Module Name:    src
Committed By:   thorpej
Date:           Tue Nov 23 02:49:56 UTC 2021

Modified Files:
        src/lib/libc/arch/aarch64: genassym.cf
        src/lib/libc/arch/aarch64/sys: __sigtramp2.S

Log Message:
Because the PC is not a general purpose register on aarch64, we need
to use DWARF pseudo-register for the signal trampoline return address.

Adjust the style to match other platforms.


To generate a diff of this commit:
cvs rdiff -u -r1.4 -r1.5 src/lib/libc/arch/aarch64/genassym.cf
cvs rdiff -u -r1.6 -r1.7 src/lib/libc/arch/aarch64/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/aarch64/genassym.cf
diff -u src/lib/libc/arch/aarch64/genassym.cf:1.4 src/lib/libc/arch/aarch64/genassym.cf:1.5
--- src/lib/libc/arch/aarch64/genassym.cf:1.4	Sat Oct 17 15:44:59 2020
+++ src/lib/libc/arch/aarch64/genassym.cf	Tue Nov 23 02:49:55 2021
@@ -1,4 +1,4 @@
-# $NetBSD: genassym.cf,v 1.4 2020/10/17 15:44:59 skrll Exp $
+# $NetBSD: genassym.cf,v 1.5 2021/11/23 02:49:55 thorpej Exp $
 
 #-
 # Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -33,40 +33,45 @@ include <sys/types.h>
 include <ucontext.h>
 include <setjmp.h>
 
+define _UC_GREGS	offsetof(ucontext_t, uc_mcontext.__gregs[0])
 define _UC_REGS_X0	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X0])
-define _UC_REGS_X1	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X1])
-define _UC_REGS_X2	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X2])
-define _UC_REGS_X3	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X3])
-define _UC_REGS_X4	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X4])
-define _UC_REGS_X5	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X5])
-define _UC_REGS_X6	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X6])
-define _UC_REGS_X7	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X7])
-define _UC_REGS_X8	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X8])
-define _UC_REGS_X9	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X9])
-define _UC_REGS_X10	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X10])
-define _UC_REGS_X11	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X11])
-define _UC_REGS_X12	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X12])
-define _UC_REGS_X13	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X13])
-define _UC_REGS_X14	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X14])
-define _UC_REGS_X15	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X15])
-define _UC_REGS_X16	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X16])
-define _UC_REGS_X17	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X17])
-define _UC_REGS_X18	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X18])
-define _UC_REGS_X19	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X19])
-define _UC_REGS_X20	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X20])
-define _UC_REGS_X21	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X21])
-define _UC_REGS_X22	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X22])
-define _UC_REGS_X23	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X23])
-define _UC_REGS_X24	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X24])
-define _UC_REGS_X25	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X25])
-define _UC_REGS_X26	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X26])
-define _UC_REGS_X27	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X27])
-define _UC_REGS_X28	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X28])
-define _UC_REGS_X29	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_X29])
-define _UC_REGS_LR	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_LR])
 define _UC_REGS_SP	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_SP])
 define _UC_REGS_PC	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_PC])
 
+define _REG_X0		_REG_X0
+define _REG_X1		_REG_X1
+define _REG_X2		_REG_X2
+define _REG_X3		_REG_X3
+define _REG_X4		_REG_X4
+define _REG_X5		_REG_X5
+define _REG_X6		_REG_X6
+define _REG_X7		_REG_X7
+define _REG_X8		_REG_X8
+define _REG_X9		_REG_X9
+define _REG_X10		_REG_X10
+define _REG_X11		_REG_X11
+define _REG_X12		_REG_X12
+define _REG_X13		_REG_X13
+define _REG_X14		_REG_X14
+define _REG_X15		_REG_X15
+define _REG_X16		_REG_X16
+define _REG_X17		_REG_X17
+define _REG_X18		_REG_X18
+define _REG_X19		_REG_X19
+define _REG_X20		_REG_X20
+define _REG_X21		_REG_X21
+define _REG_X22		_REG_X22
+define _REG_X23		_REG_X23
+define _REG_X24		_REG_X24
+define _REG_X25		_REG_X25
+define _REG_X26		_REG_X26
+define _REG_X27		_REG_X27
+define _REG_X28		_REG_X28
+define _REG_X29		_REG_X29
+define _REG_X30		_REG_X30
+define _REG_X31		_REG_X31
+define _REG_PC		_REG_PC
+
 define _JB_MAGIC_AARCH64__SETJMP _JB_MAGIC_AARCH64__SETJMP
 define _JB_MAGIC_AARCH64_SETJMP _JB_MAGIC_AARCH64_SETJMP
 define _JB_MAGIC	sizeof(_BSD_JBSLOT_T_ [_JB_MAGIC])

Index: src/lib/libc/arch/aarch64/sys/__sigtramp2.S
diff -u src/lib/libc/arch/aarch64/sys/__sigtramp2.S:1.6 src/lib/libc/arch/aarch64/sys/__sigtramp2.S:1.7
--- src/lib/libc/arch/aarch64/sys/__sigtramp2.S:1.6	Sat Oct 24 07:02:20 2020
+++ src/lib/libc/arch/aarch64/sys/__sigtramp2.S	Tue Nov 23 02:49:56 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: __sigtramp2.S,v 1.6 2020/10/24 07:02:20 skrll Exp $ */
+/* $NetBSD: __sigtramp2.S,v 1.7 2021/11/23 02:49:56 thorpej Exp $ */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -41,50 +41,67 @@
  *		ucontext structure
  *	sp->	siginfo structure
  * and x28 points to the ucontext
+ *
+ * A DWARF pseudo-register is used for the return address from the
+ * signal trampoline.
  */
 
+#if defined(__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__)
+#define	DWARF_SIGRETURN_REG		__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
+#else
+#define	DWARF_SIGRETURN_REG		96
+#endif
+
+#define	CFI_OFFSET_DWARF_REG(d, r)	.cfi_offset d, r * 8
+#define	CFI_OFFSET(r)			CFI_OFFSET_DWARF_REG(r, r)
+
+	.text
+	.cfi_startproc simple
+	.cfi_signal_frame
+	.cfi_def_cfa _REG_X28, _UC_GREGS
+	CFI_OFFSET(_REG_X0)
+	CFI_OFFSET(_REG_X1)
+	CFI_OFFSET(_REG_X2)
+	CFI_OFFSET(_REG_X3)
+	CFI_OFFSET(_REG_X4)
+	CFI_OFFSET(_REG_X5)
+	CFI_OFFSET(_REG_X6)
+	CFI_OFFSET(_REG_X7)
+	CFI_OFFSET(_REG_X8)
+	CFI_OFFSET(_REG_X9)
+	CFI_OFFSET(_REG_X10)
+	CFI_OFFSET(_REG_X11)
+	CFI_OFFSET(_REG_X12)
+	CFI_OFFSET(_REG_X13)
+	CFI_OFFSET(_REG_X14)
+	CFI_OFFSET(_REG_X15)
+	CFI_OFFSET(_REG_X16)
+	CFI_OFFSET(_REG_X17)
+	CFI_OFFSET(_REG_X18)
+	CFI_OFFSET(_REG_X19)
+	CFI_OFFSET(_REG_X20)
+	CFI_OFFSET(_REG_X21)
+	CFI_OFFSET(_REG_X22)
+	CFI_OFFSET(_REG_X23)
+	CFI_OFFSET(_REG_X24)
+	CFI_OFFSET(_REG_X25)
+	CFI_OFFSET(_REG_X26)
+	CFI_OFFSET(_REG_X27)
+	CFI_OFFSET(_REG_X28)
+	CFI_OFFSET(_REG_X29)
+	CFI_OFFSET(_REG_X30)	/* a.k.a. _REG_LR */
+	CFI_OFFSET(_REG_X31)	/* a.k.a. _REG_SP */
+	.cfi_return_column DWARF_SIGRETURN_REG
+	CFI_OFFSET_DWARF_REG(DWARF_SIGRETURN_REG, _REG_PC)
+
 /*
  * The unwind entry includes the one instruction prior to the trampoline
  * because the unwinder will look up (return PC - 1) while unwinding.
  * Normally this would be the jump / branch, but since there isn't one in
  * this case, we place an explicit nop there instead.
  */
-	.cfi_startproc simple
-	.cfi_signal_frame
-	.cfi_def_cfa x28, 0
-	.cfi_offset x0, _UC_REGS_X0
-	.cfi_offset x1, _UC_REGS_X1
-	.cfi_offset x2, _UC_REGS_X2
-	.cfi_offset x3, _UC_REGS_X3
-	.cfi_offset x4, _UC_REGS_X4
-	.cfi_offset x5, _UC_REGS_X5
-	.cfi_offset x6, _UC_REGS_X6
-	.cfi_offset x7, _UC_REGS_X7
-	.cfi_offset x8, _UC_REGS_X8
-	.cfi_offset x9, _UC_REGS_X9
-	.cfi_offset x10, _UC_REGS_X10
-	.cfi_offset x11, _UC_REGS_X11
-	.cfi_offset x12, _UC_REGS_X12
-	.cfi_offset x13, _UC_REGS_X13
-	.cfi_offset x14, _UC_REGS_X14
-	.cfi_offset x15, _UC_REGS_X15
-	.cfi_offset x16, _UC_REGS_X16
-	.cfi_offset x17, _UC_REGS_X17
-	.cfi_offset x18, _UC_REGS_X18
-	.cfi_offset x19, _UC_REGS_X19
-	.cfi_offset x20, _UC_REGS_X20
-	.cfi_offset x21, _UC_REGS_X21
-	.cfi_offset x22, _UC_REGS_X22
-	.cfi_offset x23, _UC_REGS_X23
-	.cfi_offset x24, _UC_REGS_X24
-	.cfi_offset x25, _UC_REGS_X25
-	.cfi_offset x26, _UC_REGS_X26
-	.cfi_offset x27, _UC_REGS_X27
-	.cfi_offset x28, _UC_REGS_X28
-	.cfi_offset x29, _UC_REGS_X29
-	.cfi_offset lr, _UC_REGS_LR
-	.cfi_offset sp, _UC_REGS_SP
 	nop
+
 ENTRY_NP(__sigtramp_siginfo_2)
 	mov	x0, x28				/* set the arg         */
 	SYSTRAP(setcontext)			/* and call setcontext */

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