x86, smap: Add STAC and CLAC instructions to control user space access

[cascardo/linux.git] / arch / x86 / ia32 / ia32entry.S

diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 20e5f7b..9c28950 100644 (file)
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -14,6 +14,7 @@
 #include <asm/segment.h>
 #include <asm/irqflags.h>
 #include <asm/asm.h>
+#include <asm/smap.h>
 #include <linux/linkage.h>
 #include <linux/err.h>
 
@@ -146,8 +147,10 @@ ENTRY(ia32_sysenter_target)
        SAVE_ARGS 0,1,0
        /* no need to do an access_ok check here because rbp has been
           32bit zero extended */ 
+       ASM_STAC
 1:     movl    (%rbp),%ebp
        _ASM_EXTABLE(1b,ia32_badarg)
+       ASM_CLAC
        orl     $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET)
        testl   $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
        CFI_REMEMBER_STATE
@@ -301,8 +304,10 @@ ENTRY(ia32_cstar_target)
        /* no need to do an access_ok check here because r8 has been
           32bit zero extended */ 
        /* hardware stack frame is complete now */      
+       ASM_STAC
 1:     movl    (%r8),%r9d
        _ASM_EXTABLE(1b,ia32_badarg)
+       ASM_CLAC
        orl     $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET)
        testl   $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
        CFI_REMEMBER_STATE
@@ -365,6 +370,7 @@ cstar_tracesys:
 END(ia32_cstar_target)
                                
 ia32_badarg:
+       ASM_CLAC
        movq $-EFAULT,%rax
        jmp ia32_sysret
        CFI_ENDPROC