riscv: Sparse-Memory/vmemmap out-of-bounds fix

stable inclusion
from stable-v5.10.212
commit 8af1c121b0102041809bc137ec600d1865eaeedd
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E466
CVE: CVE-2024-26795

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8af1c121b0102041809bc137ec600d1865eaeedd



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[ Upstream commit a11dd49dcb9376776193e15641f84fcc1e5980c9 ]

Offset vmemmap so that the first page of vmemmap will be mapped
to the first page of physical memory in order to ensure that
vmemmap’s bounds will be respected during
pfn_to_page()/page_to_pfn() operations.
The conversion macros will produce correct SV39/48/57 addresses
for every possible/valid DRAM_BASE inside the physical memory limits.

v2:Address Alex's comments

Suggested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Dimitris Vlachos <dvlachos@ics.forth.gr>
Reported-by: Dimitris Vlachos <dvlachos@ics.forth.gr>
Closes: https://lore.kernel.org/linux-riscv/20240202135030.42265-1-csd4492@csd.uoc.gr


Fixes: d95f1a54 ("RISC-V: Implement sparsemem")
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240229191723.32779-1-dvlachos@ics.forth.gr


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zucheng <zhengzucheng@huawei.com>
(cherry picked from commit 9428674e)