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authorAndy Lutomirski <luto@kernel.org>2017-12-12 18:56:42 +0300
committerIngo Molnar <mingo@kernel.org>2017-12-23 23:13:00 +0300
commit85900ea51577e31b186e523c8f4e068c79ecc7d3 (patch)
tree76ddd1071d7c34d45920113429de5ee6e9e21eb1 /arch/x86/entry/vsyscall
parentf55f0501cbf65ec41cca5058513031b711730b1d (diff)
downloadlinux-85900ea51577e31b186e523c8f4e068c79ecc7d3.tar.xz
x86/pti: Map the vsyscall page if needed
Make VSYSCALLs work fully in PTI mode by mapping them properly to the user space visible page tables. [ tglx: Hide unused functions (Patch by Arnd Bergmann) ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/entry/vsyscall')
-rw-r--r--arch/x86/entry/vsyscall/vsyscall_64.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 1faf40f2dda9..577fa8adb785 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -344,14 +344,14 @@ int in_gate_area_no_mm(unsigned long addr)
* vsyscalls but leave the page not present. If so, we skip calling
* this.
*/
-static void __init set_vsyscall_pgtable_user_bits(void)
+void __init set_vsyscall_pgtable_user_bits(pgd_t *root)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
- pgd = pgd_offset_k(VSYSCALL_ADDR);
+ pgd = pgd_offset_pgd(root, VSYSCALL_ADDR);
set_pgd(pgd, __pgd(pgd_val(*pgd) | _PAGE_USER));
p4d = p4d_offset(pgd, VSYSCALL_ADDR);
#if CONFIG_PGTABLE_LEVELS >= 5
@@ -373,7 +373,7 @@ void __init map_vsyscall(void)
vsyscall_mode == NATIVE
? PAGE_KERNEL_VSYSCALL
: PAGE_KERNEL_VVAR);
- set_vsyscall_pgtable_user_bits();
+ set_vsyscall_pgtable_user_bits(swapper_pg_dir);
}
BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) !=