diff options
Diffstat (limited to 'kernel/user.c')
| -rw-r--r-- | kernel/user.c | 929 |
1 files changed, 0 insertions, 929 deletions
diff --git a/kernel/user.c b/kernel/user.c deleted file mode 100644 index 5759534..0000000 --- a/kernel/user.c +++ /dev/null @@ -1,929 +0,0 @@ -/** -** @file user.c -** -** @author CSCI-452 class of 20245 -** -** @brief User-level code manipulation routines -*/ - -#define KERNEL_SRC - -#include <common.h> - -#include <bootstrap.h> -#include <elf.h> -#include <user.h> -#include <vm.h> - -/* -** PRIVATE DEFINITIONS -*/ - -/* -** PRIVATE DATA TYPES -*/ - -/* -** PRIVATE GLOBAL VARIABLES -*/ - -/* -** PUBLIC GLOBAL VARIABLES -*/ - -/* -** Location of the "user blob" in memory. -** -** These variables are filled in by the code in startup.S using values -** passed to it from the bootstrap. -** -** These are visible so that the startup code can find them. -*/ -uint16_t user_offset; // byte offset from the segment base -uint16_t user_segment; // segment base address -uint16_t user_sectors; // number of 512-byte sectors it occupies - -header_t *user_header; // filled in by the user_init routine -prog_t *prog_table; // filled in by the user_init routine - -/* -** PRIVATE FUNCTIONS -*/ - -#if TRACING_ELF - -/* -** This is debugging support code; if not debugging the ELF -** handling code, it won't be compiled into the kernel. -*/ - -// buffer used by some of these functions -static char ebuf[16]; - -/* -** File header functions -*/ - -// interpret the file class -static const char *fh_eclass(e32_si class) -{ - switch (class) { - case ELF_CLASS_NONE: - return ("None"); - break; - case ELF_CLASS_32: - return ("EC32"); - break; - case ELF_CLASS_64: - return ("EC64"); - break; - } - return ("????"); -} - -// interpret the data encoding -static const char *fh_edata(e32_si data) -{ - switch (data) { - case ELF_DATA_NONE: - return ("Invd"); - break; - case ELF_DATA_2LSB: - return ("2CLE"); - break; - case ELF_DATA_2MSB: - return ("2CBE"); - break; - } - return ("????"); -} - -// interpret the file type -static const char *fh_htype(e32_h type) -{ - switch (type) { - case ET_NONE: - return ("none"); - break; - case ET_REL: - return ("rel"); - break; - case ET_EXEC: - return ("exec"); - break; - case ET_DYN: - return ("dyn"); - break; - case ET_CORE: - return ("core"); - break; - default: - if (type >= ET_LO_OS && type <= ET_HI_OS) - return ("OSsp"); - else if (type >= ET_LO_CP && type <= ET_HI_CP) - return ("CPsp"); - } - sprint(ebuf, "0x%04x", type); - return ((const char *)ebuf); -} - -// interpret the machine type -static const char *fh_mtype(e32_h machine) -{ - switch (machine) { - case EM_NONE: - return ("None"); - break; - case EM_386: - return ("386"); - break; - case EM_ARM: - return ("ARM"); - break; - case EM_X86_64: - return ("AMD64"); - break; - case EM_AARCH64: - return ("AARCH64"); - break; - case EM_RISCV: - return ("RISC-V"); - break; - } - return ("Other"); -} - -// dump the program header -static void dump_fhdr(elfhdr_t *hdr) -{ - cio_puts("File header: magic "); - for (int i = EI_MAG0; i <= EI_MAG3; ++i) - put_char_or_code(hdr->e_ident.bytes[i]); - cio_printf(" class %s", fh_eclass(hdr->e_ident.f.class)); - cio_printf(" enc %s", fh_edata(hdr->e_ident.f.data)); - cio_printf(" ver %u\n", hdr->e_ident.f.version); - cio_printf(" type %s", fh_htype(hdr->e_type)); - cio_printf(" mach %s", fh_mtype(hdr->e_machine)); - cio_printf(" vers %d", hdr->e_version); - cio_printf(" entr %08x\n", hdr->e_entry); - - cio_printf(" phoff %08x", hdr->e_phoff); - cio_printf(" shoff %08x", hdr->e_shoff); - cio_printf(" flags %08x", (uint32_t)hdr->e_flags); - cio_printf(" ehsize %u\n", hdr->e_ehsize); - cio_printf(" phentsize %u", hdr->e_phentsize); - cio_printf(" phnum %u", hdr->e_phnum); - cio_printf(" shentsize %u", hdr->e_shentsize); - cio_printf(" shnum %u", hdr->e_shnum); - cio_printf(" shstrndx %u\n", hdr->e_shstrndx); -} - -/* -** Program header functions -*/ - -// categorize the header type -static const char *ph_type(e32_w type) -{ - switch (type) { - case PT_NULL: - return ("Unused"); - break; - case PT_LOAD: - return ("Load"); - break; - case PT_DYNAMIC: - return ("DLI"); - break; - case PT_INTERP: - return ("Interp"); - break; - case PT_NOTE: - return ("Aux"); - break; - case PT_SHLIB: - return ("RSVD"); - break; - case PT_PHDR: - return ("PTentry"); - break; - case PT_TLS: - return ("TLS"); - break; - default: - if (type >= PT_LO_OS && type <= PT_HI_OS) - return ("OSsp"); - else if (type >= PT_LO_CP && type <= PT_HI_CP) - return ("CPsp"); - } - sprint(ebuf, "0x%08x", type); - return ((const char *)ebuf); -} - -// report the individual flags -static void ph_flags(e32_w flags) -{ - if ((flags & PF_R) != 0) - cio_putchar('R'); - if ((flags & PF_W) != 0) - cio_putchar('W'); - if ((flags & PF_E) != 0) - cio_putchar('X'); -} - -// dump a program header -static void dump_phdr(elfproghdr_t *hdr, int n) -{ - cio_printf("Prog header %d, type %s\n", n, ph_type(hdr->p_type)); - cio_printf(" offset %08x", hdr->p_offset); - cio_printf(" va %08x", hdr->p_va); - cio_printf(" pa %08x\n", hdr->p_pa); - cio_printf(" filesz %08x", hdr->p_filesz); - cio_printf(" memsz %08x", hdr->p_memsz); - cio_puts(" flags "); - ph_flags(hdr->p_flags); - cio_printf(" align %08x", hdr->p_align); - cio_putchar('\n'); -} - -/* -** Section header functions -*/ - -// interpret the header type -static const char *sh_type(e32_w type) -{ - switch (type) { - case SHT_NULL: - return ("Unused"); - break; - case SHT_PROGBITS: - return ("Progbits"); - break; - case SHT_SYMTAB: - return ("Symtab"); - break; - case SHT_STRTAB: - return ("Strtab"); - break; - case SHT_RELA: - return ("Rela"); - break; - case SHT_HASH: - return ("Hash"); - break; - case SHT_DYNAMIC: - return ("Dynamic"); - break; - case SHT_NOTE: - return ("Note"); - break; - case SHT_NOBITS: - return ("Nobits"); - break; - case SHT_REL: - return ("Rel"); - break; - case SHT_SHLIB: - return ("Shlib"); - break; - case SHT_DYNSYM: - return ("Dynsym"); - break; - default: - if (type >= SHT_LO_CP && type <= SHT_HI_CP) - return ("CCsp"); - else if (type >= SHT_LO_US && type <= SHT_HI_US) - return ("User"); - } - sprint(ebuf, "0x%08x", type); - return ((const char *)ebuf); -} - -// report the various flags -static void sh_flags(unsigned int flags) -{ - if ((flags & SHF_WRITE) != 0) - cio_putchar('W'); - if ((flags & SHF_ALLOC) != 0) - cio_putchar('A'); - if ((flags & SHF_EXECINSTR) != 0) - cio_putchar('X'); - if ((flags & SHF_MERGE) != 0) - cio_putchar('M'); - if ((flags & SHF_STRINGS) != 0) - cio_putchar('S'); - if ((flags & SHF_INFO_LINK) != 0) - cio_putchar('L'); - if ((flags & SHF_LINK_ORDER) != 0) - cio_putchar('o'); - if ((flags & SHF_OS_NONCON) != 0) - cio_putchar('n'); - if ((flags & SHF_GROUP) != 0) - cio_putchar('g'); - if ((flags & SHF_TLS) != 0) - cio_putchar('t'); -} - -// dump a section header -ATTR_UNUSED -static void dump_shdr(elfsecthdr_t *hdr, int n) -{ - cio_printf("Sect header %d, type %d (%s), name %s\n", n, hdr->sh_type, - sh_type(hdr->sh_type)); - cio_printf(" flags %08x ", (uint32_t)hdr->sh_flags); - sh_flags(hdr->sh_flags); - cio_printf(" addr %08x", hdr->sh_addr); - cio_printf(" offset %08x", hdr->sh_offset); - cio_printf(" size %08x\n", hdr->sh_size); - cio_printf(" link %08x", hdr->sh_link); - cio_printf(" info %08x", hdr->sh_info); - cio_printf(" align %08x", hdr->sh_addralign); - cio_printf(" entsz %08x\n", hdr->sh_entsize); -} -#endif - -/** -** read_phdrs(addr,phoff,phentsize,phnum) -** -** Parses the ELF program headers and each segment described into memory. -** -** @param hdr Pointer to the program header -** @param pcb Pointer to the PCB (and its PDE) -** -** @return status of the attempt: -** SUCCESS everything loaded correctly -** E_LOAD_LIMIT more than N_LOADABLE PT_LOAD sections -** other status returned from vm_add() -*/ -static int read_phdrs(elfhdr_t *hdr, pcb_t *pcb) -{ - // sanity check - assert1(hdr != NULL); - assert2(pcb != NULL); - -#if TRACING_USER - cio_printf("read_phdrs(%08x,%08x)\n", (uint32_t)hdr, (uint32_t)pcb); -#endif - - // iterate through the program headers - uint_t nhdrs = hdr->e_phnum; - - // pointer to the first header table entry - elfproghdr_t *curr = (elfproghdr_t *)((uint32_t)hdr + hdr->e_phoff); - - // process them all - int loaded = 0; - for (uint_t i = 0; i < nhdrs; ++i, ++curr) { -#if TRACING_ELF - dump_phdr(curr, i); -#endif - if (curr->p_type != PT_LOAD) { - // not loadable --> we'll skip it - continue; - } - - if (loaded >= N_LOADABLE) { -#if TRACING_USER - cio_puts(" LIMIT\n"); -#endif - return E_LOAD_LIMIT; - } - - // set a pointer to the bytes within the object file - char *data = (char *)(((uint32_t)hdr) + curr->p_offset); -#if TRACING_USER - cio_printf(" data @ %08x", (uint32_t)data); -#endif - - // copy the pages into memory - int stat = vm_add(pcb->pdir, curr->p_flags & PF_W, false, - (char *)curr->p_va, curr->p_memsz, data, - curr->p_filesz); - if (stat != SUCCESS) { - // TODO what else should we do here? check for memory leak? - return stat; - } - - // set the section table entry in the PCB - pcb->sects[loaded].length = curr->p_memsz; - pcb->sects[loaded].addr = curr->p_va; -#if TRACING_USER - cio_printf(" loaded %u @ %08x\n", pcb->sects[loaded].length, - pcb->sects[loaded].addr); -#endif - ++loaded; - } - - return SUCCESS; -} - -/** -** Name: stack_setup -** -** Set up the stack for a new process -** -** @param pcb Pointer to the PCB for the process -** @param entry Entry point for the new process -** @param args Argument vector to be put in place -** @param sys Is the argument vector from kernel code? -** -** @return A (user VA) pointer to the context_t on the stack, or NULL -*/ -static context_t *stack_setup(pcb_t *pcb, uint32_t entry, const char **args, - bool_t sys) -{ -#if TRACING_USER - cio_printf("stksetup: pcb %08x, entry %08x, args %08x\n", (uint32_t)pcb, - entry, (uint32_t)args); -#endif - - /* - ** First, we need to calculate the space we'll need for the argument - ** vector and strings. - ** - ** Keeping track of kernel vs. user VAs is tricky, so we'll use - ** a prefix on variable names: kv_* is a kernel virtual address; - ** uv_* is a user virtual address. - ** - ** We rely on the C standard, section 6.7.8, to clear these arrays: - ** - ** "21 If there are fewer initializers in a brace-enclosed list - ** than there are elements or members of an aggregate, or - ** fewer characters in a string literal used to initialize an - ** array of known size than there are elements in the array, - ** the remainder of the aggregate shall be initialized - ** implicitly the same as objects that have static storage - ** duration." - */ - - int argbytes = 0; // total length of arg strings - int argc = 0; // number of argv entries - const char *kv_strs[N_ARGS] = { 0 }; // converted user arg string pointers - int strlengths[N_ARGS] = { 0 }; // length of each string - const char *uv_argv[N_ARGS] = { 0 }; // argv pointers - - /* - ** IF the argument list given to us came from user code, we need - ** to convert its address and the addresses it contains to kernel - ** VAs; otherwise, we can use them directly. - */ - char **kv_args = sys ? args : vm_uva2kva(pcb->pdir, (void *)args); - - while (kv_args[argc] != NULL) { - kv_strs[argc] = sys ? args[argc] : - vm_uva2kva(pcb->pdir, (void *)(kv_args[argc])); - strlengths[argc] = strlen(kv_strs[argc]) + 1; - // can't go over one page in size - if ((argbytes + strlengths[argc]) > SZ_PAGE) { - // oops - ignore this and any others - break; - } - argbytes += strlengths[argc]; - ++argc; - } - - // Round up the byte count to the next multiple of four. - argbytes = (argbytes + 3) & MOD4_MASK; - - /* - ** The pages for the stack were cleared when they were allocated, - ** so we don't need to remember to do that. - ** - ** We reserve one longword at the bottom of the stack to hold a - ** pointer to where argv is on the stack. - ** - ** The user code was linked with a startup function that defines - ** the entry point (_start), calls main(), and then calls exit() - ** if main() returns. We need to set up the stack this way: - ** - ** esp -> context <- context save area - ** ... <- context save area - ** context <- context save area - ** entry_pt <- return address for the ISR - ** argc <- argument count for main() - ** /-> argv <- argv pointer for main() - ** | ... <- argv array w/trailing NULL - ** | ... <- argv character strings - ** \--- ptr <- last word in stack - ** - ** Stack alignment rules for the SysV ABI i386 supplement dictate that - ** the 'argc' parameter must be at an address that is a multiple of 16; - ** see below for more information. - ** - ** Ultimately, this is what the bottom end of the stack will look like: - ** - ** kvavptr - ** kvacptr | - ** | | - ** v v - ** argc argv av[0] av[1] etc NULL str0 str1 etc. - ** [....][....][....][....] ... [0000] ... [......0......0.........] - ** | ^ | | ^ ^ - ** | | | | | | - ** ------ | ---------------------|------- - ** --------------------------- - */ - - /* - ** We need to find the last page of the user stack. Find the page - ** table for the 4MB user address space. The physical address of its - ** frame is in the first page directory entry. Extract that from the - ** entry and convert it into a virtual address for the kernel to use. - */ - pde_t *kv_userpt = (pde_t *)P2V(PTE_ADDR(pcb->pdir[USER_PDE])); - assert(kv_userpt != NULL); - - /* - ** The final entries in that PMT are for the pages of the user stack. - ** Grab the physical address of the frame for the last one. (Again, - ** we need to convert it to a virtual address we can use.) - */ - - // the PMT entry for that page - pte_t pmt_entry = kv_userpt[USER_STK_LAST_PTE]; - assert(IS_PRESENT(pmt_entry)); - - // user VA for the first byte of that page - uint32_t *uvptr = (uint32_t *)USER_STACK_P2; - - // convert that address to a kernel VA - uint32_t *kvptr = (uint32_t *)vm_uva2kva(pcb->pdir, (void *)uvptr); - - /* - ** Move these pointers to where the string area will begin. We - ** will then back up to the next lower multiple-of-four address. - */ - - uint32_t uvstrptr = ((uint32_t)uvptr) + SZ_PAGE - argbytes; - uvstrptr &= MOD4_MASK; - - uint32_t kvstrptr = ((uint32_t)kvptr) + SZ_PAGE - argbytes; - kvstrptr &= MOD4_MASK; - - // Copy over the argv strings, remembering where each string begins - for (int i = 0; i < argc; ++i) { - // copy the string using kernel addresses - strcpy((char *)kvstrptr, kv_args[i]); - - // remember the user address where this string went - uv_argv[i] = (char *)uvstrptr; - - // adjust both string addresses - kvstrptr += strlengths[i]; - uvstrptr += strlengths[i]; - } - - /* - ** Next, we need to copy over the other data. Start by determining - ** where 'argc' should go. - ** - ** Stack alignment is controlled by the SysV ABI i386 supplement, - ** version 1.2 (June 23, 2016), which states in section 2.2.2: - ** - ** "The end of the input argument area shall be aligned on a 16 - ** (32 or 64, if __m256 or __m512 is passed on stack) byte boundary. - ** In other words, the value (%esp + 4) is always a multiple of 16 - ** (32 or 64) when control is transferred to the function entry - ** point. The stack pointer, %esp, always points to the end of the - ** latest allocated stack frame." - ** - ** Isn't technical documentation fun? Ultimately, this means that - ** the first parameter to main() should be on the stack at an address - ** that is a multiple of 16. In our case, that is 'argc'. - */ - - /* - ** The space needed for argc, argv, and the argv array itself is - ** argc + 3 words (argc+1 for the argv entries, plus one word each - ** for argc and argv). We back up that much from the string area. - */ - - int nwords = argc + 3; - uint32_t *kvacptr = ((uint32_t *)kvstrptr) - nwords; - uint32_t *uvacptr = ((uint32_t *)uvstrptr) - nwords; - - // back these up to multiple-of-16 addresses for stack alignment - kvacptr = (uint32_t *)(((uint32_t)kvacptr) & MOD16_MASK); - uvacptr = (uint32_t *)(((uint32_t)uvacptr) & MOD16_MASK); - - // copy in 'argc' - *kvacptr = argc; - - // 'argv' immediately follows 'argc', and 'argv[0]' immediately - // follows 'argv' - uint32_t *kvavptr = kvacptr + 2; - *(kvavptr - 1) = (uint32_t)kvavptr; - - // now, the argv entries themselves - for (int i = 0; i < argc; ++i) { - *kvavptr++ = (uint32_t)uv_argv[i]; - } - - // and the trailing NULL - *kvavptr = NULL; - - /* - ** Almost done! - ** - ** Now we need to set up the initial context for the executing - ** process. - ** - ** When this process is dispatched, the context restore code will - ** pop all the saved context information off the stack, including - ** the saved EIP, CS, and EFLAGS. We set those fields up so that - ** the interrupt "returns" to the entry point of the process. - */ - - // Locate the context save area on the stack by backup up one - // "context" from where the argc value is saved - context_t *kvctx = ((context_t *)kvacptr) - 1; - uint32_t uvctx = (uint32_t)(((context_t *)uvacptr) - 1); - - /* - ** We cleared the entire stack earlier, so all the context - ** fields currently contain zeroes. We now need to fill in - ** all the important fields. - ** - ** Note: we don't need to set the ESP value for the process, - ** as the 'popa' that restores the general registers doesn't - ** actually restore ESP from the context area - it leaves it - ** where it winds up. - */ - - kvctx->eflags = DEFAULT_EFLAGS; // IF enabled, IOPL 0 - kvctx->eip = entry; // initial EIP - kvctx->cs = GDT_CODE; // segment registers - kvctx->ss = GDT_STACK; - kvctx->ds = kvctx->es = kvctx->fs = kvctx->gs = GDT_DATA; - - /* - ** Return the new context pointer to the caller as a user - ** space virtual address. - */ - - return ((context_t *)uvctx); -} - -/* -** PUBLIC FUNCTIONS -*/ - -/** -** Name: user_init -** -** Initializes the user support module. -*/ -void user_init(void) -{ -#if TRACING_INIT - cio_puts(" User"); -#endif - - // This is gross, but we need to get this information somehow. - // Access the "user blob" data in the second bootstrap sector - uint16_t *blobdata = (uint16_t *)P2V(USER_BLOB_DATA); - user_offset = *blobdata++; - user_segment = *blobdata++; - user_sectors = *blobdata++; - -#if TRACING_USER - cio_printf("\nUser blob: %u sectors @ %04x:%04x", user_sectors, - user_segment, user_offset); -#endif - - // calculate the location of the user blob - if (user_sectors > 0) { - // calculate the address of the header - user_header = (header_t *)(KERN_BASE + ((((uint_t)user_segment) << 4) + - ((uint_t)user_offset))); - - // the program table immediate follows the blob header - prog_table = (prog_t *)(user_header + 1); - -#if TRACING_USER - cio_printf(", hdr %08x, %u progs, tbl %08x\n", (uint32_t)user_header, - user_header->num, (uint32_t)prog_table); -#endif - - } else { - // too bad, so sad! - user_header = NULL; - prog_table = NULL; -#if TRACING_USER - cio_putchar('\n'); -#endif - } -} - -/** -** Name: user_locate -** -** Locates a user program in the user code archive. -** -** @param what The ID of the user program to find -** -** @return pointer to the program table entry in the code archive, or NULL -*/ -prog_t *user_locate(uint_t what) -{ -#if TRACING_USER - cio_printf("ulocate: %u\n", what); -#endif - - // no programs if there is no blob! - if (user_header == NULL) { - return NULL; - } - - // make sure this is a reasonable program to request - if (what >= user_header->num) { - // no such program! - return NULL; - } - - // find the entry in the program table - prog_t *prog = &prog_table[what]; - - // if there are no bytes, it's useless - if (prog->size < 1) { - return NULL; - } - - // return the program table pointer - return prog; -} - -/** -** Name: user_duplicate -** -** Duplicates the memory setup for an existing process. -** -** @param new The PCB for the new copy of the program -** @param old The PCB for the existing the program -** -** @return the status of the duplicate attempt -*/ -int user_duplicate(pcb_t *new, pcb_t *old) -{ -#if TRACING_USER - cio_printf("udup: old %08x new %08x\n", (uint32_t)old, (uint32_t)new); -#endif - - // We need to do a recursive duplication of the process address - // space of the current process. First, we create a new user - // page directory. Next, we'll duplicate the USER_PDE page - // table. Finally, we'll go through that table and duplicate - // all the frames. - - // create the initial VM hierarchy - pde_t *pdir = vm_mkuvm(); - if (pdir == NULL) { - return E_NO_MEMORY; - } - new->pdir = pdir; - - // Next, add a USER_PDE page table that's a duplicate of the - // current process' page table - if (!vm_uvmdup(new->pdir, old->pdir)) { - // check for memory leak? - return E_NO_MEMORY; - } - - // We don't do copy-on-write, so we must duplicate all the - // individual page frames. Iterate through all the user-level - // PDE entries, and replace the existing frames with duplicates. - // - // NOTE: we only deal with pdir[0] here, as we are limiting - // the user address space to the first 4MB. If the size of - // the address space goes up, this code will need to be - // modified to loop over the larger space. - - // pointer to the PMT for the user - pte_t *pt = (pte_t *)(pdir[USER_PDE]); - assert(pt != NULL); - - for (int i = 0; i < N_PTE; ++i) { - // get the current entry from the PMT - pte_t entry = *pt; - - // if this entry is present, - if (IS_PRESENT(entry)) { - // duplicate the frame pointed to by this PTE - void *tmp = vm_pagedup((void *)PTE_ADDR(entry)); - - // replace the old frame number with the new one - *pt = (pte_t)(((uint32_t)tmp) | PERMS(entry)); - - } else { - *pt = 0; - } - ++pt; - } - - return SUCCESS; -} - -/** -** Name: user_load -** -** Loads a user program from the user code archive into memory. -** Allocates all needed frames and sets up the VM tables. -** -** @param ptab A pointer to the program table entry to be loaded -** @param pcb The PCB for the program being loaded -** @param args The argument vector for the program -** @param sys Is the argument vector from kernel code? -** -** @return the status of the load attempt -*/ -int user_load(prog_t *ptab, pcb_t *pcb, const char **args, bool_t sys) -{ - // NULL pointers are bad! - assert1(ptab != NULL); - assert1(pcb != NULL); - assert1(args != NULL); - -#if TRACING_USER - cio_printf("Uload: prog '%s' pcb %08x args %08x\n", - ptab->name[0] ? ptab->name : "?", (uint32_t)pcb, (uint32_t)args); -#endif - - // locate the ELF binary - elfhdr_t *hdr = (elfhdr_t *)((uint32_t)user_header + ptab->offset); - -#if TRACING_ELF - cio_printf("Load: ptab %08x: '%s', off %08x, size %08x, flags %08x\n", - (uint32_t)ptab, ptab->name, ptab->offset, ptab->size, - ptab->flags); - cio_printf(" args %08x:", (uint32_t)args); - if (sys) { - for (int i = 0; args[i] != NULL; ++i) { - cio_printf(" [%d] %s", i, args[i]); - } - } else { - char **kv_args = vm_uva2kva(pcb->pdir, args); - for (int i = 0; kv_args[i] != NULL; ++i) { - cio_printf(" [%d] %s", i, - (char *)vm_uva2kva(pcb->pdir, kv_args[i])); - } - } - cio_printf("\n pcb %08x (pid %u)\n", (uint32_t)pcb, pcb->pid); - dump_fhdr(hdr); -#endif - - // verify the ELF header - if (hdr->e_ident.f.magic != ELF_MAGIC) { - return E_BAD_PARAM; - } - - // allocate a page directory - pcb->pdir = vm_mkuvm(); - if (pcb->pdir == NULL) { - return E_NO_MEMORY; - } - - // read all the program headers - int stat = read_phdrs(hdr, pcb); - if (stat != SUCCESS) { - cio_printf("Uload: read_phdrs('%s') returned %d\n", ptab->name, stat); - PANIC(0, "User_load: phdr read failed"); - } - - // next, set up the runtime stack - just like setting up loadable - // sections, except nothing to copy - stat = - vm_add(pcb->pdir, true, false, (void *)USER_STACK, SZ_USTACK, NULL, 0); - if (stat != SUCCESS) { - cio_printf("Uload: vm_add('%s') stack returned %d\n", ptab->name, stat); - PANIC(0, "user_load: vm_add stack failed"); - } - - // set up the command-line arguments - pcb->context = stack_setup(pcb, hdr->e_entry, args, sys); - - return SUCCESS; -} - -/** -** Name: user_cleanup -** -** "Unloads" a user program. Deallocates all memory frames and -** cleans up the VM structures. -** -** @param pcb The PCB of the program to be unloaded -*/ -void user_cleanup(pcb_t *pcb) -{ -#if TRACING_USER - cio_printf("Uclean: %08x\n", (uint32_t)pcb); -#endif - - if (pcb == NULL) { - // should this be an error? - return; - } - - vm_free(pcb->pdir); - pcb->pdir = NULL; -} |