84fe419dc7
KASLR implementation relies on a relocatable kernel so that we can move the kernel mapping. The seed needed to virtually move the kernel is taken from the device tree, so we rely on the bootloader to provide a correct seed. Zkr could be used unconditionnally instead if implemented, but that's for another patch. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Song Shuai <songshuaishuai@tinylab.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20230722123850.634544-2-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
30 lines
715 B
C
30 lines
715 B
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/libfdt.h>
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/*
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* Declare the functions that are exported (but prefixed) here so that LLVM
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* does not complain it lacks the 'static' keyword (which, if added, makes
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* LLVM complain because the function is actually unused in this file).
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*/
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u64 get_kaslr_seed(uintptr_t dtb_pa);
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u64 get_kaslr_seed(uintptr_t dtb_pa)
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{
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int node, len;
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fdt64_t *prop;
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u64 ret;
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node = fdt_path_offset((void *)dtb_pa, "/chosen");
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if (node < 0)
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return 0;
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prop = fdt_getprop_w((void *)dtb_pa, node, "kaslr-seed", &len);
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if (!prop || len != sizeof(u64))
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return 0;
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ret = fdt64_to_cpu(*prop);
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*prop = 0;
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return ret;
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}
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