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Handle ELF symbols better. This fixes "vmstat -i" for the case

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where "/var/db/kvm_kernel.db" doesn't exist.
This commit is contained in:
John Polstra 1998-10-28 06:37:49 +00:00
parent b39d7dea7b
commit 76a2643efb
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=40688
1 changed files with 77 additions and 59 deletions
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136
lib/libc/gen/nlist.c
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@ -29,6 +29,8 @@
* 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.
*
* $FreeBSD$
*/
#if defined(LIBC_SCCS) && !defined(lint)
@ -197,18 +199,7 @@ __aout_fdnlist(fd, list)
#endif
#ifdef _NLIST_DO_ELF
#if ELF_TARG_CLASS == ELFCLASS32
#define Elf(x) Elf32_##x
#define ELF(x) ELF32_##x
#else
#define Elf(x) Elf64_##x
#define ELF(x) ELF64_##x
#endif
static void elf_sym_to_nlist __P((struct nlist *, Elf_Sym *, Elf_Shdr *, int));
/*
* __elf_is_okay__ - Determine if ehdr really
@ -219,13 +210,13 @@ __aout_fdnlist(fd, list)
*/
int
__elf_is_okay__(ehdr)
register Elf(Ehdr) *ehdr;
register Elf_Ehdr *ehdr;
{
register int retval = 0;
/*
* We need to check magic, class size, endianess,
* and version before we look at the rest of the
* Elf(Ehdr) structure. These few elements are
* Elf_Ehdr structure. These few elements are
* represented in a machine independant fashion.
*/
if (IS_ELF(*ehdr) &&
@ -247,15 +238,19 @@ __elf_fdnlist(fd, list)
register struct nlist *list;
{
register struct nlist *p;
register caddr_t strtab;
register Elf_Off symoff = 0, symstroff = 0;
register Elf_Word symsize = 0, symstrsize = 0;
register Elf_Sword nent, cc, i;
register Elf_Sword cc, i;
int nent = -1;
int errsave;
Elf_Sym sbuf[1024];
Elf_Sym *s;
Elf_Ehdr ehdr;
char *strtab = NULL;
Elf_Shdr *shdr = NULL;
Elf_Shdr *sh;
Elf_Word shdr_size;
void *base;
struct stat st;
/* Make sure obj is OK */
@ -275,10 +270,11 @@ __elf_fdnlist(fd, list)
}
/* mmap section header table */
shdr = (Elf_Shdr *)mmap(NULL, (size_t)shdr_size,
PROT_READ, 0, fd, (off_t) ehdr.e_shoff);
if (shdr == (Elf_Shdr *)-1)
base = mmap(NULL, (size_t)shdr_size, PROT_READ, 0, fd,
(off_t)ehdr.e_shoff);
if (base == MAP_FAILED)
return (-1);
shdr = (Elf_Shdr *)base;
/*
* Find the symbol table entry and it's corresponding
@ -296,13 +292,10 @@ __elf_fdnlist(fd, list)
}
}
/* Flush the section header table */
munmap((caddr_t)shdr, shdr_size);
/* Check for files too large to mmap. */
if (symstrsize > SIZE_T_MAX) {
errno = EFBIG;
return (-1);
goto done;
}
/*
* Map string table into our address space. This gives us
@ -310,10 +303,11 @@ __elf_fdnlist(fd, list)
* making the memory allocation permanent as with malloc/free
* (i.e., munmap will return it to the system).
*/
strtab = mmap(NULL, (size_t)symstrsize, PROT_READ, 0, fd,
(off_t) symstroff);
if (strtab == (char *)-1)
return (-1);
base = mmap(NULL, (size_t)symstrsize, PROT_READ, 0, fd,
(off_t)symstroff);
if (base == MAP_FAILED)
goto done;
strtab = (char *)base;
/*
* clean out any left-over information for all valid entries.
@ -335,7 +329,6 @@ __elf_fdnlist(fd, list)
}
/* Don't process any further if object is stripped. */
/* ELFism - dunno if stripped by looking at header */
if (symoff == 0)
goto done;
@ -344,43 +337,24 @@ __elf_fdnlist(fd, list)
goto done;
}
while (symsize > 0) {
while (symsize > 0 && nent > 0) {
cc = MIN(symsize, sizeof(sbuf));
if (read(fd, sbuf, cc) != cc)
break;
symsize -= cc;
for (s = sbuf; cc > 0; ++s, cc -= sizeof(*s)) {
register int soff = s->st_name;
for (s = sbuf; cc > 0 && nent > 0; ++s, cc -= sizeof(*s)) {
char *name;
struct nlist *p;
if (soff == 0)
name = strtab + s->st_name;
if (name[0] == '\0')
continue;
for (p = list; !ISLAST(p); p++) {
if ((p->n_un.n_name[0] == '_' &&
!strcmp(&strtab[soff], p->n_un.n_name+1))
|| !strcmp(&strtab[soff], p->n_un.n_name)) {
p->n_value = s->st_value;
/* XXX - type conversion */
/* is pretty rude. */
switch(ELF(ST_TYPE)(s->st_info)) {
case STT_NOTYPE:
p->n_type = N_UNDF;
break;
case STT_OBJECT:
p->n_type = N_DATA;
break;
case STT_FUNC:
p->n_type = N_TEXT;
break;
case STT_FILE:
p->n_type = N_FN;
break;
}
if (ELF(ST_BIND)(s->st_info) ==
STB_LOCAL)
p->n_type = N_EXT;
p->n_desc = 0;
p->n_other = 0;
strcmp(name, p->n_un.n_name+1) == 0)
|| strcmp(name, p->n_un.n_name) == 0) {
elf_sym_to_nlist(p, s, shdr,
ehdr.e_shnum);
if (--nent <= 0)
break;
}
@ -388,8 +362,52 @@ __elf_fdnlist(fd, list)
}
}
done:
munmap(strtab, symstrsize);
errsave = errno;
if (strtab != NULL)
munmap(strtab, symstrsize);
if (shdr != NULL)
munmap(shdr, shdr_size);
errno = errsave;
return (nent);
}
/*
* Convert an Elf_Sym into an nlist structure. This fills in only the
* n_value and n_type members.
*/
static void
elf_sym_to_nlist(nl, s, shdr, shnum)
struct nlist *nl;
Elf_Sym *s;
Elf_Shdr *shdr;
int shnum;
{
nl->n_value = s->st_value;
switch (s->st_shndx) {
case SHN_UNDEF:
case SHN_COMMON:
nl->n_type = N_UNDF;
break;
case SHN_ABS:
nl->n_type = ELF_ST_TYPE(s->st_info) == STT_FILE ?
N_FN : N_ABS;
break;
default:
if (s->st_shndx >= shnum)
nl->n_type = N_UNDF;
else {
Elf_Shdr *sh = shdr + s->st_shndx;
nl->n_type = sh->sh_type == SHT_PROGBITS ?
(sh->sh_flags & SHF_WRITE ? N_DATA : N_TEXT) :
(sh->sh_type == SHT_NOBITS ? N_BSS : N_UNDF);
}
break;
}
if (ELF_ST_BIND(s->st_info) == STB_GLOBAL ||
ELF_ST_BIND(s->st_info) == STB_WEAK)
nl->n_type |= N_EXT;
}
#endif /* _NLIST_DO_ELF */