Module Name: src
Committed By: thorpej
Date: Wed Oct 21 01:55:07 UTC 2020
Modified Files:
src/lib/libc/arch/alpha/sys: __sigtramp2.S
Log Message:
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
To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/lib/libc/arch/alpha/sys/__sigtramp2.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/libc/arch/alpha/sys/__sigtramp2.S
diff -u src/lib/libc/arch/alpha/sys/__sigtramp2.S:1.3 src/lib/libc/arch/alpha/sys/__sigtramp2.S:1.4
--- src/lib/libc/arch/alpha/sys/__sigtramp2.S:1.3 Wed Oct 21 01:24:05 2020
+++ src/lib/libc/arch/alpha/sys/__sigtramp2.S Wed Oct 21 01:55:07 2020
@@ -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)
