diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index d9d4dae305f6991efa446ec0ef4e7fad8054bdc3..094fb30817abb8ea9fb6ce475a87e1c886df90b9 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -152,6 +152,11 @@ extern unsigned long perf_misc_flags(struct pt_regs *regs); (regs)->bp = caller_frame_pointer(); \ (regs)->cs = __KERNEL_CS; \ regs->flags = 0; \ + asm volatile( \ + _ASM_MOV "%%"_ASM_SP ", %0\n" \ + : "=m" ((regs)->sp) \ + :: "memory" \ + ); \ } #else diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index e71c98d3c0d2d7ff4fc2085d646d31b56bc6a476..19853ad8afc5ff940cbf6806b6ae283695296cd7 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -104,34 +104,6 @@ in_irq_stack(unsigned long *stack, unsigned long *irq_stack, return (stack >= irq_stack && stack < irq_stack_end); } -/* - * We are returning from the irq stack and go to the previous one. - * If the previous stack is also in the irq stack, then bp in the first - * frame of the irq stack points to the previous, interrupted one. - * Otherwise we have another level of indirection: We first save - * the bp of the previous stack, then we switch the stack to the irq one - * and save a new bp that links to the previous one. - * (See save_args()) - */ -static inline unsigned long -fixup_bp_irq_link(unsigned long bp, unsigned long *stack, - unsigned long *irq_stack, unsigned long *irq_stack_end) -{ -#ifdef CONFIG_FRAME_POINTER - struct stack_frame *frame = (struct stack_frame *)bp; - unsigned long next; - - if (!in_irq_stack(stack, irq_stack, irq_stack_end)) { - if (!probe_kernel_address(&frame->next_frame, next)) - return next; - else - WARN_ONCE(1, "Perf: bad frame pointer = %p in " - "callchain\n", &frame->next_frame); - } -#endif - return bp; -} - /* * x86-64 can have up to three kernel stacks: * process stack @@ -155,9 +127,12 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, task = current; if (!stack) { - stack = &dummy; - if (task && task != current) + if (regs) + stack = (unsigned long *)regs->sp; + else if (task && task != current) stack = (unsigned long *)task->thread.sp; + else + stack = &dummy; } if (!bp) @@ -205,8 +180,6 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, * pointer (index -1 to end) in the IRQ stack: */ stack = (unsigned long *) (irq_stack_end[-1]); - bp = fixup_bp_irq_link(bp, stack, irq_stack, - irq_stack_end); irq_stack_end = NULL; ops->stack(data, "EOI"); continue; diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 8a445a0c989e095bc84557861d4a4e73e09e3e90..d656f68371a4afdac2cd98b7a06cfac88f4f5769 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -297,27 +297,26 @@ ENDPROC(native_usergs_sysret64) .endm /* save partial stack frame */ - .pushsection .kprobes.text, "ax" -ENTRY(save_args) - XCPT_FRAME + .macro SAVE_ARGS_IRQ cld - /* - * start from rbp in pt_regs and jump over - * return address. - */ - movq_cfi rdi, RDI+8-RBP - movq_cfi rsi, RSI+8-RBP - movq_cfi rdx, RDX+8-RBP - movq_cfi rcx, RCX+8-RBP - movq_cfi rax, RAX+8-RBP - movq_cfi r8, R8+8-RBP - movq_cfi r9, R9+8-RBP - movq_cfi r10, R10+8-RBP - movq_cfi r11, R11+8-RBP - - leaq -RBP+8(%rsp),%rdi /* arg1 for handler */ - movq_cfi rbp, 8 /* push %rbp */ - leaq 8(%rsp), %rbp /* mov %rsp, %ebp */ + /* start from rbp in pt_regs and jump over */ + movq_cfi rdi, RDI-RBP + movq_cfi rsi, RSI-RBP + movq_cfi rdx, RDX-RBP + movq_cfi rcx, RCX-RBP + movq_cfi rax, RAX-RBP + movq_cfi r8, R8-RBP + movq_cfi r9, R9-RBP + movq_cfi r10, R10-RBP + movq_cfi r11, R11-RBP + + /* Save rbp so that we can unwind from get_irq_regs() */ + movq_cfi rbp, 0 + + /* Save previous stack value */ + movq %rsp, %rsi + + leaq -RBP(%rsp),%rdi /* arg1 for handler */ testl $3, CS(%rdi) je 1f SWAPGS @@ -329,19 +328,14 @@ ENTRY(save_args) */ 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 %rbp /* backlink for unwinder */ - 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) - .popsection + +2: /* Store previous stack value */ + pushq %rsi + /* We entered an interrupt context - irqs are off: */ + TRACE_IRQS_OFF + .endm ENTRY(save_rest) PARTIAL_FRAME 1 REST_SKIP+8 @@ -791,7 +785,7 @@ END(interrupt) /* reserve pt_regs for scratch regs and rbp */ subq $ORIG_RAX-RBP, %rsp CFI_ADJUST_CFA_OFFSET ORIG_RAX-RBP - call save_args + SAVE_ARGS_IRQ PARTIAL_FRAME 0 call \func .endm @@ -814,15 +808,14 @@ ret_from_intr: DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF decl PER_CPU_VAR(irq_count) - leaveq - CFI_RESTORE rbp + /* Restore saved previous stack */ + popq %rsi + leaq 16(%rsi), %rsp + CFI_DEF_CFA_REGISTER rsp - CFI_ADJUST_CFA_OFFSET -8 + CFI_ADJUST_CFA_OFFSET -16 - /* we did not save rbx, restore only from ARGOFFSET */ - addq $8, %rsp - CFI_ADJUST_CFA_OFFSET -8 exit_intr: GET_THREAD_INFO(%rcx) testl $3,CS-ARGOFFSET(%rsp)