Commit 338b9bb3 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents 7f9dce38 af0575bb
......@@ -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
......
......@@ -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)
......
......@@ -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
......
......@@ -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
......
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