*
* NOTE: This code handles signal-recognition, which happens every time
* after an interrupt and after each system call.
- *
- * Normal syscalls and interrupts don't save a full stack frame, this is
+ *
+ * Normal syscalls and interrupts don't save a full stack frame, this is
* only done for syscall tracing, signals or fork/exec et.al.
- *
- * A note on terminology:
- * - top of stack: Architecture defined interrupt frame from SS to RIP
- * at the top of the kernel process stack.
+ *
+ * A note on terminology:
+ * - top of stack: Architecture defined interrupt frame from SS to RIP
+ * at the top of the kernel process stack.
* - partial stack frame: partially saved registers upto R11.
- * - full stack frame: Like partial stack frame, but all register saved.
+ * - full stack frame: Like partial stack frame, but all register saved.
*
* Some macro usage:
* - CFI macros are used to generate dwarf2 unwind information for better
#include <asm/irqflags.h>
#include <asm/paravirt.h>
#include <asm/ftrace.h>
+#include <asm/percpu.h>
- .code64
+/* 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
-#ifdef CONFIG_FTRACE
+ .code64
+#ifdef CONFIG_FUNCTION_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
ENTRY(mcount)
-
- subq $0x38, %rsp
- movq %rax, (%rsp)
- movq %rcx, 8(%rsp)
- movq %rdx, 16(%rsp)
- movq %rsi, 24(%rsp)
- movq %rdi, 32(%rsp)
- movq %r8, 40(%rsp)
- movq %r9, 48(%rsp)
-
- movq 0x38(%rsp), %rdi
- subq $MCOUNT_INSN_SIZE, %rdi
-
-.globl mcount_call
-mcount_call:
- call ftrace_stub
-
- movq 48(%rsp), %r9
- movq 40(%rsp), %r8
- movq 32(%rsp), %rdi
- movq 24(%rsp), %rsi
- movq 16(%rsp), %rdx
- movq 8(%rsp), %rcx
- movq (%rsp), %rax
- addq $0x38, %rsp
-
retq
END(mcount)
ENTRY(ftrace_caller)
+ cmpl $0, function_trace_stop
+ jne ftrace_stub
- /* taken from glibc */
- subq $0x38, %rsp
- movq %rax, (%rsp)
- movq %rcx, 8(%rsp)
- movq %rdx, 16(%rsp)
- movq %rsi, 24(%rsp)
- movq %rdi, 32(%rsp)
- movq %r8, 40(%rsp)
- movq %r9, 48(%rsp)
+ MCOUNT_SAVE_FRAME
movq 0x38(%rsp), %rdi
movq 8(%rbp), %rsi
ftrace_call:
call ftrace_stub
- movq 48(%rsp), %r9
- movq 40(%rsp), %r8
- movq 32(%rsp), %rdi
- movq 24(%rsp), %rsi
- movq 16(%rsp), %rdx
- movq 8(%rsp), %rcx
- movq (%rsp), %rax
- addq $0x38, %rsp
+ MCOUNT_RESTORE_FRAME
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.globl ftrace_graph_call
+ftrace_graph_call:
+ jmp ftrace_stub
+#endif
.globl ftrace_stub
ftrace_stub:
#else /* ! CONFIG_DYNAMIC_FTRACE */
ENTRY(mcount)
+ cmpl $0, function_trace_stop
+ jne ftrace_stub
+
cmpq $ftrace_stub, ftrace_trace_function
jnz trace
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ cmpq $ftrace_stub, ftrace_graph_return
+ jnz ftrace_graph_caller
+
+ cmpq $ftrace_graph_entry_stub, ftrace_graph_entry
+ jnz ftrace_graph_caller
+#endif
+
.globl ftrace_stub
ftrace_stub:
retq
trace:
- /* taken from glibc */
- subq $0x38, %rsp
+ MCOUNT_SAVE_FRAME
+
+ movq 0x38(%rsp), %rdi
+ movq 8(%rbp), %rsi
+ subq $MCOUNT_INSN_SIZE, %rdi
+
+ call *ftrace_trace_function
+
+ MCOUNT_RESTORE_FRAME
+
+ jmp ftrace_stub
+END(mcount)
+#endif /* CONFIG_DYNAMIC_FTRACE */
+#endif /* CONFIG_FUNCTION_TRACER */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
+ cmpl $0, function_trace_stop
+ jne ftrace_stub
+
+ MCOUNT_SAVE_FRAME
+
+ leaq 8(%rbp), %rdi
+ movq 0x38(%rsp), %rsi
+ subq $MCOUNT_INSN_SIZE, %rsi
+
+ call prepare_ftrace_return
+
+ MCOUNT_RESTORE_FRAME
+
+ retq
+END(ftrace_graph_caller)
+
+
+.globl return_to_handler
+return_to_handler:
+ subq $80, %rsp
+
movq %rax, (%rsp)
movq %rcx, 8(%rsp)
movq %rdx, 16(%rsp)
movq %rdi, 32(%rsp)
movq %r8, 40(%rsp)
movq %r9, 48(%rsp)
+ movq %r10, 56(%rsp)
+ movq %r11, 64(%rsp)
- movq 0x38(%rsp), %rdi
- movq 8(%rbp), %rsi
- subq $MCOUNT_INSN_SIZE, %rdi
-
- call *ftrace_trace_function
+ call ftrace_return_to_handler
+ movq %rax, 72(%rsp)
+ movq 64(%rsp), %r11
+ movq 56(%rsp), %r10
movq 48(%rsp), %r9
movq 40(%rsp), %r8
movq 32(%rsp), %rdi
movq 16(%rsp), %rdx
movq 8(%rsp), %rcx
movq (%rsp), %rax
- addq $0x38, %rsp
+ addq $72, %rsp
+ retq
+#endif
- jmp ftrace_stub
-END(mcount)
-#endif /* CONFIG_DYNAMIC_FTRACE */
-#endif /* CONFIG_FTRACE */
#ifndef CONFIG_PREEMPT
#define retint_kernel retint_restore_args
-#endif
+#endif
#ifdef CONFIG_PARAVIRT
ENTRY(native_usergs_sysret64)
.endm
/*
- * C code is not supposed to know about undefined top of stack. Every time
- * a C function with an pt_regs argument is called from the SYSCALL based
+ * C code is not supposed to know about undefined top of stack. Every time
+ * a C function with an pt_regs argument is called from the SYSCALL based
* fast path FIXUP_TOP_OF_STACK is needed.
* RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs
* manipulation.
- */
-
- /* %rsp:at FRAMEEND */
- .macro FIXUP_TOP_OF_STACK tmp
- movq %gs:pda_oldrsp,\tmp
- movq \tmp,RSP(%rsp)
- movq $__USER_DS,SS(%rsp)
- movq $__USER_CS,CS(%rsp)
- movq $-1,RCX(%rsp)
- movq R11(%rsp),\tmp /* get eflags */
- movq \tmp,EFLAGS(%rsp)
+ */
+
+ /* %rsp:at FRAMEEND */
+ .macro FIXUP_TOP_OF_STACK tmp offset=0
+ movq PER_CPU_VAR(old_rsp),\tmp
+ movq \tmp,RSP+\offset(%rsp)
+ movq $__USER_DS,SS+\offset(%rsp)
+ movq $__USER_CS,CS+\offset(%rsp)
+ movq $-1,RCX+\offset(%rsp)
+ movq R11+\offset(%rsp),\tmp /* get eflags */
+ movq \tmp,EFLAGS+\offset(%rsp)
.endm
- .macro RESTORE_TOP_OF_STACK tmp,offset=0
- movq RSP-\offset(%rsp),\tmp
- movq \tmp,%gs:pda_oldrsp
- movq EFLAGS-\offset(%rsp),\tmp
- movq \tmp,R11-\offset(%rsp)
+ .macro RESTORE_TOP_OF_STACK tmp offset=0
+ movq RSP+\offset(%rsp),\tmp
+ movq \tmp,PER_CPU_VAR(old_rsp)
+ movq EFLAGS+\offset(%rsp),\tmp
+ movq \tmp,R11+\offset(%rsp)
.endm
.macro FAKE_STACK_FRAME child_rip
pushq %rax /* rsp */
CFI_ADJUST_CFA_OFFSET 8
CFI_REL_OFFSET rsp,0
- pushq $(1<<9) /* eflags - interrupts on */
+ pushq $X86_EFLAGS_IF /* eflags - interrupts on */
CFI_ADJUST_CFA_OFFSET 8
/*CFI_REL_OFFSET rflags,0*/
pushq $__KERNEL_CS /* cs */
CFI_ADJUST_CFA_OFFSET -(6*8)
.endm
- .macro CFI_DEFAULT_STACK start=1
+/*
+ * initial frame state for interrupts (and exceptions without error code)
+ */
+ .macro EMPTY_FRAME start=1 offset=0
.if \start
- CFI_STARTPROC simple
+ CFI_STARTPROC simple
CFI_SIGNAL_FRAME
- CFI_DEF_CFA rsp,SS+8
+ CFI_DEF_CFA rsp,8+\offset
.else
- CFI_DEF_CFA_OFFSET SS+8
+ CFI_DEF_CFA_OFFSET 8+\offset
.endif
- CFI_REL_OFFSET r15,R15
- CFI_REL_OFFSET r14,R14
- CFI_REL_OFFSET r13,R13
- CFI_REL_OFFSET r12,R12
- CFI_REL_OFFSET rbp,RBP
- CFI_REL_OFFSET rbx,RBX
- CFI_REL_OFFSET r11,R11
- CFI_REL_OFFSET r10,R10
- CFI_REL_OFFSET r9,R9
- CFI_REL_OFFSET r8,R8
- CFI_REL_OFFSET rax,RAX
- CFI_REL_OFFSET rcx,RCX
- CFI_REL_OFFSET rdx,RDX
- CFI_REL_OFFSET rsi,RSI
- CFI_REL_OFFSET rdi,RDI
- CFI_REL_OFFSET rip,RIP
- /*CFI_REL_OFFSET cs,CS*/
- /*CFI_REL_OFFSET rflags,EFLAGS*/
- CFI_REL_OFFSET rsp,RSP
- /*CFI_REL_OFFSET ss,SS*/
.endm
+
+/*
+ * initial frame state for interrupts (and exceptions without error code)
+ */
+ .macro INTR_FRAME start=1 offset=0
+ EMPTY_FRAME \start, SS+8+\offset-RIP
+ /*CFI_REL_OFFSET ss, SS+\offset-RIP*/
+ CFI_REL_OFFSET rsp, RSP+\offset-RIP
+ /*CFI_REL_OFFSET rflags, EFLAGS+\offset-RIP*/
+ /*CFI_REL_OFFSET cs, CS+\offset-RIP*/
+ CFI_REL_OFFSET rip, RIP+\offset-RIP
+ .endm
+
+/*
+ * initial frame state for exceptions with error code (and interrupts
+ * with vector already pushed)
+ */
+ .macro XCPT_FRAME start=1 offset=0
+ INTR_FRAME \start, RIP+\offset-ORIG_RAX
+ /*CFI_REL_OFFSET orig_rax, ORIG_RAX-ORIG_RAX*/
+ .endm
+
/*
- * A newly forked process directly context switches into this.
- */
-/* rdi: prev */
+ * frame that enables calling into C.
+ */
+ .macro PARTIAL_FRAME start=1 offset=0
+ XCPT_FRAME \start, ORIG_RAX+\offset-ARGOFFSET
+ CFI_REL_OFFSET rdi, RDI+\offset-ARGOFFSET
+ CFI_REL_OFFSET rsi, RSI+\offset-ARGOFFSET
+ CFI_REL_OFFSET rdx, RDX+\offset-ARGOFFSET
+ CFI_REL_OFFSET rcx, RCX+\offset-ARGOFFSET
+ CFI_REL_OFFSET rax, RAX+\offset-ARGOFFSET
+ CFI_REL_OFFSET r8, R8+\offset-ARGOFFSET
+ CFI_REL_OFFSET r9, R9+\offset-ARGOFFSET
+ CFI_REL_OFFSET r10, R10+\offset-ARGOFFSET
+ CFI_REL_OFFSET r11, R11+\offset-ARGOFFSET
+ .endm
+
+/*
+ * frame that enables passing a complete pt_regs to a C function.
+ */
+ .macro DEFAULT_FRAME start=1 offset=0
+ PARTIAL_FRAME \start, R11+\offset-R15
+ CFI_REL_OFFSET rbx, RBX+\offset
+ CFI_REL_OFFSET rbp, RBP+\offset
+ CFI_REL_OFFSET r12, R12+\offset
+ CFI_REL_OFFSET r13, R13+\offset
+ CFI_REL_OFFSET r14, R14+\offset
+ CFI_REL_OFFSET r15, R15+\offset
+ .endm
+
+/* save partial stack frame */
+ENTRY(save_args)
+ XCPT_FRAME
+ cld
+ movq_cfi rdi, RDI+16-ARGOFFSET
+ movq_cfi rsi, RSI+16-ARGOFFSET
+ movq_cfi rdx, RDX+16-ARGOFFSET
+ movq_cfi rcx, RCX+16-ARGOFFSET
+ movq_cfi rax, RAX+16-ARGOFFSET
+ movq_cfi r8, R8+16-ARGOFFSET
+ movq_cfi r9, R9+16-ARGOFFSET
+ movq_cfi r10, R10+16-ARGOFFSET
+ movq_cfi r11, R11+16-ARGOFFSET
+
+ leaq -ARGOFFSET+16(%rsp),%rdi /* arg1 for handler */
+ movq_cfi rbp, 8 /* push %rbp */
+ leaq 8(%rsp), %rbp /* mov %rsp, %ebp */
+ testl $3, CS(%rdi)
+ je 1f
+ SWAPGS
+ /*
+ * irq_count is used to check if a CPU is already on an interrupt stack
+ * or not. While this is essentially redundant with preempt_count it is
+ * a little cheaper to use a separate counter in the PDA (short of
+ * moving irq_enter into assembly, which would be too much work)
+ */
+1: incl PER_CPU_VAR(irq_count)
+ jne 2f
+ popq_cfi %rax /* move return address... */
+ mov PER_CPU_VAR(irq_stack_ptr),%rsp
+ EMPTY_FRAME 0
+ pushq_cfi %rax /* ... to the new stack */
+ /*
+ * We entered an interrupt context - irqs are off:
+ */
+2: TRACE_IRQS_OFF
+ ret
+ CFI_ENDPROC
+END(save_args)
+
+ENTRY(save_rest)
+ PARTIAL_FRAME 1 REST_SKIP+8
+ movq 5*8+16(%rsp), %r11 /* save return address */
+ movq_cfi rbx, RBX+16
+ movq_cfi rbp, RBP+16
+ movq_cfi r12, R12+16
+ movq_cfi r13, R13+16
+ movq_cfi r14, R14+16
+ movq_cfi r15, R15+16
+ movq %r11, 8(%rsp) /* return address */
+ FIXUP_TOP_OF_STACK %r11, 16
+ ret
+ CFI_ENDPROC
+END(save_rest)
+
+/* save complete stack frame */
+ENTRY(save_paranoid)
+ XCPT_FRAME 1 RDI+8
+ cld
+ movq_cfi rdi, RDI+8
+ movq_cfi rsi, RSI+8
+ movq_cfi rdx, RDX+8
+ movq_cfi rcx, RCX+8
+ movq_cfi rax, RAX+8
+ movq_cfi r8, R8+8
+ movq_cfi r9, R9+8
+ movq_cfi r10, R10+8
+ movq_cfi r11, R11+8
+ movq_cfi rbx, RBX+8
+ movq_cfi rbp, RBP+8
+ movq_cfi r12, R12+8
+ movq_cfi r13, R13+8
+ movq_cfi r14, R14+8
+ movq_cfi r15, R15+8
+ movl $1,%ebx
+ movl $MSR_GS_BASE,%ecx
+ rdmsr
+ testl %edx,%edx
+ js 1f /* negative -> in kernel */
+ SWAPGS
+ xorl %ebx,%ebx
+1: ret
+ CFI_ENDPROC
+END(save_paranoid)
+
+/*
+ * A newly forked process directly context switches into this address.
+ *
+ * rdi: prev task we switched from
+ */
ENTRY(ret_from_fork)
- CFI_DEFAULT_STACK
+ DEFAULT_FRAME
+
push kernel_eflags(%rip)
- CFI_ADJUST_CFA_OFFSET 4
- popf # reset kernel eflags
- CFI_ADJUST_CFA_OFFSET -4
- call schedule_tail
+ CFI_ADJUST_CFA_OFFSET 8
+ popf # reset kernel eflags
+ CFI_ADJUST_CFA_OFFSET -8
+
+ call schedule_tail # rdi: 'prev' task parameter
+
GET_THREAD_INFO(%rcx)
- testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%rcx)
- jnz rff_trace
-rff_action:
+
+ CFI_REMEMBER_STATE
RESTORE_REST
- testl $3,CS-ARGOFFSET(%rsp) # from kernel_thread?
+
+ testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread?
je int_ret_from_sys_call
- testl $_TIF_IA32,TI_flags(%rcx)
+
+ testl $_TIF_IA32, TI_flags(%rcx) # 32-bit compat task needs IRET
jnz int_ret_from_sys_call
- RESTORE_TOP_OF_STACK %rdi,ARGOFFSET
- jmp ret_from_sys_call
-rff_trace:
- movq %rsp,%rdi
- call syscall_trace_leave
- GET_THREAD_INFO(%rcx)
- jmp rff_action
+
+ RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET
+ jmp ret_from_sys_call # go to the SYSRET fastpath
+
+ CFI_RESTORE_STATE
CFI_ENDPROC
END(ret_from_fork)
* SYSCALL does not save anything on the stack and does not change the
* stack pointer.
*/
-
+
/*
- * Register setup:
+ * Register setup:
* rax system call number
* rdi arg0
- * rcx return address for syscall/sysret, C arg3
+ * rcx return address for syscall/sysret, C arg3
* rsi arg1
- * rdx arg2
+ * rdx arg2
* r10 arg3 (--> moved to rcx for C)
* r8 arg4
* r9 arg5
* r11 eflags for syscall/sysret, temporary for C
- * r12-r15,rbp,rbx saved by C code, not touched.
- *
+ * r12-r15,rbp,rbx saved by C code, not touched.
+ *
* Interrupts are off on entry.
* Only called from user space.
*
* When user can change the frames always force IRET. That is because
* it deals with uncanonical addresses better. SYSRET has trouble
* with them due to bugs in both AMD and Intel CPUs.
- */
+ */
ENTRY(system_call)
CFI_STARTPROC simple
CFI_SIGNAL_FRAME
- CFI_DEF_CFA rsp,PDA_STACKOFFSET
+ CFI_DEF_CFA rsp,KERNEL_STACK_OFFSET
CFI_REGISTER rip,rcx
/*CFI_REGISTER rflags,r11*/
SWAPGS_UNSAFE_STACK
*/
ENTRY(system_call_after_swapgs)
- movq %rsp,%gs:pda_oldrsp
- movq %gs:pda_kernelstack,%rsp
+ movq %rsp,PER_CPU_VAR(old_rsp)
+ movq PER_CPU_VAR(kernel_stack),%rsp
/*
* No need to follow this irqs off/on section - it's straight
* and short:
*/
ENABLE_INTERRUPTS(CLBR_NONE)
SAVE_ARGS 8,1
- movq %rax,ORIG_RAX-ARGOFFSET(%rsp)
+ movq %rax,ORIG_RAX-ARGOFFSET(%rsp)
movq %rcx,RIP-ARGOFFSET(%rsp)
CFI_REL_OFFSET rip,RIP-ARGOFFSET
GET_THREAD_INFO(%rcx)
- testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP), \
- TI_flags(%rcx)
+ testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%rcx)
jnz tracesys
+system_call_fastpath:
cmpq $__NR_syscall_max,%rax
ja badsys
movq %r10,%rcx
movq %rax,RAX-ARGOFFSET(%rsp)
/*
* Syscall return path ending with SYSRET (fast path)
- * Has incomplete stack frame and undefined top of stack.
- */
+ * Has incomplete stack frame and undefined top of stack.
+ */
ret_from_sys_call:
movl $_TIF_ALLWORK_MASK,%edi
/* edi: flagmask */
-sysret_check:
+sysret_check:
LOCKDEP_SYS_EXIT
GET_THREAD_INFO(%rcx)
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
movl TI_flags(%rcx),%edx
andl %edi,%edx
- jnz sysret_careful
+ jnz sysret_careful
CFI_REMEMBER_STATE
/*
* sysretq will re-enable interrupts:
CFI_REGISTER rip,rcx
RESTORE_ARGS 0,-ARG_SKIP,1
/*CFI_REGISTER rflags,r11*/
- movq %gs:pda_oldrsp, %rsp
+ movq PER_CPU_VAR(old_rsp), %rsp
USERGS_SYSRET64
CFI_RESTORE_STATE
/* Handle reschedules */
- /* edx: work, edi: workmask */
+ /* edx: work, edi: workmask */
sysret_careful:
bt $TIF_NEED_RESCHED,%edx
jnc sysret_signal
CFI_ADJUST_CFA_OFFSET -8
jmp sysret_check
- /* Handle a signal */
+ /* Handle a signal */
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
+ SAVE_REST
+ FIXUP_TOP_OF_STACK %r11
+ call do_notify_resume
+ RESTORE_TOP_OF_STACK %r11
+ RESTORE_REST
+ 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)
TRACE_IRQS_OFF
jmp int_with_check
-
+
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:
+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
movq %rsp,%rdi
call syscall_trace_enter
- LOAD_ARGS ARGOFFSET /* reload args from stack in case ptrace changed it */
+ /*
+ * Reload arg registers from stack in case ptrace changed them.
+ * We don't reload %rax because syscall_trace_enter() returned
+ * the value it wants us to use in the table lookup.
+ */
+ LOAD_ARGS ARGOFFSET, 1
RESTORE_REST
cmpq $__NR_syscall_max,%rax
ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */
call *sys_call_table(,%rax,8)
movq %rax,RAX-ARGOFFSET(%rsp)
/* Use IRET because user could have changed frame */
-
-/*
+
+/*
* Syscall return path ending with IRET.
* 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
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
SAVE_REST
- /* Check for syscall exit trace */
- testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edx
+ /* Check for syscall exit trace */
+ testl $_TIF_WORK_SYSCALL_EXIT,%edx
jz int_signal
pushq %rdi
CFI_ADJUST_CFA_OFFSET 8
- leaq 8(%rsp),%rdi # &ptregs -> arg1
+ leaq 8(%rsp),%rdi # &ptregs -> arg1
call syscall_trace_leave
popq %rdi
CFI_ADJUST_CFA_OFFSET -8
- andl $~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edi
+ andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi
jmp int_restore_rest
-
+
int_signal:
testl $_TIF_DO_NOTIFY_MASK,%edx
jz 1f
jmp int_with_check
CFI_ENDPROC
END(system_call)
-
-/*
+
+/*
* Certain special system calls that need to save a complete full stack frame.
- */
-
+ */
.macro PTREGSCALL label,func,arg
- .globl \label
-\label:
- leaq \func(%rip),%rax
- leaq -ARGOFFSET+8(%rsp),\arg /* 8 for return address */
- jmp ptregscall_common
+ENTRY(\label)
+ PARTIAL_FRAME 1 8 /* offset 8: return address */
+ subq $REST_SKIP, %rsp
+ CFI_ADJUST_CFA_OFFSET REST_SKIP
+ call save_rest
+ DEFAULT_FRAME 0 8 /* offset 8: return address */
+ leaq 8(%rsp), \arg /* pt_regs pointer */
+ call \func
+ jmp ptregscall_common
+ CFI_ENDPROC
END(\label)
.endm
- CFI_STARTPROC
-
PTREGSCALL stub_clone, sys_clone, %r8
PTREGSCALL stub_fork, sys_fork, %rdi
PTREGSCALL stub_vfork, sys_vfork, %rdi
PTREGSCALL stub_iopl, sys_iopl, %rsi
ENTRY(ptregscall_common)
- popq %r11
- CFI_ADJUST_CFA_OFFSET -8
- CFI_REGISTER rip, r11
- SAVE_REST
- movq %r11, %r15
- CFI_REGISTER rip, r15
- FIXUP_TOP_OF_STACK %r11
- call *%rax
- RESTORE_TOP_OF_STACK %r11
- movq %r15, %r11
- CFI_REGISTER rip, r11
- RESTORE_REST
- pushq %r11
- CFI_ADJUST_CFA_OFFSET 8
- CFI_REL_OFFSET rip, 0
- ret
+ DEFAULT_FRAME 1 8 /* offset 8: return address */
+ RESTORE_TOP_OF_STACK %r11, 8
+ movq_cfi_restore R15+8, r15
+ movq_cfi_restore R14+8, r14
+ movq_cfi_restore R13+8, r13
+ movq_cfi_restore R12+8, r12
+ movq_cfi_restore RBP+8, rbp
+ movq_cfi_restore RBX+8, rbx
+ ret $REST_SKIP /* pop extended registers */
CFI_ENDPROC
END(ptregscall_common)
-
+
ENTRY(stub_execve)
CFI_STARTPROC
popq %r11
jmp int_ret_from_sys_call
CFI_ENDPROC
END(stub_execve)
-
+
/*
* sigreturn is special because it needs to restore all registers on return.
* This cannot be done with SYSRET, so use the IRET return path instead.
- */
+ */
ENTRY(stub_rt_sigreturn)
CFI_STARTPROC
addq $8, %rsp
END(stub_rt_sigreturn)
/*
- * initial frame state for interrupts and exceptions
+ * Build the entry stubs and pointer table with some assembler magic.
+ * We pack 7 stubs into a single 32-byte chunk, which will fit in a
+ * single cache line on all modern x86 implementations.
*/
- .macro _frame ref
- CFI_STARTPROC simple
- CFI_SIGNAL_FRAME
- CFI_DEF_CFA rsp,SS+8-\ref
- /*CFI_REL_OFFSET ss,SS-\ref*/
- CFI_REL_OFFSET rsp,RSP-\ref
- /*CFI_REL_OFFSET rflags,EFLAGS-\ref*/
- /*CFI_REL_OFFSET cs,CS-\ref*/
- CFI_REL_OFFSET rip,RIP-\ref
- .endm
+ .section .init.rodata,"a"
+ENTRY(interrupt)
+ .text
+ .p2align 5
+ .p2align CONFIG_X86_L1_CACHE_SHIFT
+ENTRY(irq_entries_start)
+ INTR_FRAME
+vector=FIRST_EXTERNAL_VECTOR
+.rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7
+ .balign 32
+ .rept 7
+ .if vector < NR_VECTORS
+ .if vector <> FIRST_EXTERNAL_VECTOR
+ CFI_ADJUST_CFA_OFFSET -8
+ .endif
+1: pushq $(~vector+0x80) /* Note: always in signed byte range */
+ CFI_ADJUST_CFA_OFFSET 8
+ .if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6
+ jmp 2f
+ .endif
+ .previous
+ .quad 1b
+ .text
+vector=vector+1
+ .endif
+ .endr
+2: jmp common_interrupt
+.endr
+ CFI_ENDPROC
+END(irq_entries_start)
-/* initial frame state for interrupts (and exceptions without error code) */
-#define INTR_FRAME _frame RIP
-/* initial frame state for exceptions with error code (and interrupts with
- vector already pushed) */
-#define XCPT_FRAME _frame ORIG_RAX
+.previous
+END(interrupt)
+.previous
-/*
+/*
* Interrupt entry/exit.
*
* Interrupt entry points save only callee clobbered registers in fast path.
- *
- * Entry runs with interrupts off.
- */
+ *
+ * Entry runs with interrupts off.
+ */
-/* 0(%rsp): interrupt number */
+/* 0(%rsp): ~(interrupt number) */
.macro interrupt func
- cld
- SAVE_ARGS
- leaq -ARGOFFSET(%rsp),%rdi # arg1 for handler
- pushq %rbp
- CFI_ADJUST_CFA_OFFSET 8
- CFI_REL_OFFSET rbp, 0
- movq %rsp,%rbp
- CFI_DEF_CFA_REGISTER rbp
- testl $3,CS(%rdi)
- je 1f
- SWAPGS
- /* irqcount is used to check if a CPU is already on an interrupt
- stack or not. While this is essentially redundant with preempt_count
- it is a little cheaper to use a separate counter in the PDA
- (short of moving irq_enter into assembly, which would be too
- much work) */
-1: incl %gs:pda_irqcount
- cmoveq %gs:pda_irqstackptr,%rsp
- push %rbp # backlink for old unwinder
- /*
- * We entered an interrupt context - irqs are off:
- */
- TRACE_IRQS_OFF
+ subq $10*8, %rsp
+ CFI_ADJUST_CFA_OFFSET 10*8
+ call save_args
+ PARTIAL_FRAME 0
call \func
.endm
-ENTRY(common_interrupt)
+ /*
+ * The interrupt stubs push (~vector+0x80) onto the stack and
+ * then jump to common_interrupt.
+ */
+ .p2align CONFIG_X86_L1_CACHE_SHIFT
+common_interrupt:
XCPT_FRAME
+ addq $-0x80,(%rsp) /* Adjust vector to [-256,-1] range */
interrupt do_IRQ
- /* 0(%rsp): oldrsp-ARGOFFSET */
+ /* 0(%rsp): old_rsp-ARGOFFSET */
ret_from_intr:
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
- decl %gs:pda_irqcount
+ decl PER_CPU_VAR(irq_count)
leaveq
CFI_DEF_CFA_REGISTER rsp
CFI_ADJUST_CFA_OFFSET -8
GET_THREAD_INFO(%rcx)
testl $3,CS-ARGOFFSET(%rsp)
je retint_kernel
-
+
/* Interrupt came from user space */
/*
* Has a correct top of stack, but a partial stack frame
* %rcx: thread info. Interrupts off.
- */
+ */
retint_with_reschedule:
movl $_TIF_WORK_MASK,%edi
retint_check:
pushq %rdi
CFI_ADJUST_CFA_OFFSET 8
call schedule
- popq %rdi
+ popq %rdi
CFI_ADJUST_CFA_OFFSET -8
GET_THREAD_INFO(%rcx)
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
jmp retint_check
-
+
retint_signal:
testl $_TIF_DO_NOTIFY_MASK,%edx
jz retint_swapgs
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
SAVE_REST
- movq $-1,ORIG_RAX(%rsp)
+ movq $-1,ORIG_RAX(%rsp)
xorl %esi,%esi # oldset
movq %rsp,%rdi # &pt_regs
call do_notify_resume
jnc retint_restore_args
call preempt_schedule_irq
jmp exit_intr
-#endif
+#endif
CFI_ENDPROC
END(common_interrupt)
-
+
/*
* APIC interrupts.
- */
- .macro apicinterrupt num,func
+ */
+.macro apicinterrupt num sym do_sym
+ENTRY(\sym)
INTR_FRAME
pushq $~(\num)
CFI_ADJUST_CFA_OFFSET 8
- interrupt \func
+ interrupt \do_sym
jmp ret_from_intr
CFI_ENDPROC
- .endm
-
-ENTRY(thermal_interrupt)
- apicinterrupt THERMAL_APIC_VECTOR,smp_thermal_interrupt
-END(thermal_interrupt)
-
-ENTRY(threshold_interrupt)
- apicinterrupt THRESHOLD_APIC_VECTOR,mce_threshold_interrupt
-END(threshold_interrupt)
-
-#ifdef CONFIG_SMP
-ENTRY(reschedule_interrupt)
- apicinterrupt RESCHEDULE_VECTOR,smp_reschedule_interrupt
-END(reschedule_interrupt)
-
- .macro INVALIDATE_ENTRY num
-ENTRY(invalidate_interrupt\num)
- apicinterrupt INVALIDATE_TLB_VECTOR_START+\num,smp_invalidate_interrupt
-END(invalidate_interrupt\num)
- .endm
+END(\sym)
+.endm
- INVALIDATE_ENTRY 0
- INVALIDATE_ENTRY 1
- INVALIDATE_ENTRY 2
- INVALIDATE_ENTRY 3
- INVALIDATE_ENTRY 4
- INVALIDATE_ENTRY 5
- INVALIDATE_ENTRY 6
- INVALIDATE_ENTRY 7
-
-ENTRY(call_function_interrupt)
- apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt
-END(call_function_interrupt)
-ENTRY(call_function_single_interrupt)
- apicinterrupt CALL_FUNCTION_SINGLE_VECTOR,smp_call_function_single_interrupt
-END(call_function_single_interrupt)
-ENTRY(irq_move_cleanup_interrupt)
- apicinterrupt IRQ_MOVE_CLEANUP_VECTOR,smp_irq_move_cleanup_interrupt
-END(irq_move_cleanup_interrupt)
+#ifdef CONFIG_SMP
+apicinterrupt IRQ_MOVE_CLEANUP_VECTOR \
+ irq_move_cleanup_interrupt smp_irq_move_cleanup_interrupt
#endif
-ENTRY(apic_timer_interrupt)
- apicinterrupt LOCAL_TIMER_VECTOR,smp_apic_timer_interrupt
-END(apic_timer_interrupt)
+#ifdef CONFIG_X86_UV
+apicinterrupt UV_BAU_MESSAGE \
+ uv_bau_message_intr1 uv_bau_message_interrupt
+#endif
+apicinterrupt LOCAL_TIMER_VECTOR \
+ apic_timer_interrupt smp_apic_timer_interrupt
+
+#ifdef CONFIG_SMP
+apicinterrupt INVALIDATE_TLB_VECTOR_START+0 \
+ invalidate_interrupt0 smp_invalidate_interrupt
+apicinterrupt INVALIDATE_TLB_VECTOR_START+1 \
+ invalidate_interrupt1 smp_invalidate_interrupt
+apicinterrupt INVALIDATE_TLB_VECTOR_START+2 \
+ invalidate_interrupt2 smp_invalidate_interrupt
+apicinterrupt INVALIDATE_TLB_VECTOR_START+3 \
+ invalidate_interrupt3 smp_invalidate_interrupt
+apicinterrupt INVALIDATE_TLB_VECTOR_START+4 \
+ invalidate_interrupt4 smp_invalidate_interrupt
+apicinterrupt INVALIDATE_TLB_VECTOR_START+5 \
+ invalidate_interrupt5 smp_invalidate_interrupt
+apicinterrupt INVALIDATE_TLB_VECTOR_START+6 \
+ invalidate_interrupt6 smp_invalidate_interrupt
+apicinterrupt INVALIDATE_TLB_VECTOR_START+7 \
+ invalidate_interrupt7 smp_invalidate_interrupt
+#endif
-ENTRY(uv_bau_message_intr1)
- apicinterrupt 220,uv_bau_message_interrupt
-END(uv_bau_message_intr1)
+apicinterrupt THRESHOLD_APIC_VECTOR \
+ threshold_interrupt mce_threshold_interrupt
+apicinterrupt THERMAL_APIC_VECTOR \
+ thermal_interrupt smp_thermal_interrupt
+
+#ifdef CONFIG_SMP
+apicinterrupt CALL_FUNCTION_SINGLE_VECTOR \
+ call_function_single_interrupt smp_call_function_single_interrupt
+apicinterrupt CALL_FUNCTION_VECTOR \
+ call_function_interrupt smp_call_function_interrupt
+apicinterrupt RESCHEDULE_VECTOR \
+ reschedule_interrupt smp_reschedule_interrupt
+#endif
-ENTRY(error_interrupt)
- apicinterrupt ERROR_APIC_VECTOR,smp_error_interrupt
-END(error_interrupt)
+apicinterrupt ERROR_APIC_VECTOR \
+ error_interrupt smp_error_interrupt
+apicinterrupt SPURIOUS_APIC_VECTOR \
+ spurious_interrupt smp_spurious_interrupt
-ENTRY(spurious_interrupt)
- apicinterrupt SPURIOUS_APIC_VECTOR,smp_spurious_interrupt
-END(spurious_interrupt)
-
/*
* Exception entry points.
- */
- .macro zeroentry sym
+ */
+.macro zeroentry sym do_sym
+ENTRY(\sym)
INTR_FRAME
PARAVIRT_ADJUST_EXCEPTION_FRAME
- pushq $0 /* push error code/oldrax */
- CFI_ADJUST_CFA_OFFSET 8
- pushq %rax /* push real oldrax to the rdi slot */
- CFI_ADJUST_CFA_OFFSET 8
- CFI_REL_OFFSET rax,0
- leaq \sym(%rip),%rax
- jmp error_entry
+ pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */
+ subq $15*8,%rsp
+ CFI_ADJUST_CFA_OFFSET 15*8
+ call error_entry
+ DEFAULT_FRAME 0
+ movq %rsp,%rdi /* pt_regs pointer */
+ xorl %esi,%esi /* no error code */
+ call \do_sym
+ jmp error_exit /* %ebx: no swapgs flag */
CFI_ENDPROC
- .endm
+END(\sym)
+.endm
- .macro errorentry sym
- XCPT_FRAME
+.macro paranoidzeroentry sym do_sym
+ENTRY(\sym)
+ INTR_FRAME
PARAVIRT_ADJUST_EXCEPTION_FRAME
- pushq %rax
+ pushq $-1 /* ORIG_RAX: no syscall to restart */
CFI_ADJUST_CFA_OFFSET 8
- CFI_REL_OFFSET rax,0
- leaq \sym(%rip),%rax
- jmp error_entry
+ subq $15*8, %rsp
+ call save_paranoid
+ TRACE_IRQS_OFF
+ movq %rsp,%rdi /* pt_regs pointer */
+ xorl %esi,%esi /* no error code */
+ call \do_sym
+ jmp paranoid_exit /* %ebx: no swapgs flag */
CFI_ENDPROC
- .endm
+END(\sym)
+.endm
- /* error code is on the stack already */
- /* handle NMI like exceptions that can happen everywhere */
- .macro paranoidentry sym, ist=0, irqtrace=1
- SAVE_ALL
- cld
- movl $1,%ebx
- movl $MSR_GS_BASE,%ecx
- rdmsr
- testl %edx,%edx
- js 1f
- SWAPGS
- xorl %ebx,%ebx
-1:
- .if \ist
- movq %gs:pda_data_offset, %rbp
- .endif
- movq %rsp,%rdi
- movq ORIG_RAX(%rsp),%rsi
- movq $-1,ORIG_RAX(%rsp)
- .if \ist
- subq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp)
- .endif
- call \sym
- .if \ist
- addq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp)
- .endif
- DISABLE_INTERRUPTS(CLBR_NONE)
- .if \irqtrace
+.macro paranoidzeroentry_ist sym do_sym ist
+ENTRY(\sym)
+ INTR_FRAME
+ PARAVIRT_ADJUST_EXCEPTION_FRAME
+ pushq $-1 /* ORIG_RAX: no syscall to restart */
+ CFI_ADJUST_CFA_OFFSET 8
+ subq $15*8, %rsp
+ call save_paranoid
TRACE_IRQS_OFF
- .endif
- .endm
+ movq %rsp,%rdi /* pt_regs pointer */
+ xorl %esi,%esi /* no error code */
+ PER_CPU(init_tss, %rbp)
+ subq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%rbp)
+ call \do_sym
+ addq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%rbp)
+ jmp paranoid_exit /* %ebx: no swapgs flag */
+ CFI_ENDPROC
+END(\sym)
+.endm
- /*
- * "Paranoid" exit path from exception stack.
- * Paranoid because this is used by NMIs and cannot take
- * any kernel state for granted.
- * We don't do kernel preemption checks here, because only
- * NMI should be common and it does not enable IRQs and
- * cannot get reschedule ticks.
- *
- * "trace" is 0 for the NMI handler only, because irq-tracing
- * is fundamentally NMI-unsafe. (we cannot change the soft and
- * hard flags at once, atomically)
- */
- .macro paranoidexit trace=1
- /* ebx: no swapgs flag */
-paranoid_exit\trace:
- testl %ebx,%ebx /* swapgs needed? */
- jnz paranoid_restore\trace
- testl $3,CS(%rsp)
- jnz paranoid_userspace\trace
-paranoid_swapgs\trace:
- .if \trace
- TRACE_IRQS_IRETQ 0
- .endif
- SWAPGS_UNSAFE_STACK
-paranoid_restore\trace:
- RESTORE_ALL 8
- jmp irq_return
-paranoid_userspace\trace:
- GET_THREAD_INFO(%rcx)
- movl TI_flags(%rcx),%ebx
- andl $_TIF_WORK_MASK,%ebx
- jz paranoid_swapgs\trace
- movq %rsp,%rdi /* &pt_regs */
- call sync_regs
- movq %rax,%rsp /* switch stack for scheduling */
- testl $_TIF_NEED_RESCHED,%ebx
- jnz paranoid_schedule\trace
- movl %ebx,%edx /* arg3: thread flags */
- .if \trace
- TRACE_IRQS_ON
- .endif
- ENABLE_INTERRUPTS(CLBR_NONE)
- xorl %esi,%esi /* arg2: oldset */
- movq %rsp,%rdi /* arg1: &pt_regs */
- call do_notify_resume
- DISABLE_INTERRUPTS(CLBR_NONE)
- .if \trace
- TRACE_IRQS_OFF
- .endif
- jmp paranoid_userspace\trace
-paranoid_schedule\trace:
- .if \trace
- TRACE_IRQS_ON
- .endif
- ENABLE_INTERRUPTS(CLBR_ANY)
- call schedule
- DISABLE_INTERRUPTS(CLBR_ANY)
- .if \trace
- TRACE_IRQS_OFF
- .endif
- jmp paranoid_userspace\trace
+.macro errorentry sym do_sym
+ENTRY(\sym)
+ XCPT_FRAME
+ PARAVIRT_ADJUST_EXCEPTION_FRAME
+ subq $15*8,%rsp
+ CFI_ADJUST_CFA_OFFSET 15*8
+ call error_entry
+ DEFAULT_FRAME 0
+ movq %rsp,%rdi /* pt_regs pointer */
+ movq ORIG_RAX(%rsp),%rsi /* get error code */
+ movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */
+ call \do_sym
+ jmp error_exit /* %ebx: no swapgs flag */
CFI_ENDPROC
- .endm
+END(\sym)
+.endm
-/*
- * Exception entry point. This expects an error code/orig_rax on the stack
- * and the exception handler in %rax.
- */
-KPROBE_ENTRY(error_entry)
- _frame RDI
- CFI_REL_OFFSET rax,0
- /* rdi slot contains rax, oldrax contains error code */
- cld
- subq $14*8,%rsp
- CFI_ADJUST_CFA_OFFSET (14*8)
- movq %rsi,13*8(%rsp)
- CFI_REL_OFFSET rsi,RSI
- movq 14*8(%rsp),%rsi /* load rax from rdi slot */
- CFI_REGISTER rax,rsi
- movq %rdx,12*8(%rsp)
- CFI_REL_OFFSET rdx,RDX
- movq %rcx,11*8(%rsp)
- CFI_REL_OFFSET rcx,RCX
- movq %rsi,10*8(%rsp) /* store rax */
- CFI_REL_OFFSET rax,RAX
- movq %r8, 9*8(%rsp)
- CFI_REL_OFFSET r8,R8
- movq %r9, 8*8(%rsp)
- CFI_REL_OFFSET r9,R9
- movq %r10,7*8(%rsp)
- CFI_REL_OFFSET r10,R10
- movq %r11,6*8(%rsp)
- CFI_REL_OFFSET r11,R11
- movq %rbx,5*8(%rsp)
- CFI_REL_OFFSET rbx,RBX
- movq %rbp,4*8(%rsp)
- CFI_REL_OFFSET rbp,RBP
- movq %r12,3*8(%rsp)
- CFI_REL_OFFSET r12,R12
- movq %r13,2*8(%rsp)
- CFI_REL_OFFSET r13,R13
- movq %r14,1*8(%rsp)
- CFI_REL_OFFSET r14,R14
- movq %r15,(%rsp)
- CFI_REL_OFFSET r15,R15
- xorl %ebx,%ebx
- testl $3,CS(%rsp)
- je error_kernelspace
-error_swapgs:
- SWAPGS
-error_sti:
- movq %rdi,RDI(%rsp)
- CFI_REL_OFFSET rdi,RDI
- movq %rsp,%rdi
- movq ORIG_RAX(%rsp),%rsi /* get error code */
- movq $-1,ORIG_RAX(%rsp)
- call *%rax
- /* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */
-error_exit:
- movl %ebx,%eax
- RESTORE_REST
- DISABLE_INTERRUPTS(CLBR_NONE)
+ /* error code is on the stack already */
+.macro paranoiderrorentry sym do_sym
+ENTRY(\sym)
+ XCPT_FRAME
+ PARAVIRT_ADJUST_EXCEPTION_FRAME
+ subq $15*8,%rsp
+ CFI_ADJUST_CFA_OFFSET 15*8
+ call save_paranoid
+ DEFAULT_FRAME 0
TRACE_IRQS_OFF
- GET_THREAD_INFO(%rcx)
- testl %eax,%eax
- jne retint_kernel
- LOCKDEP_SYS_EXIT_IRQ
- movl TI_flags(%rcx),%edx
- movl $_TIF_WORK_MASK,%edi
- andl %edi,%edx
- jnz retint_careful
- jmp retint_swapgs
+ movq %rsp,%rdi /* pt_regs pointer */
+ movq ORIG_RAX(%rsp),%rsi /* get error code */
+ movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */
+ call \do_sym
+ jmp paranoid_exit /* %ebx: no swapgs flag */
CFI_ENDPROC
+END(\sym)
+.endm
-error_kernelspace:
- incl %ebx
- /* There are two places in the kernel that can potentially fault with
- usergs. Handle them here. The exception handlers after
- iret run with kernel gs again, so don't set the user space flag.
- B stepping K8s sometimes report an truncated RIP for IRET
- exceptions returning to compat mode. Check for these here too. */
- leaq irq_return(%rip),%rcx
- cmpq %rcx,RIP(%rsp)
- je error_swapgs
- movl %ecx,%ecx /* zero extend */
- cmpq %rcx,RIP(%rsp)
- je error_swapgs
- cmpq $gs_change,RIP(%rsp)
- je error_swapgs
- jmp error_sti
-KPROBE_END(error_entry)
-
- /* Reload gs selector with exception handling */
- /* edi: new selector */
+zeroentry divide_error do_divide_error
+zeroentry overflow do_overflow
+zeroentry bounds do_bounds
+zeroentry invalid_op do_invalid_op
+zeroentry device_not_available do_device_not_available
+paranoiderrorentry double_fault do_double_fault
+zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun
+errorentry invalid_TSS do_invalid_TSS
+errorentry segment_not_present do_segment_not_present
+zeroentry spurious_interrupt_bug do_spurious_interrupt_bug
+zeroentry coprocessor_error do_coprocessor_error
+errorentry alignment_check do_alignment_check
+zeroentry simd_coprocessor_error do_simd_coprocessor_error
+
+ /* Reload gs selector with exception handling */
+ /* edi: new selector */
ENTRY(native_load_gs_index)
CFI_STARTPROC
pushf
CFI_ADJUST_CFA_OFFSET 8
DISABLE_INTERRUPTS(CLBR_ANY | ~(CLBR_RDI))
- SWAPGS
-gs_change:
- movl %edi,%gs
+ SWAPGS
+gs_change:
+ movl %edi,%gs
2: mfence /* workaround */
SWAPGS
- popf
+ popf
CFI_ADJUST_CFA_OFFSET -8
- ret
+ ret
CFI_ENDPROC
-ENDPROC(native_load_gs_index)
-
- .section __ex_table,"a"
- .align 8
- .quad gs_change,bad_gs
- .previous
- .section .fixup,"ax"
+END(native_load_gs_index)
+
+ .section __ex_table,"a"
+ .align 8
+ .quad gs_change,bad_gs
+ .previous
+ .section .fixup,"ax"
/* running with kernelgs */
-bad_gs:
+bad_gs:
SWAPGS /* switch back to user gs */
xorl %eax,%eax
- movl %eax,%gs
- jmp 2b
- .previous
-
+ movl %eax,%gs
+ jmp 2b
+ .previous
+
/*
* Create a kernel thread.
*
xorl %r8d,%r8d
xorl %r9d,%r9d
-
+
# clone now
call do_fork
movq %rax,RAX(%rsp)
* so internally to the x86_64 port you can rely on kernel_thread()
* not to reschedule the child before returning, this avoids the need
* of hacks for example to fork off the per-CPU idle tasks.
- * [Hopefully no generic code relies on the reschedule -AK]
+ * [Hopefully no generic code relies on the reschedule -AK]
*/
RESTORE_ALL
UNFAKE_STACK_FRAME
ret
CFI_ENDPROC
-ENDPROC(kernel_thread)
-
-child_rip:
+END(kernel_thread)
+
+ENTRY(child_rip)
pushq $0 # fake return address
CFI_STARTPROC
/*
# exit
mov %eax, %edi
call do_exit
+ ud2 # padding for call trace
CFI_ENDPROC
-ENDPROC(child_rip)
+END(child_rip)
/*
* execve(). This function needs to use IRET, not SYSRET, to set up all state properly.
ENTRY(kernel_execve)
CFI_STARTPROC
FAKE_STACK_FRAME $0
- SAVE_ALL
+ SAVE_ALL
movq %rsp,%rcx
call sys_execve
- movq %rax, RAX(%rsp)
+ movq %rax, RAX(%rsp)
RESTORE_REST
testq %rax,%rax
je int_ret_from_sys_call
UNFAKE_STACK_FRAME
ret
CFI_ENDPROC
-ENDPROC(kernel_execve)
+END(kernel_execve)
-KPROBE_ENTRY(page_fault)
- errorentry do_page_fault
-KPROBE_END(page_fault)
-
-ENTRY(coprocessor_error)
- zeroentry do_coprocessor_error
-END(coprocessor_error)
-
-ENTRY(simd_coprocessor_error)
- zeroentry do_simd_coprocessor_error
-END(simd_coprocessor_error)
-
-ENTRY(device_not_available)
- zeroentry math_state_restore
-END(device_not_available)
+/* Call softirq on interrupt stack. Interrupts are off. */
+ENTRY(call_softirq)
+ CFI_STARTPROC
+ push %rbp
+ CFI_ADJUST_CFA_OFFSET 8
+ CFI_REL_OFFSET rbp,0
+ mov %rsp,%rbp
+ CFI_DEF_CFA_REGISTER rbp
+ incl PER_CPU_VAR(irq_count)
+ cmove PER_CPU_VAR(irq_stack_ptr),%rsp
+ push %rbp # backlink for old unwinder
+ call __do_softirq
+ leaveq
+ CFI_DEF_CFA_REGISTER rsp
+ CFI_ADJUST_CFA_OFFSET -8
+ decl PER_CPU_VAR(irq_count)
+ ret
+ CFI_ENDPROC
+END(call_softirq)
- /* runs on exception stack */
-KPROBE_ENTRY(debug)
- INTR_FRAME
- pushq $0
- CFI_ADJUST_CFA_OFFSET 8
- paranoidentry do_debug, DEBUG_STACK
- paranoidexit
-KPROBE_END(debug)
+#ifdef CONFIG_XEN
+zeroentry xen_hypervisor_callback xen_do_hypervisor_callback
- /* runs on exception stack */
-KPROBE_ENTRY(nmi)
- INTR_FRAME
- pushq $-1
- CFI_ADJUST_CFA_OFFSET 8
- paranoidentry do_nmi, 0, 0
-#ifdef CONFIG_TRACE_IRQFLAGS
- paranoidexit 0
-#else
- jmp paranoid_exit1
- CFI_ENDPROC
-#endif
-KPROBE_END(nmi)
+/*
+ * A note on the "critical region" in our callback handler.
+ * We want to avoid stacking callback handlers due to events occurring
+ * during handling of the last event. To do this, we keep events disabled
+ * until we've done all processing. HOWEVER, we must enable events before
+ * popping the stack frame (can't be done atomically) and so it would still
+ * be possible to get enough handler activations to overflow the stack.
+ * Although unlikely, bugs of that kind are hard to track down, so we'd
+ * like to avoid the possibility.
+ * So, on entry to the handler we detect whether we interrupted an
+ * existing activation in its critical region -- if so, we pop the current
+ * activation and restart the handler using the previous one.
+ */
+ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
+ CFI_STARTPROC
+/*
+ * Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will
+ * see the correct pointer to the pt_regs
+ */
+ movq %rdi, %rsp # we don't return, adjust the stack frame
+ CFI_ENDPROC
+ DEFAULT_FRAME
+11: incl PER_CPU_VAR(irq_count)
+ movq %rsp,%rbp
+ CFI_DEF_CFA_REGISTER rbp
+ cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp
+ pushq %rbp # backlink for old unwinder
+ call xen_evtchn_do_upcall
+ popq %rsp
+ CFI_DEF_CFA_REGISTER rsp
+ decl PER_CPU_VAR(irq_count)
+ jmp error_exit
+ CFI_ENDPROC
+END(do_hypervisor_callback)
-KPROBE_ENTRY(int3)
- INTR_FRAME
- pushq $0
- CFI_ADJUST_CFA_OFFSET 8
- paranoidentry do_int3, DEBUG_STACK
- jmp paranoid_exit1
- CFI_ENDPROC
-KPROBE_END(int3)
+/*
+ * Hypervisor uses this for application faults while it executes.
+ * We get here for two reasons:
+ * 1. Fault while reloading DS, ES, FS or GS
+ * 2. Fault while executing IRET
+ * Category 1 we do not need to fix up as Xen has already reloaded all segment
+ * registers that could be reloaded and zeroed the others.
+ * Category 2 we fix up by killing the current process. We cannot use the
+ * normal Linux return path in this case because if we use the IRET hypercall
+ * to pop the stack frame we end up in an infinite loop of failsafe callbacks.
+ * We distinguish between categories by comparing each saved segment register
+ * with its current contents: any discrepancy means we in category 1.
+ */
+ENTRY(xen_failsafe_callback)
+ INTR_FRAME 1 (6*8)
+ /*CFI_REL_OFFSET gs,GS*/
+ /*CFI_REL_OFFSET fs,FS*/
+ /*CFI_REL_OFFSET es,ES*/
+ /*CFI_REL_OFFSET ds,DS*/
+ CFI_REL_OFFSET r11,8
+ CFI_REL_OFFSET rcx,0
+ movw %ds,%cx
+ cmpw %cx,0x10(%rsp)
+ CFI_REMEMBER_STATE
+ jne 1f
+ movw %es,%cx
+ cmpw %cx,0x18(%rsp)
+ jne 1f
+ movw %fs,%cx
+ cmpw %cx,0x20(%rsp)
+ jne 1f
+ movw %gs,%cx
+ cmpw %cx,0x28(%rsp)
+ jne 1f
+ /* All segments match their saved values => Category 2 (Bad IRET). */
+ movq (%rsp),%rcx
+ CFI_RESTORE rcx
+ movq 8(%rsp),%r11
+ CFI_RESTORE r11
+ addq $0x30,%rsp
+ CFI_ADJUST_CFA_OFFSET -0x30
+ pushq_cfi $0 /* RIP */
+ pushq_cfi %r11
+ pushq_cfi %rcx
+ jmp general_protection
+ CFI_RESTORE_STATE
+1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */
+ movq (%rsp),%rcx
+ CFI_RESTORE rcx
+ movq 8(%rsp),%r11
+ CFI_RESTORE r11
+ addq $0x30,%rsp
+ CFI_ADJUST_CFA_OFFSET -0x30
+ pushq_cfi $0
+ SAVE_ALL
+ jmp error_exit
+ CFI_ENDPROC
+END(xen_failsafe_callback)
-ENTRY(overflow)
- zeroentry do_overflow
-END(overflow)
+#endif /* CONFIG_XEN */
-ENTRY(bounds)
- zeroentry do_bounds
-END(bounds)
+/*
+ * Some functions should be protected against kprobes
+ */
+ .pushsection .kprobes.text, "ax"
-ENTRY(invalid_op)
- zeroentry do_invalid_op
-END(invalid_op)
+paranoidzeroentry_ist debug do_debug DEBUG_STACK
+paranoidzeroentry_ist int3 do_int3 DEBUG_STACK
+paranoiderrorentry stack_segment do_stack_segment
+errorentry general_protection do_general_protection
+errorentry page_fault do_page_fault
+#ifdef CONFIG_X86_MCE
+paranoidzeroentry machine_check do_machine_check
+#endif
-ENTRY(coprocessor_segment_overrun)
- zeroentry do_coprocessor_segment_overrun
-END(coprocessor_segment_overrun)
+ /*
+ * "Paranoid" exit path from exception stack.
+ * Paranoid because this is used by NMIs and cannot take
+ * any kernel state for granted.
+ * We don't do kernel preemption checks here, because only
+ * NMI should be common and it does not enable IRQs and
+ * cannot get reschedule ticks.
+ *
+ * "trace" is 0 for the NMI handler only, because irq-tracing
+ * is fundamentally NMI-unsafe. (we cannot change the soft and
+ * hard flags at once, atomically)
+ */
- /* runs on exception stack */
-ENTRY(double_fault)
- XCPT_FRAME
- paranoidentry do_double_fault
- jmp paranoid_exit1
+ /* ebx: no swapgs flag */
+ENTRY(paranoid_exit)
+ INTR_FRAME
+ DISABLE_INTERRUPTS(CLBR_NONE)
+ TRACE_IRQS_OFF
+ testl %ebx,%ebx /* swapgs needed? */
+ jnz paranoid_restore
+ testl $3,CS(%rsp)
+ jnz paranoid_userspace
+paranoid_swapgs:
+ TRACE_IRQS_IRETQ 0
+ SWAPGS_UNSAFE_STACK
+paranoid_restore:
+ RESTORE_ALL 8
+ jmp irq_return
+paranoid_userspace:
+ GET_THREAD_INFO(%rcx)
+ movl TI_flags(%rcx),%ebx
+ andl $_TIF_WORK_MASK,%ebx
+ jz paranoid_swapgs
+ movq %rsp,%rdi /* &pt_regs */
+ call sync_regs
+ movq %rax,%rsp /* switch stack for scheduling */
+ testl $_TIF_NEED_RESCHED,%ebx
+ jnz paranoid_schedule
+ movl %ebx,%edx /* arg3: thread flags */
+ TRACE_IRQS_ON
+ ENABLE_INTERRUPTS(CLBR_NONE)
+ xorl %esi,%esi /* arg2: oldset */
+ movq %rsp,%rdi /* arg1: &pt_regs */
+ call do_notify_resume
+ DISABLE_INTERRUPTS(CLBR_NONE)
+ TRACE_IRQS_OFF
+ jmp paranoid_userspace
+paranoid_schedule:
+ TRACE_IRQS_ON
+ ENABLE_INTERRUPTS(CLBR_ANY)
+ call schedule
+ DISABLE_INTERRUPTS(CLBR_ANY)
+ TRACE_IRQS_OFF
+ jmp paranoid_userspace
CFI_ENDPROC
-END(double_fault)
-
-ENTRY(invalid_TSS)
- errorentry do_invalid_TSS
-END(invalid_TSS)
+END(paranoid_exit)
-ENTRY(segment_not_present)
- errorentry do_segment_not_present
-END(segment_not_present)
-
- /* runs on exception stack */
-ENTRY(stack_segment)
+/*
+ * Exception entry point. This expects an error code/orig_rax on the stack.
+ * returns in "no swapgs flag" in %ebx.
+ */
+ENTRY(error_entry)
XCPT_FRAME
- paranoidentry do_stack_segment
- jmp paranoid_exit1
+ CFI_ADJUST_CFA_OFFSET 15*8
+ /* oldrax contains error code */
+ cld
+ movq_cfi rdi, RDI+8
+ movq_cfi rsi, RSI+8
+ movq_cfi rdx, RDX+8
+ movq_cfi rcx, RCX+8
+ movq_cfi rax, RAX+8
+ movq_cfi r8, R8+8
+ movq_cfi r9, R9+8
+ movq_cfi r10, R10+8
+ movq_cfi r11, R11+8
+ movq_cfi rbx, RBX+8
+ movq_cfi rbp, RBP+8
+ movq_cfi r12, R12+8
+ movq_cfi r13, R13+8
+ movq_cfi r14, R14+8
+ movq_cfi r15, R15+8
+ xorl %ebx,%ebx
+ testl $3,CS+8(%rsp)
+ je error_kernelspace
+error_swapgs:
+ SWAPGS
+error_sti:
+ TRACE_IRQS_OFF
+ ret
CFI_ENDPROC
-END(stack_segment)
-KPROBE_ENTRY(general_protection)
- errorentry do_general_protection
-KPROBE_END(general_protection)
+/*
+ * There are two places in the kernel that can potentially fault with
+ * usergs. Handle them here. The exception handlers after iret run with
+ * kernel gs again, so don't set the user space flag. B stepping K8s
+ * sometimes report an truncated RIP for IRET exceptions returning to
+ * compat mode. Check for these here too.
+ */
+error_kernelspace:
+ incl %ebx
+ leaq irq_return(%rip),%rcx
+ cmpq %rcx,RIP+8(%rsp)
+ je error_swapgs
+ movl %ecx,%ecx /* zero extend */
+ cmpq %rcx,RIP+8(%rsp)
+ je error_swapgs
+ cmpq $gs_change,RIP+8(%rsp)
+ je error_swapgs
+ jmp error_sti
+END(error_entry)
-ENTRY(alignment_check)
- errorentry do_alignment_check
-END(alignment_check)
-ENTRY(divide_error)
- zeroentry do_divide_error
-END(divide_error)
+/* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */
+ENTRY(error_exit)
+ DEFAULT_FRAME
+ movl %ebx,%eax
+ RESTORE_REST
+ DISABLE_INTERRUPTS(CLBR_NONE)
+ TRACE_IRQS_OFF
+ GET_THREAD_INFO(%rcx)
+ testl %eax,%eax
+ jne retint_kernel
+ LOCKDEP_SYS_EXIT_IRQ
+ movl TI_flags(%rcx),%edx
+ movl $_TIF_WORK_MASK,%edi
+ andl %edi,%edx
+ jnz retint_careful
+ jmp retint_swapgs
+ CFI_ENDPROC
+END(error_exit)
-ENTRY(spurious_interrupt_bug)
- zeroentry do_spurious_interrupt_bug
-END(spurious_interrupt_bug)
-#ifdef CONFIG_X86_MCE
/* runs on exception stack */
-ENTRY(machine_check)
+ENTRY(nmi)
INTR_FRAME
- pushq $0
- CFI_ADJUST_CFA_OFFSET 8
- paranoidentry do_machine_check
- jmp paranoid_exit1
+ PARAVIRT_ADJUST_EXCEPTION_FRAME
+ pushq_cfi $-1
+ subq $15*8, %rsp
+ CFI_ADJUST_CFA_OFFSET 15*8
+ call save_paranoid
+ DEFAULT_FRAME 0
+ /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */
+ movq %rsp,%rdi
+ movq $-1,%rsi
+ call do_nmi
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* paranoidexit; without TRACE_IRQS_OFF */
+ /* ebx: no swapgs flag */
+ DISABLE_INTERRUPTS(CLBR_NONE)
+ testl %ebx,%ebx /* swapgs needed? */
+ jnz nmi_restore
+ testl $3,CS(%rsp)
+ jnz nmi_userspace
+nmi_swapgs:
+ SWAPGS_UNSAFE_STACK
+nmi_restore:
+ RESTORE_ALL 8
+ jmp irq_return
+nmi_userspace:
+ GET_THREAD_INFO(%rcx)
+ movl TI_flags(%rcx),%ebx
+ andl $_TIF_WORK_MASK,%ebx
+ jz nmi_swapgs
+ movq %rsp,%rdi /* &pt_regs */
+ call sync_regs
+ movq %rax,%rsp /* switch stack for scheduling */
+ testl $_TIF_NEED_RESCHED,%ebx
+ jnz nmi_schedule
+ movl %ebx,%edx /* arg3: thread flags */
+ ENABLE_INTERRUPTS(CLBR_NONE)
+ xorl %esi,%esi /* arg2: oldset */
+ movq %rsp,%rdi /* arg1: &pt_regs */
+ call do_notify_resume
+ DISABLE_INTERRUPTS(CLBR_NONE)
+ jmp nmi_userspace
+nmi_schedule:
+ ENABLE_INTERRUPTS(CLBR_ANY)
+ call schedule
+ DISABLE_INTERRUPTS(CLBR_ANY)
+ jmp nmi_userspace
CFI_ENDPROC
-END(machine_check)
-#endif
-
-/* Call softirq on interrupt stack. Interrupts are off. */
-ENTRY(call_softirq)
- CFI_STARTPROC
- push %rbp
- CFI_ADJUST_CFA_OFFSET 8
- CFI_REL_OFFSET rbp,0
- mov %rsp,%rbp
- CFI_DEF_CFA_REGISTER rbp
- incl %gs:pda_irqcount
- cmove %gs:pda_irqstackptr,%rsp
- push %rbp # backlink for old unwinder
- call __do_softirq
- leaveq
- CFI_DEF_CFA_REGISTER rsp
- CFI_ADJUST_CFA_OFFSET -8
- decl %gs:pda_irqcount
- ret
+#else
+ jmp paranoid_exit
CFI_ENDPROC
-ENDPROC(call_softirq)
+#endif
+END(nmi)
-KPROBE_ENTRY(ignore_sysret)
+ENTRY(ignore_sysret)
CFI_STARTPROC
mov $-ENOSYS,%eax
sysret
CFI_ENDPROC
-ENDPROC(ignore_sysret)
+END(ignore_sysret)
+
+/*
+ * End of kprobes section
+ */
+ .popsection
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff