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authorJinyang He <hejinyang@loongson.cn>2020-11-25 13:07:46 +0300
committerThomas Bogendoerfer <tsbogend@alpha.franken.de>2020-11-27 12:20:25 +0300
commita307a4ce9ecd2e23c71318201330d9d648b3f818 (patch)
treee2b26a56a7076629a7e05e6ecb560466641b8dec /arch/mips
parent74a2810b7c1fcd60c87a8c47f95660628e00e97c (diff)
downloadlinux-a307a4ce9ecd2e23c71318201330d9d648b3f818.tar.xz
MIPS: Loongson64: Add KASLR support
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>
Diffstat (limited to 'arch/mips')
-rw-r--r--arch/mips/Kconfig5
-rw-r--r--arch/mips/kernel/relocate.c7
2 files changed, 11 insertions, 1 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 0f638bfaf63a..44a47adb1275 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -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
diff --git a/arch/mips/kernel/relocate.c b/arch/mips/kernel/relocate.c
index 8561c7ac94dc..57bdd2761c78 100644
--- a/arch/mips/kernel/relocate.c
+++ b/arch/mips/kernel/relocate.c
@@ -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;