From: monojenkins <jo.shields+jenkins@xamarin.com>
Date: Thu, 27 Aug 2020 15:38:44 +0000 (-0400)
Subject: Issue18826 fix (#35137)
X-Git-Tag: submit/tizen/20210909.063632~5744
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=02b24db7cada5d5806c5cc513e61e44fb2a41944;p=platform%2Fupstream%2Fdotnet%2Fruntime.git

Issue18826 fix (#35137)

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Fixes mono/mono#18826

Co-authored-by: HinTak <HinTak@users.noreply.github.com>
---

diff --git a/src/mono/mono/mini/main.c b/src/mono/mono/mini/main.c
index b857ec3..7cc3fec 100644
--- a/src/mono/mono/mini/main.c
+++ b/src/mono/mono/mini/main.c
@@ -35,6 +35,9 @@
 #    include "buildver-boehm.h"
 #  endif
 #endif
+#ifdef TARGET_OSX
+#include <mach-o/loader.h>
+#endif
 
 //#define TEST_ICALL_SYMBOL_MAP 1
 
@@ -179,8 +182,68 @@ probe_embedded (const char *program, int *ref_argc, char **ref_argv [])
 		goto doclose;
 	if (read (fd, sigbuffer, sizeof (sigbuffer)) == -1)
 		goto doclose;
-	if (memcmp (sigbuffer+sizeof(uint64_t), "xmonkeysloveplay", 16) != 0)
-		goto doclose;
+	// First, see if "xmonkeysloveplay" is at the end of file
+	if (memcmp (sigbuffer + sizeof (uint64_t), "xmonkeysloveplay", 16) == 0)
+		goto found;
+
+#ifdef TARGET_OSX
+	{
+		/*
+		 * If "xmonkeysloveplay" is not at the end of file,
+		 * on Mac OS X, we try a little harder, by actually
+		 * reading the binary's header structure, to see
+		 * if it is located at the end of a LC_SYMTAB section.
+		 *
+		 * This is because Apple code-signing appends a
+		 * LC_CODE_SIGNATURE section to the binary, so
+		 * for a signed binary, "xmonkeysloveplay" is no
+		 * longer at the end of file.
+		 *
+		 * The rest is sanity-checks for the header and section structures.
+		 */
+		struct mach_header_64 bin_header;
+		if ((sigstart = lseek (fd, 0, SEEK_SET)) == -1)
+			goto doclose;
+		// Find and check binary header
+		if (read (fd, &bin_header, sizeof (bin_header)) == -1)
+			goto doclose;
+		if (bin_header.magic != MH_MAGIC_64)
+			goto doclose;
+
+		off_t total = bin_header.sizeofcmds;
+		uint32_t count = bin_header.ncmds;
+		while (total > 0 && count > 0) {
+			struct load_command lc;
+			off_t sig_stored = lseek (fd, 0, SEEK_CUR); // get current offset
+			if (read (fd, &lc, sizeof (lc)) == -1)
+				goto doclose;
+			if (lc.cmd == LC_SYMTAB) {
+				struct symtab_command stc;
+				if ((sigstart = lseek (fd, -sizeof (lc), SEEK_CUR)) == -1)
+					goto doclose;
+				if (read (fd, &stc, sizeof (stc)) == -1)
+					goto doclose;
+
+				// Check the end of the LC_SYMTAB section for "xmonkeysloveplay"
+				if ((sigstart = lseek (fd, -(16 + sizeof (uint64_t)) + stc.stroff + stc.strsize, SEEK_SET)) == -1)
+					goto doclose;
+				if (read (fd, sigbuffer, sizeof (sigbuffer)) == -1)
+					goto doclose;
+				if (memcmp (sigbuffer + sizeof (uint64_t), "xmonkeysloveplay", 16) == 0)
+					goto found;
+			}
+			if ((sigstart = lseek (fd, sig_stored + lc.cmdsize, SEEK_SET)) == -1)
+				goto doclose;
+			total -= sizeof (lc.cmdsize);
+			count--;
+		}
+	}
+#endif
+
+	// did not find "xmonkeysloveplay" at end of file or end of LC_SYMTAB section
+	goto doclose;
+
+found:
 	directory_location = GUINT64_FROM_LE ((*(uint64_t *) &sigbuffer [0]));
 	if (lseek (fd, directory_location, SEEK_SET) == -1)
 		goto doclose;