Teach the readelf about arm64 gnu properties

On arm64 binaries can be tagged as using BTI or PAC. Add support to
decode these to the elftoolchain readelf.

To simplify the code use a table based method to find the flag
description table.

Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32315

1 files changed, 63 insertions, 6 deletions

diff --git a/contrib/elftoolchain/readelf/readelf.c b/contrib/elftoolchain/readelf/readelf.c
index d5f9205e354d..f33519112eb4 100644
--- a/contrib/elftoolchain/readelf/readelf.c
+++ b/contrib/elftoolchain/readelf/readelf.c
@@ -229,6 +229,12 @@ struct flag_desc {
 	const char *desc;
 };
 
+struct flag_desc_list {
+	uint32_t type;
+	const char *desc_str;
+	struct flag_desc *desc;
+};
+
 struct mips_option {
 	uint64_t flag;
 	const char *desc;
@@ -3539,15 +3545,50 @@ dump_gnu_hash(struct readelf *re, struct section *s)
 	free(bl);
 }
 
+static struct flag_desc gnu_property_aarch64_feature_1_and_bits[] = {
+	{ GNU_PROPERTY_AARCH64_FEATURE_1_BTI,	"BTI" },
+	{ GNU_PROPERTY_AARCH64_FEATURE_1_PAC,	"PAC" },
+	{ 0, NULL }
+};
+
+static struct flag_desc_list gnu_property_aarch64[] = {
+	{
+	    GNU_PROPERTY_AARCH64_FEATURE_1_AND,
+	    "AArch64 features",
+	    gnu_property_aarch64_feature_1_and_bits
+	},
+	{ 0, NULL, NULL }
+};
+
 static struct flag_desc gnu_property_x86_feature_1_and_bits[] = {
 	{ GNU_PROPERTY_X86_FEATURE_1_IBT,	"IBT" },
 	{ GNU_PROPERTY_X86_FEATURE_1_SHSTK,	"SHSTK" },
 	{ 0, NULL }
 };
 
+static struct flag_desc_list gnu_property_x86[] = {
+	{
+	    GNU_PROPERTY_X86_FEATURE_1_AND,
+	    "x64 features",
+	    gnu_property_x86_feature_1_and_bits
+	},
+	{ 0, NULL, NULL }
+};
+
+static struct {
+	unsigned int emachine;
+	struct flag_desc_list *flag_list;
+} gnu_property_archs[] = {
+	{ EM_AARCH64, gnu_property_aarch64 },
+	{ EM_X86_64, gnu_property_x86 },
+	{ 0, NULL }
+};
+
 static void
 dump_gnu_property_type_0(struct readelf *re, const char *buf, size_t sz)
 {
+	struct flag_desc_list *desc_list;
+	struct flag_desc *desc;
 	size_t i;
 	uint32_t type, prop_sz;
 
@@ -3566,19 +3607,35 @@ dump_gnu_property_type_0(struct readelf *re, const char *buf, size_t sz)
 
 		if (type >= GNU_PROPERTY_LOPROC &&
 		    type <= GNU_PROPERTY_HIPROC) {
-			if (re->ehdr.e_machine != EM_X86_64) {
+			desc_list = NULL;
+			for (i = 0; gnu_property_archs[i].flag_list != NULL;
+			    i++) {
+				if (gnu_property_archs[i].emachine ==
+				    re->ehdr.e_machine) {
+					desc_list =
+					    gnu_property_archs[i].flag_list;
+					break;
+				}
+			}
+			if (desc_list == NULL) {
 				printf("machine type %x unknown\n",
 				    re->ehdr.e_machine);
 				goto unknown;
 			}
-			switch (type) {
-			case GNU_PROPERTY_X86_FEATURE_1_AND:
-				printf("x86 features:");
+
+			desc = NULL;
+			for (i = 0; desc_list[i].desc != NULL; i++) {
+				if (desc_list[i].type == type) {
+					desc = desc_list[i].desc;
+					break;
+				}
+			}
+			if (desc != NULL) {
+				printf("%s:", desc_list[i].desc_str);
 				if (prop_sz != 4)
 					goto bad;
-				dump_flags(gnu_property_x86_feature_1_and_bits,
+				dump_flags(desc,
 				    *(const uint32_t *)(const void *)buf);
-				break;
 			}
 		}