minhtrannhat/os161
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Initial Spring 2016 commit.

Browse Source
This commit is contained in:
Geoffrey Challen
2015-12-23 00:50:04 +00:00
commit cafa9f5690
732 changed files with 92195 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

307
kern/syscall/loadelf.c Normal file
View File

@@ -0,0 +1,307 @@
/*
* Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
* The President and Fellows of Harvard College.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY 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 UNIVERSITY 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.
*/
/*
* Code to load an ELF-format executable into the current address space.
*
* It makes the following address space calls:
* - first, as_define_region once for each segment of the program;
* - then, as_prepare_load;
* - then it loads each chunk of the program;
* - finally, as_complete_load.
*
* This gives the VM code enough flexibility to deal with even grossly
* mis-linked executables if that proves desirable. Under normal
* circumstances, as_prepare_load and as_complete_load probably don't
* need to do anything.
*
* If you wanted to support memory-mapped executables you would need
* to rearrange this to map each segment.
*
* To support dynamically linked executables with shared libraries
* you'd need to change this to load the "ELF interpreter" (dynamic
* linker). And you'd have to write a dynamic linker...
*/
#include <types.h>
#include <kern/errno.h>
#include <lib.h>
#include <uio.h>
#include <proc.h>
#include <current.h>
#include <addrspace.h>
#include <vnode.h>
#include <elf.h>
/*
* Load a segment at virtual address VADDR. The segment in memory
* extends from VADDR up to (but not including) VADDR+MEMSIZE. The
* segment on disk is located at file offset OFFSET and has length
* FILESIZE.
*
* FILESIZE may be less than MEMSIZE; if so the remaining portion of
* the in-memory segment should be zero-filled.
*
* Note that uiomove will catch it if someone tries to load an
* executable whose load address is in kernel space. If you should
* change this code to not use uiomove, be sure to check for this case
* explicitly.
*/
static
int
load_segment(struct addrspace *as, struct vnode *v,
off_t offset, vaddr_t vaddr,
size_t memsize, size_t filesize,
int is_executable)
{
struct iovec iov;
struct uio u;
int result;
if (filesize > memsize) {
kprintf("ELF: warning: segment filesize > segment memsize\n");
filesize = memsize;
}
DEBUG(DB_EXEC, "ELF: Loading %lu bytes to 0x%lx\n",
(unsigned long) filesize, (unsigned long) vaddr);
iov.iov_ubase = (userptr_t)vaddr;
iov.iov_len = memsize; // length of the memory space
u.uio_iov = &iov;
u.uio_iovcnt = 1;
u.uio_resid = filesize; // amount to read from the file
u.uio_offset = offset;
u.uio_segflg = is_executable ? UIO_USERISPACE : UIO_USERSPACE;
u.uio_rw = UIO_READ;
u.uio_space = as;
result = VOP_READ(v, &u);
if (result) {
return result;
}
if (u.uio_resid != 0) {
/* short read; problem with executable? */
kprintf("ELF: short read on segment - file truncated?\n");
return ENOEXEC;
}
/*
* If memsize > filesize, the remaining space should be
* zero-filled. There is no need to do this explicitly,
* because the VM system should provide pages that do not
* contain other processes' data, i.e., are already zeroed.
*
* During development of your VM system, it may have bugs that
* cause it to (maybe only sometimes) not provide zero-filled
* pages, which can cause user programs to fail in strange
* ways. Explicitly zeroing program BSS may help identify such
* bugs, so the following disabled code is provided as a
* diagnostic tool. Note that it must be disabled again before
* you submit your code for grading.
*/
#if 0
{
size_t fillamt;
fillamt = memsize - filesize;
if (fillamt > 0) {
DEBUG(DB_EXEC, "ELF: Zero-filling %lu more bytes\n",
(unsigned long) fillamt);
u.uio_resid += fillamt;
result = uiomovezeros(fillamt, &u);
}
}
#endif
return result;
}
/*
* Load an ELF executable user program into the current address space.
*
* Returns the entry point (initial PC) for the program in ENTRYPOINT.
*/
int
load_elf(struct vnode *v, vaddr_t *entrypoint)
{
Elf_Ehdr eh; /* Executable header */
Elf_Phdr ph; /* "Program header" = segment header */
int result, i;
struct iovec iov;
struct uio ku;
struct addrspace *as;
as = proc_getas();
/*
* Read the executable header from offset 0 in the file.
*/
uio_kinit(&iov, &ku, &eh, sizeof(eh), 0, UIO_READ);
result = VOP_READ(v, &ku);
if (result) {
return result;
}
if (ku.uio_resid != 0) {
/* short read; problem with executable? */
kprintf("ELF: short read on header - file truncated?\n");
return ENOEXEC;
}
/*
* Check to make sure it's a 32-bit ELF-version-1 executable
* for our processor type. If it's not, we can't run it.
*
* Ignore EI_OSABI and EI_ABIVERSION - properly, we should
* define our own, but that would require tinkering with the
* linker to have it emit our magic numbers instead of the
* default ones. (If the linker even supports these fields,
* which were not in the original elf spec.)
*/
if (eh.e_ident[EI_MAG0] != ELFMAG0 ||
eh.e_ident[EI_MAG1] != ELFMAG1 ||
eh.e_ident[EI_MAG2] != ELFMAG2 ||
eh.e_ident[EI_MAG3] != ELFMAG3 ||
eh.e_ident[EI_CLASS] != ELFCLASS32 ||
eh.e_ident[EI_DATA] != ELFDATA2MSB ||
eh.e_ident[EI_VERSION] != EV_CURRENT ||
eh.e_version != EV_CURRENT ||
eh.e_type!=ET_EXEC ||
eh.e_machine!=EM_MACHINE) {
return ENOEXEC;
}
/*
* Go through the list of segments and set up the address space.
*
* Ordinarily there will be one code segment, one read-only
* data segment, and one data/bss segment, but there might
* conceivably be more. You don't need to support such files
* if it's unduly awkward to do so.
*
* Note that the expression eh.e_phoff + i*eh.e_phentsize is
* mandated by the ELF standard - we use sizeof(ph) to load,
* because that's the structure we know, but the file on disk
* might have a larger structure, so we must use e_phentsize
* to find where the phdr starts.
*/
for (i=0; i<eh.e_phnum; i++) {
off_t offset = eh.e_phoff + i*eh.e_phentsize;
uio_kinit(&iov, &ku, &ph, sizeof(ph), offset, UIO_READ);
result = VOP_READ(v, &ku);
if (result) {
return result;
}
if (ku.uio_resid != 0) {
/* short read; problem with executable? */
kprintf("ELF: short read on phdr - file truncated?\n");
return ENOEXEC;
}
switch (ph.p_type) {
case PT_NULL: /* skip */ continue;
case PT_PHDR: /* skip */ continue;
case PT_MIPS_REGINFO: /* skip */ continue;
case PT_LOAD: break;
default:
kprintf("loadelf: unknown segment type %d\n",
ph.p_type);
return ENOEXEC;
}
result = as_define_region(as,
ph.p_vaddr, ph.p_memsz,
ph.p_flags & PF_R,
ph.p_flags & PF_W,
ph.p_flags & PF_X);
if (result) {
return result;
}
}
result = as_prepare_load(as);
if (result) {
return result;
}
/*
* Now actually load each segment.
*/
for (i=0; i<eh.e_phnum; i++) {
off_t offset = eh.e_phoff + i*eh.e_phentsize;
uio_kinit(&iov, &ku, &ph, sizeof(ph), offset, UIO_READ);
result = VOP_READ(v, &ku);
if (result) {
return result;
}
if (ku.uio_resid != 0) {
/* short read; problem with executable? */
kprintf("ELF: short read on phdr - file truncated?\n");
return ENOEXEC;
}
switch (ph.p_type) {
case PT_NULL: /* skip */ continue;
case PT_PHDR: /* skip */ continue;
case PT_MIPS_REGINFO: /* skip */ continue;
case PT_LOAD: break;
default:
kprintf("loadelf: unknown segment type %d\n",
ph.p_type);
return ENOEXEC;
}
result = load_segment(as, v, ph.p_offset, ph.p_vaddr,
ph.p_memsz, ph.p_filesz,
ph.p_flags & PF_X);
if (result) {
return result;
}
}
result = as_complete_load(as);
if (result) {
return result;
}
*entrypoint = eh.e_entry;
return 0;
}

109
kern/syscall/runprogram.c Normal file
View File

@@ -0,0 +1,109 @@
/*
* Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
* The President and Fellows of Harvard College.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY 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 UNIVERSITY 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.
*/
/*
* Sample/test code for running a user program. You can use this for
* reference when implementing the execv() system call. Remember though
* that execv() needs to do more than runprogram() does.
*/
#include <types.h>
#include <kern/errno.h>
#include <kern/fcntl.h>
#include <lib.h>
#include <proc.h>
#include <current.h>
#include <addrspace.h>
#include <vm.h>
#include <vfs.h>
#include <syscall.h>
#include <test.h>
/*
* Load program "progname" and start running it in usermode.
* Does not return except on error.
*
* Calls vfs_open on progname and thus may destroy it.
*/
int
runprogram(char *progname)
{
struct addrspace *as;
struct vnode *v;
vaddr_t entrypoint, stackptr;
int result;
/* Open the file. */
result = vfs_open(progname, O_RDONLY, 0, &v);
if (result) {
return result;
}
/* We should be a new process. */
KASSERT(proc_getas() == NULL);
/* Create a new address space. */
as = as_create();
if (as == NULL) {
vfs_close(v);
return ENOMEM;
}
/* Switch to it and activate it. */
proc_setas(as);
as_activate();
/* Load the executable. */
result = load_elf(v, &entrypoint);
if (result) {
/* p_addrspace will go away when curproc is destroyed */
vfs_close(v);
return result;
}
/* Done with the file now. */
vfs_close(v);
/* Define the user stack in the address space */
result = as_define_stack(as, &stackptr);
if (result) {
/* p_addrspace will go away when curproc is destroyed */
return result;
}
/* Warp to user mode. */
enter_new_process(0 /*argc*/, NULL /*userspace addr of argv*/,
NULL /*userspace addr of environment*/,
stackptr, entrypoint);
/* enter_new_process does not return. */
panic("enter_new_process returned\n");
return EINVAL;
}

58
kern/syscall/time_syscalls.c Normal file
View File

@@ -0,0 +1,58 @@
/*
* Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
* The President and Fellows of Harvard College.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY 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 UNIVERSITY 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.
*/
#include <types.h>
#include <clock.h>
#include <copyinout.h>
#include <syscall.h>
/*
* Example system call: get the time of day.
*/
int
sys___time(userptr_t user_seconds_ptr, userptr_t user_nanoseconds_ptr)
{
struct timespec ts;
int result;
gettime(&ts);
result = copyout(&ts.tv_sec, user_seconds_ptr, sizeof(ts.tv_sec));
if (result) {
return result;
}
result = copyout(&ts.tv_nsec, user_nanoseconds_ptr,
sizeof(ts.tv_nsec));
if (result) {
return result;
}
return 0;
}