Hi--
On 7/5/23 11:59, Charlie Jenkins wrote:
Add documentation explaining the behavior of mmap. Include a simple test that ensures that mmap returns an address less than the hint address while there are still addresses available.
Signed-off-by: Charlie Jenkins charlie@rivosinc.com
Documentation/riscv/vm-layout.rst | 22 +++++++++ arch/riscv/include/asm/pgtable.h | 8 +-- tools/testing/selftests/riscv/Makefile | 2 +- tools/testing/selftests/riscv/mm/.gitignore | 1 + tools/testing/selftests/riscv/mm/Makefile | 21 ++++++++ .../selftests/riscv/mm/testcases/mmap.c | 49 +++++++++++++++++++ 6 files changed, 99 insertions(+), 4 deletions(-) create mode 100644 tools/testing/selftests/riscv/mm/.gitignore create mode 100644 tools/testing/selftests/riscv/mm/Makefile create mode 100644 tools/testing/selftests/riscv/mm/testcases/mmap.c
diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst index 5462c84f4723..a610c68c9f3f 100644 --- a/Documentation/riscv/vm-layout.rst +++ b/Documentation/riscv/vm-layout.rst @@ -133,3 +133,25 @@ 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 39-bits, the kernel will, by default, return virtual
39 bits,
+return virtual addresses to userspace from a 48-bit range (sv48). This
^^ duplicate "return virtual"
+default behavior is achieved by passing 0 into the hint address parameter +of mmap.
diff --git a/tools/testing/selftests/riscv/mm/.gitignore b/tools/testing/selftests/riscv/mm/.gitignore new file mode 100644 index 000000000000..022ea0a3f7df --- /dev/null +++ b/tools/testing/selftests/riscv/mm/.gitignore @@ -0,0 +1 @@ +mmap \ No newline at end of file
add a newline, please.
diff --git a/tools/testing/selftests/riscv/mm/Makefile b/tools/testing/selftests/riscv/mm/Makefile new file mode 100644 index 000000000000..d41a0b3d2ca2 --- /dev/null +++ b/tools/testing/selftests/riscv/mm/Makefile @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0 +# Originally tools/testing/selftests/arm64/signal
+# Additional include paths needed by kselftest.h and local headers +CFLAGS += -D_GNU_SOURCE -std=gnu99 -I.
+SRCS := $(filter-out testcases/testcases.c,$(wildcard testcases/*.c)) +PROGS := $(patsubst %.c,%,$(SRCS))
+# Generated binaries to be installed by top KSFT script +TEST_GEN_PROGS := $(notdir $(PROGS))
+# Get Kernel headers installed and use them.
+# Including KSFT lib.mk here will also mangle the TEST_GEN_PROGS list +# to account for any OUTPUT target-dirs optionally provided by +# the toplevel makefile +include ../../lib.mk
+$(TEST_GEN_PROGS): $(PROGS)
- cp $(PROGS) $(OUTPUT)/
\ No newline at end of file
add a newline, please.