From: Michael Tremer <michael.tremer@ipfire.org>
Date: Fri, 3 Jan 2025 08:42:07 +0000 (+0000)
Subject: ELF: Create a function to easily walk through all program headers
X-Git-Tag: 0.9.30~571
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=40b7c05b2dea72c83c0548cc15394765d43c4e41;p=pakfire.git

ELF: Create a function to easily walk through all program headers

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/pakfire/elf.c b/src/pakfire/elf.c
index 10f25a22b..c6c681fab 100644
--- a/src/pakfire/elf.c
+++ b/src/pakfire/elf.c
@@ -282,6 +282,30 @@ const char* pakfire_elf_debuglink(struct pakfire_elf* self) {
 	return self->debuglink;
 }
 
+typedef int (*pakfire_elf_foreach_program_header_callback)
+	(struct pakfire_elf* self, const GElf_Phdr* phdr, void* data);
+
+static int pakfire_elf_foreach_program_header(struct pakfire_elf* self,
+		pakfire_elf_foreach_program_header_callback callback, void* data) {
+	GElf_Phdr phdr = {};
+	int r;
+
+	// Walk through all program headers
+	for (unsigned int i = 0; i < self->phnum; i++) {
+		if (!gelf_getphdr(self->elf, i, &phdr)) {
+			ERROR(self->ctx, "Could not parse program header: %s\n", elf_errmsg(-1));
+			return -ENOTSUP;
+		}
+
+		// Call the callback
+		r = callback(self, &phdr, data);
+		if (r)
+			break;
+	}
+
+	return r;
+}
+
 static int pakfire_elf_get_section(struct pakfire_elf* self,
 		const Elf64_Word type, const char* name, Elf_Scn** section, GElf_Shdr* header, Elf_Data** data) {
 	const char* sname = NULL;
@@ -480,38 +504,33 @@ int pakfire_elf_has_ssp(struct pakfire_elf* self) {
 	return 0;
 }
 
-int pakfire_elf_has_execstack(struct pakfire_elf* self) {
-	GElf_Phdr phdr;
-
-	// Walk through all program headers
-	for (unsigned int i = 0; i < self->phnum; i++) {
-		if (!gelf_getphdr(self->elf, i, &phdr)) {
-			ERROR(self->ctx, "Could not parse program header: %s\n", elf_errmsg(-1));
-			return -ENOTSUP;
-		}
-
-		switch (phdr.p_type) {
-			case PT_GNU_STACK:
-				DEBUG(self->ctx,
-					"%s: GNU_STACK flags: %c%c%c\n",
-					self->path,
-					(phdr.p_flags & PF_R) ? 'R' : '-',
-					(phdr.p_flags & PF_W) ? 'W' : '-',
-					(phdr.p_flags & PF_X) ? 'X' : '-'
-				);
-
-				// The stack cannot be writable and executable
-				if ((phdr.p_flags & PF_W) && (phdr.p_flags & PF_X))
-					return 1;
+static int pakfire_elf_check_execstack(
+		struct pakfire_elf* self, const GElf_Phdr* phdr, void* data) {
+	switch (phdr->p_type) {
+		case PT_GNU_STACK:
+			DEBUG(self->ctx,
+				"%s: GNU_STACK flags: %c%c%c\n",
+				self->path,
+				(phdr->p_flags & PF_R) ? 'R' : '-',
+				(phdr->p_flags & PF_W) ? 'W' : '-',
+				(phdr->p_flags & PF_X) ? 'X' : '-'
+			);
+
+			// The stack cannot be writable and executable
+			if ((phdr->p_flags & PF_W) && (phdr->p_flags & PF_X))
+				return 1;
 
-			default:
-				break;
-		}
+		default:
+			break;
 	}
 
 	return 0;
 }
 
+int pakfire_elf_has_execstack(struct pakfire_elf* self) {
+	return pakfire_elf_foreach_program_header(self, pakfire_elf_check_execstack, NULL);
+}
+
 static int pakfire_elf_has_bind_now(struct pakfire_elf* self,
 		const GElf_Shdr* shdr, const GElf_Dyn* dyn, void* data) {
 	switch (dyn->d_tag) {