[ Upstream commit 5d9cea8a552ee122e21fbd5a3c5d4eb85f648e06 ]
On 8xx, PAGE_NONE is handled by setting _PAGE_NA instead of clearing
_PAGE_USER.
But then pte_user() returns 1 also for PAGE_NONE.
As _PAGE_NA prevent reads, add a specific version of pte_read()
that returns 0 when _PAGE_NA is set instead of always returning 1.
Fixes: 351750331fc1 ("powerpc/mm: Introduce _PAGE_NA")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/57bcfbe578e43123f9ed73e040229b80f1ad56ec.1695659959.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f454b18e07f518bcd0c05af17a2239138bff52de upstream.
Fix erratum #1485 on Zen4 parts where running with STIBP disabled can
cause an #UD exception. The performance impact of the fix is negligible.
Reported-by: René Rebe <rene@exactcode.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: René Rebe <rene@exactcode.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/D99589F4-BC5D-430B-87B2-72C20370CF57@exactcode.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2f1b0d3d733169eb11680bfa97c266ae5e757148 ]
The RISC-V architecture does not expose sub-registers, and hold all
32-bit values in a sign-extended format [1] [2]:
| The compiler and calling convention maintain an invariant that all
| 32-bit values are held in a sign-extended format in 64-bit
| registers. Even 32-bit unsigned integers extend bit 31 into bits
| 63 through 32. Consequently, conversion between unsigned and
| signed 32-bit integers is a no-op, as is conversion from a signed
| 32-bit integer to a signed 64-bit integer.
While BPF, on the other hand, exposes sub-registers, and use
zero-extension (similar to arm64/x86).
This has led to some subtle bugs, where a BPF JITted program has not
sign-extended the a0 register (return value in RISC-V land), passed
the return value up the kernel, e.g.:
| int from_bpf(void);
|
| long foo(void)
| {
| return from_bpf();
| }
Here, a0 would be 0xffff_ffff, instead of the expected
0xffff_ffff_ffff_ffff.
Internally, the RISC-V JIT uses a5 as a dedicated register for BPF
return values.
Keep a5 zero-extended, but explicitly sign-extend a0 (which is used
outside BPF land). Now that a0 (RISC-V ABI) and a5 (BPF ABI) differs,
a0 is only moved to a5 for non-BPF native calls (BPF_PSEUDO_CALL).
Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://github.com/riscv/riscv-isa-manual/releases/download/riscv-isa-release-056b6ff-2023-10-02/unpriv-isa-asciidoc.pdf # [2]
Link: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/releases/download/draft-20230929-e5c800e661a53efe3c2678d71a306323b60eb13b/riscv-abi.pdf # [2]
Link: https://lore.kernel.org/bpf/20231004120706.52848-2-bjorn@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0fd1fd0104954380477353aea29c347e85dff16d ]
The current emit_call function is not suitable for kernel function call as
it store return value to bpf R0 register. We can separate it out for common
use. Meanwhile, simplify judgment logic, that is, fixed function address
can use jal or auipc+jalr, while the unfixed can use only auipc+jalr.
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/bpf/20230215135205.1411105-3-pulehui@huaweicloud.com
Stable-dep-of: 2f1b0d3d7331 ("riscv, bpf: Sign-extend return values")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This reverts commit 447dabc1fedbafb1f9894e0c3054bf546a1af913
as it causes this issue with the Android build system:
out/soong/.intermediates/vendor/lineage/build/soong/generated_kernel_includes/ge
n/usr/include/asm/sigcontext.h:53:2: error: unknown type name '__uint128_t'
__uint128_t vregs[32];
^
1 error generated.
