Merge branch 'x86/auditsc' of git://git.kernel.org/pub/scm/linux/kernel/git/frob/linux-2.6-roland

* 'x86/auditsc' of git://git.kernel.org/pub/scm/linux/kernel/git/frob/linux-2.6-roland:
  i386 syscall audit fast-path
  x86_64 ia32 syscall audit fast-path
  x86_64 syscall audit fast-path
  x86_64: remove bogus optimization in sysret_signal

4 files changed, 192 insertions, 12 deletions

diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 23d146ce676b..021d71bc69b5 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -15,6 +15,16 @@
 #include <asm/irqflags.h>
 #include <linux/linkage.h>
 
+/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this.  */
+#include <linux/elf-em.h>
+#define AUDIT_ARCH_I386         (EM_386|__AUDIT_ARCH_LE)
+#define __AUDIT_ARCH_LE    0x40000000
+
+#ifndef CONFIG_AUDITSYSCALL
+#define sysexit_audit int_ret_from_sys_call
+#define sysretl_audit int_ret_from_sys_call
+#endif
+
 #define IA32_NR_syscalls ((ia32_syscall_end - ia32_sys_call_table)/8)
 
         .macro IA32_ARG_FIXUP noebp=0
@@ -148,13 +158,15 @@ ENTRY(ia32_sysenter_target)
         ja      ia32_badsys
 sysenter_do_call:
         IA32_ARG_FIXUP 1
+sysenter_dispatch:
         call    *ia32_sys_call_table(,%rax,8)
         movq    %rax,RAX-ARGOFFSET(%rsp)
         GET_THREAD_INFO(%r10)
         DISABLE_INTERRUPTS(CLBR_NONE)
         TRACE_IRQS_OFF
         testl   $_TIF_ALLWORK_MASK,TI_flags(%r10)
-        jnz     int_ret_from_sys_call
+        jnz     sysexit_audit
+sysexit_from_sys_call:
         andl    $~TS_COMPAT,TI_status(%r10)
         /* clear IF, that popfq doesn't enable interrupts early */
         andl  $~0x200,EFLAGS-R11(%rsp) 
@@ -170,9 +182,63 @@ sysenter_do_call:
         TRACE_IRQS_ON
         ENABLE_INTERRUPTS_SYSEXIT32
 
-sysenter_tracesys:
+#ifdef CONFIG_AUDITSYSCALL
+        .macro auditsys_entry_common
+        movl %esi,%r9d                  /* 6th arg: 4th syscall arg */
+        movl %edx,%r8d                  /* 5th arg: 3rd syscall arg */
+        /* (already in %ecx)               4th arg: 2nd syscall arg */
+        movl %ebx,%edx                  /* 3rd arg: 1st syscall arg */
+        movl %eax,%esi                  /* 2nd arg: syscall number */
+        movl $AUDIT_ARCH_I386,%edi      /* 1st arg: audit arch */
+        call audit_syscall_entry
+        movl RAX-ARGOFFSET(%rsp),%eax   /* reload syscall number */
+        cmpl $(IA32_NR_syscalls-1),%eax
+        ja ia32_badsys
+        movl %ebx,%edi                  /* reload 1st syscall arg */
+        movl RCX-ARGOFFSET(%rsp),%esi   /* reload 2nd syscall arg */
+        movl RDX-ARGOFFSET(%rsp),%edx   /* reload 3rd syscall arg */
+        movl RSI-ARGOFFSET(%rsp),%ecx   /* reload 4th syscall arg */
+        movl RDI-ARGOFFSET(%rsp),%r8d   /* reload 5th syscall arg */
+        .endm
+
+        .macro auditsys_exit exit
+        testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10)
+        jnz int_ret_from_sys_call
+        TRACE_IRQS_ON
+        sti
+        movl %eax,%esi          /* second arg, syscall return value */
+        cmpl $0,%eax            /* is it < 0? */
+        setl %al                /* 1 if so, 0 if not */
+        movzbl %al,%edi         /* zero-extend that into %edi */
+        inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */
+        call audit_syscall_exit
+        GET_THREAD_INFO(%r10)
+        movl RAX-ARGOFFSET(%rsp),%eax   /* reload syscall return value */
+        movl RBP-ARGOFFSET(%rsp),%ebp   /* reload user register value */
+        movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
+        cli
+        TRACE_IRQS_OFF
+        testl %edi,TI_flags(%r10)
+        jnz int_with_check
+        jmp \exit
+        .endm
+
+sysenter_auditsys:
         CFI_RESTORE_STATE
+        auditsys_entry_common
+        movl %ebp,%r9d                  /* reload 6th syscall arg */
+        jmp sysenter_dispatch
+
+sysexit_audit:
+        auditsys_exit sysexit_from_sys_call
+#endif
+
+sysenter_tracesys:
         xchgl   %r9d,%ebp
+#ifdef CONFIG_AUDITSYSCALL
+        testl   $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10)
+        jz      sysenter_auditsys
+#endif
         SAVE_REST
         CLEAR_RREGS
         movq    %r9,R9(%rsp)
@@ -252,13 +318,15 @@ cstar_do_call:
         cmpl $IA32_NR_syscalls-1,%eax
         ja  ia32_badsys
         IA32_ARG_FIXUP 1
+cstar_dispatch:
         call *ia32_sys_call_table(,%rax,8)
         movq %rax,RAX-ARGOFFSET(%rsp)
         GET_THREAD_INFO(%r10)
         DISABLE_INTERRUPTS(CLBR_NONE)
         TRACE_IRQS_OFF
         testl $_TIF_ALLWORK_MASK,TI_flags(%r10)
-        jnz  int_ret_from_sys_call
+        jnz sysretl_audit
+sysretl_from_sys_call:
         andl $~TS_COMPAT,TI_status(%r10)
         RESTORE_ARGS 1,-ARG_SKIP,1,1,1
         movl RIP-ARGOFFSET(%rsp),%ecx
@@ -270,8 +338,23 @@ cstar_do_call:
         CFI_RESTORE rsp
         USERGS_SYSRET32
         
-cstar_tracesys: 
+#ifdef CONFIG_AUDITSYSCALL
+cstar_auditsys:
         CFI_RESTORE_STATE
+        movl %r9d,R9-ARGOFFSET(%rsp)    /* register to be clobbered by call */
+        auditsys_entry_common
+        movl R9-ARGOFFSET(%rsp),%r9d    /* reload 6th syscall arg */
+        jmp cstar_dispatch
+
+sysretl_audit:
+        auditsys_exit sysretl_from_sys_call
+#endif
+
+cstar_tracesys:
+#ifdef CONFIG_AUDITSYSCALL
+        testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10)
+        jz cstar_auditsys
+#endif
         xchgl %r9d,%ebp
         SAVE_REST
         CLEAR_RREGS
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index cdfd94cc6b14..109792bc7cfa 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -54,6 +54,16 @@
 #include <asm/ftrace.h>
 #include <asm/irq_vectors.h>
 
+/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this.  */
+#include <linux/elf-em.h>
+#define AUDIT_ARCH_I386         (EM_386|__AUDIT_ARCH_LE)
+#define __AUDIT_ARCH_LE    0x40000000
+
+#ifndef CONFIG_AUDITSYSCALL
+#define sysenter_audit  syscall_trace_entry
+#define sysexit_audit   syscall_exit_work
+#endif
+
 /*
  * We use macros for low-level operations which need to be overridden
  * for paravirtualization.  The following will never clobber any registers:
@@ -333,7 +343,8 @@ sysenter_past_esp:
 
         /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
         testw $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp)
-        jnz syscall_trace_entry
+        jnz sysenter_audit
+sysenter_do_call:
         cmpl $(nr_syscalls), %eax
         jae syscall_badsys
         call *sys_call_table(,%eax,4)
@@ -343,7 +354,8 @@ sysenter_past_esp:
         TRACE_IRQS_OFF
         movl TI_flags(%ebp), %ecx
         testw $_TIF_ALLWORK_MASK, %cx
-        jne syscall_exit_work
+        jne sysexit_audit
+sysenter_exit:
 /* if something modifies registers it must also disable sysexit */
         movl PT_EIP(%esp), %edx
         movl PT_OLDESP(%esp), %ecx
@@ -351,6 +363,45 @@ sysenter_past_esp:
         TRACE_IRQS_ON
 1:      mov  PT_FS(%esp), %fs
         ENABLE_INTERRUPTS_SYSEXIT
+
+#ifdef CONFIG_AUDITSYSCALL
+sysenter_audit:
+        testw $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
+        jnz syscall_trace_entry
+        addl $4,%esp
+        CFI_ADJUST_CFA_OFFSET -4
+        /* %esi already in 8(%esp)         6th arg: 4th syscall arg */
+        /* %edx already in 4(%esp)         5th arg: 3rd syscall arg */
+        /* %ecx already in 0(%esp)         4th arg: 2nd syscall arg */
+        movl %ebx,%ecx                  /* 3rd arg: 1st syscall arg */
+        movl %eax,%edx                  /* 2nd arg: syscall number */
+        movl $AUDIT_ARCH_I386,%eax      /* 1st arg: audit arch */
+        call audit_syscall_entry
+        pushl %ebx
+        CFI_ADJUST_CFA_OFFSET 4
+        movl PT_EAX(%esp),%eax          /* reload syscall number */
+        jmp sysenter_do_call
+
+sysexit_audit:
+        testw $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %cx
+        jne syscall_exit_work
+        TRACE_IRQS_ON
+        ENABLE_INTERRUPTS(CLBR_ANY)
+        movl %eax,%edx          /* second arg, syscall return value */
+        cmpl $0,%eax            /* is it < 0? */
+        setl %al                /* 1 if so, 0 if not */
+        movzbl %al,%eax         /* zero-extend that */
+        inc %eax /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */
+        call audit_syscall_exit
+        DISABLE_INTERRUPTS(CLBR_ANY)
+        TRACE_IRQS_OFF
+        movl TI_flags(%ebp), %ecx
+        testw $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %cx
+        jne syscall_exit_work
+        movl PT_EAX(%esp),%eax  /* reload syscall return value */
+        jmp sysenter_exit
+#endif
+
         CFI_ENDPROC
 .pushsection .fixup,"ax"
 2:      movl $0,PT_FS(%esp)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 8410e26f4183..89434d439605 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -53,6 +53,12 @@
 #include <asm/paravirt.h>
 #include <asm/ftrace.h>
 
+/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this.  */
+#include <linux/elf-em.h>
+#define AUDIT_ARCH_X86_64       (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
+#define __AUDIT_ARCH_64BIT 0x80000000
+#define __AUDIT_ARCH_LE    0x40000000
+
         .code64
 
 #ifdef CONFIG_FTRACE
@@ -351,6 +357,7 @@ ENTRY(system_call_after_swapgs)
         GET_THREAD_INFO(%rcx)
         testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%rcx)
         jnz tracesys
+system_call_fastpath:
         cmpq $__NR_syscall_max,%rax
         ja badsys
         movq %r10,%rcx
@@ -402,16 +409,16 @@ sysret_careful:
 sysret_signal:
         TRACE_IRQS_ON
         ENABLE_INTERRUPTS(CLBR_NONE)
-        testl $_TIF_DO_NOTIFY_MASK,%edx
-        jz    1f
-
-        /* Really a signal */
+#ifdef CONFIG_AUDITSYSCALL
+        bt $TIF_SYSCALL_AUDIT,%edx
+        jc sysret_audit
+#endif
         /* edx: work flags (arg3) */
         leaq do_notify_resume(%rip),%rax
         leaq -ARGOFFSET(%rsp),%rdi # &pt_regs -> arg1
         xorl %esi,%esi # oldset -> arg2
         call ptregscall_common
-1:      movl $_TIF_WORK_MASK,%edi
+        movl $_TIF_WORK_MASK,%edi
         /* Use IRET because user could have changed frame. This
            works because ptregscall_common has called FIXUP_TOP_OF_STACK. */
         DISABLE_INTERRUPTS(CLBR_NONE)
@@ -422,8 +429,45 @@ badsys:
         movq $-ENOSYS,RAX-ARGOFFSET(%rsp)
         jmp ret_from_sys_call
 
+#ifdef CONFIG_AUDITSYSCALL
+        /*
+         * Fast path for syscall audit without full syscall trace.
+         * We just call audit_syscall_entry() directly, and then
+         * jump back to the normal fast path.
+         */
+auditsys:
+        movq %r10,%r9                   /* 6th arg: 4th syscall arg */
+        movq %rdx,%r8                   /* 5th arg: 3rd syscall arg */
+        movq %rsi,%rcx                  /* 4th arg: 2nd syscall arg */
+        movq %rdi,%rdx                  /* 3rd arg: 1st syscall arg */
+        movq %rax,%rsi                  /* 2nd arg: syscall number */
+        movl $AUDIT_ARCH_X86_64,%edi    /* 1st arg: audit arch */
+        call audit_syscall_entry
+        LOAD_ARGS 0             /* reload call-clobbered registers */
+        jmp system_call_fastpath
+
+        /*
+         * Return fast path for syscall audit.  Call audit_syscall_exit()
+         * directly and then jump back to the fast path with TIF_SYSCALL_AUDIT
+         * masked off.
+         */
+sysret_audit:
+        movq %rax,%rsi          /* second arg, syscall return value */
+        cmpq $0,%rax            /* is it < 0? */
+        setl %al                /* 1 if so, 0 if not */
+        movzbl %al,%edi         /* zero-extend that into %edi */
+        inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */
+        call audit_syscall_exit
+        movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
+        jmp sysret_check
+#endif  /* CONFIG_AUDITSYSCALL */
+
         /* Do syscall tracing */
 tracesys:                        
+#ifdef CONFIG_AUDITSYSCALL
+        testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%rcx)
+        jz auditsys
+#endif
         SAVE_REST
         movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
         FIXUP_TOP_OF_STACK %rdi
@@ -448,6 +492,7 @@ tracesys:
  * Has correct top of stack, but partial stack frame.
  */
         .globl int_ret_from_sys_call
+        .globl int_with_check
 int_ret_from_sys_call:
         DISABLE_INTERRUPTS(CLBR_NONE)
         TRACE_IRQS_OFF
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index c10e7aae04d7..4699950e65bd 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1476,7 +1476,8 @@ void audit_syscall_entry(int arch, int major,
         struct audit_context *context = tsk->audit_context;
         enum audit_state     state;
 
-        BUG_ON(!context);
+        if (unlikely(!context))
+                return;
 
         /*
          * This happens only on certain architectures that make system