[PATCH 5.11 270/775] MIPS: relocatable: Provide kaslr_offset() to get the kernel offset
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-03-02 00:24:04
Also in:
lkml
Subsystem:
mips, the rest · Maintainers:
Thomas Bogendoerfer, Linus Torvalds
From: Jinyang He <redacted>
[ Upstream commit d4d3ef8b347b73aa60f60f4be06acf1643e79f34 ]
Provide kaslr_offset() to get the kernel offset when KASLR is enabled.
Error may occur before update_kaslr_offset(), so put it at the end of
the offset branch.
Fixes: a307a4ce9ecd ("MIPS: Loongson64: Add KASLR support")
Reported-by: kernel test robot <redacted>
Signed-off-by: Jinyang He <redacted>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/mips/include/asm/page.h | 6 ++++++
arch/mips/kernel/relocate.c | 10 ++++++++++
arch/mips/kernel/setup.c | 3 +++
3 files changed, 19 insertions(+)
diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h
index 6a77bc4a6eec4..74082e35d57c8 100644
--- a/arch/mips/include/asm/page.h
+++ b/arch/mips/include/asm/page.h@@ -255,6 +255,12 @@ extern bool __virt_addr_valid(const volatile void *kaddr); #define VM_DATA_DEFAULT_FLAGS VM_DATA_FLAGS_TSK_EXEC +extern unsigned long __kaslr_offset; +static inline unsigned long kaslr_offset(void) +{ + return __kaslr_offset; +} + #include <asm-generic/memory_model.h> #include <asm-generic/getorder.h>
diff --git a/arch/mips/kernel/relocate.c b/arch/mips/kernel/relocate.c
index 0e365b7c742d9..ac16cf2716df5 100644
--- a/arch/mips/kernel/relocate.c
+++ b/arch/mips/kernel/relocate.c@@ -300,6 +300,13 @@ static inline int __init relocation_addr_valid(void *loc_new) return 1; } +static inline void __init update_kaslr_offset(unsigned long *addr, long offset) +{ + unsigned long *new_addr = (unsigned long *)RELOCATED(addr); + + *new_addr = (unsigned long)offset; +} + #if defined(CONFIG_USE_OF) void __weak *plat_get_fdt(void) {
@@ -410,6 +417,9 @@ void *__init relocate_kernel(void) /* Return the new kernel's entry point */ kernel_entry = RELOCATED(start_kernel); + + /* Error may occur before, so keep it at last */ + update_kaslr_offset(&__kaslr_offset, offset); } out: return kernel_entry;
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 7e1f8e2774373..83ec0d5a0918b 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c@@ -84,6 +84,9 @@ static struct resource code_resource = { .name = "Kernel code", }; static struct resource data_resource = { .name = "Kernel data", }; static struct resource bss_resource = { .name = "Kernel bss", }; +unsigned long __kaslr_offset __ro_after_init; +EXPORT_SYMBOL(__kaslr_offset); + static void *detect_magic __initdata = detect_memory_region; #ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
--
2.27.0