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authorLinus Torvalds <torvalds@linux-foundation.org>2024-09-06 13:00:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2024-09-06 13:00:59 -0700
commit890daedec4f483bcb5cea0a4ce290830d12d78b2 (patch)
tree80844966b7e77f92cb559864aecacc0a4f3f8fde /Documentation
parenta78d7dce1e71231cef671ccf5ab48b31606fe352 (diff)
parent1ff95eb2bebda50c4c5406caaf201e0fcb24cc8f (diff)
Merge tag 'riscv-for-linus-6.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt: - A revert for the mmap() change that ties the allocation range to the hint adress, as what we tried to do ended up regressing on other userspace workloads. - A fix to avoid a kernel memory leak when emulating misaligned accesses from userspace. - A Kconfig fix for toolchain vector detection, which now correctly detects vector support on toolchains where the V extension depends on the M extension. - A fix to avoid failing the linear mapping bootmem bounds check on NOMMU systems. - A fix for early alternatives on relocatable kernels. * tag 'riscv-for-linus-6.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Fix RISCV_ALTERNATIVE_EARLY riscv: Do not restrict memory size because of linear mapping on nommu riscv: Fix toolchain vector detection riscv: misaligned: Restrict user access to kernel memory riscv: mm: Do not restrict mmap address based on hint riscv: selftests: Remove mmap hint address checks Revert "RISC-V: mm: Document mmap changes"
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/arch/riscv/vm-layout.rst16
1 files changed, 0 insertions, 16 deletions
diff --git a/Documentation/arch/riscv/vm-layout.rst b/Documentation/arch/riscv/vm-layout.rst
index 077b968dcc81..eabec99b5852 100644
--- a/Documentation/arch/riscv/vm-layout.rst
+++ b/Documentation/arch/riscv/vm-layout.rst
@@ -134,19 +134,3 @@ RISC-V Linux Kernel SV57
ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF
ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel
__________________|____________|__________________|_________|____________________________________________________________
-
-
-Userspace VAs
---------------------
-To maintain compatibility with software that relies on the VA space with a
-maximum of 48 bits the kernel will, by default, return virtual addresses to
-userspace from a 48-bit range (sv48). This default behavior is achieved by
-passing 0 into the hint address parameter of mmap. On CPUs with an address space
-smaller than sv48, the CPU maximum supported address space will be the default.
-
-Software can "opt-in" to receiving VAs from another VA space by providing
-a hint address to mmap. When a hint address is passed to mmap, the returned
-address will never use more bits than the hint address. For example, if a hint
-address of `1 << 40` is passed to mmap, a valid returned address will never use
-bits 41 through 63. If no mappable addresses are available in that range, mmap
-will return `MAP_FAILED`.