[v7,03/12] powerpc: introduce kernstart_virt_addr to store the kernel base

Commit Message

Jason Yan Sept. 20, 2019, 9:45 a.m. UTC

Now the kernel base is a fixed value - KERNELBASE. To support KASLR, we
need a variable to store the kernel base.

Signed-off-by: Jason Yan <[e-mail]>
Cc: Diana Craciun <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Christophe Leroy <[e-mail]>
Cc: Benjamin Herrenschmidt <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Nicholas Piggin <[e-mail]>
Cc: Kees Cook <[e-mail]>
Reviewed-by: Christophe Leroy <[e-mail]>
Reviewed-by: Diana Craciun <[e-mail]>
Tested-by: Diana Craciun <[e-mail]>
---
 arch/powerpc/include/asm/page.h | 2 ++
 arch/powerpc/mm/init-common.c   | 2 ++
 2 files changed, 4 insertions(+)

Patch

diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 0d52f57fca04..4d32d1b561d6 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -315,6 +315,8 @@  void arch_free_page(struct page *page, int order);
 
 struct vm_area_struct;
 
+extern unsigned long kernstart_virt_addr;
+
 #include <asm-generic/memory_model.h>
 #endif /* __ASSEMBLY__ */
 #include <asm/slice.h>
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index e223da482c0c..42ef7a6e6098 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -25,6 +25,8 @@  phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull;
 EXPORT_SYMBOL_GPL(memstart_addr);
 phys_addr_t kernstart_addr __ro_after_init;
 EXPORT_SYMBOL_GPL(kernstart_addr);
+unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE;
+EXPORT_SYMBOL_GPL(kernstart_virt_addr);
 
 static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
 static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);