# git rev-parse -q --verify 4a7aee96200ad281a5cc4cf5c7a2e2a49d2b97b0^{commit}
4a7aee96200ad281a5cc4cf5c7a2e2a49d2b97b0
already have revision, skipping fetch
# git checkout -q -f -B kisskb 4a7aee96200ad281a5cc4cf5c7a2e2a49d2b97b0
# git clean -qxdf
# < git log -1
# commit 4a7aee96200ad281a5cc4cf5c7a2e2a49d2b97b0
# Author: Jiangfeng Xiao <xiaojiangfeng@huawei.com>
# Date:   Tue Jan 23 09:45:59 2024 +0800
# 
#     powerpc/kasan: Fix addr error caused by page alignment
#     
#     In kasan_init_region, when k_start is not page aligned, at the begin of
#     for loop, k_cur = k_start & PAGE_MASK is less than k_start, and then
#     `va = block + k_cur - k_start` is less than block, the addr va is invalid,
#     because the memory address space from va to block is not alloced by
#     memblock_alloc, which will not be reserved by memblock_reserve later, it
#     will be used by other places.
#     
#     As a result, memory overwriting occurs.
#     
#     for example:
#     int __init __weak kasan_init_region(void *start, size_t size)
#     {
#     [...]
#             /* if say block(dcd97000) k_start(feef7400) k_end(feeff3fe) */
#             block = memblock_alloc(k_end - k_start, PAGE_SIZE);
#             [...]
#             for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
#                     /* at the begin of for loop
#                      * block(dcd97000) va(dcd96c00) k_cur(feef7000) k_start(feef7400)
#                      * va(dcd96c00) is less than block(dcd97000), va is invalid
#                      */
#                     void *va = block + k_cur - k_start;
#                     [...]
#             }
#     [...]
#     }
#     
#     Therefore, page alignment is performed on k_start before
#     memblock_alloc() to ensure the validity of the VA address.
#     
#     Fixes: 663c0c9496a6 ("powerpc/kasan: Fix shadow area set up for modules.")
#     Signed-off-by: Jiangfeng Xiao <xiaojiangfeng@huawei.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://msgid.link/1705974359-43790-1-git-send-email-xiaojiangfeng@huawei.com
# < /opt/cross/kisskb/korg/gcc-8.5.0-nolibc/s390-linux/bin/s390-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.5.0-nolibc/s390-linux/bin/s390-linux-ld --version
# < git log --format=%s --max-count=1 4a7aee96200ad281a5cc4cf5c7a2e2a49d2b97b0
# make -s -j 160 ARCH=s390 O=/kisskb/build/powerpc-fixes_defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/s390-linux/bin/s390-linux-  defconfig
# Added to kconfig CONFIG_DEBUG_INFO_BTF=n
# Added to kconfig 
# < make -s -j 160 ARCH=s390 O=/kisskb/build/powerpc-fixes_defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/s390-linux/bin/s390-linux-  help
# make -s -j 160 ARCH=s390 O=/kisskb/build/powerpc-fixes_defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/s390-linux/bin/s390-linux-  olddefconfig
.config:3740:warning: override: reassigning to symbol DEBUG_INFO_BTF
# make -s -j 160 ARCH=s390 O=/kisskb/build/powerpc-fixes_defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/s390-linux/bin/s390-linux-  
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_defconfig_s390x-gcc8
# Build took: 0:05:03.328000