Commit 05d9a952 authored by Thiago Jung Bauermann's avatar Thiago Jung Bauermann Committed by Michael Ellerman
Browse files

powerpc/prom_init: Undo relocation before entering secure mode 



The ultravisor will do an integrity check of the kernel image but we
relocated it so the check will fail. Restore the original image by
relocating it back to the kernel virtual base address.

This works because during build vmlinux is linked with an expected
virtual runtime address of KERNELBASE.

Fixes: 6a9c930b ("powerpc/prom_init: Add the ESM call to prom_init")
Signed-off-by: default avatarThiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: default avatarMichael Anderson <andmike@linux.ibm.com>
[mpe: Add IS_ENABLED() to fix the CONFIG_RELOCATABLE=n build]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190911163433.12822-1-bauerman@linux.ibm.com
parent a8a30219

arch/powerpc/include/asm/elf.h

+3 −0
Original line number Diff line number Diff line
@@ -175,4 +175,7 @@ do { \ 
	ARCH_DLINFO_CACHE_GEOMETRY;					\

} while (0)



/* Relocate the kernel image to @final_address */

void relocate(unsigned long final_address);



#endif /* _ASM_POWERPC_ELF_H */

arch/powerpc/kernel/prom_init.c

+13 −0
Original line number Diff line number Diff line
@@ -3249,7 +3249,20 @@ static void setup_secure_guest(unsigned long kbase, unsigned long fdt) 
	/* Switch to secure mode. */

	prom_printf("Switching to secure mode.\n");



	/*

	 * The ultravisor will do an integrity check of the kernel image but we

	 * relocated it so the check will fail. Restore the original image by

	 * relocating it back to the kernel virtual base address.

	 */

	if (IS_ENABLED(CONFIG_RELOCATABLE))

		relocate(KERNELBASE);



	ret = enter_secure_mode(kbase, fdt);



	/* Relocate the kernel again. */

	if (IS_ENABLED(CONFIG_RELOCATABLE))

		relocate(kbase);



	if (ret != U_SUCCESS) {

		prom_printf("Returned %d from switching to secure mode.\n", ret);

		prom_rtas_os_term("Switch to secure mode failed.\n");

arch/powerpc/kernel/prom_init_check.sh

+2 −1
Original line number Diff line number Diff line
@@ -26,7 +26,8 @@ _end enter_prom $MEM_FUNCS reloc_offset __secondary_hold 
__secondary_hold_acknowledge __secondary_hold_spinloop __start

logo_linux_clut224 btext_prepare_BAT

reloc_got2 kernstart_addr memstart_addr linux_banner _stext

__prom_init_toc_start __prom_init_toc_end btext_setup_display TOC."

__prom_init_toc_start __prom_init_toc_end btext_setup_display TOC.

relocate"



NM="$1"

OBJ="$2"

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