From: Sami Tolvanen <samitolvanen@google.com>
Date: Fri, 13 Sep 2019 14:14:02 -0700
Subject: x86/mm: Use the correct function type for native_set_fixmap()
Git-commit: f53e2cd0b8ab7d9e390414470bdbd830f660133f
Patch-mainline: 5.5-rc1
References: git-fixes
We call native_set_fixmap indirectly through the function pointer
struct pv_mmu_ops::set_fixmap, which expects the first parameter to be
'unsigned' instead of 'enum fixed_addresses'. This patch changes the
function type for native_set_fixmap to match the pointer, which fixes
indirect call mismatches with Control-Flow Integrity (CFI) checking.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H . Peter Anvin <hpa@zytor.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190913211402.193018-1-samitolvanen@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
arch/x86/include/asm/fixmap.h | 2 +-
arch/x86/mm/pgtable.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -157,7 +157,7 @@ extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
-void native_set_fixmap(enum fixed_addresses idx,
+void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
phys_addr_t phys, pgprot_t flags);
#ifndef CONFIG_PARAVIRT
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -594,8 +594,8 @@ void __native_set_fixmap(enum fixed_addr
fixmaps_set++;
}
-void native_set_fixmap(enum fixed_addresses idx, phys_addr_t phys,
- pgprot_t flags)
+void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
+ phys_addr_t phys, pgprot_t flags)
{
__native_set_fixmap(idx, pfn_pte(phys >> PAGE_SHIFT, flags));
}