amd64 native vdso: add unwind annotations to the signal trampoline

Reviewed by:	emaste
Discussed with:	jhb, jrtc27
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Differential revision:	https://reviews.freebsd.org/D32960

3 files changed, 78 insertions, 1 deletions

diff --git a/sys/amd64/amd64/genassym.c b/sys/amd64/amd64/genassym.c
index 7c29368828d0..f61ce120d156 100644
--- a/sys/amd64/amd64/genassym.c
+++ b/sys/amd64/amd64/genassym.c
@@ -205,6 +205,33 @@ ASSYM(PTI_SIZE, sizeof(struct pti_frame));
 ASSYM(SIGF_HANDLER, offsetof(struct sigframe, sf_ahu.sf_handler));
 ASSYM(SIGF_UC, offsetof(struct sigframe, sf_uc));
 ASSYM(UC_EFLAGS, offsetof(ucontext_t, uc_mcontext.mc_rflags));
+ASSYM(UC_RDI, offsetof(ucontext_t, uc_mcontext.mc_rdi));
+ASSYM(UC_RSI, offsetof(ucontext_t, uc_mcontext.mc_rsi));
+ASSYM(UC_RDX, offsetof(ucontext_t, uc_mcontext.mc_rdx));
+ASSYM(UC_RCX, offsetof(ucontext_t, uc_mcontext.mc_rcx));
+ASSYM(UC_R8, offsetof(ucontext_t, uc_mcontext.mc_r8));
+ASSYM(UC_R9, offsetof(ucontext_t, uc_mcontext.mc_r9));
+ASSYM(UC_RAX, offsetof(ucontext_t, uc_mcontext.mc_rax));
+ASSYM(UC_RBX, offsetof(ucontext_t, uc_mcontext.mc_rbx));
+ASSYM(UC_RBP, offsetof(ucontext_t, uc_mcontext.mc_rbp));
+ASSYM(UC_R10, offsetof(ucontext_t, uc_mcontext.mc_r10));
+ASSYM(UC_R11, offsetof(ucontext_t, uc_mcontext.mc_r11));
+ASSYM(UC_R12, offsetof(ucontext_t, uc_mcontext.mc_r12));
+ASSYM(UC_R13, offsetof(ucontext_t, uc_mcontext.mc_r13));
+ASSYM(UC_R14, offsetof(ucontext_t, uc_mcontext.mc_r14));
+ASSYM(UC_R15, offsetof(ucontext_t, uc_mcontext.mc_r15));
+ASSYM(UC_FS, offsetof(ucontext_t, uc_mcontext.mc_fs));
+ASSYM(UC_GS, offsetof(ucontext_t, uc_mcontext.mc_gs));
+ASSYM(UC_ES, offsetof(ucontext_t, uc_mcontext.mc_es));
+ASSYM(UC_DS, offsetof(ucontext_t, uc_mcontext.mc_ds));
+ASSYM(UC_RIP, offsetof(ucontext_t, uc_mcontext.mc_rip));
+ASSYM(UC_CS, offsetof(ucontext_t, uc_mcontext.mc_cs));
+ASSYM(UC_RFLAGS, offsetof(ucontext_t, uc_mcontext.mc_rflags));
+ASSYM(UC_RSP, offsetof(ucontext_t, uc_mcontext.mc_rsp));
+ASSYM(UC_SS, offsetof(ucontext_t, uc_mcontext.mc_ss));
+ASSYM(UC_FSBASE, offsetof(ucontext_t, uc_mcontext.mc_fsbase));
+ASSYM(UC_GSBASE, offsetof(ucontext_t, uc_mcontext.mc_gsbase));
+
 ASSYM(ENOENT, ENOENT);
 ASSYM(EFAULT, EFAULT);
 ASSYM(ENAMETOOLONG, ENAMETOOLONG);
diff --git a/sys/amd64/amd64/sigtramp.S b/sys/amd64/amd64/sigtramp.S
index 05bf30293a9a..6c2895a14a0a 100644
--- a/sys/amd64/amd64/sigtramp.S
+++ b/sys/amd64/amd64/sigtramp.S
@@ -2,6 +2,11 @@
  * Copyright (c) 2003 Peter Wemm <peter@freeBSD.org>
  * All rights reserved.
  *
+ * Copyright (c) 2021 The FreeBSD Foundation
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -36,13 +41,58 @@
  * Signal trampoline, mapped as vdso into shared page.
  */
 ENTRY(__vdso_sigcode)
+	.cfi_startproc
+	.cfi_signal_frame
+	.cfi_def_cfa	%rsp, 0
+	.cfi_offset	%rdi, SIGF_UC + UC_RDI
+	.cfi_offset	%rsi, SIGF_UC + UC_RSI
+	.cfi_offset	%rdx, SIGF_UC + UC_RDX
+	.cfi_offset	%rcx, SIGF_UC + UC_RCX
+	.cfi_offset	%r8,  SIGF_UC + UC_R8
+	.cfi_offset	%r9,  SIGF_UC + UC_R9
+	.cfi_offset	%rax, SIGF_UC + UC_RAX
+	.cfi_offset	%rbx, SIGF_UC + UC_RBX
+	.cfi_offset	%rbp, SIGF_UC + UC_RBP
+	.cfi_offset	%r10, SIGF_UC + UC_R10
+	.cfi_offset	%r11, SIGF_UC + UC_R11
+	.cfi_offset	%r12, SIGF_UC + UC_R12
+	.cfi_offset	%r13, SIGF_UC + UC_R13
+	.cfi_offset	%r14, SIGF_UC + UC_R14
+	.cfi_offset	%r15, SIGF_UC + UC_R15
+#if 0
+/*
+ * Gnu as complains about %fs/%gs/%es/%ds registers offsets not being
+ * multiple of 8, but gas + ld.bfd work for %cs/%ss.
+ *
+ * Clang IAS + ld.lld combination cannot handle any of the segment
+ * registers.  Also, clang IAS does not know %rflags/%fs.base/%gs.base
+ * registers names, use dwarf registers numbers from psABI directly.
+ */	
+	.cfi_offset	%fs,  SIGF_UC + UC_FS
+	.cfi_offset	%gs,  SIGF_UC + UC_GS
+	.cfi_offset	%es,  SIGF_UC + UC_ES
+	.cfi_offset	%ds,  SIGF_UC + UC_DS
+#endif
+	.cfi_offset	%rip, SIGF_UC + UC_RIP
+#if 0
+	.cfi_offset	%cs,  SIGF_UC + UC_CS
+#endif
+	.cfi_offset	49 /* %rflags */, SIGF_UC + UC_RFLAGS
+	.cfi_offset	%rsp, SIGF_UC + UC_RSP
+#if 0
+	.cfi_offset	%ss,  SIGF_UC + UC_SS
+#endif
+	.cfi_offset	58 /* %fs.base */, SIGF_UC + UC_FSBASE
+	.cfi_offset	59 /* %gs.base */, SIGF_UC + UC_GSBASE
 	call	*SIGF_HANDLER(%rsp)	/* call signal handler */
 	lea	SIGF_UC(%rsp),%rdi	/* get ucontext_t */
 	pushq	$0			/* junk to fake return addr. */
+	.cfi_def_cfa	%rsp, 8
 	movq	$SYS_sigreturn,%rax
 	syscall				/* enter kernel with args */
 0:	hlt				/* trap priviliged instruction */
 	jmp	0b
+	.cfi_endproc
 END(__vdso_sigcode)
 
 	.section .note.GNU-stack,"",%progbits
diff --git a/sys/tools/amd64_vdso.sh b/sys/tools/amd64_vdso.sh
index 39406eccd2ef..6a4111ffabc8 100644
--- a/sys/tools/amd64_vdso.sh
+++ b/sys/tools/amd64_vdso.sh
@@ -55,5 +55,5 @@ ${CC} -x assembler-with-cpp -DLOCORE -fPIC -nostdinc -c \
    "${S}"/tools/vdso_wrap.S
 
 ${NM} -D elf-vdso.so.1 | \
-   awk '/__vdso_sigcode/{printf "#define VDSO_SIGCODE_OFFSET 0x%s\n",$1}' \
+   ${AWK} '/__vdso_sigcode/{printf "#define VDSO_SIGCODE_OFFSET 0x%s\n",$1}' \
    >vdso_offsets.h