x86/fault/32: Move is_f00f_bug() to do_kern_addr_fault()

bad_area() and its relatives are called from many places in fault.c, and
exactly one of them wants the F00F workaround.

__bad_area_nosemaphore() no longer contains any kernel fault code, which
prepares for further cleanups.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/e9668729a48ce6754022b0a4415631e8ebdd00e7.1612924255.git.luto@kernel.org

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 91cf7a672c043c84d3e3d7e375d5129e56b3b4ac..3ffed003f2811d9f2135894adce7de16c7f20037 100644 (file)
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -482,10 +482,12 @@ static int is_errata100(struct pt_regs *regs, unsigned long address)
 }
 
 /* Pentium F0 0F C7 C8 bug workaround: */
-static int is_f00f_bug(struct pt_regs *regs, unsigned long address)
+static int is_f00f_bug(struct pt_regs *regs, unsigned long error_code,
+                      unsigned long address)
 {
 #ifdef CONFIG_X86_F00F_BUG
-       if (boot_cpu_has_bug(X86_BUG_F00F) && idt_is_f00f_address(address)) {
+       if (boot_cpu_has_bug(X86_BUG_F00F) && !(error_code & X86_PF_USER) &&
+           idt_is_f00f_address(address)) {
                handle_invalid_op(regs);
                return 1;
        }
@@ -853,9 +855,6 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
                return;
        }
 
-       if (is_f00f_bug(regs, address))
-               return;
-
        no_context(regs, error_code, address, SIGSEGV, si_code);
 }
 
@@ -1195,6 +1194,9 @@ do_kern_addr_fault(struct pt_regs *regs, unsigned long hw_error_code,
        }
 #endif
 
+       if (is_f00f_bug(regs, hw_error_code, address))
+               return;
+
        /* Was the fault spurious, caused by lazy TLB invalidation? */
        if (spurious_kernel_fault(hw_error_code, address))
                return;