From ec30e84671aac9a2e9549754eb7bc6201728db4c Mon Sep 17 00:00:00 2001
From: Jerome Forissier <jerome.forissier@linaro.org>
Date: Tue, 23 Aug 2022 12:31:46 +0000
Subject: [PATCH] arm32: libutils, libutee, ta: add .note.GNU-stack section to

 .S files

When building for arm32 with GNU binutils 2.39, the linker outputs
warnings when linking Trusted Applications:

 arm-unknown-linux-uclibcgnueabihf-ld.bfd: warning: utee_syscalls_a32.o: missing .note.GNU-stack section implies executable stack
 arm-unknown-linux-uclibcgnueabihf-ld.bfd: NOTE: This behaviour is deprecated and will be removed in a future version of the linker

We could silence the warning by adding the '-z execstack' option to the
TA link flags, like we did in the parent commit for the TEE core and
ldelf. Indeed, ldelf always allocates a non-executable piece of memory
for the TA to use as a stack.

However it seems preferable to comply with the common ELF practices in
this case. A better fix is therefore to add the missing .note.GNU-stack
sections in the assembler files.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>

Signed-off-by: Anton Antonov <Anton.Antonov@arm.com>
Upstream-Status: Backport [https://github.com/OP-TEE/optee_os/pull/5499]

---
 lib/libutee/arch/arm/utee_syscalls_a32.S             | 2 ++
 lib/libutils/ext/arch/arm/atomic_a32.S               | 2 ++
 lib/libutils/ext/arch/arm/mcount_a32.S               | 2 ++
 lib/libutils/isoc/arch/arm/arm32_aeabi_divmod_a32.S  | 2 ++
 lib/libutils/isoc/arch/arm/arm32_aeabi_ldivmod_a32.S | 2 ++
 lib/libutils/isoc/arch/arm/setjmp_a32.S              | 2 ++
 ta/arch/arm/ta_entry_a32.S                           | 2 ++
 7 files changed, 14 insertions(+)

diff --git a/lib/libutee/arch/arm/utee_syscalls_a32.S b/lib/libutee/arch/arm/utee_syscalls_a32.S
index 6e621ca6..af405f62 100644
--- a/lib/libutee/arch/arm/utee_syscalls_a32.S
+++ b/lib/libutee/arch/arm/utee_syscalls_a32.S
@@ -7,6 +7,8 @@
 #include <tee_syscall_numbers.h>
 #include <asm.S>
 
+	.section .note.GNU-stack,"",%progbits
+
         .section .text
         .balign 4
         .code 32
diff --git a/lib/libutils/ext/arch/arm/atomic_a32.S b/lib/libutils/ext/arch/arm/atomic_a32.S
index eaef6914..2be73ffa 100644
--- a/lib/libutils/ext/arch/arm/atomic_a32.S
+++ b/lib/libutils/ext/arch/arm/atomic_a32.S
@@ -5,6 +5,8 @@
 
 #include <asm.S>
 
+	.section .note.GNU-stack,"",%progbits
+
 /* uint32_t atomic_inc32(uint32_t *v); */
 FUNC atomic_inc32 , :
 	ldrex	r1, [r0]
diff --git a/lib/libutils/ext/arch/arm/mcount_a32.S b/lib/libutils/ext/arch/arm/mcount_a32.S
index 51439a23..54dc3c02 100644
--- a/lib/libutils/ext/arch/arm/mcount_a32.S
+++ b/lib/libutils/ext/arch/arm/mcount_a32.S
@@ -7,6 +7,8 @@
 
 #if defined(CFG_TA_GPROF_SUPPORT) || defined(CFG_FTRACE_SUPPORT)
 
+	.section .note.GNU-stack,"",%progbits
+
 /*
  * Convert return address to call site address by subtracting the size of the
  * mcount call instruction (blx __gnu_mcount_nc).
diff --git a/lib/libutils/isoc/arch/arm/arm32_aeabi_divmod_a32.S b/lib/libutils/isoc/arch/arm/arm32_aeabi_divmod_a32.S
index a600c879..37ae9ec6 100644
--- a/lib/libutils/isoc/arch/arm/arm32_aeabi_divmod_a32.S
+++ b/lib/libutils/isoc/arch/arm/arm32_aeabi_divmod_a32.S
@@ -5,6 +5,8 @@
 
 #include <asm.S>
 
+	.section .note.GNU-stack,"",%progbits
+
 /*
  * signed ret_idivmod_values(signed quot, signed rem);
  * return quotient and remaining the EABI way (regs r0,r1)
diff --git a/lib/libutils/isoc/arch/arm/arm32_aeabi_ldivmod_a32.S b/lib/libutils/isoc/arch/arm/arm32_aeabi_ldivmod_a32.S
index 2dc50bc9..5c3353e2 100644
--- a/lib/libutils/isoc/arch/arm/arm32_aeabi_ldivmod_a32.S
+++ b/lib/libutils/isoc/arch/arm/arm32_aeabi_ldivmod_a32.S
@@ -5,6 +5,8 @@
 
 #include <asm.S>
 
+	.section .note.GNU-stack,"",%progbits
+
 /*
  * __value_in_regs lldiv_t __aeabi_ldivmod( long long n, long long d)
  */
diff --git a/lib/libutils/isoc/arch/arm/setjmp_a32.S b/lib/libutils/isoc/arch/arm/setjmp_a32.S
index 43ea5937..f8a0b70d 100644
--- a/lib/libutils/isoc/arch/arm/setjmp_a32.S
+++ b/lib/libutils/isoc/arch/arm/setjmp_a32.S
@@ -51,6 +51,8 @@
 #define SIZE(x)
 #endif
 
+	.section .note.GNU-stack,"",%progbits
+
 /* Arm/Thumb interworking support:
 
    The interworking scheme expects functions to use a BX instruction
diff --git a/ta/arch/arm/ta_entry_a32.S b/ta/arch/arm/ta_entry_a32.S
index d2f8a69d..cd9a12f9 100644
--- a/ta/arch/arm/ta_entry_a32.S
+++ b/ta/arch/arm/ta_entry_a32.S
@@ -5,6 +5,8 @@
 
 #include <asm.S>
 
+	.section .note.GNU-stack,"",%progbits
+
 /*
  * This function is the bottom of the user call stack. Mark it as such so that
  * the unwinding code won't try to go further down.
