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authorRoland McGrath <roland@gnu.org>1995-12-15 06:52:58 +0000
committerRoland McGrath <roland@gnu.org>1995-12-15 06:52:58 +0000
commita67b5d1c30d9ea7493adf3512d5fec22be6d6cb3 (patch)
tree7f2636113cbfbd5f07dbe10297afce445fc45498
parentc634e35d9f53ccf101e4f92a3670a696c00baab1 (diff)
(map): Rearrange code to fix some bugs and not remap unless necessary.
(input_room): Simplify. (check_elf): Extract all information from file header before calling `map' for program headers.
-rw-r--r--exec/exec.c55
1 files changed, 23 insertions, 32 deletions
diff --git a/exec/exec.c b/exec/exec.c
index 607faeea..25bb9c38 100644
--- a/exec/exec.c
+++ b/exec/exec.c
@@ -445,18 +445,18 @@ map (struct execdata *e, off_t posn, size_t len)
{
FILE *f = &e->stream;
const size_t size = e->file_size;
- size_t offset = 0;
+ size_t offset;
- f->__target = posn;
-
- if (e->filemap == MACH_PORT_NULL)
+ if ((f->__target & ~(f->__bufsize - 1)) == (posn & ~(f->__bufsize - 1)) &&
+ f->__buffer + (posn + len - f->__target) <= f->__get_limit)
+ /* The current mapping window covers it. */
+ offset = posn & (f->__bufsize - 1);
+ else if (e->filemap == MACH_PORT_NULL)
{
+ /* No mapping for the file. Read the data by RPC. */
char *buffer = f->__buffer;
mach_msg_type_number_t nread = f->__bufsize;
- while (nread < len)
- nread += __vm_page_size;
- e->error = io_read (e->file, &buffer, &nread,
- f->__target, e->optimal_block);
+ e->error = io_read (e->file, &buffer, &nread, posn, len);
if (e->error)
{
errno = e->error;
@@ -466,19 +466,16 @@ map (struct execdata *e, off_t posn, size_t len)
if (buffer != f->__buffer)
{
/* The data was returned out of line. Discard the old buffer. */
- vm_deallocate (mach_task_self (), (vm_address_t) f->__buffer,
- f->__bufsize);
+ if (f->__bufsize != 0)
+ vm_deallocate (mach_task_self (),
+ (vm_address_t) f->__buffer, f->__bufsize);
f->__buffer = buffer;
f->__bufsize = round_page (nread);
}
+ f->__target = posn;
f->__get_limit = f->__buffer + nread;
-
- if (nread < len)
- {
- f->__eof = 1;
- return NULL;
- }
+ offset = 0;
}
else
{
@@ -489,9 +486,8 @@ map (struct execdata *e, off_t posn, size_t len)
f->__buffer = NULL;
/* Make sure our mapping is page-aligned in the file. */
- offset = f->__target % vm_page_size;
- if (offset != 0)
- f->__target -= offset;
+ offset = posn & (vm_page_size - 1);
+ f->__target = trunc_page (posn);
f->__bufsize = round_page (posn + len) - f->__target;
/* Map the data from the file. */
@@ -517,7 +513,7 @@ map (struct execdata *e, off_t posn, size_t len)
f->__offset = f->__target;
f->__bufp = f->__buffer + offset;
- if (f->__bufp + len >= f->__get_limit)
+ if (f->__bufp + len > f->__get_limit)
{
f->__eof = 1;
return NULL;
@@ -530,14 +526,7 @@ map (struct execdata *e, off_t posn, size_t len)
static int
input_room (FILE *f)
{
- struct execdata *e = f->__cookie;
- if (f->__target >= e->file_size)
- {
- f->__eof = 1;
- return EOF;
- }
-
- return (map (e, f->__target, 1) == NULL ? EOF :
+ return (map (f->__cookie, f->__target, 1) == NULL ? EOF :
(unsigned char) *f->__bufp++);
}
@@ -724,8 +713,14 @@ check_elf (struct execdata *e)
return;
}
+ /* Extract all this information now, while EHDR is mapped.
+ The `map' call below for the phdrs may reuse the mapping window. */
e->entry = ehdr->e_entry;
+ e->info.elf.anywhere = (ehdr->e_type == ET_DYN ||
+ ehdr->e_type == ET_REL);
+ e->info.elf.loadbase = 0;
e->info.elf.phnum = ehdr->e_phnum;
+
phdr = map (e, ehdr->e_phoff, ehdr->e_phnum * sizeof (Elf32_Phdr));
if (! phdr)
{
@@ -734,10 +729,6 @@ check_elf (struct execdata *e)
return;
}
e->info.elf.phdr = phdr;
-
- e->info.elf.anywhere = (ehdr->e_type == ET_DYN ||
- ehdr->e_type == ET_REL);
- e->info.elf.loadbase = 0;
}
static void