MIPS: Loongson64: Add KASLR support (a307a4ce) · Commits · 戴 / test

Provide a weak plat_get_fdt() in relocate.c in case some platform enable USE_OF while plat_get_fdt() is useless. 1MB RELOCATION_TABLE_SIZE is small for Loongson64 because too many instructions should be relocated. 2MB is enough in present. Add KASLR support for Loongson64. KASLR(kernel address space layout randomization) To enable KASLR on Loongson64: First, make loongson3_defconfig. Then, enable CONFIG_RELOCATABLE and CONFIG_RANDOMIZE_BASE. Finally, compile the kernel. To test KASLR on Loongson64: Start machine with KASLR kernel. The first time: # cat /proc/iomem 00200000-0effffff : System RAM 02f30000-03895e9f : Kernel code 03895ea0-03bc7fff : Kernel data 03e30000-04f43f7f : Kernel bss The second time: # cat /proc/iomem 00200000-0effffff : System RAM 022f0000-02c55e9f : Kernel code 02c55ea0-02f87fff : Kernel data 031f0000-04303f7f : Kernel bss We see that code, data and bss sections become randomize. Signed-off-by:

Jinyang He <hejinyang@loongson.cn> Signed-off-by:

Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/Kconfig

+4 −1

Original line number	Diff line number	Diff line
		@@ -488,6 +488,7 @@ config MACH_LOONGSON64
		select SYS_SUPPORTS_HIGHMEM
		select SYS_SUPPORTS_LITTLE_ENDIAN
		select SYS_SUPPORTS_ZBOOT
		select SYS_SUPPORTS_RELOCATABLE
		select ZONE_DMA32
		select NUMA
		select SMP
		@@ -2778,7 +2779,8 @@ config RELOCATABLE
		depends on CPU_MIPS32_R2 \|\| CPU_MIPS64_R2 \|\| \
		CPU_MIPS32_R5 \|\| CPU_MIPS64_R5 \|\| \
		CPU_MIPS32_R6 \|\| CPU_MIPS64_R6 \|\| \
		CPU_P5600 \|\| CAVIUM_OCTEON_SOC
		CPU_P5600 \|\| CAVIUM_OCTEON_SOC \|\| \
		CPU_LOONGSON64
		help
		This builds a kernel image that retains relocation information
		so it can be loaded someplace besides the default 1MB.
		@@ -2789,6 +2791,7 @@ config RELOCATION_TABLE_SIZE
		hex "Relocation table size"
		depends on RELOCATABLE
		range 0x0 0x01000000
		default "0x00200000" if CPU_LOONGSON64
		default "0x00100000"
		help
		A table of relocation data will be appended to the kernel binary

arch/mips/kernel/relocate.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -294,6 +294,13 @@ static inline int __init relocation_addr_valid(void *loc_new)
		return 1;
		}

		#if defined(CONFIG_USE_OF)
		void __weak *plat_get_fdt(void)
		{
		return NULL;
		}
		#endif

		void *__init relocate_kernel(void)
		{
		void *loc_new;

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