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