Chunyan Zhang bc75552b80 raid6: riscv: Fix NULL pointer dereference caused by a missing clobber ... When running the raid6 user-space test program on RISC-V QEMU, there's a segmentation fault which seems caused by accessing a NULL pointer, which is the pointer variable p/q in raid6_rvv*_gen/xor_syndrome_real(), p/q should have been equal to dptr[x], but when I use GDB command to see its value, which was 0x10 like below: " Program received signal SIGSEGV, Segmentation fault. 0x0000000000011062 in raid6_rvv2_xor_syndrome_real (disks=<optimized out>, start=0, stop=<optimized out>, bytes=4096, ptrs=<optimized out>) at rvv.c:386 (gdb) p p $1 = (u8 *) 0x10 <error: Cannot access memory at address 0x10> " The issue was found to be related with: 1) Compile optimization There's no segmentation fault if compiling the raid6test program with the optimization flag -O0. 2) The RISC-V vector command vsetvli If not used t0 as the first parameter in vsetvli, there's no segmentation fault either. This patch selects the 2nd solution to fix the issue. [Palmer: The actual issue here is a missing clobber in the vsetvli code. It's a little tricky: we've already probed for VLENB so we don't need to look at the output register, we just need to have an X register in the instruction as that's the form required to actually set VL. Thus we clobber a register, and without describing that we end up breaking compilers.] Fixes: 6093faaf95 ("raid6: Add RISC-V SIMD syndrome and recovery calculations") Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250610101234.1100660-3-zhangchunyan@iscas.ac.cn Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>		2025-06-12 12:21:48 -07:00
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test	raid6: skip avx512 checks	2025-04-30 21:53:48 +02:00
.gitignore
algos.c	RISC-V Patches for the 6.16 Merge Window, Part 1	2025-06-06 18:05:18 -07:00
altivec.uc
avx2.c
avx512.c	raid6: skip avx512 checks	2025-04-30 21:53:48 +02:00
int.uc
loongarch_simd.c
loongarch.h
Makefile	raid6: Add RISC-V SIMD syndrome and recovery calculations	2025-06-05 14:03:07 -07:00
mktables.c
mmx.c
neon.c
neon.h
neon.uc
recov_avx2.c
recov_avx512.c	raid6: skip avx512 checks	2025-04-30 21:53:48 +02:00
recov_loongarch_simd.c
recov_neon_inner.c
recov_neon.c
recov_rvv.c	raid6: Add RISC-V SIMD syndrome and recovery calculations	2025-06-05 14:03:07 -07:00
recov_s390xc.c
recov_ssse3.c
recov.c
rvv.c	raid6: riscv: Fix NULL pointer dereference caused by a missing clobber	2025-06-12 12:21:48 -07:00
rvv.h	raid6: Add RISC-V SIMD syndrome and recovery calculations	2025-06-05 14:03:07 -07:00
s390vx.uc	s390/vx: Convert cpu_has_vx() to cpu feature function	2025-03-04 17:18:07 +01:00
sse1.c
sse2.c
unroll.awk
vpermxor.uc
x86.h