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Add call frame unwind info to the Alpha signal trampoline. Using 

kamil@'s test program:

Before:
Backtrace 2 stack frames.
0x120000a74 <handler+0x54> at ./test
0x3fffdca6550 <__sigtramp_siginfo_2> at /usr/lib/libc.so.12

After:
Backtrace 4 stack frames.
0x120000a74 <handler+0x54> at ./test
0x3fffdca6554 <__sigtramp_siginfo_2> at /usr/lib/libc.so.12
0x120000b10 <main+0x38> at ./test
0x1200009b4 <___start+0x1a4> at ./test
This commit is contained in:
thorpej 2020-10-21 01:55:07 +00:00
parent 48c5aec857
commit 521b46f7aa
1 changed files with 48 additions and 1 deletions
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49
lib/libc/arch/alpha/sys/__sigtramp2.S
View File

@ -1,4 +1,4 @@
/* $NetBSD: __sigtramp2.S,v 1.3 2020/10/21 01:24:05 thorpej Exp $ */
/* $NetBSD: __sigtramp2.S,v 1.4 2020/10/21 01:55:07 thorpej Exp $ */
/*
* Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
@ -39,10 +39,57 @@
* ucontext structure [128] == sp + sizeof(siginfo_t)]
* sp-> siginfo structure [0]
*/
#define CFI_OFFSET(r) .cfi_offset r, SIZEOF_SIGINFO + UC_GREGS + r*8
.cfi_startproc simple
.cfi_signal_frame
.cfi_def_cfa _REG_SP, 0
CFI_OFFSET(_REG_V0)
CFI_OFFSET(_REG_T0)
CFI_OFFSET(_REG_T1)
CFI_OFFSET(_REG_T2)
CFI_OFFSET(_REG_T3)
CFI_OFFSET(_REG_T4)
CFI_OFFSET(_REG_T5)
CFI_OFFSET(_REG_T6)
CFI_OFFSET(_REG_T7)
CFI_OFFSET(_REG_S0)
CFI_OFFSET(_REG_S1)
CFI_OFFSET(_REG_S2)
CFI_OFFSET(_REG_S3)
CFI_OFFSET(_REG_S4)
CFI_OFFSET(_REG_S5)
CFI_OFFSET(_REG_S6)
CFI_OFFSET(_REG_A0)
CFI_OFFSET(_REG_A1)
CFI_OFFSET(_REG_A2)
CFI_OFFSET(_REG_A3)
CFI_OFFSET(_REG_A4)
CFI_OFFSET(_REG_A5)
CFI_OFFSET(_REG_T8)
CFI_OFFSET(_REG_T9)
CFI_OFFSET(_REG_T10)
CFI_OFFSET(_REG_T11)
CFI_OFFSET(_REG_RA)
CFI_OFFSET(_REG_T12) /* a.k.a. _REG_PV */
CFI_OFFSET(_REG_AT)
CFI_OFFSET(_REG_GP)
CFI_OFFSET(_REG_SP)
/*
* The unwind entry includes one instruction slot prior to the trampoline
* because the unwinder will look up to (return PC - 1 insn) while unwinding.
* Normally this would be the jump / branch, but since there isn't one in
* this case, we place an explcit nop there instead.
*/
nop
NESTED_NOPROFILE(__sigtramp_siginfo_2,0,0,ra,0,0)
ldgp gp,0(ra)
lda a0,(SIZEOF_SIGINFO)(sp) /* get pointer to ucontext */
CALLSYS_NOERROR(setcontext) /* and call setcontext() with it */
ldiq a0,-1 /* if that failed, set an exit code */
CALLSYS_NOERROR(exit) /* and call exit() */
.cfi_endproc
END(__sigtramp_siginfo_2)