From: Matthew Malcomson <matthew.malcomson@arm.com>
Date: Mon, 20 Sep 2021 15:29:01 +0000 (+0100)
Subject: morello-binutils: Adjust c64_valid_cap_range calculation
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=81c4eb38b2f87ab648f536b0d565e8c90286f611;p=thirdparty%2Fbinutils-gdb.git

morello-binutils: Adjust c64_valid_cap_range calculation

This function had a buggy implementation of rounding a value up to a
given power of 2.  Aligning to a multiple of 16 would align to a
multiple of 32 and so on.

This was observable when linking object files that had very large
objects in them.  The compiler would ensure that these objects are large
enough that they are exactly representable, but the linker would
complain that they are not because the linker asserted extra alignment
than the compiler.

Here we fix the bug, add a few testcases, and adjust an existing
testcase in the area.
---

diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c
index 84286a7ee28..14b149a4007 100644
--- a/bfd/elfnn-aarch64.c
+++ b/bfd/elfnn-aarch64.c
@@ -4797,7 +4797,7 @@ exponent (uint64_t len)
 #undef CAP_MAX_EXPONENT
 }
 
-#define ONES(x)         ((1ULL << ((x) + 1)) - 1)
+#define ONES(x)         ((1ULL << (x)) - 1)
 #define ALIGN_UP(x, a)  (((x) + ONES (a)) & (~ONES (a)))
 
 static bool
diff --git a/ld/testsuite/ld-aarch64/aarch64-elf.exp b/ld/testsuite/ld-aarch64/aarch64-elf.exp
index df1b6dbc2e9..21fdfd26a0e 100644
--- a/ld/testsuite/ld-aarch64/aarch64-elf.exp
+++ b/ld/testsuite/ld-aarch64/aarch64-elf.exp
@@ -244,6 +244,8 @@ run_dump_test_lp64 "emit-relocs-morello-2"
 run_dump_test_lp64 "emit-relocs-morello-2-a64c"
 run_dump_test_lp64 "emit-relocs-morello-3"
 run_dump_test_lp64 "emit-relocs-morello-3-a64c"
+run_dump_test_lp64 "emit-relocs-morello-4"
+run_dump_test_lp64 "emit-relocs-morello-5"
 
 run_dump_test_lp64 "morello-capinit"
 run_dump_test_lp64 "morello-stubs"
diff --git a/ld/testsuite/ld-aarch64/emit-relocs-morello-4.d b/ld/testsuite/ld-aarch64/emit-relocs-morello-4.d
new file mode 100644
index 00000000000..04cfa79a042
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/emit-relocs-morello-4.d
@@ -0,0 +1,14 @@
+#source: emit-relocs-morello-4.s
+#as: -march=morello+c64
+#ld: -static
+#readelf: --relocs --syms
+
+
+#...
+Relocation section[^\n]*contains 1 entry:
+#...
+Symbol table[^\n]*contains[^\n]*:
+   Num:    Value          Size.*
+#...
+    [0-9]+: [0-9a-f]+0 64016 [^\n]* bigarray
+#pass
diff --git a/ld/testsuite/ld-aarch64/emit-relocs-morello-4.s b/ld/testsuite/ld-aarch64/emit-relocs-morello-4.s
new file mode 100644
index 00000000000..d91d85ab5eb
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/emit-relocs-morello-4.s
@@ -0,0 +1,17 @@
+// Checking that having a relocation against very large arrays that are not
+// problematic w.r.t. capability bounds representation do not error.
+// The below is somthing that requires being padded
+.bss
+.globl bigarray
+.p2align 4
+bigarray:
+	.zero 64004
+	.zero 12                 // Tail padding to ensure precise bounds.
+	.size bigarray, 64016
+
+.text
+.globl _start
+.type _start STT_FUNC
+_start:
+	adrp	c0, :got:bigarray
+	ldr	c0, [c0, #:got_lo12:bigarray]
diff --git a/ld/testsuite/ld-aarch64/emit-relocs-morello-5.d b/ld/testsuite/ld-aarch64/emit-relocs-morello-5.d
new file mode 100644
index 00000000000..05bbef145e0
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/emit-relocs-morello-5.d
@@ -0,0 +1,6 @@
+#source: emit-relocs-morello-5.s
+#as: -march=morello+c64
+#ld: -static
+#error: .*: capability range may exceed object bounds
+#error: .*: in function `_start':.*
+#error: .*: dangerous relocation: unsupported relocation
diff --git a/ld/testsuite/ld-aarch64/emit-relocs-morello-5.s b/ld/testsuite/ld-aarch64/emit-relocs-morello-5.s
new file mode 100644
index 00000000000..0493c26065c
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/emit-relocs-morello-5.s
@@ -0,0 +1,15 @@
+// Checking that having a relocation against very large arrays whose size can
+// not be represented gives the corresponding error.
+.bss
+.globl bigarray
+.p2align 4
+bigarray:
+	.zero 64004
+	.size bigarray, 64004
+
+.text
+.globl _start
+.type _start STT_FUNC
+_start:
+	adrp	c0, :got:bigarray
+	ldr	c0, [c0, #:got_lo12:bigarray]
diff --git a/ld/testsuite/ld-aarch64/morello-sec-round.d b/ld/testsuite/ld-aarch64/morello-sec-round.d
index 00eceb0386a..b553a604acd 100644
--- a/ld/testsuite/ld-aarch64/morello-sec-round.d
+++ b/ld/testsuite/ld-aarch64/morello-sec-round.d
@@ -7,5 +7,5 @@ Idx Name          Size      VMA               LMA               File off  Algn
 #...
   1 .text_sec     00020004  ...........20000  [0-9a-f]+  [0-9a-f]+  2\*\*17
                   CONTENTS, ALLOC, LOAD, READONLY, CODE
-  2 \..*       [0-9a-f]+  ...........40080  [0-9a-f]+  [0-9a-f]+  .*
+  2 \..*       [0-9a-f]+  ...........40040  [0-9a-f]+  [0-9a-f]+  .*
 #pass