ARM gcc 10.2+ patch backport

Backport a number of fixes that are queued up for GCC 10.3 for arm.  The
main reason for this is for fixes related to Cortex-M55 support.

Signed-off-by: Kumar Gala <[email protected]>

Author: galak

patches/gcc/10.2.0/0019-arm-Clear-canary-value-after-stack_protect_test-PR96.patch

@@ -0,0 +1,165 @@
+From 3202535093c445463fa259983149fea8d97e2cfd Mon Sep 17 00:00:00 2001
+From: Richard Sandiford <[email protected]>
+Date: Fri, 7 Aug 2020 12:15:02 +0100
+Subject: [PATCH 19/49] arm: Clear canary value after stack_protect_test
+ [PR96191]
+
+The stack_protect_test patterns were leaving the canary value in the
+temporary register, meaning that it was often still in registers on
+return from the function.  An attacker might therefore have been
+able to use it to defeat stack-smash protection for a later function.
+
+gcc/
+	PR target/96191
+	* config/arm/arm.md (arm_stack_protect_test_insn): Zero out
+	operand 2 after use.
+	* config/arm/thumb1.md (thumb1_stack_protect_test_insn): Likewise.
+
+gcc/testsuite/
+	* gcc.target/arm/stack-protector-1.c: New test.
+	* gcc.target/arm/stack-protector-2.c: Likewise.
+
+(cherry picked from commit 6a3f3e08723063ea2dadb7ddf503f02972a724e2)
+---
+ gcc/config/arm/arm.md                         |  6 +-
+ gcc/config/arm/thumb1.md                      |  8 ++-
+ .../gcc.target/arm/stack-protector-1.c        | 63 +++++++++++++++++++
+ .../gcc.target/arm/stack-protector-2.c        |  6 ++
+ 4 files changed, 78 insertions(+), 5 deletions(-)
+ create mode 100644 gcc/testsuite/gcc.target/arm/stack-protector-1.c
+ create mode 100644 gcc/testsuite/gcc.target/arm/stack-protector-2.c
+
+diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md
+index 9367be59083..0fa044b5ac0 100644
+--- a/gcc/config/arm/arm.md
++++ b/gcc/config/arm/arm.md
+@@ -9320,6 +9320,8 @@
+   [(set_attr "arch" "t1,32")]
+ )
+ 
++;; DO NOT SPLIT THIS PATTERN.  It is important for security reasons that the
++;; canary value does not live beyond the end of this sequence.
+ (define_insn "arm_stack_protect_test_insn"
+   [(set (reg:CC_Z CC_REGNUM)
+ 	(compare:CC_Z (unspec:SI [(match_operand:SI 1 "memory_operand" "m,m")
+@@ -9329,8 +9331,8 @@
+    (clobber (match_operand:SI 0 "register_operand" "=&l,&r"))
+    (clobber (match_dup 2))]
+   "TARGET_32BIT"
+-  "ldr\t%0, [%2]\;ldr\t%2, %1\;eors\t%0, %2, %0"
+-  [(set_attr "length" "8,12")
++  "ldr\t%0, [%2]\;ldr\t%2, %1\;eors\t%0, %2, %0\;mov\t%2, #0"
++  [(set_attr "length" "12,16")
+    (set_attr "conds" "set")
+    (set_attr "type" "multiple")
+    (set_attr "arch" "t,32")]
+diff --git a/gcc/config/arm/thumb1.md b/gcc/config/arm/thumb1.md
+index 24861635fa5..0ff819090d9 100644
+--- a/gcc/config/arm/thumb1.md
++++ b/gcc/config/arm/thumb1.md
+@@ -2020,6 +2020,8 @@
+   [(set_attr "type" "mov_reg")]
+ )
+ 
++;; DO NOT SPLIT THIS PATTERN.  It is important for security reasons that the
++;; canary value does not live beyond the end of this sequence.
+ (define_insn "thumb1_stack_protect_test_insn"
+   [(set (match_operand:SI 0 "register_operand" "=&l")
+ 	(unspec:SI [(match_operand:SI 1 "memory_operand" "m")
+@@ -2027,9 +2029,9 @@
+ 	 UNSPEC_SP_TEST))
+    (clobber (match_dup 2))]
+   "TARGET_THUMB1"
+-  "ldr\t%0, [%2]\;ldr\t%2, %1\;eors\t%0, %2, %0"
+-  [(set_attr "length" "8")
+-   (set_attr "conds" "set")
++  "ldr\t%0, [%2]\;ldr\t%2, %1\;eors\t%0, %2, %0\;movs\t%2, #0"
++  [(set_attr "length" "10")
++   (set_attr "conds" "clob")
+    (set_attr "type" "multiple")]
+ )
+ 
+diff --git a/gcc/testsuite/gcc.target/arm/stack-protector-1.c b/gcc/testsuite/gcc.target/arm/stack-protector-1.c
+new file mode 100644
+index 00000000000..b03ea14c4e2
+--- /dev/null
++++ b/gcc/testsuite/gcc.target/arm/stack-protector-1.c
+@@ -0,0 +1,63 @@
++/* { dg-do run } */
++/* { dg-require-effective-target fstack_protector } */
++/* { dg-options "-fstack-protector-all -O2" } */
++
++extern volatile long *stack_chk_guard_ptr;
++
++volatile long *
++get_ptr (void)
++{
++  return stack_chk_guard_ptr;
++}
++
++void __attribute__ ((noipa))
++f (void)
++{
++  volatile int x;
++  x = 1;
++  x += 1;
++}
++
++#define CHECK(REG) "\tcmp\tr0, " #REG "\n\tbeq\t1f\n"
++
++asm (
++"	.data\n"
++"	.align	3\n"
++"	.globl	stack_chk_guard_ptr\n"
++"stack_chk_guard_ptr:\n"
++"	.word	__stack_chk_guard\n"
++"	.weak	__stack_chk_guard\n"
++"__stack_chk_guard:\n"
++"	.word	0xdead4321\n"
++"	.text\n"
++"	.globl	main\n"
++"	.type	main, %function\n"
++"main:\n"
++"	bl	get_ptr\n"
++"	str	r0, [sp, #-8]!\n"
++"	bl	f\n"
++"	str	r0, [sp, #4]\n"
++"	ldr     r0, [sp]\n"
++"	ldr     r0, [r0]\n"
++	CHECK (r1)
++	CHECK (r2)
++	CHECK (r3)
++	CHECK (r4)
++	CHECK (r5)
++	CHECK (r6)
++	CHECK (r7)
++	CHECK (r8)
++	CHECK (r9)
++	CHECK (r10)
++	CHECK (r11)
++	CHECK (r12)
++	CHECK (r13)
++	CHECK (r14)
++"	ldr	r1, [sp, #4]\n"
++	CHECK (r1)
++"	mov	r0, #0\n"
++"	b	exit\n"
++"1:\n"
++"	b	abort\n"
++"	.size	main, .-main"
++);
+diff --git a/gcc/testsuite/gcc.target/arm/stack-protector-2.c b/gcc/testsuite/gcc.target/arm/stack-protector-2.c
+new file mode 100644
+index 00000000000..266c36fdbc6
+--- /dev/null
++++ b/gcc/testsuite/gcc.target/arm/stack-protector-2.c
+@@ -0,0 +1,6 @@
++/* { dg-do run } */
++/* { dg-require-effective-target fstack_protector } */
++/* { dg-require-effective-target fpic } */
++/* { dg-options "-fstack-protector-all -O2 -fpic" } */
++
++#include "stack-protector-1.c"
+-- 
+2.29.2
+

patches/gcc/10.2.0/0020-Arm-Add-GCC_CPUINFO-override.patch

@@ -0,0 +1,48 @@
+From a2eb01ef646b1c8d950abf23abde8d6de200c865 Mon Sep 17 00:00:00 2001
+From: Tamar Christina <[email protected]>
+Date: Fri, 17 Jul 2020 13:12:00 +0100
+Subject: [PATCH 20/49] Arm: Add GCC_CPUINFO override
+
+This adds an in intentionally undocumented environment variable
+GCC_CPUINFO which can be used to test -mcpu=native.
+
+Tests using these are added later on.
+
+gcc/ChangeLog:
+
+	* config/arm/driver-arm.c (host_detect_local_cpu): Add GCC_CPUINFO.
+
+(cherry picked from commit 34a6c43487caf3a2a0ec9c7c79c526d116abc8b9)
+---
+ gcc/config/arm/driver-arm.c | 8 +++++++-
+ 1 file changed, 7 insertions(+), 1 deletion(-)
+
+diff --git a/gcc/config/arm/driver-arm.c b/gcc/config/arm/driver-arm.c
+index 254e5ba53a6..85058f257c9 100644
+--- a/gcc/config/arm/driver-arm.c
++++ b/gcc/config/arm/driver-arm.c
+@@ -61,6 +61,7 @@ host_detect_local_cpu (int argc, const char **argv)
+   FILE *f = NULL;
+   bool arch;
+   const struct vendor_cpu *cpu_table = NULL;
++  char *fcpu_info = NULL;
+ 
+   if (argc < 1)
+     goto not_found;
+@@ -69,7 +70,12 @@ host_detect_local_cpu (int argc, const char **argv)
+   if (!arch && strcmp (argv[0], "cpu") != 0 && strcmp (argv[0], "tune"))
+     goto not_found;
+ 
+-  f = fopen ("/proc/cpuinfo", "r");
++  fcpu_info = getenv ("GCC_CPUINFO");
++  if (fcpu_info)
++    f = fopen (fcpu_info, "r");
++  else
++    f = fopen ("/proc/cpuinfo", "r");
++
+   if (f == NULL)
+     goto not_found;
+ 
+-- 
+2.29.2
+