[PATCH 5/9] sandbox: use native setjmp/longjmp/initjmp implementation by default

[Ahmad Fatoum]

In order to implement initjmp, we have two ways with available
functionality: The sigaltstack we are currently using and
makecontext/swapcontext. makecontext/swapcontext are unfortunately
deprecated in favor of POSIX threads and the sigaltstack runs afoul of
AddressSanitizer.

Let's therefore use the assembly version if we are using ASAN.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 arch/arm/um/Makefile      | 12 ++++++++++++
 arch/kvx/um/Makefile      |  6 ++++++
 arch/mips/um/Makefile     |  6 ++++++
 arch/openrisc/um/Makefile |  6 ++++++
 arch/powerpc/um/Makefile  |  6 ++++++
 arch/riscv/um/Makefile    |  6 ++++++
 arch/sandbox/Kconfig      |  8 ++++++++
 arch/x86/um/Makefile      | 12 ++++++++++++
 8 files changed, 62 insertions(+)
 create mode 100644 arch/arm/um/Makefile
 create mode 100644 arch/kvx/um/Makefile
 create mode 100644 arch/mips/um/Makefile
 create mode 100644 arch/openrisc/um/Makefile
 create mode 100644 arch/powerpc/um/Makefile
 create mode 100644 arch/riscv/um/Makefile
 create mode 100644 arch/x86/um/Makefile

diff --git a/arch/arm/um/Makefile b/arch/arm/um/Makefile
new file mode 100644
index 000000000000..380f59fdade2
--- /dev/null
+++ b/arch/arm/um/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj- := __dummy__.o
+
+ifeq ($(CONFIG_32BIT),y)
+	BITS := 32
+else
+	BITS := 64
+endif
+
+AFLAGS_../lib$(BITS)/setjmp.pbl.o := -Dsetjmp=barebox_setjmp -Dlongjmp=barebox_longjmp
+pbl-$(CONFIG_SANDBOX_SJLJ_ASM) += ../lib$(BITS)/setjmp.o
diff --git a/arch/kvx/um/Makefile b/arch/kvx/um/Makefile
new file mode 100644
index 000000000000..367946d33ac3
--- /dev/null
+++ b/arch/kvx/um/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj- := __dummy__.o
+
+AFLAGS_../lib/setjmp.pbl.o := -Dsetjmp=barebox_setjmp -Dlongjmp=barebox_longjmp
+pbl-$(CONFIG_SANDBOX_SJLJ_ASM) += ../lib/setjmp.o
diff --git a/arch/mips/um/Makefile b/arch/mips/um/Makefile
new file mode 100644
index 000000000000..367946d33ac3
--- /dev/null
+++ b/arch/mips/um/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj- := __dummy__.o
+
+AFLAGS_../lib/setjmp.pbl.o := -Dsetjmp=barebox_setjmp -Dlongjmp=barebox_longjmp
+pbl-$(CONFIG_SANDBOX_SJLJ_ASM) += ../lib/setjmp.o
diff --git a/arch/openrisc/um/Makefile b/arch/openrisc/um/Makefile
new file mode 100644
index 000000000000..367946d33ac3
--- /dev/null
+++ b/arch/openrisc/um/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj- := __dummy__.o
+
+AFLAGS_../lib/setjmp.pbl.o := -Dsetjmp=barebox_setjmp -Dlongjmp=barebox_longjmp
+pbl-$(CONFIG_SANDBOX_SJLJ_ASM) += ../lib/setjmp.o
diff --git a/arch/powerpc/um/Makefile b/arch/powerpc/um/Makefile
new file mode 100644
index 000000000000..367946d33ac3
--- /dev/null
+++ b/arch/powerpc/um/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj- := __dummy__.o
+
+AFLAGS_../lib/setjmp.pbl.o := -Dsetjmp=barebox_setjmp -Dlongjmp=barebox_longjmp
+pbl-$(CONFIG_SANDBOX_SJLJ_ASM) += ../lib/setjmp.o
diff --git a/arch/riscv/um/Makefile b/arch/riscv/um/Makefile
new file mode 100644
index 000000000000..367946d33ac3
--- /dev/null
+++ b/arch/riscv/um/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj- := __dummy__.o
+
+AFLAGS_../lib/setjmp.pbl.o := -Dsetjmp=barebox_setjmp -Dlongjmp=barebox_longjmp
+pbl-$(CONFIG_SANDBOX_SJLJ_ASM) += ../lib/setjmp.o
diff --git a/arch/sandbox/Kconfig b/arch/sandbox/Kconfig
index caff3a138fea..4cc3b201c399 100644
--- a/arch/sandbox/Kconfig
+++ b/arch/sandbox/Kconfig
@@ -65,6 +65,14 @@ config CMD_SANDBOX_CPUINFO
 	help
 	  Say yes here to get a dummy cpuinfo command.
 
+config SANDBOX_SJLJ_ASM
+	bool "use setjmp/longjmp/initjmp implemented in assembly" if COMPILE_TEST
+	default y
+	help
+	  sandbox has a C implementation of initjmp, which can run afoul of code
+	  hardening measures like ASAN. The assembly version isn't immune to these
+	  issues, but it's easier to reason about than the sigaltstack hack.
+
 config SDL
 	bool
 
diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile
new file mode 100644
index 000000000000..d3764221a4c6
--- /dev/null
+++ b/arch/x86/um/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj- := __dummy__.o
+
+ifeq ($(CONFIG_32BIT),y)
+	BITS := 32
+else
+	BITS := 64
+endif
+
+AFLAGS_../lib/setjmp_$(BITS).o := -Dsetjmp=barebox_setjmp -Dlongjmp=barebox_longjmp
+obj-$(CONFIG_SANDBOX_SJLJ_ASM) += ../lib/setjmp_$(BITS).o
-- 
2.39.5