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authorSamuel Holland <samuel.holland@sifive.com>2024-02-27 03:34:47 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-05-02 17:32:49 +0300
commitb008e327fa570aca210f98c817757649bae56694 (patch)
treeb9230e44b393445e6894e0aee89eac980422d081 /arch
parenta0f0dbbb1bc49fa0de18e92c36492ff6d804cdaa (diff)
downloadlinux-b008e327fa570aca210f98c817757649bae56694.tar.xz
riscv: Fix loading 64-bit NOMMU kernels past the start of RAM
[ Upstream commit aea702dde7e9876fb00571a2602f25130847bf0f ] commit 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping") added logic to allow using RAM below the kernel load address. However, this does not work for NOMMU, where PAGE_OFFSET is fixed to the kernel load address. Since that range of memory corresponds to PFNs below ARCH_PFN_OFFSET, mm initialization runs off the beginning of mem_map and corrupts adjacent kernel memory. Fix this by restoring the previous behavior for NOMMU kernels. Fixes: 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping") Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20240227003630.3634533-3-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/riscv/include/asm/page.h2
-rw-r--r--arch/riscv/mm/init.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index 57e887bfa34c..94b3d6930fc3 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -89,7 +89,7 @@ typedef struct page *pgtable_t;
#define PTE_FMT "%08lx"
#endif
-#ifdef CONFIG_64BIT
+#if defined(CONFIG_64BIT) && defined(CONFIG_MMU)
/*
* We override this value as its generic definition uses __pa too early in
* the boot process (before kernel_map.va_pa_offset is set).
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index b50faa232b5e..ec02ea86aa39 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -230,7 +230,7 @@ static void __init setup_bootmem(void)
* In 64-bit, any use of __va/__pa before this point is wrong as we
* did not know the start of DRAM before.
*/
- if (IS_ENABLED(CONFIG_64BIT))
+ if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU))
kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base;
/*