* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
* Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
- *
- * $Id$
*/
/*
* 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.
- *
- * TODO:
- * - schedule it carefully for the final hardware.
+ *
+ * Some macro usage:
+ * - CFI macros are used to generate dwarf2 unwind information for better
+ * backtraces. They don't change any code.
+ * - SAVE_ALL/RESTORE_ALL - Save/restore all registers
+ * - SAVE_ARGS/RESTORE_ARGS - Save/restore registers that C functions modify.
+ * There are unfortunately lots of special cases where some registers
+ * not touched. The macro is a big mess that should be cleaned up.
+ * - SAVE_REST/RESTORE_REST - Handle the registers not saved by SAVE_ARGS.
+ * Gives a full stack frame.
+ * - ENTRY/END Define functions in the symbol table.
+ * - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack
+ * frame that is otherwise undefined after a SYSCALL
+ * - TRACE_IRQ_* - Trace hard interrupt state for lock debugging.
+ * - errorentry/paranoidentry/zeroentry - Define exception entry points.
*/
-#define ASSEMBLY 1
#include <linux/linkage.h>
#include <asm/segment.h>
-#include <asm/smp.h>
#include <asm/cache.h>
#include <asm/errno.h>
#include <asm/dwarf2.h>
.macro CFI_DEFAULT_STACK start=1
.if \start
CFI_STARTPROC simple
+ CFI_SIGNAL_FRAME
CFI_DEF_CFA rsp,SS+8
.else
CFI_DEF_CFA_OFFSET SS+8
/* rdi: prev */
ENTRY(ret_from_fork)
CFI_DEFAULT_STACK
+ push kernel_eflags(%rip)
+ CFI_ADJUST_CFA_OFFSET 4
+ popf # reset kernel eflags
+ CFI_ADJUST_CFA_OFFSET -4
call schedule_tail
GET_THREAD_INFO(%rcx)
testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),threadinfo_flags(%rcx)
ENTRY(system_call)
CFI_STARTPROC simple
+ CFI_SIGNAL_FRAME
CFI_DEF_CFA rsp,PDA_STACKOFFSET
CFI_REGISTER rip,rcx
/*CFI_REGISTER rflags,r11*/
LOAD_ARGS ARGOFFSET /* reload args from stack in case ptrace changed it */
RESTORE_REST
cmpq $__NR_syscall_max,%rax
+ movq $-ENOSYS,%rcx
+ cmova %rcx,%rax
ja 1f
movq %r10,%rcx /* fixup for C */
call *sys_call_table(,%rax,8)
*/
ENTRY(int_ret_from_sys_call)
CFI_STARTPROC simple
+ CFI_SIGNAL_FRAME
CFI_DEF_CFA rsp,SS+8-ARGOFFSET
/*CFI_REL_OFFSET ss,SS-ARGOFFSET*/
CFI_REL_OFFSET rsp,RSP-ARGOFFSET
*/
.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
testl $3,CS(%rdi)
je 1f
swapgs
-1: incl %gs:pda_irqcount # RED-PEN should check preempt count
+ /* 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
+ CFI_ADJUST_CFA_OFFSET 8
+ CFI_REL_OFFSET rbp,0
/*
* We entered an interrupt context - irqs are off:
*/
#ifdef CONFIG_PREEMPT
/* Returning to kernel space. Check if we need preemption */
/* rcx: threadinfo. interrupts off. */
- .p2align
-retint_kernel:
+ENTRY(retint_kernel)
cmpl $0,threadinfo_preempt_count(%rcx)
jnz retint_restore_args
bt $TIF_NEED_RESCHED,threadinfo_flags(%rcx)
END(call_function_interrupt)
#endif
-#ifdef CONFIG_X86_LOCAL_APIC
ENTRY(apic_timer_interrupt)
apicinterrupt LOCAL_TIMER_VECTOR,smp_apic_timer_interrupt
END(apic_timer_interrupt)
ENTRY(spurious_interrupt)
apicinterrupt SPURIOUS_APIC_VECTOR,smp_spurious_interrupt
END(spurious_interrupt)
-#endif
/*
* Exception entry points.
testl $3,CS(%rsp)
jnz paranoid_userspace\trace
paranoid_swapgs\trace:
+ .if \trace
TRACE_IRQS_IRETQ 0
+ .endif
swapgs
paranoid_restore\trace:
RESTORE_ALL 8
* Exception entry point. This expects an error code/orig_rax on the stack
* and the exception handler in %rax.
*/
-ENTRY(error_entry)
+KPROBE_ENTRY(error_entry)
_frame RDI
/* rdi slot contains rax, oldrax contains error code */
cld
cmpq $gs_change,RIP(%rsp)
je error_swapgs
jmp error_sti
-END(error_entry)
+KPROBE_END(error_entry)
/* Reload gs selector with exception handling */
/* edi: new selector */
call do_fork
movq %rax,RAX(%rsp)
xorl %edi,%edi
+ test %rax,%rax
+ jnz 1f
+ /* terminate stack in child */
+ movq %rdi,RIP(%rsp)
+1:
/*
* It isn't worth to check for reschedule here,
ENDPROC(kernel_thread)
child_rip:
+ pushq $0 # fake return address
+ CFI_STARTPROC
/*
* Here we are in the child and the registers are set as they were
* at kernel_thread() invocation in the parent.
# exit
xorl %edi, %edi
call do_exit
+ CFI_ENDPROC
ENDPROC(child_rip)
/*
* do_sys_execve asm fallback arguments:
* rdi: name, rsi: argv, rdx: envp, fake frame on the stack
*/
-ENTRY(execve)
+ENTRY(kernel_execve)
CFI_STARTPROC
FAKE_STACK_FRAME $0
SAVE_ALL
UNFAKE_STACK_FRAME
ret
CFI_ENDPROC
-ENDPROC(execve)
+ENDPROC(kernel_execve)
KPROBE_ENTRY(page_fault)
errorentry do_page_fault
-END(page_fault)
- .previous .text
+KPROBE_END(page_fault)
ENTRY(coprocessor_error)
zeroentry do_coprocessor_error
CFI_ADJUST_CFA_OFFSET 8
paranoidentry do_debug, DEBUG_STACK
paranoidexit
-END(debug)
- .previous .text
+KPROBE_END(debug)
/* runs on exception stack */
KPROBE_ENTRY(nmi)
jmp paranoid_exit1
CFI_ENDPROC
#endif
-END(nmi)
- .previous .text
+KPROBE_END(nmi)
KPROBE_ENTRY(int3)
INTR_FRAME
paranoidentry do_int3, DEBUG_STACK
jmp paranoid_exit1
CFI_ENDPROC
-END(int3)
- .previous .text
+KPROBE_END(int3)
ENTRY(overflow)
zeroentry do_overflow
KPROBE_ENTRY(general_protection)
errorentry do_general_protection
-END(general_protection)
- .previous .text
+KPROBE_END(general_protection)
ENTRY(alignment_check)
errorentry do_alignment_check
incl %gs:pda_irqcount
cmove %gs:pda_irqstackptr,%rsp
push %rbp # backlink for old unwinder
+ CFI_ADJUST_CFA_OFFSET 8
call __do_softirq
leaveq
CFI_DEF_CFA_REGISTER rsp
projects / powerpc.git / blobdiff