path: root/sys-apps/proot/files/proot-5.1.0-loader.patch

commit 77d5ba4e5bb35f91d026a3240ad0a91a2d4b662a
Author: Cédric VINCENT <cedric.vincent@st.com>
Date:   Fri Feb 20 14:28:55 2015 +0100

    Set tracee's stack executable when the loaded program requires this.
    
    This is required for UMEQ and for some older versions of PRoot.  For
    example:
    
        $ proot -q umeq-arm64-dce01957 -R ~/gentoo-arm64-20140718
    
    Before:
    
        proot info: vpid 1 terminated with signal 11
    
    Now, it is OK.

diff --git a/src/compat.h b/src/compat.h
index 2b603f1..5009490 100644
--- a/src/compat.h
+++ b/src/compat.h
@@ -243,5 +243,17 @@
 #    ifndef MAP_ANONYMOUS
 #        define MAP_ANONYMOUS			0x20
 #    endif
+#    ifndef PROT_READ
+#        define PROT_READ		0x1
+#    endif
+#    ifndef PROT_WRITE
+#        define PROT_WRITE		0x2
+#    endif
+#    ifndef PROT_EXEC
+#        define PROT_EXEC		0x4
+#    endif
+#    ifndef PROT_GROWSDOWN
+#        define PROT_GROWSDOWN		0x01000000
+#    endif
 
 #endif /* COMPAT_H */
diff --git a/src/execve/elf.h b/src/execve/elf.h
index 3ced10c..a5b367b 100644
--- a/src/execve/elf.h
+++ b/src/execve/elf.h
@@ -108,7 +108,8 @@ typedef union {
 typedef enum {
 	PT_LOAD    = 1,
 	PT_DYNAMIC = 2,
-	PT_INTERP  = 3
+	PT_INTERP  = 3,
+	PT_GNU_STACK = 0x6474e551,
 } SegmentType;
 
 typedef struct {
diff --git a/src/execve/enter.c b/src/execve/enter.c
index cb84ec6..f0f3e7f 100644
--- a/src/execve/enter.c
+++ b/src/execve/enter.c
@@ -252,6 +252,11 @@ static int add_load_info(const ElfHeader *elf_header,
 			return status;
 		break;
 
+	case PT_GNU_STACK:
+		data->load_info->needs_executable_stack |=
+			((PROGRAM_FIELD(*elf_header, *program_header, flags) & PF_X) != 0);
+		break;
+
 	default:
 		break;
 	}
diff --git a/src/execve/execve.h b/src/execve/execve.h
index 11eca10..98b8d03 100644
--- a/src/execve/execve.h
+++ b/src/execve/execve.h
@@ -49,6 +49,7 @@ typedef struct load_info {
 	char *raw_path;
 	Mapping *mappings;
 	ElfHeader elf_header;
+	bool needs_executable_stack;
 
 	struct load_info *interp;
 } LoadInfo;
diff --git a/src/execve/exit.c b/src/execve/exit.c
index e6eff44..36cc51f 100644
--- a/src/execve/exit.c
+++ b/src/execve/exit.c
@@ -174,6 +174,9 @@ static void *transcript_mappings(void *cursor, const Mapping *mappings)
 static int transfer_load_script(Tracee *tracee)
 {
 	const word_t stack_pointer = peek_reg(tracee, CURRENT, STACK_POINTER);
+	static word_t page_size = 0;
+	static word_t page_mask = 0;
+
 	word_t entry_point;
 
 	size_t script_size;
@@ -190,10 +193,22 @@ static int transfer_load_script(Tracee *tracee)
 	void *buffer;
 	size_t buffer_size;
 
+	bool needs_executable_stack;
 	LoadStatement *statement;
 	void *cursor;
 	int status;
 
+	if (page_size == 0) {
+		page_size = sysconf(_SC_PAGE_SIZE);
+		if ((int) page_size <= 0)
+			page_size = 0x1000;
+		page_mask = ~(page_size - 1);
+	}
+
+	needs_executable_stack = (tracee->load_info->needs_executable_stack
+				|| (   tracee->load_info->interp != NULL
+				    && tracee->load_info->interp->needs_executable_stack));
+
 	/* Strings addresses are required to generate the load script,
 	 * for "open" actions.  Since I want to generate it in one
 	 * pass, these strings will be put right below the current
@@ -208,7 +223,7 @@ static int transfer_load_script(Tracee *tracee)
 			: strlen(tracee->load_info->raw_path) + 1);
 
 	/* A padding will be appended at the end of the load script
-	 * (a.k.a "strings area") to ensure this latter is aligned on
+	 * (a.k.a "strings area") to ensure this latter is aligned to
 	 * a word boundary, for sake of performance.  */
 	padding_size = (stack_pointer - string1_size - string2_size - string3_size)
 			% sizeof_word(tracee);
@@ -229,6 +244,7 @@ static int transfer_load_script(Tracee *tracee)
 			: LOAD_STATEMENT_SIZE(*statement, open)
 			+ (LOAD_STATEMENT_SIZE(*statement, mmap)
 				* talloc_array_length(tracee->load_info->interp->mappings)))
+		+ (needs_executable_stack ? LOAD_STATEMENT_SIZE(*statement, make_stack_exec) : 0)
 		+ LOAD_STATEMENT_SIZE(*statement, start);
 
 	/* Allocate enough room for both the load script and the
@@ -266,6 +282,16 @@ static int transfer_load_script(Tracee *tracee)
 	else
 		entry_point = ELF_FIELD(tracee->load_info->elf_header, entry);
 
+	if (needs_executable_stack) {
+		/* Load script statement: stack_exec.  */
+		statement = cursor;
+
+		statement->action = LOAD_ACTION_MAKE_STACK_EXEC;
+		statement->make_stack_exec.start = stack_pointer & page_mask;
+
+		cursor += LOAD_STATEMENT_SIZE(*statement, make_stack_exec);
+	}
+
 	/* Load script statement: start.  */
 	statement = cursor;
 
@@ -352,7 +378,7 @@ static int transfer_load_script(Tracee *tracee)
 	 *   | mmap file  |
 	 *   +------------+
 	 *   |   open     |
-	 *   +------------+ <- stack pointer, sysarg1 (word aligned)
+	 *   +------------+ <- stack pointer, userarg1 (word aligned)
 	 */
 
 	/* Remember we are in the sysexit stage, so be sure the
diff --git a/src/loader/assembly-arm.h b/src/loader/assembly-arm.h
index ee5bb85..59a7fe0 100644
--- a/src/loader/assembly-arm.h
+++ b/src/loader/assembly-arm.h
@@ -89,4 +89,5 @@
 #define EXECVE	11
 #define EXIT	1
 #define PRCTL	172
+#define MPROTECT 125
 
diff --git a/src/loader/assembly-x86.h b/src/loader/assembly-x86.h
index c83b3ef..4045144 100644
--- a/src/loader/assembly-x86.h
+++ b/src/loader/assembly-x86.h
@@ -65,3 +65,4 @@ extern word_t syscall_1(word_t number, word_t arg1);
 #define EXECVE	11
 #define EXIT	1
 #define PRCTL	172
+#define MPROTECT 125
diff --git a/src/loader/assembly-x86_64.h b/src/loader/assembly-x86_64.h
index c581208..6f431be 100644
--- a/src/loader/assembly-x86_64.h
+++ b/src/loader/assembly-x86_64.h
@@ -93,3 +93,4 @@
 #define EXECVE	59
 #define EXIT	60
 #define PRCTL	157
+#define MPROTECT 10
diff --git a/src/loader/loader.c b/src/loader/loader.c
index 5b31b02..9c2037b 100644
--- a/src/loader/loader.c
+++ b/src/loader/loader.c
@@ -171,6 +171,14 @@ void _start(void *cursor)
 			cursor += LOAD_STATEMENT_SIZE(*stmt, mmap);
 			break;
 
+		case LOAD_ACTION_MAKE_STACK_EXEC:
+			SYSCALL(MPROTECT, 3,
+				stmt->make_stack_exec.start, 1,
+				PROT_READ | PROT_WRITE | PROT_EXEC | PROT_GROWSDOWN);
+
+			cursor += LOAD_STATEMENT_SIZE(*stmt, make_stack_exec);
+			break;
+
 		case LOAD_ACTION_START_TRACED:
 			traced = true;
 			/* Fall through.  */
diff --git a/src/loader/script.h b/src/loader/script.h
index bb48af5..6ae7621 100644
--- a/src/loader/script.h
+++ b/src/loader/script.h
@@ -42,6 +42,10 @@ struct load_statement {
 			word_t clear_length;
 		} mmap;
 
+		struct {
+			word_t start;
+		} make_stack_exec;
+
 		struct {
 			word_t stack_pointer;
 			word_t entry_point;
@@ -67,7 +71,8 @@ typedef struct load_statement LoadStatement;
 #define LOAD_ACTION_OPEN		1
 #define LOAD_ACTION_MMAP_FILE		2
 #define LOAD_ACTION_MMAP_ANON		3
-#define LOAD_ACTION_START_TRACED	4
-#define LOAD_ACTION_START		5
+#define LOAD_ACTION_MAKE_STACK_EXEC	4
+#define LOAD_ACTION_START_TRACED	5
+#define LOAD_ACTION_START		6
 
 #endif /* SCRIPT */

commit d649854ddb66779950954aac99d960379c631a71
Author: Nicolas Cornu <ncornu@aldebaran.com>
Date:   Wed Jul 29 14:52:57 2015 +0200

    Fix use of size

diff --git a/src/execve/enter.c b/src/execve/enter.c
index 8f22d9c..4c163a1 100644
--- a/src/execve/enter.c
+++ b/src/execve/enter.c
@@ -454,10 +454,10 @@ static int expand_runner(Tracee* tracee, char host_path[PATH_MAX], char user_pat
 }
 
 extern unsigned char _binary_loader_exe_start;
-extern unsigned char _binary_loader_exe_size;
+extern unsigned char _binary_loader_exe_end;
 
 extern unsigned char WEAK _binary_loader_m32_exe_start;
-extern unsigned char WEAK _binary_loader_m32_exe_size;
+extern unsigned char WEAK _binary_loader_m32_exe_end;
 
 /**
  * Extract the built-in loader.  This function returns NULL if an
@@ -483,11 +483,11 @@ static char *extract_loader(const Tracee *tracee, bool wants_32bit_version)
 
 	if (wants_32bit_version) {
 		start = (void *) &_binary_loader_m32_exe_start;
-		size  = (size_t) &_binary_loader_m32_exe_size;
+		size  = (size_t)(&_binary_loader_m32_exe_end-&_binary_loader_m32_exe_start);
 	}
 	else {
 		start = (void *) &_binary_loader_exe_start;
-		size  = (size_t) &_binary_loader_exe_size;
+		size  = (size_t) (&_binary_loader_exe_end-&_binary_loader_exe_start);
 	}
 
 	status2 = write(fd, start, size);