recognize and execute dynamically linked executables

. generalize libexec slightly to get some more necessary information
	  from ELF files, e.g. the interpreter
	. execute dynamically linked executables when exec()ed by VFS
	. switch to netbsd variant of elf32.h exclusively, solves some
	  conflicting headers

common/include/sys/Makefile.inc

@@ -2,7 +2,7 @@
 
 .PATH: ${MINIXSRCDIR}/common/include/sys
 
-INCS+= 	elf32.h elf64.h elf_common.h elf_generic.h \
+INCS+= 	elf64.h elf_common.h elf_generic.h \
 	ioc_block.h ioc_fbd.h ioc_file.h ioc_tape.h ioc_disk.h \
 	ioc_memory.h ioc_sound.h ioc_tty.h \
 	kbdio.h mtio.h svrctl.h video.h vm.h procfs.h elf_core.h exec_elf.h \

common/include/sys/elf32.h

@@ -1,249 +0,0 @@
-/*-
- * Copyright (c) 1996-1998 John D. Polstra.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * $FreeBSD$
- */
-
-#ifndef _SYS_ELF32_H_
-#define _SYS_ELF32_H_ 1
-
-#include <sys/elf_common.h>
-
-/*
- * ELF definitions common to all 32-bit architectures.
- */
-
-typedef uint32_t	Elf32_Addr;
-typedef uint16_t	Elf32_Half;
-typedef uint32_t	Elf32_Off;
-typedef int32_t		Elf32_Sword;
-typedef uint32_t	Elf32_Word;
-#if defined(__ACK__)
-typedef uint32_t	Elf32_Lword;
-#else
-typedef uint64_t	Elf32_Lword;
-#endif
-
-typedef Elf32_Word	Elf32_Hashelt;
-
-/* Non-standard class-dependent datatype used for abstraction. */
-typedef Elf32_Word	Elf32_Size;
-typedef Elf32_Sword	Elf32_Ssize;
-
-/*
- * ELF header.
- */
-
-typedef struct {
-	unsigned char	e_ident[EI_NIDENT];	/* File identification. */
-	Elf32_Half	e_type;		/* File type. */
-	Elf32_Half	e_machine;	/* Machine architecture. */
-	Elf32_Word	e_version;	/* ELF format version. */
-	Elf32_Addr	e_entry;	/* Entry point. */
-	Elf32_Off	e_phoff;	/* Program header file offset. */
-	Elf32_Off	e_shoff;	/* Section header file offset. */
-	Elf32_Word	e_flags;	/* Architecture-specific flags. */
-	Elf32_Half	e_ehsize;	/* Size of ELF header in bytes. */
-	Elf32_Half	e_phentsize;	/* Size of program header entry. */
-	Elf32_Half	e_phnum;	/* Number of program header entries. */
-	Elf32_Half	e_shentsize;	/* Size of section header entry. */
-	Elf32_Half	e_shnum;	/* Number of section header entries. */
-	Elf32_Half	e_shstrndx;	/* Section name strings section. */
-} Elf32_Ehdr;
-
-/*
- * Section header.
- */
-
-typedef struct {
-	Elf32_Word	sh_name;	/* Section name (index into the
-					   section header string table). */
-	Elf32_Word	sh_type;	/* Section type. */
-	Elf32_Word	sh_flags;	/* Section flags. */
-	Elf32_Addr	sh_addr;	/* Address in memory image. */
-	Elf32_Off	sh_offset;	/* Offset in file. */
-	Elf32_Word	sh_size;	/* Size in bytes. */
-	Elf32_Word	sh_link;	/* Index of a related section. */
-	Elf32_Word	sh_info;	/* Depends on section type. */
-	Elf32_Word	sh_addralign;	/* Alignment in bytes. */
-	Elf32_Word	sh_entsize;	/* Size of each entry in section. */
-} Elf32_Shdr;
-
-/*
- * Program header.
- */
-
-typedef struct {
-	Elf32_Word	p_type;		/* Entry type. */
-	Elf32_Off	p_offset;	/* File offset of contents. */
-	Elf32_Addr	p_vaddr;	/* Virtual address in memory image. */
-	Elf32_Addr	p_paddr;	/* Physical address (not used). */
-	Elf32_Word	p_filesz;	/* Size of contents in file. */
-	Elf32_Word	p_memsz;	/* Size of contents in memory. */
-	Elf32_Word	p_flags;	/* Access permission flags. */
-	Elf32_Word	p_align;	/* Alignment in memory and file. */
-} Elf32_Phdr;
-
-/*
- * Dynamic structure.  The ".dynamic" section contains an array of them.
- */
-
-typedef struct {
-	Elf32_Sword	d_tag;		/* Entry type. */
-	union {
-		Elf32_Word	d_val;	/* Integer value. */
-		Elf32_Addr	d_ptr;	/* Address value. */
-	} d_un;
-} Elf32_Dyn;
-
-/*
- * Relocation entries.
- */
-
-/* Relocations that don't need an addend field. */
-typedef struct {
-	Elf32_Addr	r_offset;	/* Location to be relocated. */
-	Elf32_Word	r_info;		/* Relocation type and symbol index. */
-} Elf32_Rel;
-
-/* Relocations that need an addend field. */
-typedef struct {
-	Elf32_Addr	r_offset;	/* Location to be relocated. */
-	Elf32_Word	r_info;		/* Relocation type and symbol index. */
-	Elf32_Sword	r_addend;	/* Addend. */
-} Elf32_Rela;
-
-/* Macros for accessing the fields of r_info. */
-#define ELF32_R_SYM(info)	((info) >> 8)
-#define ELF32_R_TYPE(info)	((unsigned char)(info))
-
-/* Macro for constructing r_info from field values. */
-#define ELF32_R_INFO(sym, type)	(((sym) << 8) + (unsigned char)(type))
-
-/*
- *	Note entry header
- */
-typedef Elf_Note Elf32_Nhdr;
-
-/*
- *	Move entry
- */
-typedef struct {
-	Elf32_Lword	m_value;	/* symbol value */
-	Elf32_Word 	m_info;		/* size + index */
-	Elf32_Word	m_poffset;	/* symbol offset */
-	Elf32_Half	m_repeat;	/* repeat count */
-	Elf32_Half	m_stride;	/* stride info */
-} Elf32_Move;
-
-/*
- *	The macros compose and decompose values for Move.r_info
- *
- *	sym = ELF32_M_SYM(M.m_info)
- *	size = ELF32_M_SIZE(M.m_info)
- *	M.m_info = ELF32_M_INFO(sym, size)
- */
-#define	ELF32_M_SYM(info)	((info)>>8)
-#define	ELF32_M_SIZE(info)	((unsigned char)(info))
-#define	ELF32_M_INFO(sym, size)	(((sym)<<8)+(unsigned char)(size))
-
-/*
- *	Hardware/Software capabilities entry
- */
-typedef struct {
-	Elf32_Word	c_tag;		/* how to interpret value */
-	union {
-		Elf32_Word	c_val;
-		Elf32_Addr	c_ptr;
-	} c_un;
-} Elf32_Cap;
-
-/*
- * Symbol table entries.
- */
-
-typedef struct {
-	Elf32_Word	st_name;	/* String table index of name. */
-	Elf32_Addr	st_value;	/* Symbol value. */
-	Elf32_Word	st_size;	/* Size of associated object. */
-	unsigned char	st_info;	/* Type and binding information. */
-	unsigned char	st_other;	/* Reserved (not used). */
-	Elf32_Half	st_shndx;	/* Section index of symbol. */
-} Elf32_Sym;
-
-/* Macros for accessing the fields of st_info. */
-#define ELF32_ST_BIND(info)		((info) >> 4)
-#define ELF32_ST_TYPE(info)		((info) & 0xf)
-
-/* Macro for constructing st_info from field values. */
-#define ELF32_ST_INFO(bind, type)	(((bind) << 4) + ((type) & 0xf))
-
-/* Macro for accessing the fields of st_other. */
-#define ELF32_ST_VISIBILITY(oth)	((oth) & 0x3)
-
-/* Structures used by Sun & GNU symbol versioning. */
-typedef struct
-{
-	Elf32_Half	vd_version;
-	Elf32_Half	vd_flags;
-	Elf32_Half	vd_ndx;
-	Elf32_Half	vd_cnt;
-	Elf32_Word	vd_hash;
-	Elf32_Word	vd_aux;
-	Elf32_Word	vd_next;
-} Elf32_Verdef;
-
-typedef struct
-{
-	Elf32_Word	vda_name;
-	Elf32_Word	vda_next;
-} Elf32_Verdaux;
-
-typedef struct
-{
-	Elf32_Half	vn_version;
-	Elf32_Half	vn_cnt;
-	Elf32_Word	vn_file;
-	Elf32_Word	vn_aux;
-	Elf32_Word	vn_next;
-} Elf32_Verneed;
-
-typedef struct
-{
-	Elf32_Word	vna_hash;
-	Elf32_Half	vna_flags;
-	Elf32_Half	vna_other;
-	Elf32_Word	vna_name;
-	Elf32_Word	vna_next;
-} Elf32_Vernaux;
-
-typedef Elf32_Half Elf32_Versym;
-
-typedef struct {
-	Elf32_Half	si_boundto;	/* direct bindings - symbol bound to */
-	Elf32_Half	si_flags;	/* per symbol flags */
-} Elf32_Syminfo;
-
-#endif /* !_SYS_ELF32_H_ */

include/arch/i386/include/elf.h

@@ -33,84 +33,10 @@
  * ELF definitions for the i386 architecture.
  */
 
-#include <sys/elf32.h>	/* Definitions common to all 32 bit architectures. */
-#if defined(__ELF_WORD_SIZE) && __ELF_WORD_SIZE == 64
-#include <sys/elf64.h>	/* Definitions common to all 64 bit architectures. */
-#endif
-
-#ifndef __ELF_WORD_SIZE
-#define	__ELF_WORD_SIZE	32	/* Used by <sys/elf_generic.h> */
-#endif
-
-#include <sys/elf_generic.h>
-
-#define	ELF_ARCH	EM_386
-
-#define	ELF_MACHINE_OK(x) ((x) == EM_386 || (x) == EM_486)
-
-/*
- * Auxiliary vector entries for passing information to the interpreter.
- *
- * The i386 supplement to the SVR4 ABI specification names this "auxv_t",
- * but POSIX lays claim to all symbols ending with "_t".
- */
-
-typedef struct {	/* Auxiliary vector entry on initial stack */
-	int	a_type;			/* Entry type. */
-	union {
-		long	a_val;		/* Integer value. */
-		void	*a_ptr;		/* Address. */
-		void	(*a_fcn)(void);	/* Function pointer (not used). */
-	} a_un;
-} Elf32_Auxinfo;
-
-#if __ELF_WORD_SIZE == 64
-/* Fake for amd64 loader support */
-typedef struct {
-	int fake;
-} Elf64_Auxinfo;
-#endif
-
-__ElfType(Auxinfo);
-
-/* Values for a_type. */
-#define	AT_NULL		0	/* Terminates the vector. */
-#define	AT_IGNORE	1	/* Ignored entry. */
-#define	AT_EXECFD	2	/* File descriptor of program to load. */
-#define	AT_PHDR		3	/* Program header of program already loaded. */
-#define	AT_PHENT	4	/* Size of each program header entry. */
-#define	AT_PHNUM	5	/* Number of program header entries. */
-#define	AT_PAGESZ	6	/* Page size in bytes. */
-#define	AT_BASE		7	/* Interpreter's base address. */
-#define	AT_FLAGS	8	/* Flags (unused for i386). */
-#define	AT_ENTRY	9	/* Where interpreter should transfer control. */
-#define	AT_NOTELF	10	/* Program is not ELF ?? */
-#define	AT_UID		11	/* Real uid. */
-#define	AT_EUID		12	/* Effective uid. */
-#define	AT_GID		13	/* Real gid. */
-#define	AT_EGID		14	/* Effective gid. */
-#define	AT_EXECPATH	15	/* Path to the executable. */
-#define	AT_CANARY	16	/* Canary for SSP. */
-#define	AT_CANARYLEN	17	/* Length of the canary. */
-#define	AT_OSRELDATE	18	/* OSRELDATE. */
-#define	AT_NCPUS	19	/* Number of CPUs. */
-#define	AT_PAGESIZES	20	/* Pagesizes. */
-#define	AT_PAGESIZESLEN	21	/* Number of pagesizes. */
-
-#define	AT_COUNT	22	/* Count of defined aux entry types. */
-
-/*
- * Relocation types.
- */
-
-#define	R_386_COUNT	38	/* Count of defined relocation types. */
-
 /* Define "machine" characteristics */
 #define	ELF_TARG_CLASS	ELFCLASS32
 #define	ELF_TARG_DATA	ELFDATA2LSB
 #define	ELF_TARG_MACH	EM_386
 #define	ELF_TARG_VER	1
 
-#define	ET_DYN_LOAD_ADDR 0x01001000
-
 #endif /* !_MACHINE_ELF_H_ */

include/minix/com.h

@@ -542,6 +542,12 @@
 #define PR_FORK_MSGADDR m1_p1	/* reply message address of forked child */
 #define PR_CTX_PTR	m1_p1	/* pointer to mcontext_t structure */
 
+/* Field names for EXEC sent from userland to PM. */
+#define PMEXEC_FLAGS	m1_i3	/* PMEF_* */
+
+#define PMEF_AUXVECTORS	20
+#define PMEF_AUXVECTORSPACE 0x01 /* space for PMEF_AUXVECTORS on stack */
+
 /* Flags for PR_FORK_FLAGS. */
 #define PFF_VMINHIBIT	0x01	/* Don't schedule until release by VM. */
 
@@ -797,10 +803,12 @@
 					 */
 #  define PM_FRAME		m7_p2	/* arguments and environment */
 #  define PM_FRAME_LEN		m7_i3	/* size of frame */
+#  define PM_EXECFLAGS		m7_i4	/* PMEXEC_FLAGS */
 
 /* Additional parameters for PM_EXEC_REPLY and PM_CORE_REPLY */
 #  define PM_STATUS		m7_i2	/* OK or failure */
 #  define PM_PC			m7_p1	/* program counter */
+#  define PM_NEWSP		m7_p2	/* possibly-changed stack ptr */
 
 /* Additional parameters for PM_FORK and PM_SRV_FORK */
 #  define PM_PPROC		m7_i2	/* parent process endpoint */

include/sys/Makefile

@@ -47,9 +47,7 @@ INCSYMLINKS=\
 	sys/sha1.h ${NETBSDINCSDIR}/sha1.h \
 	sys/sha2.h ${NETBSDINCSDIR}/sha2.h \
 	sys/md4.h ${NETBSDINCSDIR}/md4.h \
-	sys/md5.h ${NETBSDINCSDIR}/md5.h \
+	sys/md5.h ${NETBSDINCSDIR}/md5.h 
-	sys/exec_elf.h ${NETBSDINCSDIR}/elf.h \
-
 
 #INCSYMLINKS+=	../soundcard.h ${INCSDIR}/soundcard.h
 

kernel/arch/i386/pre_init.c

@@ -369,6 +369,7 @@ static void mb_extract_image(multiboot_info_t mbi)
 
 	/* Save memory map for kernel tasks */
 	r = read_header_elf((const char *)MULTIBOOT_KERNEL_ADDR,
+				4096, /* everything is there */
 			    &text_vaddr, &text_paddr,
 			    &text_filebytes, &text_membytes,
 			    &data_vaddr, &data_paddr,
@@ -401,6 +402,7 @@ static void mb_extract_image(multiboot_info_t mbi)
 	/* Load boot image services into memory and save memory map */
 	for (i = 0; module < &mb_module_info[mods_count]; ++module, ++i) {
 	    r = read_header_elf((const char *)module->mod_start,
+				module->mod_end - module->mod_start + 1,
 				&text_vaddr, &text_paddr,
 				&text_filebytes, &text_membytes,
 				&data_vaddr, &data_paddr,

lib/libc/sys-minix/execve.c

@@ -10,6 +10,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <stddef.h>
+#include <sys/exec_elf.h>
 
 #ifdef __weak_alias
 __weak_alias(execve, _execve)
@@ -23,6 +24,7 @@ int execve(const char *path, char * const *argv, char * const *envp)
 	char **vp;
 	char *sp;
 	size_t argc;
+	int vectors;
 	size_t frame_size;
 	size_t string_off;
 	size_t n;
@@ -55,9 +57,14 @@ int execve(const char *path, char * const *argv, char * const *envp)
 		string_off+= sizeof(*ap);
 	}
 
-	/* Add an argument count and two terminating nulls. */
+	/* Add an argument count, two terminating nulls and
-	frame_size+= sizeof(argc) + sizeof(*ap) + sizeof(*ep);
+	 * space for the ELF aux vectors, that must come before
-	string_off+= sizeof(argc) + sizeof(*ap) + sizeof(*ep);
+	 * (i.e. at a higher address) then the strings.
+	 */
+	vectors = sizeof(argc) + sizeof(*ap) + sizeof(*ep) +
+		sizeof(AuxInfo) * PMEF_AUXVECTORS;
+	frame_size+= vectors;
+	string_off+= vectors;
 
 	/* Align. */
 	frame_size= (frame_size + sizeof(char *) - 1) & ~(sizeof(char *) - 1);
@@ -100,15 +107,17 @@ int execve(const char *path, char * const *argv, char * const *envp)
 	/* Padding. */
 	while (sp < frame + frame_size) *sp++= 0;
 
+	/* Clear unused message fields */
+	memset(&m, 0, sizeof(m));
+
 	/* We can finally make the system call. */
 	m.m1_i1 = strlen(path) + 1;
 	m.m1_i2 = frame_size;
 	m.m1_p1 = (char *) __UNCONST(path);
 	m.m1_p2 = frame;
 
-	/* Clear unused fields */
+	/* Tell PM/VFS we have left space for the aux vectors */
-	m.m1_i3 = 0;
+	m.PMEXEC_FLAGS = PMEF_AUXVECTORSPACE;
-	m.m1_p3 = NULL;
 
 	(void) _syscall(PM_PROC_NR, EXEC, &m);
 

lib/libexec/exec_elf.c

@@ -7,6 +7,8 @@
 #include <unistd.h>
 #include <errno.h>
 #include <libexec.h>
+#include <string.h>
+#include <machine/elf.h>
 
 /* For verbose logging */
 #define ELF_DEBUG 0
@@ -16,10 +18,63 @@
 
 #define SECTOR_SIZE 512
 
-static int __elfN(check_header)(const Elf_Ehdr *hdr);
+static int check_header(const Elf_Ehdr *hdr);
+
+static int elf_sane(const Elf_Ehdr *hdr)
+{
+  if (check_header(hdr) != OK) {
+     return 0;
+  }
+
+  if((hdr->e_type != ET_EXEC) && (hdr->e_type != ET_DYN)) {
+     return 0;
+  }
+
+  if ((hdr->e_phoff > SECTOR_SIZE) ||
+      (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > SECTOR_SIZE) {
+#if ELF_DEBUG
+	printf("peculiar phoff\n");
+#endif
+     return 0;
+  }
+
+  return 1;
+}
+
+static int elf_ph_sane(const Elf_Phdr *phdr)
+{
+  if (rounddown((uintptr_t)phdr, sizeof(Elf_Addr)) != (uintptr_t)phdr) {
+     return 0;
+  }
+  return 1;
+}
+
+static int elf_unpack(const char *exec_hdr,
+	int hdr_len, const Elf_Ehdr **hdr, const Elf_Phdr **phdr)
+{
+  *hdr = (const Elf_Ehdr *)exec_hdr;
+  if(!elf_sane(*hdr)) {
+#if ELF_DEBUG
+	printf("elf_sane failed\n");
+#endif
+  	return ENOEXEC;
+  }
+  *phdr = (const Elf_Phdr *)(exec_hdr + (*hdr)->e_phoff);
+  if(!elf_ph_sane(*phdr)) {
+#if ELF_DEBUG
+	printf("elf_ph_sane failed\n");
+#endif
+  	return ENOEXEC;
+  }
+#if 0
+  if((int)((*phdr) + (*hdr)->e_phnum) >= hdr_len) return ENOEXEC;
+#endif
+  return OK;
+}
 
 int read_header_elf(
   const char *exec_hdr,		/* executable header */
+  int hdr_len,			/* significant bytes in exec_hdr */
   vir_bytes *text_vaddr,	/* text virtual address */
   phys_bytes *text_paddr,	/* text physical address */
   vir_bytes *text_filebytes,	/* text segment size (in the file) */
@@ -36,7 +91,7 @@ int read_header_elf(
   const Elf_Ehdr *hdr = NULL;
   const Elf_Phdr *phdr = NULL;
   unsigned long seg_filebytes, seg_membytes;
-  int i = 0;
+  int e, i = 0;
 
   *text_vaddr = *text_paddr = 0;
   *text_filebytes = *text_membytes = 0;
@@ -44,27 +99,12 @@ int read_header_elf(
   *data_filebytes = *data_membytes = 0;
   *pc = *text_offset = *data_offset = 0;
 
-  hdr = (const Elf_Ehdr *)exec_hdr;
+  if((e=elf_unpack(exec_hdr, hdr_len, &hdr, &phdr)) != OK) {
-  if (__elfN(check_header)(hdr) != OK || (hdr->e_type != ET_EXEC))
+#if ELF_DEBUG
-  {
+	printf("elf_unpack failed\n");
-     return ENOEXEC;
-  }
-
-  if ((hdr->e_phoff > SECTOR_SIZE) ||
-      (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > SECTOR_SIZE) {
-     return ENOEXEC;
-  }
-
-  phdr = (const Elf_Phdr *)(exec_hdr + hdr->e_phoff);
-  if (
-#ifdef __NBSD_LIBC
-      rounddown((uintptr_t)phdr, sizeof(Elf_Addr)) != (uintptr_t)phdr
-#else
-      !_minix_aligned(hdr->e_phoff, Elf_Addr)
 #endif
-     ) {
+  	return e;
-     return ENOEXEC;
+   }
-  }
 
 #if ELF_DEBUG
   printf("Program header file offset (phoff): %ld\n", hdr->e_phoff);
@@ -124,7 +164,12 @@ int read_header_elf(
   return OK;
 }
 
-static int __elfN(check_header)(const Elf_Ehdr *hdr)
+#define IS_ELF(ehdr)	((ehdr).e_ident[EI_MAG0] == ELFMAG0 && \
+			 (ehdr).e_ident[EI_MAG1] == ELFMAG1 && \
+			 (ehdr).e_ident[EI_MAG2] == ELFMAG2 && \
+			 (ehdr).e_ident[EI_MAG3] == ELFMAG3)
+
+static int check_header(const Elf_Ehdr *hdr)
 {
   if (!IS_ELF(*hdr) ||
       hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
@@ -135,3 +180,66 @@ static int __elfN(check_header)(const Elf_Ehdr *hdr)
 
   return OK;
 }
+
+int elf_phdr(const char *exec_hdr, int hdr_len, vir_bytes *ret_phdr)
+{
+  const Elf_Ehdr *hdr = NULL;
+  const Elf_Phdr *phdr = NULL;
+  int e, i, have_computed_phdr = 1;
+
+  if((e=elf_unpack(exec_hdr, hdr_len, &hdr, &phdr)) != OK) return e;
+
+  for (i = 0; i < hdr->e_phnum; i++) {
+      switch (phdr[i].p_type) {
+      case PT_LOAD:
+      		/* compute phdr based on this heuristic, to be used
+		 * if there is no PT_PHDR
+		 */
+      		if(phdr[i].p_offset == 0) {
+			*ret_phdr = phdr[i].p_vaddr + hdr->e_phoff;
+			have_computed_phdr = 1;
+		}
+		break;
+      case PT_PHDR:
+      	  *ret_phdr = phdr[i].p_vaddr;
+	  return OK;
+      default:
+	  break;;
+      }
+  }
+  if(have_computed_phdr) return OK;
+  return ENOENT;
+}
+
+/* Return >0 if there is an ELF interpreter (i.e. it is a dynamically linked
+ * executable) and we could extract it successfully.
+ * Return 0 if there isn't one.
+ * Return <0 on error.
+ */
+int elf_has_interpreter(const char *exec_hdr,		/* executable header */
+		int hdr_len, char *interp, int maxsz)
+{
+  const Elf_Ehdr *hdr = NULL;
+  const Elf_Phdr *phdr = NULL;
+  int e, i;
+
+  if((e=elf_unpack(exec_hdr, hdr_len, &hdr, &phdr)) != OK) return e;
+
+  for (i = 0; i < hdr->e_phnum; i++) {
+      switch (phdr[i].p_type) {
+      case PT_INTERP:
+      	  if(!interp) return 1;
+      	  if(phdr[i].p_filesz >= maxsz)
+	  	return -1;
+	  if(phdr[i].p_offset + phdr[i].p_filesz >= hdr_len)
+	  	return -1;
+	  memcpy(interp, exec_hdr + phdr[i].p_offset, phdr[i].p_filesz);
+	  interp[phdr[i].p_filesz] = '\0';
+	  return 1;
+      default:
+	  continue;
+      }
+  }
+  return 0;
+}
+

lib/libexec/libexec.h

@@ -1,7 +1,7 @@
 #ifndef _LIBEXEC_H_
 #define _LIBEXEC_H_ 1
 
-#include <machine/elf.h>
+#include <sys/exec_elf.h>
 
 /* a.out routines */
 int read_header_aout(const char *exec_hdr, size_t exec_len, int *sep_id,
@@ -10,11 +10,14 @@ int read_header_aout(const char *exec_hdr, size_t exec_len, int *sep_id,
    int *hdrlenp);
 
 /* ELF routines */
-int read_header_elf(const char *exec_hdr,
+int read_header_elf(const char *exec_hdr, int hdr_len,
    vir_bytes *text_vaddr, phys_bytes *text_paddr,
    vir_bytes *text_filebytes, vir_bytes *text_membytes,
    vir_bytes *data_vaddr, phys_bytes *data_paddr,
    vir_bytes *data_filebytes, vir_bytes *data_membytes,
    vir_bytes *pc, off_t *text_offset, off_t *data_offset);
 
+int elf_has_interpreter(const char *exec_hdr, int hdr_len, char *interp, int maxsz);
+int elf_phdr(const char *exec_hdr, int hdr_len, vir_bytes *phdr);
+
 #endif /* !_LIBEXEC_H_ */

libexec/ld.elf_so/Makefile

@@ -38,7 +38,11 @@ M=		${.CURDIR}/arch/${ARCHSUBDIR}
      (${MACHINE_ARCH} == "vax")) &&					\
     ${MKPIC} != "no"
 
+.if ${CC} == "gcc"
 LDFLAGS+=	-shared -symbolic -nostartfiles
+.else
+LDFLAGS+=	-shared -Wl,-Bsymbolic -nostartfiles
+.endif
 LDFLAGS+=	-Wl,-static
 LDFLAGS+=	-Wl,--warn-shared-textrel
 

libexec/ld.elf_so/map_object.c

@@ -53,6 +53,53 @@ static int protflags(int);	/* Elf flags -> mmap protection */
 
 #define EA_UNDEF		(~(Elf_Addr)0)
 
+#ifdef __minix
+#define mmap	minix_mmap_emulator
+#define munmap	minix_munmap
+
+/* for minix, ignore MAP_SHARED and MAP_FILE for now. */
+#define MAP_SHARED 0
+#define MAP_FILE 0
+#endif
+
+#undef MINIXVERBOSE
+
+static void * minix_mmap_emulator(void *addrhint, size_t size, int prot, int flags, int fd, off_t off)
+{
+	void *ret;
+	int mapflags;
+	size_t s;
+
+	mapflags = flags & (MAP_FIXED);
+
+#ifdef MINIXVERBOSE
+	if(addrhint) {
+		fprintf(stderr, "0x%lx-0x%lx requested\n", addrhint,
+			(char *) addrhint + size);
+	}
+#endif
+
+	if((ret = minix_mmap(addrhint, size, PROT_READ|PROT_WRITE,
+		MAP_ANON|MAP_PRIVATE|MAP_PREALLOC|mapflags, -1, 0)) == MAP_FAILED) {
+		return ret;
+	}
+
+	if(!(mapflags & MAP_ANON)) {
+		if((s=pread(fd, ret, size, off)) <= 0) {
+			munmap(ret, size);
+			return MAP_FAILED;
+		}
+	}
+
+#ifdef MINIXVERBOSE
+	fprintf(stderr, "0x%lx-0x%lx mapped\n",
+		ret, (char *) ret + size);
+
+#endif
+
+	return ret;
+}
+
 /*
  * Map a shared object into memory.  The argument is a file descriptor,
  * which must be open on the object and positioned at its beginning.
@@ -296,8 +343,15 @@ _rtld_map_object(const char *path, int fd, const struct stat *sb)
 	base_addr = NULL;
 #endif
 	mapsize = base_vlimit - base_vaddr;
+
+#ifndef __minix
 	mapbase = mmap(base_addr, mapsize, text_flags,
 	    mapflags | MAP_FILE | MAP_PRIVATE, fd, base_offset);
+#else
+	/* minix doesn't want overlapping mmap()s */
+	mapbase = mmap(base_addr, obj->textsize, text_flags,
+	    mapflags | MAP_FILE | MAP_PRIVATE, fd, base_offset);
+#endif
 	if (mapbase == MAP_FAILED) {
 		_rtld_error("mmap of entire address space failed: %s",
 		    xstrerror(errno));

servers/pm/exec.c

@@ -47,6 +47,7 @@ int do_exec()
 	m.PM_PATH_LEN = m_in.exec_len;
 	m.PM_FRAME = m_in.frame_ptr;
 	m.PM_FRAME_LEN = m_in.frame_len;
+	m.PM_EXECFLAGS = m_in.PMEXEC_FLAGS;
 
 	tell_vfs(mp, &m);
 
@@ -148,7 +149,7 @@ int do_execrestart()
 	result= m_in.EXC_RS_RESULT;
 	pc= (vir_bytes)m_in.EXC_RS_PC;
 
-	exec_restart(rmp, result, pc);
+	exec_restart(rmp, result, pc, rmp->mp_frame_addr);
 
 	return OK;
 }
@@ -157,13 +158,13 @@ int do_execrestart()
 /*===========================================================================*
  *				exec_restart				     *
  *===========================================================================*/
-void exec_restart(rmp, result, pc)
+void exec_restart(rmp, result, pc, vfs_newsp)
 struct mproc *rmp;
 int result;
 vir_bytes pc;
+vir_bytes vfs_newsp;
 {
 	int r, sn;
-	char *new_sp;
 
 	if (result != OK)
 	{
@@ -202,8 +203,8 @@ vir_bytes pc;
 	}
 #endif /* USE_TRACE */
 
-	new_sp= (char *)rmp->mp_frame_addr;
+	/* Call kernel to exec with SP and PC set by VFS. */
-	r= sys_exec(rmp->mp_endpoint, new_sp, rmp->mp_name, pc);
+	r= sys_exec(rmp->mp_endpoint, (char *) vfs_newsp, rmp->mp_name, pc);
 	if (r != OK) panic("sys_exec failed: %d", r);
 }
 

servers/pm/main.c

@@ -447,7 +447,8 @@ static void handle_vfs_reply()
 	break;
 
   case PM_EXEC_REPLY:
-	exec_restart(rmp, m_in.PM_STATUS, (vir_bytes)m_in.PM_PC);
+	exec_restart(rmp, m_in.PM_STATUS, (vir_bytes)m_in.PM_PC,
+		(vir_bytes)m_in.PM_NEWSP);
 
 	break;
 

servers/pm/proto.h

@@ -20,7 +20,7 @@ int do_brk(void);
 int do_exec(void);
 int do_exec_newmem(void);
 int do_execrestart(void);
-void exec_restart(struct mproc *rmp, int result, vir_bytes pc);
+void exec_restart(struct mproc *rmp, int result, vir_bytes pc, vir_bytes sp);
 
 /* forkexit.c */
 int do_fork(void);

servers/rs/exec.c

@@ -253,7 +253,7 @@ static int load_elf(struct exec_info *execi)
   proc_e = execi->proc_e;
 
   /* Read the file header and extract the segment sizes. */
-  r = read_header_elf(execi->image, &text_vaddr, &text_paddr,
+  r = read_header_elf(execi->image, execi->image_len, &text_vaddr, &text_paddr,
 		      &text_filebytes, &text_membytes,
 		      &data_vaddr, &data_paddr,
 		      &data_filebytes, &data_membytes,
@@ -262,6 +262,11 @@ static int load_elf(struct exec_info *execi)
       return(r);
   }
 
+  if(elf_has_interpreter(execi->image, execi->image_len, NULL, 0)) {
+  	printf("RS: can't execute dynamically linked executables\n");
+	return ENOEXEC;
+  }
+
   new_uid= getuid();
   new_gid= getgid();
   allow_setuid = 0;

servers/vfs/coredump.c

@@ -4,11 +4,12 @@
 #include "fproc.h"
 #include <minix/vm.h>
 #include <sys/mman.h>
-#include <machine/elf.h>
+#include <sys/exec_elf.h>
 #include "param.h"
 
 /* Include ELF headers */
 #include <sys/elf_core.h>
+#include <machine/elf.h>
 
 static void fill_elf_header(Elf32_Ehdr *elf_header, int phnum);
 static void fill_prog_header(Elf32_Phdr *prog_header, Elf32_Word

servers/vfs/exec.c

@@ -31,10 +31,14 @@
 #include "param.h"
 #include "vnode.h"
 #include <minix/vfsif.h>
+#include <machine/vmparam.h>
 #include <assert.h>
-#include <libexec.h>
+#include <fcntl.h>
 #include "exec.h"
 
+#define _KERNEL	/* for ELF_AUX_ENTRIES */
+#include <libexec.h>
+
 static void lock_exec(void);
 static void unlock_exec(void);
 static int exec_newmem(int proc_e, vir_bytes text_addr, vir_bytes text_bytes,
@@ -42,9 +46,9 @@ static int exec_newmem(int proc_e, vir_bytes text_addr, vir_bytes text_bytes,
 	vir_bytes frame_len, int sep_id, int is_elf, dev_t st_dev,
 	ino_t st_ino, time_t ctime, char *progname, int new_uid, int new_gid,
 	vir_bytes *stack_topp, int *load_textp, int *setugidp);
-static int is_script(const char *exec_hdr, size_t exec_len);
 static int patch_stack(struct vnode *vp, char stack[ARG_MAX],
 	size_t *stk_bytes, char path[PATH_MAX]);
+static int is_script(struct exec_info *execi);
 static int insert_arg(char stack[ARG_MAX], size_t *stk_bytes, char *arg,
 	int replace);
 static void patch_ptr(char stack[ARG_MAX], vir_bytes base);
@@ -53,23 +57,27 @@ static int read_seg(struct vnode *vp, off_t off, int proc_e, int seg,
 	vir_bytes seg_addr, phys_bytes seg_bytes);
 static int load_aout(struct exec_info *execi);
 static int load_elf(struct exec_info *execi);
-static int map_header(char **exec_hdr, const struct vnode *vp);
+static int stack_prepare_elf(struct exec_info *execi,
+	char *curstack, size_t *frame_len, int *extrabase);
+static int map_header(struct exec_info *execi);
 
 #define PTRSIZE	sizeof(char *) /* Size of pointers in argv[] and envp[]. */
 
 /* 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);
 struct exec_loaders {
-	int (*load_object)(struct exec_info *);
+	exechook_t load_object;	 /* load executable into memory */
+	stackhook_t setup_stack; /* prepare stack before argc and argv push */
 };
 
 static const struct exec_loaders exec_loaders[] = {
-	{ load_aout },
+	{ load_aout, NULL },
-	{ load_elf },
+	{ load_elf,  stack_prepare_elf },
-	{ NULL }
+	{ NULL, NULL }
 };
 
-static char hdr[PAGE_SIZE]; /* Assume that header is not larger than a page */
-
 /*===========================================================================*
  *				lock_exec				     *
  *===========================================================================*/
@@ -101,112 +109,186 @@ static void unlock_exec(void)
 	panic("Could not release lock on exec");
 }
 
+/*===========================================================================*
+ *				get_read_vp				     *
+ *===========================================================================*/
+static int get_read_vp(struct exec_info *execi, char *fullpath,
+	int copyprogname, int sugid, struct lookup *resolve, struct fproc *fp)
+{
+/* Make the executable that we want to exec() into the binary pointed
+ * to by 'fullpath.' This function fills in necessary details in the execi
+ * structure, such as opened vnode. It unlocks and releases the vnode if
+ * it was already there. This makes it easy to change the executable
+ * during the exec(), which is often necessary, by calling this function
+ * more than once. This is specifically necessary when we discover the
+ * executable is actually a script or a dynamically linked executable.
+ */
+	int r;
+
+	/* Caller wants to switch vp to the file in 'fullpath.'
+	 * unlock and put it first if there is any there.
+	 */
+	if(execi->vp) {
+		unlock_vnode(execi->vp);
+		put_vnode(execi->vp);
+		execi->vp = NULL;
+	}
+
+	/* Remember/overwrite the executable name if requested. */
+	if(copyprogname) {
+		char *cp = strrchr(fullpath, '/');
+		if(cp) cp++;
+		else cp = fullpath;
+		strncpy(execi->progname, cp, sizeof(execi->progname)-1);
+		execi->progname[sizeof(execi->progname)-1] = '\0';
+	}
+
+	/* Open executable */
+	if ((execi->vp = eat_path(resolve, fp)) == NULL)
+		return err_code;
+
+	unlock_vmnt(execi->vmp);
+
+	if ((execi->vp->v_mode & I_TYPE) != I_REGULAR)
+		return ENOEXEC;
+	else if ((r = forbidden(fp, execi->vp, X_BIT)) != OK)
+		return r;
+	else
+		r = req_stat(execi->vp->v_fs_e, execi->vp->v_inode_nr,
+			VFS_PROC_NR, (vir_bytes) &(execi->sb), 0, 0);
+
+	if (r != OK) return r;
+
+	/* If caller wants us to, honour suid/guid mode bits. */
+        if (sugid) {
+		/* Deal with setuid/setgid executables */
+		if (execi->vp->v_mode & I_SET_UID_BIT) {
+			execi->new_uid = execi->vp->v_uid;
+			execi->setugid = 1;
+		}
+		if (execi->vp->v_mode & I_SET_GID_BIT) {
+			execi->new_gid = execi->vp->v_gid;
+			execi->setugid = 1;
+		}
+        }
+
+	/* Read in first chunk of file. */
+	if((r=map_header(execi)) != OK)
+		return r;
+
+	return OK;
+}
+
+#define FAILCHECK(expr) if((r=(expr)) != OK) { goto pm_execfinal; } while(0)
+#define Get_read_vp(e,f,p,s,rs,fp) do { \
+	r=get_read_vp(&e,f,p,s,rs,fp); if(r != OK) { FAILCHECK(r); }	\
+	} while(0)
+
 /*===========================================================================*
  *				pm_exec					     *
  *===========================================================================*/
 int pm_exec(endpoint_t proc_e, vir_bytes path, size_t path_len,
-		   vir_bytes frame, size_t frame_len, vir_bytes *pc)
+		   vir_bytes frame, size_t frame_len, vir_bytes *pc,
+		   vir_bytes *newsp, int user_exec_flags)
 {
 /* Perform the execve(name, argv, envp) call.  The user library builds a
  * complete stack image, including pointers, args, environ, etc.  The stack
  * is copied to a buffer inside VFS, and then to the new core image.
  */
-  int r, r1, round, slot;
+  int r, slot;
   vir_bytes vsp;
   struct fproc *rfp;
-  struct vnode *vp;
+  int extrabase = 0;
-  struct vmnt *vmp;
-  char *cp;
   static char mbuf[ARG_MAX];	/* buffer for stack and zeroes */
   struct exec_info execi;
   int i;
-  char fullpath[PATH_MAX];
+  static char fullpath[PATH_MAX],
+  	elf_interpreter[PATH_MAX],
+	finalexec[PATH_MAX];
   struct lookup resolve;
+  stackhook_t makestack = NULL;
 
   lock_exec();
 
+  /* unset execi values are 0. */
+  memset(&execi, 0, sizeof(execi));
+
+  /* passed from exec() libc code */
+  execi.userflags = user_exec_flags;
+
   okendpt(proc_e, &slot);
   rfp = fp = &fproc[slot];
-  vp = NULL;
 
-  lookup_init(&resolve, fullpath, PATH_NOFLAGS, &vmp, &vp);
+  lookup_init(&resolve, fullpath, PATH_NOFLAGS, &execi.vmp, &execi.vp);
   resolve.l_vmnt_lock = VMNT_READ;
   resolve.l_vnode_lock = VNODE_READ;
 
-  /* Get the exec file name. */
-  if ((r = fetch_name(path, path_len, fullpath)) != OK)
-	goto pm_execfinal;
-
   /* Fetch the stack from the user before destroying the old core image. */
-  if (frame_len > ARG_MAX) {
+  if (frame_len > ARG_MAX)
-		r = ENOMEM; /* stack too big */
+	FAILCHECK(ENOMEM); /* stack too big */
-		goto pm_execfinal;
+
-  }
   r = sys_datacopy(proc_e, (vir_bytes) frame, SELF, (vir_bytes) mbuf,
 		   (size_t) frame_len);
   if (r != OK) { /* can't fetch stack (e.g. bad virtual addr) */
         printf("VFS: pm_exec: sys_datacopy failed\n");
-        goto pm_execfinal;
+	FAILCHECK(r);
   }
 
   /* The default is to keep the original user and group IDs */
   execi.new_uid = rfp->fp_effuid;
   execi.new_gid = rfp->fp_effgid;
 
-  for (round = 0; round < 2; round++) {
+  /* Get the exec file name. */
-	/* round = 0 (first attempt), or 1 (interpreted script) */
+  FAILCHECK(fetch_name(path, path_len, fullpath));
-	/* Save the name of the program */
+  strcpy(finalexec, fullpath);
-	(cp = strrchr(fullpath, '/')) ? cp++ : (cp = fullpath);
 
-	strncpy(execi.progname, cp, PROC_NAME_LEN-1);
+  /* Get_read_vp will return an opened vn in execi.
-	execi.progname[PROC_NAME_LEN-1] = '\0';
+   * if necessary it releases the existing vp so we can
-	execi.setugid = 0;
+   * switch after we find out what's inside the file.
+   * It reads the start of the file.
+   */
+  Get_read_vp(execi, fullpath, 1, 1, &resolve, fp);
 
-	/* Open executable */
+  /* If this is a script (i.e. has a #!/interpreter line),
-	if ((vp = eat_path(&resolve, fp)) == NULL) {
+   * retrieve the name of the interpreter and open that
-		r = err_code;
+   * executable instead.
-		goto pm_execfinal;
+   */
+  if(is_script(&execi)) {
+  	/* patch_stack will add interpreter name and
+	 * args to stack and retrieve the new binary
+	 * name into fullpath.
+	 */
+  	FAILCHECK(fetch_name(path, path_len, fullpath));
+	FAILCHECK(patch_stack(execi.vp, mbuf, &frame_len, fullpath));
+  	strcpy(finalexec, fullpath);
+	Get_read_vp(execi, fullpath, 1, 0, &resolve, fp);
+  }
+
+  /* If this is a dynamically linked executable, retrieve
+   * the name of that interpreter in elf_interpreter and open that
+   * executable instead. But open the current executable in an
+   * fd for the current process.
+   */
+  if(elf_has_interpreter(execi.hdr, execi.hdr_len,
+	elf_interpreter, sizeof(elf_interpreter))) {
+	/* Switch the executable vnode to the interpreter */
+	execi.is_dyn = 1;
+
+	/* The interpreter (loader) needs an fd to the main program,
+	 * which is currently in finalexec
+	 */
+	if((r = execi.elf_main_fd = common_open(finalexec, O_RDONLY, 0)) < 0) {
+		printf("VFS: exec: dynamic: open main exec failed %s (%d)\n",
+			fullpath, r);
+		FAILCHECK(r);
 	}
-	execi.vp = vp;
-	unlock_vmnt(vmp);
 
-	if ((vp->v_mode & I_TYPE) != I_REGULAR)
+	/* The executable we need to execute first (loader)
-		r = ENOEXEC;
+	 * is in elf_interpreter, and has to be in fullpath to
-	else if ((r1 = forbidden(fp, vp, X_BIT)) != OK)
+	 * be looked up
-		r = r1;
+	 */
-	else
+	strcpy(fullpath, elf_interpreter);
-		r = req_stat(vp->v_fs_e, vp->v_inode_nr, VFS_PROC_NR,
+	Get_read_vp(execi, fullpath, 0, 0, &resolve, fp);
-			     (vir_bytes) &(execi.sb), 0, 0);
-	if (r != OK) goto pm_execfinal;
-
-        if (round == 0) {
-		/* Deal with setuid/setgid executables */
-		if (vp->v_mode & I_SET_UID_BIT) {
-			execi.new_uid = vp->v_uid;
-			execi.setugid = 1;
-		}
-		if (vp->v_mode & I_SET_GID_BIT) {
-			execi.new_gid = vp->v_gid;
-			execi.setugid = 1;
-		}
-        }
-
-	r = map_header(&execi.hdr, execi.vp);
-	if (r != OK) goto pm_execfinal;
-
-	if (!is_script(execi.hdr, execi.vp->v_size) || round != 0)
-		break;
-
-	/* Get fresh copy of the file name. */
-	if ((r = fetch_name(path, path_len, fullpath)) != OK)
-		printf("VFS pm_exec: 2nd fetch_name failed\n");
-	else
-		r = patch_stack(vp, mbuf, &frame_len, fullpath);
-
-	unlock_vnode(vp);
-	put_vnode(vp);
-	vp = NULL;
-	if (r != OK) goto pm_execfinal;
   }
 
   execi.proc_e = proc_e;
@@ -215,28 +297,27 @@ int pm_exec(endpoint_t proc_e, vir_bytes path, size_t path_len,
   for (i = 0; exec_loaders[i].load_object != NULL; i++) {
       r = (*exec_loaders[i].load_object)(&execi);
       /* Loaded successfully, so no need to try other loaders */
-      if (r == OK) break;
+      if (r == OK) { makestack = exec_loaders[i].setup_stack; break; }
   }
 
-  if (r != OK) {   /* No exec loader could load the object */
+  FAILCHECK(r);
-	r = ENOEXEC;
-	goto pm_execfinal;
-  }
 
   /* Save off PC */
   *pc = execi.pc;
 
-  /* Patch up stack and copy it from VFS to new core image. */
+  /* call a stack-setup function if this executable type wants it */
   vsp = execi.stack_top;
-  vsp -= frame_len;
+  if(makestack) FAILCHECK(makestack(&execi, mbuf, &frame_len, &extrabase));
-  patch_ptr(mbuf, vsp);
+
-  if ((r = sys_datacopy(SELF, (vir_bytes) mbuf, proc_e, (vir_bytes) vsp,
+  /* Patch up stack and copy it from VFS to new core image. */
-		   (phys_bytes)frame_len)) != OK) {
+  vsp -= frame_len;
-	printf("VFS: datacopy failed (%d) trying to copy to %lu\n", r, vsp);
+  patch_ptr(mbuf, vsp + extrabase);
-	goto pm_execfinal;
+  FAILCHECK(sys_datacopy(SELF, (vir_bytes) mbuf, proc_e, (vir_bytes) vsp,
-  }
+		   (phys_bytes)frame_len));
+  
+  /* Return new stack pointer to caller */
+  *newsp = vsp;
 
-  if (r != OK) goto pm_execfinal;
   clo_exec(rfp);
 
   if (execi.setugid) {
@@ -246,10 +327,13 @@ int pm_exec(endpoint_t proc_e, vir_bytes path, size_t path_len,
 	rfp->fp_effgid = execi.new_gid;
   }
 
+  /* Remember the new name of the process */
+  strcpy(rfp->fp_name, execi.progname);
+
 pm_execfinal:
-  if (vp != NULL) {
+  if (execi.vp != NULL) {
-	unlock_vnode(vp);
+	unlock_vnode(execi.vp);
-	put_vnode(vp);
+	put_vnode(execi.vp);
   }
   unlock_exec();
   return(r);
@@ -306,6 +390,79 @@ 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)
+{
+	AuxInfo *a;
+	Elf_Ehdr *elf_header;
+	int nulls;
+	char	**mysp = (char **) frame,
+		**mysp_end = (char **) ((char *)frame + *framelen);
+
+	if(!execi->is_dyn)
+		return OK;
+
+	assert(execi->hdr_len >= sizeof(*elf_header));
+	elf_header = (Elf_Ehdr *) execi->hdr;
+
+	/* exec() promises stack space. Now find it. */
+	mysp++;	/* skip argc */
+
+	/* find a terminating NULL entry twice: one for argv[], one for envp[]. */
+	for(nulls = 0; nulls < 2; nulls++) {
+		assert(mysp < mysp_end);
+		while(*mysp && mysp < mysp_end) mysp++;	/* find terminating NULL */
+		if(mysp >= mysp_end) {
+			printf("VFS: malformed stack for exec()\n");
+			return ENOEXEC;
+		}
+		assert(!*mysp);
+		mysp++;
+	}
+
+	/* Userland provides a fully filled stack frame, with argc, argv, envp
+	 * and then all the argv and envp strings; consistent with ELF ABI, except
+	 * for a list of Aux vectors that should be between envp points and the
+	 * start of the strings.
+	 *
+	 * It would take some very unpleasant hackery to insert the aux vectors before
+	 * the strings, and correct all the pointers, so the exec code in libc makes
+	 * space for us first and indicates the fact it did this with this flag.
+	 */
+	if(!(execi->userflags & PMEF_AUXVECTORSPACE)) {
+		char *f = (char *) mysp;
+		int remain;
+		vir_bytes extrabytes = sizeof(*a) * PMEF_AUXVECTORS;
+		
+		/* Create extrabytes more space */
+		remain = *framelen - (int)(f - frame);
+		if(*framelen + extrabytes >= ARG_MAX)
+			return ENOMEM;
+		*framelen += extrabytes;
+		*extrabase += extrabytes;
+		memmove(f+extrabytes, f, remain);
+		memset(f, 0, extrabytes);
+	}
+
+	/* Ok, what mysp points to now we can use for the aux vectors. */
+	a = (AuxInfo *) mysp;
+#define AUXINFO(type, value) \
+	{ assert((char *) a < (char *) mysp_end); a->a_type = type; a->a_v = value; a++; }
+#if 0
+	AUXINFO(AT_PHDR, execi->elf_phdr);
+	AUXINFO(AT_PHENT, elf_header->e_phentsize);
+	AUXINFO(AT_PHNUM, elf_header->e_phnum);
+#endif
+	AUXINFO(AT_BASE, execi->elf_base);
+	AUXINFO(AT_ENTRY, execi->pc);
+	AUXINFO(AT_PAGESZ, PAGE_SIZE);
+	AUXINFO(AT_EXECFD, execi->elf_main_fd);
+
+	/* Always terminate with AT_NULL */
+	AUXINFO(AT_NULL, 0);
+
+	return OK;
+}
+
 /*===========================================================================*
  *				load_elf				     *
  *===========================================================================*/
@@ -318,7 +475,8 @@ static int load_elf(struct exec_info *execi)
   vir_bytes text_vaddr, text_paddr, text_filebytes, text_membytes;
   vir_bytes data_vaddr, data_paddr, data_filebytes, data_membytes;
   off_t text_offset, data_offset;
-  int sep_id, is_elf;
+  int sep_id, is_elf, i;
+  vir_bytes text_base, data_base;
 
   assert(execi != NULL);
   assert(execi->hdr != NULL);
@@ -327,20 +485,39 @@ static int load_elf(struct exec_info *execi)
   proc_e = execi->proc_e;
   vp = execi->vp;
 
+  /* this function can load the dynamic linker, but that 
+   * shouldn't require an interpreter itself.
+   */
+  i = elf_has_interpreter(execi->hdr, execi->hdr_len, NULL, 0);
+  if(i > 0) {
+  	printf("VFS: cannot load dynamically linked executable\n");
+	return ENOEXEC;
+  }
+
   /* Read the file header and extract the segment sizes. */
-  r = read_header_elf(execi->hdr, &text_vaddr, &text_paddr,
+  r = read_header_elf(execi->hdr, execi->hdr_len, &text_vaddr, &text_paddr,
 		      &text_filebytes, &text_membytes,
 		      &data_vaddr, &data_paddr,
 		      &data_filebytes, &data_membytes,
 		      &execi->pc, &text_offset, &data_offset);
-  if (r != OK) return(r);
+
+  if (r != OK) {
+  	return(r);
+  }
+
+  if(elf_phdr(execi->hdr, execi->hdr_len, &execi->elf_phdr) == OK)
+  	if(execi->elf_phdr == 0)	/* 0 should indicate: not known */
+  		printf("VFS: warning: unexpected zero elf_phdr\n");
 
   sep_id = 0;
   is_elf = 1;
   tot_bytes = 0; /* Use default stack size */
+  text_base = trunc_page(text_vaddr);
+  data_base = trunc_page(data_vaddr);
+  execi->elf_base = MIN(text_base, data_base);
   r = exec_newmem(proc_e,
-		  trunc_page(text_vaddr), text_membytes,
+                  text_base, text_membytes,
-		  trunc_page(data_vaddr), data_membytes,
+                  data_base, data_membytes,
 		  tot_bytes, execi->frame_len, sep_id, is_elf,
 		  vp->v_dev, vp->v_inode_nr, execi->sb.st_ctime,
 		  execi->progname, execi->new_uid, execi->new_gid,
@@ -424,12 +601,12 @@ static int exec_newmem(
 /*===========================================================================*
  *				is_script				     *
  *===========================================================================*/
-static int is_script(const char *exec_hdr, size_t exec_len)
+static int is_script(struct exec_info *execi)
 {
 /* Is Interpreted script? */
-  assert(exec_hdr != NULL);
+  assert(execi->hdr != NULL);
 
-  return(exec_hdr[0] == '#' && exec_hdr[1] == '!' && exec_len >= 2);
+  return(execi->hdr[0] == '#' && execi->hdr[1] == '!' && execi->hdr_len >= 2);
 }
 
 /*===========================================================================*
@@ -695,23 +872,27 @@ static void clo_exec(struct fproc *rfp)
 /*===========================================================================*
  *				map_header				     *
  *===========================================================================*/
-static int map_header(char **exec_hdr, const struct vnode *vp)
+static int map_header(struct exec_info *execi)
 {
   int r;
   u64_t new_pos;
   unsigned int cum_io;
   off_t pos;
+  static char hdr[PAGE_SIZE]; /* Assume that header is not larger than a page */
 
   pos = 0;	/* Read from the start of the file */
 
-  r = req_readwrite(vp->v_fs_e, vp->v_inode_nr, cvul64(pos), READING,
+  /* How much is sensible to read */
-		    VFS_PROC_NR, hdr, MIN(vp->v_size, PAGE_SIZE),
+  execi->hdr_len = MIN(execi->vp->v_size, sizeof(hdr));
-		    &new_pos, &cum_io);
+  execi->hdr = hdr;
+
+  r = req_readwrite(execi->vp->v_fs_e, execi->vp->v_inode_nr,
+  	cvul64(pos), READING, VFS_PROC_NR, hdr,
+	execi->hdr_len, &new_pos, &cum_io);
   if (r != OK) {
 	printf("VFS: exec: map_header: req_readwrite failed\n");
 	return(r);
   }
 
-  *exec_hdr = hdr;
   return(OK);
 }

servers/vfs/exec.h

@@ -4,6 +4,7 @@
 struct exec_info {
     int  proc_e;			/* Process endpoint */
     char *hdr;				/* Exec file's header */
+    int hdr_len;			/* How many bytes are in hdr */
     vir_bytes pc;			/* Entry point of exec file */
     vir_bytes stack_top;		/* Top of the stack */
     vir_bytes frame_len;		/* Stack size */
@@ -12,8 +13,16 @@ struct exec_info {
     int load_text;			/* Load text section? */
     int setugid;			/* Allow set{u,g}id execution? */
     struct vnode *vp;			/* Exec file's vnode */
+    struct vmnt *vmp;			/* Exec file's vmnt */
     struct stat sb;			/* Exec file's stat structure */
     char progname[PROC_NAME_LEN];	/* Program name */
+    int userflags;			/* exec() flags from userland */
+
+    /* fields only used by elf and in VFS */
+    int is_dyn;				/* Dynamically linked executable */
+    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 */
 };
 
 #endif /* !_VFS_EXEC_H_ */

servers/vfs/fproc.h

@@ -46,6 +46,7 @@ EXTERN struct fproc {
   mutex_t fp_lock;		/* mutex to lock fproc object */
   struct job fp_job;		/* pending job */
   thread_t fp_wtid;		/* Thread ID of worker */
+  char fp_name[PROC_NAME_LEN];	/* Last exec() */
 #if LOCK_DEBUG
   int fp_vp_rdlocks;		/* number of read-only locks on vnodes */
   int fp_vmnt_rdlocks;		/* number of read-only locks on vmnts */

servers/vfs/main.c

@@ -791,7 +791,7 @@ void reply(endpoint_t whom, int result)
 static void service_pm_postponed(void)
 {
   int r;
-  vir_bytes pc;
+  vir_bytes pc, newsp;
 
   switch(job_call_nr) {
     case PM_EXEC:
@@ -807,13 +807,14 @@ 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);
+			    stack_frame_len, &pc, &newsp, m_in.PM_EXECFLAGS);
 
 		/* Reply status to PM */
 		m_out.m_type = PM_EXEC_REPLY;
 		m_out.PM_PROC = proc_e;
 		m_out.PM_PC = (void*) pc;
 		m_out.PM_STATUS = r;
+		m_out.PM_NEWSP = (void *) newsp;
 	}
 	break;
 

servers/vfs/proto.h

@@ -70,8 +70,8 @@ int map_service(struct rprocpub *rpub);
 void write_elf_core_file(struct filp *f, int csig, char *exe_name);
 
 /* exec.c */
-int pm_exec(int proc_e, vir_bytes path, size_t path_len, vir_bytes frame,
+int pm_exec(endpoint_t proc_e, vir_bytes path, size_t path_len, vir_bytes frame,
-	size_t frame_len, vir_bytes *pc);
+	size_t frame_len, vir_bytes *pc, vir_bytes *newsp, int flags);
 #define check_bsf_lock() do {						\
 	assert(mutex_trylock(&bsf_lock) == 0);				\
 	unlock_bsf();							\