linux-kernel - [PATCH] riscv: add a warning when physical memory address overflows

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240814062625.19794-1-cuiyunhui@bytedance.com>
Date: Wed, 14 Aug 2024 14:26:25 +0800
From: Yunhui Cui <cuiyunhui@...edance.com>
To: punit.agrawal@...edance.com,
	paul.walmsley@...ive.com,
	palmer@...belt.com,
	aou@...s.berkeley.edu,
	alexghiti@...osinc.com,
	cuiyunhui@...edance.com,
	chenjiahao16@...wei.com,
	guoren@...nel.org,
	vishal.moola@...il.com,
	stuart.menefy@...asip.com,
	linux-riscv@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] riscv: add a warning when physical memory address overflows

The part of physical memory that exceeds the size of the linear mapping
will be discarded. When the system starts up normally, a warning message
will be printed to prevent confusion caused by the mismatch between the
system memory and the actual physical memory.

Signed-off-by: Yunhui Cui <cuiyunhui@...edance.com>
---
 arch/riscv/mm/init.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 52290c9bd04bd..c93164dc51658 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -236,8 +236,12 @@ static void __init setup_bootmem(void)
 	 */
 	if (IS_ENABLED(CONFIG_64BIT)) {
 		max_mapped_addr = __pa(PAGE_OFFSET) + KERN_VIRT_SIZE;
-		memblock_cap_memory_range(phys_ram_base,
-					  max_mapped_addr - phys_ram_base);
+		if (memblock_end_of_DRAM() > max_mapped_addr) {
+			memblock_cap_memory_range(phys_ram_base,
+						  max_mapped_addr - phys_ram_base);
+			pr_warn("Physical memory overflows the linear mapping size: region above 0x%llx removed",
+				max_mapped_addr);
+		}
 	}
 
 
-- 
2.39.2