AT_SUN_EXECNAME support

. vfs: pass execname in aux vectors
	. ld.elf_so: use this to expand $ORIGIN
	. this requires the executable to reserve more
	  space at exec() calling time

include/minix/com.h

@@ -546,7 +546,9 @@
 #define PMEXEC_FLAGS	m1_i3	/* PMEF_* */
 
 #define PMEF_AUXVECTORS	20
+#define PMEF_EXECNAMELEN1 256
 #define PMEF_AUXVECTORSPACE 0x01 /* space for PMEF_AUXVECTORS on stack */
+#define PMEF_EXECNAMESPACE1 0x02 /* space for PMEF_EXECNAMELEN1 execname */
 
 /* Flags for PR_FORK_FLAGS. */
 #define PFF_VMINHIBIT	0x01	/* Don't schedule until release by VM. */

lib/libc/sys-minix/execve.c

@@ -24,6 +24,7 @@ int execve(const char *path, char * const *argv, char * const *envp)
 	char **vp;
 	char *sp;
 	size_t argc;
+	int extra;
 	int vectors;
 	size_t frame_size;
 	size_t string_off;
@@ -63,8 +64,9 @@ int execve(const char *path, char * const *argv, char * const *envp)
 	 */
 	vectors = sizeof(argc) + sizeof(*ap) + sizeof(*ep) +
 		sizeof(AuxInfo) * PMEF_AUXVECTORS;
-	frame_size+= vectors;
-	string_off+= vectors;
+	extra = vectors + PMEF_EXECNAMELEN1;
+	frame_size+= extra;
+	string_off+= extra;
 
 	/* Align. */
 	frame_size= (frame_size + sizeof(char *) - 1) & ~(sizeof(char *) - 1);
@@ -116,8 +118,10 @@ int execve(const char *path, char * const *argv, char * const *envp)
 	m.m1_p1 = (char *) __UNCONST(path);
 	m.m1_p2 = frame;
 
-	/* Tell PM/VFS we have left space for the aux vectors */
-	m.PMEXEC_FLAGS = PMEF_AUXVECTORSPACE;
+	/* Tell PM/VFS we have left space for the aux vectors
+	 * and executable name
+	 */
+	m.PMEXEC_FLAGS = PMEF_AUXVECTORSPACE | PMEF_EXECNAMESPACE1;
 
 	(void) _syscall(PM_PROC_NR, EXEC, &m);
 

libexec/ld.elf_so/expand.c

@@ -73,9 +73,6 @@ static int mib[3][2] = {
 static size_t
 expand(char *buf, const char *execname, int what, size_t bl)
 {
-#ifdef __minix
-	return 0;
-#else
 	const char *p, *ep;
 	char *bp = buf;
 	size_t len;
@@ -93,6 +90,7 @@ expand(char *buf, const char *execname, int what, size_t bl)
 			xerr(1, "bad execname `%s' in AUX vector", execname);
 		break;
 
+#ifndef __minix
 	case 3:	/* OSNAME */
 	case 4:	/* OSREL */
 	case 5:	/* PLATFORM */
@@ -103,6 +101,7 @@ expand(char *buf, const char *execname, int what, size_t bl)
 		}
 		ep = (p = name) + len - 1;
 		break;
+#endif
 	default:
 		return 0;
 	}
@@ -111,7 +110,6 @@ expand(char *buf, const char *execname, int what, size_t bl)
 		*bp++ = *p++, bl--;
 
 	return bp - buf;
-#endif
 }
 		
 

servers/vfs/exec.c

@@ -58,7 +58,7 @@ static int read_seg(struct vnode *vp, off_t off, int proc_e, int seg,
 static int load_aout(struct exec_info *execi);
 static int load_elf(struct exec_info *execi);
 static int stack_prepare_elf(struct exec_info *execi,
-	char *curstack, size_t *frame_len, int *extrabase);
+	char *curstack, size_t *frame_len, vir_bytes *vsp, int *extrabase);
 static int map_header(struct exec_info *execi);
 
 #define PTRSIZE	sizeof(char *) /* Size of pointers in argv[] and envp[]. */
@@ -66,7 +66,7 @@ static int map_header(struct exec_info *execi);
 /* Array of loaders for different object file formats */
 typedef int (*exechook_t)(struct exec_info *execpackage);
 typedef int (*stackhook_t)(struct exec_info *execi, char *curstack,
-	size_t *frame_len, int *extrabase);
+	size_t *frame_len, vir_bytes *, int *extrabase);
 struct exec_loaders {
 	exechook_t load_object;	 /* load executable into memory */
 	stackhook_t setup_stack; /* prepare stack before argc and argv push */
@@ -283,6 +283,9 @@ int pm_exec(endpoint_t proc_e, vir_bytes path, size_t path_len,
 		FAILCHECK(r);
 	}
 
+	/* Remember it */
+	strcpy(execi.execname, finalexec);
+
 	/* The executable we need to execute first (loader)
 	 * is in elf_interpreter, and has to be in fullpath to
 	 * be looked up
@@ -306,11 +309,10 @@ int pm_exec(endpoint_t proc_e, vir_bytes path, size_t path_len,
   *pc = execi.pc;
 
   /* call a stack-setup function if this executable type wants it */
-  vsp = execi.stack_top;
-  if(makestack) FAILCHECK(makestack(&execi, mbuf, &frame_len, &extrabase));
+  vsp = execi.stack_top - frame_len;
+  if(makestack) FAILCHECK(makestack(&execi, mbuf, &frame_len, &vsp, &extrabase));
 
   /* Patch up stack and copy it from VFS to new core image. */
-  vsp -= frame_len;
   patch_ptr(mbuf, vsp + extrabase);
   FAILCHECK(sys_datacopy(SELF, (vir_bytes) mbuf, proc_e, (vir_bytes) vsp,
 		   (phys_bytes)frame_len));
@@ -390,9 +392,10 @@ static int load_aout(struct exec_info *execi)
   return(r);
 }
 
-static int stack_prepare_elf(struct exec_info *execi, char *frame, size_t *framelen, int *extrabase)
+static int stack_prepare_elf(struct exec_info *execi, char *frame, size_t *framelen,
+	vir_bytes *newsp, int *extrabase)
 {
-	AuxInfo *a;
+	AuxInfo *a, *term;
 	Elf_Ehdr *elf_header;
 	int nulls;
 	char	**mysp = (char **) frame,
@@ -438,6 +441,7 @@ static int stack_prepare_elf(struct exec_info *execi, char *frame, size_t *frame
 		if(*framelen + extrabytes >= ARG_MAX)
 			return ENOMEM;
 		*framelen += extrabytes;
+		*newsp -= extrabytes;
 		*extrabase += extrabytes;
 		memmove(f+extrabytes, f, remain);
 		memset(f, 0, extrabytes);
@@ -457,9 +461,34 @@ static int stack_prepare_elf(struct exec_info *execi, char *frame, size_t *frame
 	AUXINFO(AT_PAGESZ, PAGE_SIZE);
 	AUXINFO(AT_EXECFD, execi->elf_main_fd);
 
+	/* This is where we add the AT_NULL */
+	term = a;
+
 	/* Always terminate with AT_NULL */
 	AUXINFO(AT_NULL, 0);
 
+	/* Empty space starts here, if any. */
+	if((execi->userflags & PMEF_EXECNAMESPACE1)
+	   && strlen(execi->execname) < PMEF_EXECNAMELEN1) {
+		char *spacestart;
+		vir_bytes userp;
+
+		/* Make space for the real closing AT_NULL entry. */
+		AUXINFO(AT_NULL, 0);
+
+		/* Empty space starts here; we can put the name here. */
+		spacestart = (char *) a;
+		strcpy(spacestart, execi->execname);
+
+		/* What will the address of the string for the user be */
+		userp = *newsp + (spacestart-frame);
+
+		/* Move back to where the AT_NULL is */
+		a = term;
+		AUXINFO(AT_SUN_EXECNAME, userp);
+		AUXINFO(AT_NULL, 0);
+	}
+
 	return OK;
 }
 

servers/vfs/exec.h

@@ -23,6 +23,7 @@ struct exec_info {
     vir_bytes elf_phdr;			/* Program header location */
     vir_bytes elf_base;			/* Userland addr load address */
     int elf_main_fd;			/* Dyn: FD of main program execuatble */
+    char execname[PATH_MAX];		/* Full executable invocation */
 };
 
 #endif /* !_VFS_EXEC_H_ */

servers/vfs/main.c

@@ -807,7 +807,7 @@ static void service_pm_postponed(void)
 		stack_frame_len = (size_t) job_m_in.PM_FRAME_LEN;
 
 		r = pm_exec(proc_e, exec_path, exec_path_len, stack_frame,
-			    stack_frame_len, &pc, &newsp, m_in.PM_EXECFLAGS);
+			    stack_frame_len, &pc, &newsp, job_m_in.PM_EXECFLAGS);
 
 		/* Reply status to PM */
 		m_out.m_type = PM_EXEC_REPLY;