#include "tss.h"
/* We load ELF binaries. The following definitions are taken
- from the ELF specification more-or-less verbatim. */
+ from the ELF specification, [ELF], more-or-less verbatim. */
/* ELF types. */
typedef uint32_t Elf32_Word, Elf32_Addr, Elf32_Off;
#define PF_W 2 /* Writable. */
#define PF_R 4 /* Readable. */
+static bool install_page (struct thread *, void *upage, void *kpage);
+static bool load_segment (struct thread *, struct file *,
+ const struct Elf32_Phdr *);
+static bool setup_stack (struct thread *);
+
+/* Aborts loading an executable, with an error message. */
#define LOAD_ERROR(MSG) \
do { \
printk ("addrspace_load: %s: ", filename); \
goto error; \
} while (0)
-static bool
-install_page (struct thread *t, void *upage, void *kpage)
-{
- /* Verify that there's not already a page at that virtual
- address, then map our page there. */
- if (pagedir_get_page (t->pagedir, upage) == NULL
- && pagedir_set_page (t->pagedir, upage, kpage, true))
- return true;
- else
- {
- palloc_free (kpage);
- return false;
- }
-}
-
-static bool
-load_segment (struct thread *t, struct file *file,
- const struct Elf32_Phdr *phdr)
-{
- void *start, *end;
- uint8_t *upage;
- off_t filesz_left;
-
- ASSERT (t != NULL);
- ASSERT (file != NULL);
- ASSERT (phdr != NULL);
- ASSERT (phdr->p_type == PT_LOAD);
-
- /* p_offset and p_vaddr must be congruent modulo PGSIZE. */
- if (phdr->p_offset % PGSIZE != phdr->p_vaddr % PGSIZE)
- {
- printk ("%#08"PE32Ox" and %#08"PE32Ax" not congruent modulo %#x\n",
- phdr->p_offset, phdr->p_vaddr, (unsigned) PGSIZE);
- return false;
- }
-
- /* p_memsz must be at least as big as p_filesz. */
- if (phdr->p_memsz < phdr->p_filesz)
- {
- printk ("p_memsz (%08"PE32Wx") < p_filesz (%08"PE32Wx")\n",
- phdr->p_memsz, phdr->p_filesz);
- return false;
- }
-
- /* Validate virtual memory region to be mapped. */
- start = pg_round_down ((void *) phdr->p_vaddr);
- end = pg_round_up ((void *) (phdr->p_vaddr + phdr->p_memsz));
- if (start >= PHYS_BASE || end >= PHYS_BASE || end < start)
- {
- printk ("bad virtual region %08lx...%08lx\n",
- (unsigned long) start, (unsigned long) end);
- return false;
- }
-
- filesz_left = phdr->p_filesz + (phdr->p_vaddr & PGMASK);
- file_seek (file, ROUND_DOWN (phdr->p_offset, PGSIZE));
- for (upage = start; upage < (uint8_t *) end; upage += PGSIZE)
- {
- size_t read_bytes = filesz_left >= PGSIZE ? PGSIZE : filesz_left;
- size_t zero_bytes = PGSIZE - read_bytes;
- uint8_t *kpage = palloc_get (0);
- if (kpage == NULL)
- return false;
-
- if (file_read (file, kpage, read_bytes) != (int) read_bytes)
- return false;
- memset (kpage + read_bytes, 0, zero_bytes);
- filesz_left -= read_bytes;
-
- if (!install_page (t, upage, kpage))
- return false;
- }
-
- return true;
-}
-
-static bool
-setup_stack (struct thread *t)
-{
- uint8_t *kpage = palloc_get (PAL_ZERO);
- if (kpage == NULL)
- {
- printk ("failed to allocate process stack\n");
- return false;
- }
-
- return install_page (t, ((uint8_t *) PHYS_BASE) - PGSIZE, kpage);
-}
-
bool
addrspace_load (struct thread *t, const char *filename,
void (**start) (void))
pagedir_activate (t->pagedir);
tss_set_esp0 ((uint8_t *) t + PGSIZE);
}
+\f
+/* addrspace_load() helpers. */
+
+static bool
+install_page (struct thread *t, void *upage, void *kpage)
+{
+ /* Verify that there's not already a page at that virtual
+ address, then map our page there. */
+ if (pagedir_get_page (t->pagedir, upage) == NULL
+ && pagedir_set_page (t->pagedir, upage, kpage, true))
+ return true;
+ else
+ {
+ palloc_free (kpage);
+ return false;
+ }
+}
+
+static bool
+load_segment (struct thread *t, struct file *file,
+ const struct Elf32_Phdr *phdr)
+{
+ void *start, *end;
+ uint8_t *upage;
+ off_t filesz_left;
+
+ ASSERT (t != NULL);
+ ASSERT (file != NULL);
+ ASSERT (phdr != NULL);
+ ASSERT (phdr->p_type == PT_LOAD);
+
+ /* p_offset and p_vaddr must be congruent modulo PGSIZE. */
+ if (phdr->p_offset % PGSIZE != phdr->p_vaddr % PGSIZE)
+ {
+ printk ("%#08"PE32Ox" and %#08"PE32Ax" not congruent modulo %#x\n",
+ phdr->p_offset, phdr->p_vaddr, (unsigned) PGSIZE);
+ return false;
+ }
+
+ /* p_memsz must be at least as big as p_filesz. */
+ if (phdr->p_memsz < phdr->p_filesz)
+ {
+ printk ("p_memsz (%08"PE32Wx") < p_filesz (%08"PE32Wx")\n",
+ phdr->p_memsz, phdr->p_filesz);
+ return false;
+ }
+
+ /* Validate virtual memory region to be mapped. */
+ start = pg_round_down ((void *) phdr->p_vaddr);
+ end = pg_round_up ((void *) (phdr->p_vaddr + phdr->p_memsz));
+ if (start >= PHYS_BASE || end >= PHYS_BASE || end < start)
+ {
+ printk ("bad virtual region %08lx...%08lx\n",
+ (unsigned long) start, (unsigned long) end);
+ return false;
+ }
+
+ filesz_left = phdr->p_filesz + (phdr->p_vaddr & PGMASK);
+ file_seek (file, ROUND_DOWN (phdr->p_offset, PGSIZE));
+ for (upage = start; upage < (uint8_t *) end; upage += PGSIZE)
+ {
+ size_t read_bytes = filesz_left >= PGSIZE ? PGSIZE : filesz_left;
+ size_t zero_bytes = PGSIZE - read_bytes;
+ uint8_t *kpage = palloc_get (0);
+ if (kpage == NULL)
+ return false;
+
+ if (file_read (file, kpage, read_bytes) != (int) read_bytes)
+ return false;
+ memset (kpage + read_bytes, 0, zero_bytes);
+ filesz_left -= read_bytes;
+
+ if (!install_page (t, upage, kpage))
+ return false;
+ }
+
+ return true;
+}
+
+static bool
+setup_stack (struct thread *t)
+{
+ uint8_t *kpage = palloc_get (PAL_ZERO);
+ if (kpage == NULL)
+ {
+ printk ("failed to allocate process stack\n");
+ return false;
+ }
+
+ return install_page (t, ((uint8_t *) PHYS_BASE) - PGSIZE, kpage);
+}
+
projects / pintos-anon / blobdiff