Linux Module broken
Matthew Dillon
dillon at apollo.backplane.com
Thu Jul 17 16:23:35 PDT 2003
:kldload: can't load linux.ko: Exec format error
:link_elf: symbol globaldata not found
:
:Rob
Hmm. How odd. The ELF loader is assuming that symbols with values
of 0 are the same as not finding the symbol, or that they are common
symbols when they could be absolute symbols (globaldata is an absolute
symbol with a value of 0).
Please try this patch. It's unfortunately rather involved because
the ELF loader is making all sorts of assumptions that it shouldn't
be making, and I haven't completely fixed it due to an opaque structure,
but it should handle absolute symbols properly now.
-Matt
Matthew Dillon
<dillon at xxxxxxxxxxxxx>
Index: i386/i386/elf_machdep.c
===================================================================
RCS file: /cvs/src/sys/i386/i386/elf_machdep.c,v
retrieving revision 1.2
diff -u -r1.2 elf_machdep.c
--- i386/i386/elf_machdep.c 17 Jun 2003 04:28:35 -0000 1.2
+++ i386/i386/elf_machdep.c 17 Jul 2003 23:21:47 -0000
@@ -40,6 +40,7 @@
Elf_Addr addr;
Elf_Addr addend;
Elf_Word rtype;
+ caddr_t caddr;
const Elf_Rel *rel;
const Elf_Rela *rela;
@@ -68,9 +69,9 @@
case R_386_32: /* S + A */
if (sym == NULL)
return -1;
- addr = (Elf_Addr)linker_file_lookup_symbol(lf, sym, 1);
- if (addr == 0)
+ if (linker_file_lookup_symbol(lf, sym, 1, &caddr) != 0)
return -1;
+ addr = (Elf_Addr)caddr;
addr += addend;
if (*where != addr)
*where = addr;
@@ -79,9 +80,9 @@
case R_386_PC32: /* S + A - P */
if (sym == NULL)
return -1;
- addr = (Elf_Addr)linker_file_lookup_symbol(lf, sym, 1);
- if (addr == 0)
+ if (linker_file_lookup_symbol(lf, sym, 1, &caddr) != 0)
return -1;
+ addr = (Elf_Addr)caddr;
addr += addend - (Elf_Addr)where;
if (*where != addr)
*where = addr;
@@ -99,9 +100,9 @@
case R_386_GLOB_DAT: /* S */
if (sym == NULL)
return -1;
- addr = (Elf_Addr)linker_file_lookup_symbol(lf, sym, 1);
- if (addr == 0)
+ if (linker_file_lookup_symbol(lf, sym, 1, &caddr) != 0)
return -1;
+ addr = (Elf_Addr)caddr;
if (*where != addr)
*where = addr;
break;
Index: kern/kern_linker.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_linker.c,v
retrieving revision 1.6
diff -u -r1.6 kern_linker.c
--- kern/kern_linker.c 27 Jun 2003 01:53:25 -0000 1.6
+++ kern/kern_linker.c 17 Jul 2003 23:21:47 -0000
@@ -102,11 +102,12 @@
KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
lf->filename));
- sysinits = (struct linker_set*)
- linker_file_lookup_symbol(lf, "sysinit_set", 0);
-
+ if (linker_file_lookup_symbol(lf, "sysinit_set", 0, (caddr_t *)&sysinits)) {
+ KLD_DPF(FILE, ("linker_file_sysinit: SYSINITs not found\n"));
+ return 0; /* XXX is this correct ? No sysinit ? */
+ }
KLD_DPF(FILE, ("linker_file_sysinit: SYSINITs %p\n", sysinits));
- if (!sysinits)
+ if (sysinits == NULL)
return 0; /* XXX is this correct ? No sysinit ? */
/* HACK ALERT! */
@@ -167,11 +168,12 @@
KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
lf->filename));
- sysuninits = (struct linker_set*)
- linker_file_lookup_symbol(lf, "sysuninit_set", 0);
-
+ if (linker_file_lookup_symbol(lf, "sysuninit_set", 0, (caddr_t *)&sysuninits)) {
+ KLD_DPF(FILE, ("linker_file_sysuninit: SYSUNINITs not found\n"));
+ return;
+ }
KLD_DPF(FILE, ("linker_file_sysuninit: SYSUNINITs %p\n", sysuninits));
- if (!sysuninits)
+ if (sysuninits == NULL)
return;
/*
@@ -215,11 +217,12 @@
KLD_DPF(FILE, ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
lf->filename));
- sysctls = (struct linker_set*)
- linker_file_lookup_symbol(lf, "sysctl_set", 0);
-
+ if (linker_file_lookup_symbol(lf, "sysctl_set", 0, (caddr_t *)&sysctls)) {
+ KLD_DPF(FILE, ("linker_file_register_sysctls: SYSCTLs not found\n"));
+ return;
+ }
KLD_DPF(FILE, ("linker_file_register_sysctls: SYSCTLs %p\n", sysctls));
- if (!sysctls)
+ if (sysctls == NULL)
return;
sysctl_register_set(sysctls);
@@ -233,11 +236,12 @@
KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs for %s\n",
lf->filename));
- sysctls = (struct linker_set*)
- linker_file_lookup_symbol(lf, "sysctl_set", 0);
-
+ if (linker_file_lookup_symbol(lf, "sysctl_set", 0, (caddr_t *)&sysctls)) {
+ KLD_DPF(FILE, ("linker_file_unregister_sysctls: SYSCTLs not found\n"));
+ return;
+ }
KLD_DPF(FILE, ("linker_file_unregister_sysctls: SYSCTLs %p\n", sysctls));
- if (!sysctls)
+ if (sysctls == NULL)
return;
sysctl_unregister_set(sysctls);
@@ -478,13 +482,12 @@
return 0;
}
-caddr_t
-linker_file_lookup_symbol(linker_file_t file, const char* name, int deps)
+int
+linker_file_lookup_symbol(linker_file_t file, const char* name, int deps, caddr_t *raddr)
{
c_linker_sym_t sym;
linker_symval_t symval;
linker_file_t lf;
- caddr_t address;
size_t common_size = 0;
int i;
@@ -493,24 +496,28 @@
if (file->ops->lookup_symbol(file, name, &sym) == 0) {
file->ops->symbol_values(file, sym, &symval);
- if (symval.value == 0)
+
+ /*
+ * XXX Assume a common symbol if its value is 0 and it has a non-zero
+ * size, otherwise it could be an absolute symbol with a value of 0.
+ */
+ if (symval.value == 0 && symval.size != 0) {
/*
* For commons, first look them up in the dependancies and
* only allocate space if not found there.
*/
common_size = symval.size;
- else {
+ } else {
KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%x\n", symval.value));
- return symval.value;
+ *raddr = symval.value;
+ return 0;
}
}
-
if (deps) {
for (i = 0; i < file->ndeps; i++) {
- address = linker_file_lookup_symbol(file->deps[i], name, 0);
- if (address) {
- KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", address));
- return address;
+ if (linker_file_lookup_symbol(file->deps[i], name, 0, raddr) == 0) {
+ KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", *raddr));
+ return 0;
}
}
@@ -525,10 +532,9 @@
break;
if (i < file->ndeps)
continue;
- address = linker_file_lookup_symbol(lf, name, 0);
- if (address) {
- KLD_DPF(SYM, ("linker_file_lookup_symbol: global value=%x\n", address));
- return address;
+ if (linker_file_lookup_symbol(lf, name, 0, raddr) == 0) {
+ KLD_DPF(SYM, ("linker_file_lookup_symbol: global value=%x\n", *raddr));
+ return 0;
}
}
}
@@ -545,7 +551,8 @@
cp = STAILQ_NEXT(cp, link))
if (!strcmp(cp->name, name)) {
KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\n", cp->address));
- return cp->address;
+ *raddr = cp->address;
+ return 0;
}
/*
@@ -558,7 +565,7 @@
M_LINKER, M_WAITOK);
if (!cp) {
KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n"));
- return 0;
+ return ENOMEM;
}
bzero(cp, sizeof(struct common_symbol) + common_size + strlen(name)+ 1);
@@ -569,11 +576,12 @@
STAILQ_INSERT_TAIL(&file->common, cp, link);
KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%x\n", cp->address));
- return cp->address;
+ *raddr = cp->address;
+ return 0;
}
KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
- return 0;
+ return ENOENT;
}
#ifdef DDB
@@ -947,9 +955,7 @@
if (lf) {
lf->userrefs++;
- sysinits = (struct linker_set*)
- linker_file_lookup_symbol(lf, "sysinit_set", 0);
- if (sysinits) {
+ if (linker_file_lookup_symbol(lf, "sysinit_set", 0, (caddr_t *)&sysinits) == 0 && sysinits) {
/* HACK ALERT!
* This is to set the sysinit moduledata so that the module
* can attach itself to the correct containing file.
Index: kern/link_aout.c
===================================================================
RCS file: /cvs/src/sys/kern/link_aout.c,v
retrieving revision 1.4
diff -u -r1.4 link_aout.c
--- kern/link_aout.c 26 Jun 2003 05:55:14 -0000 1.4
+++ kern/link_aout.c 17 Jul 2003 23:21:47 -0000
@@ -408,14 +408,14 @@
if (sym[0] != '_') {
printf("link_aout: bad symbol name %s\n", sym);
- relocation = 0;
- } else
- relocation = (intptr_t)
- linker_file_lookup_symbol(lf, sym + 1,
- np->nz_type != (N_SETV+N_EXT));
- if (!relocation) {
printf("link_aout: symbol %s not found\n", sym);
return ENOENT;
+ } else {
+ if (linker_file_lookup_symbol(lf, sym + 1,
+ (np->nz_type != (N_SETV+N_EXT)), (caddr_t *)&relocation)) {
+ printf("link_aout: symbol %s not found\n", sym);
+ return ENOENT;
+ }
}
relocation += read_relocation(r, addr);
Index: kern/link_elf.c
===================================================================
RCS file: /cvs/src/sys/kern/link_elf.c,v
retrieving revision 1.4
diff -u -r1.4 link_elf.c
--- kern/link_elf.c 26 Jun 2003 05:55:14 -0000 1.4
+++ kern/link_elf.c 17 Jul 2003 23:21:47 -0000
@@ -896,11 +896,13 @@
if (strcmp(name, strp) == 0) {
if (symp->st_shndx != SHN_UNDEF ||
(symp->st_value != 0 &&
- ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
+ ELF_ST_TYPE(symp->st_info) == STT_FUNC)
+ ) {
*sym = (c_linker_sym_t) symp;
return 0;
- } else
+ } else {
return ENOENT;
+ }
}
symnum = ef->chains[symnum];
@@ -919,11 +921,11 @@
ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
*sym = (c_linker_sym_t) symp;
return 0;
- } else
+ } else {
return ENOENT;
+ }
}
}
-
return ENOENT;
}
Index: sys/linker.h
===================================================================
RCS file: /cvs/src/sys/sys/linker.h,v
retrieving revision 1.2
diff -u -r1.2 linker.h
--- sys/linker.h 17 Jun 2003 04:28:58 -0000 1.2
+++ sys/linker.h 17 Jul 2003 23:21:47 -0000
@@ -180,10 +180,11 @@
/*
* Lookup a symbol in a file. If deps is TRUE, look in dependancies
- * if not found in file.
+ * if not found in file. The symbol's value is returned in the
+ * caddr_t. An error is returned, 0 if no error occured.
*/
-caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name,
- int _deps);
+int linker_file_lookup_symbol(linker_file_t _file, const char* _name,
+ int _deps, caddr_t *);
/*
* Search the linker path for the module. Return the full pathname in
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