits
that were left [*]. Future work will look at disentangling the header
files properly.
Other than that, we have some important fixes all over, including one
papering over the miscompilation fallout from forcing
CONFIG_OPTIMIZE_INLINING=y, which I'm still unhappy about. Harumph.
We've still got a couple of open issues, so I'm expecting to have some
more fixes later this cycle.
Summary:
- Numerous fixes to the compat vDSO build system, especially when
combining gcc and clang
- Fix parsing of PAR_EL1 in spurious kernel fault detection
- Partial workaround for Neoverse-N1 erratum #1542419
- Fix IRQ priority masking on entry from compat syscalls
- Fix advertisment of FRINT HWCAP to userspace
- Attempt to workaround inlining breakage with '__always_inline'
- Fix accidental freeing of parent SVE state on fork() error path
- Add some missing NULL pointer checks in instruction emulation init
- Some formatting and comment fixes"
[*] Will's final fixes were
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
but they were already in linux-next by then and he didn't rebase
just to add those.
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (21 commits)
arm64: armv8_deprecated: Checking return value for memory allocation
arm64: Kconfig: Make CONFIG_COMPAT_VDSO a proper Kconfig option
arm64: vdso32: Rename COMPATCC to CC_COMPAT
arm64: vdso32: Pass '--target' option to clang via VDSO_CAFLAGS
arm64: vdso32: Don't use KBUILD_CPPFLAGS unconditionally
arm64: vdso32: Move definition of COMPATCC into vdso32/Makefile
arm64: Default to building compat vDSO with clang when CONFIG_CC_IS_CLANG
lib: vdso: Remove CROSS_COMPILE_COMPAT_VDSO
arm64: vdso32: Remove jump label config option in Makefile
arm64: vdso32: Detect binutils support for dmb ishld
arm64: vdso: Remove stale files from old assembly implementation
arm64: vdso32: Fix broken compat vDSO build warnings
arm64: mm: fix spurious fault detection
arm64: ftrace: Ensure synchronisation in PLT setup for Neoverse-N1 #1542419
arm64: Fix incorrect irqflag restore for priority masking for compat
arm64: mm: avoid virt_to_phys(init_mm.pgd)
arm64: cpufeature: Effectively expose FRINT capability to userspace
arm64: Mark functions using explicit register variables as '__always_inline'
docs: arm64: Fix indentation and doc formatting
arm64/sve: Fix wrong free for task->thread.sve_state
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/arm64/memory.rst | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/Documentation/arm64/memory.rst b/Documentation/arm64/memory.rst index b040909e45f8..02e02175e6f5 100644 --- a/Documentation/arm64/memory.rst +++ b/Documentation/arm64/memory.rst @@ -154,11 +154,18 @@ return virtual addresses to userspace from a 48-bit range. Software can "opt-in" to receiving VAs from a 52-bit space by specifying an mmap hint parameter that is larger than 48-bit. + For example: - maybe_high_address = mmap(~0UL, size, prot, flags,...); + +.. code-block:: c + + maybe_high_address = mmap(~0UL, size, prot, flags,...); It is also possible to build a debug kernel that returns addresses from a 52-bit space by enabling the following kernel config options: + +.. code-block:: sh + CONFIG_EXPERT=y && CONFIG_ARM64_FORCE_52BIT=y Note that this option is only intended for debugging applications |