diff options
-rw-r--r-- | arch/x86/kernel/entry_64.S | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index e41734a537bd..3194636a4293 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S | |||
@@ -361,34 +361,35 @@ ENTRY(save_paranoid) | |||
361 | END(save_paranoid) | 361 | END(save_paranoid) |
362 | 362 | ||
363 | /* | 363 | /* |
364 | * A newly forked process directly context switches into this. | 364 | * A newly forked process directly context switches into this address. |
365 | * | ||
366 | * rdi: prev task we switched from | ||
365 | */ | 367 | */ |
366 | /* rdi: prev */ | ||
367 | ENTRY(ret_from_fork) | 368 | ENTRY(ret_from_fork) |
368 | DEFAULT_FRAME | 369 | DEFAULT_FRAME |
370 | |||
369 | push kernel_eflags(%rip) | 371 | push kernel_eflags(%rip) |
370 | CFI_ADJUST_CFA_OFFSET 8 | 372 | CFI_ADJUST_CFA_OFFSET 8 |
371 | popf # reset kernel eflags | 373 | popf # reset kernel eflags |
372 | CFI_ADJUST_CFA_OFFSET -8 | 374 | CFI_ADJUST_CFA_OFFSET -8 |
373 | call schedule_tail | 375 | |
376 | call schedule_tail # rdi: 'prev' task parameter | ||
377 | |||
374 | GET_THREAD_INFO(%rcx) | 378 | GET_THREAD_INFO(%rcx) |
375 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%rcx) | 379 | |
376 | CFI_REMEMBER_STATE | 380 | CFI_REMEMBER_STATE |
377 | jnz rff_trace | ||
378 | rff_action: | ||
379 | RESTORE_REST | 381 | RESTORE_REST |
380 | testl $3,CS-ARGOFFSET(%rsp) # from kernel_thread? | 382 | |
383 | testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread? | ||
381 | je int_ret_from_sys_call | 384 | je int_ret_from_sys_call |
382 | testl $_TIF_IA32,TI_flags(%rcx) | 385 | |
386 | testl $_TIF_IA32, TI_flags(%rcx) # 32-bit compat task needs IRET | ||
383 | jnz int_ret_from_sys_call | 387 | jnz int_ret_from_sys_call |
388 | |||
384 | RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET | 389 | RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET |
385 | jmp ret_from_sys_call | 390 | jmp ret_from_sys_call # go to the SYSRET fastpath |
391 | |||
386 | CFI_RESTORE_STATE | 392 | CFI_RESTORE_STATE |
387 | rff_trace: | ||
388 | movq %rsp,%rdi | ||
389 | call syscall_trace_leave | ||
390 | GET_THREAD_INFO(%rcx) | ||
391 | jmp rff_action | ||
392 | CFI_ENDPROC | 393 | CFI_ENDPROC |
393 | END(ret_from_fork) | 394 | END(ret_from_fork) |
394 | 395 | ||