diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/nios2/setcontext.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/nios2/setcontext.S | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/sysdeps/unix/sysv/linux/nios2/setcontext.S b/sysdeps/unix/sysv/linux/nios2/setcontext.S index f10e8ffc0f..5e82bc99bb 100644 --- a/sysdeps/unix/sysv/linux/nios2/setcontext.S +++ b/sysdeps/unix/sysv/linux/nios2/setcontext.S @@ -1,5 +1,5 @@ /* Set current context. - Copyright (C) 2015-2016 Free Software Foundation, Inc. + Copyright (C) 2015-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -85,6 +85,18 @@ ENTRY(__setcontext) PSEUDO_END (__setcontext) weak_alias (__setcontext, setcontext) + /* We add an NOP here to separate between __setcontext/__startcontext. + The wanted behavior that happens is: when unwinding from a function + called inside a makecontext() context, FDE lookup will use + '&__startcontext - 1', then returns NULL for no FDE found, + and immediately ends the unwind, in a normal fashion. + + If this NOP word does not exist, FDE lookup just repeatedly finds + __setcontext's FDE in an infinite loop, due to the convention of + using 'address - 1' for FDE lookup. Modifiying/deleting the below + __startcontext's FDE has no help on this. */ + nop + ENTRY(__startcontext) mov r4, r16 bne r4, zero, __setcontext |