[PATCH] x86/power/64: Use char arrays for asm function names

From: Kees Cook
Date: Tue May 09 2017 - 17:00:58 EST


This switches the hibernate_64.S function names into character arrays
to match other areas of the kernel where this is done (e.g., linker
scripts). Specifically this fixes a compile-time error noticed by the
future CONFIG_FORTIFY_SOURCE routines that complained about PAGE_SIZE
being copied out of the "single byte" core_restore_code variable.

Additionally drops the "acpi_save_state_mem" exern which does not
appear to be used anywhere else in the kernel.

Cc: Daniel Micay <danielmicay@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
arch/x86/include/asm/suspend_64.h | 5 ++---
arch/x86/power/hibernate_64.c | 6 +++---
2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/suspend_64.h b/arch/x86/include/asm/suspend_64.h
index 6136a18152af..2bd96b4df140 100644
--- a/arch/x86/include/asm/suspend_64.h
+++ b/arch/x86/include/asm/suspend_64.h
@@ -42,8 +42,7 @@ struct saved_context {
set_debugreg((thread)->debugreg##register, register)

/* routines for saving/restoring kernel state */
-extern int acpi_save_state_mem(void);
-extern char core_restore_code;
-extern char restore_registers;
+extern char core_restore_code[];
+extern char restore_registers[];

#endif /* _ASM_X86_SUSPEND_64_H */
diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index 6a61194ffd58..2cc419990ab7 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -147,7 +147,7 @@ static int relocate_restore_code(void)
if (!relocated_restore_code)
return -ENOMEM;

- memcpy((void *)relocated_restore_code, &core_restore_code, PAGE_SIZE);
+ memcpy((void *)relocated_restore_code, core_restore_code, PAGE_SIZE);

/* Make the page containing the relocated code executable */
pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code);
@@ -292,8 +292,8 @@ int arch_hibernation_header_save(void *addr, unsigned int max_size)

if (max_size < sizeof(struct restore_data_record))
return -EOVERFLOW;
- rdr->jump_address = (unsigned long)&restore_registers;
- rdr->jump_address_phys = __pa_symbol(&restore_registers);
+ rdr->jump_address = (unsigned long)restore_registers;
+ rdr->jump_address_phys = __pa_symbol(restore_registers);
rdr->cr3 = restore_cr3;
rdr->magic = RESTORE_MAGIC;

--
2.7.4


--
Kees Cook
Pixel Security