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Fix the variant I allocation for KSE: Allow a larger TCB and assume

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that the documented TCB is at the tail of the extended TCB. In other
words, the base of the TCB has a negative offset from the TLS.
This commit is contained in:
Marcel Moolenaar 2006-09-01 06:13:16 +00:00
parent 9d34b1a911
commit 3614156c7d
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=161800
2 changed files with 74 additions and 97 deletions
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83
lib/libc/gen/tls.c
View File

@ -58,7 +58,7 @@ void _rtld_free_tls(void *tls, size_t tcbsize, size_t tcbalign);
void *__libc_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign);
void __libc_free_tls(void *tls, size_t tcbsize, size_t tcbalign);
#if defined(__ia64__) || defined(__alpha__) || defined(__powerpc__)
#if defined(__ia64__) || defined(__powerpc__)
#define TLS_VARIANT_I
#endif
#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) || \
@ -73,9 +73,6 @@ void __libc_free_tls(void *tls, size_t tcbsize, size_t tcbalign);
static size_t tls_static_space;
static size_t tls_init_size;
#ifdef TLS_VARIANT_I
static size_t tls_init_offset;
#endif
static void *tls_init;
#endif
@ -102,67 +99,69 @@ __libc_tls_get_addr(void *ti __unused)
#ifdef TLS_VARIANT_I
#define TLS_TCB_SIZE (2 * sizeof(void *))
/*
* Free Static TLS using the Variant I method.
*/
void
__libc_free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign __unused)
__libc_free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused)
{
Elf_Addr* dtv;
Elf_Addr *dtv;
Elf_Addr **tls;
dtv = ((Elf_Addr**)tls)[0];
free(tls);
tls = (Elf_Addr **)((Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE);
dtv = tls[0];
free(dtv);
free(tcb);
}
/*
* Allocate Static TLS using the Variant I method.
*/
void *
__libc_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign __unused)
__libc_allocate_tls(void *oldtcb, size_t tcbsize, size_t tcbalign __unused)
{
size_t size;
char *tls;
Elf_Addr *dtv;
Elf_Addr **tls;
char *tcb;
size = tls_static_space;
if (size < tcbsize)
size = tcbsize;
if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
return (oldtcb);
tls = calloc(1, size);
dtv = malloc(3 * sizeof(Elf_Addr));
tcb = calloc(1, tls_static_space + tcbsize);
tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
*(Elf_Addr **) tls = dtv;
if (oldtcb != NULL) {
memcpy(tls, oldtcb, tls_static_space + TLS_TCB_SIZE);
free(oldtcb);
dtv[0] = 1;
dtv[1] = 1;
dtv[2] = (Elf_Addr)(tls + tls_init_offset);
if (oldtls) {
/*
* Copy the static TLS block over whole.
*/
memcpy(tls + tls_init_offset,
(char *)oldtls + tls_init_offset,
tls_static_space - tls_init_offset);
/*
* We assume that this block was the one we created with
* allocate_initial_tls().
*/
_rtld_free_tls(oldtls, 2 * sizeof(Elf_Addr), sizeof(Elf_Addr));
/* Adjust the DTV. */
dtv = tls[0];
dtv[2] = (Elf_Addr)tls + TLS_TCB_SIZE;
} else {
memcpy(tls + tls_init_offset, tls_init, tls_init_size);
memset(tls + tls_init_offset + tls_init_size,
0, tls_static_space - tls_init_size);
dtv = malloc(3 * sizeof(Elf_Addr));
tls[0] = dtv;
dtv[0] = 1;
dtv[1] = 1;
dtv[2] = (Elf_Addr)tls + TLS_TCB_SIZE;
if (tls_init_size > 0)
memcpy((void*)dtv[2], tls_init, tls_init_size);
if (tls_static_space > tls_init_size)
memset((void*)(dtv[2] + tls_init_size), 0,
tls_static_space - tls_init_size);
}
return tls;
return(tcb);
}
#endif
#ifdef TLS_VARIANT_II
#define TLS_TCB_SIZE (3 * sizeof(Elf_Addr))
/*
* Free Static TLS using the Variant II method.
*/
@ -293,22 +292,14 @@ _init_tls()
for (i = 0; (unsigned) i < phnum; i++) {
if (phdr[i].p_type == PT_TLS) {
#ifdef TLS_VARIANT_I
tls_static_space = round(2*sizeof(Elf_Addr),
phdr[i].p_align) + phdr[i].p_memsz;
tls_init_offset = round(2*sizeof(Elf_Addr),
phdr[i].p_align);
#else
tls_static_space = round(phdr[i].p_memsz,
phdr[i].p_align);
#endif
tls_init_size = phdr[i].p_filesz;
tls_init = (void*) phdr[i].p_vaddr;
}
}
tls = _rtld_allocate_tls(NULL, 3*sizeof(Elf_Addr),
sizeof(Elf_Addr));
tls = _rtld_allocate_tls(NULL, TLS_TCB_SIZE, 1);
_set_tp(tls);
#endif

88
libexec/rtld-elf/rtld.c
View File

@ -2690,56 +2690,46 @@ tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset)
/* XXX not sure what variants to use for arm. */
#if defined(__ia64__) || defined(__alpha__) || defined(__powerpc__)
#if defined(__ia64__) || defined(__powerpc__)
/*
* Allocate Static TLS using the Variant I method.
*/
void *
allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
{
Obj_Entry *obj;
size_t size;
char *tls;
Elf_Addr *dtv, *olddtv;
char *tcb;
Elf_Addr **tls;
Elf_Addr *dtv;
Elf_Addr addr;
int i;
size = tls_static_space;
if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
return (oldtcb);
tls = calloc(1, size);
dtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
assert(tcbsize >= TLS_TCB_SIZE);
tcb = calloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize);
tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
*(Elf_Addr**) tls = dtv;
if (oldtcb != NULL) {
memcpy(tls, oldtcb, tls_static_space);
free(oldtcb);
dtv[0] = tls_dtv_generation;
dtv[1] = tls_max_index;
if (oldtls) {
/*
* Copy the static TLS block over whole.
*/
memcpy(tls + tcbsize, oldtls + tcbsize, tls_static_space - tcbsize);
/*
* If any dynamic TLS blocks have been created tls_get_addr(),
* move them over.
*/
olddtv = *(Elf_Addr**) oldtls;
for (i = 0; i < olddtv[1]; i++) {
if (olddtv[i+2] < (Elf_Addr)oldtls ||
olddtv[i+2] > (Elf_Addr)oldtls + tls_static_space) {
dtv[i+2] = olddtv[i+2];
olddtv[i+2] = 0;
/* Adjust the DTV. */
dtv = tls[0];
for (i = 0; i < dtv[1]; i++) {
if (dtv[i+2] >= (Elf_Addr)oldtcb &&
dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls;
}
}
/*
* We assume that all tls blocks are allocated with the same
* size and alignment.
*/
free_tls(oldtls, tcbsize, tcbalign);
} else {
dtv = calloc(tls_max_index + 2, sizeof(Elf_Addr));
tls[0] = dtv;
dtv[0] = tls_dtv_generation;
dtv[1] = tls_max_index;
for (obj = objs; obj; obj = obj->next) {
if (obj->tlsoffset) {
addr = (Elf_Addr)tls + obj->tlsoffset;
@ -2753,34 +2743,30 @@ allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
}
}
return tls;
return (tcb);
}
void
free_tls(void *tls, size_t tcbsize, size_t tcbalign)
free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
{
size_t size;
Elf_Addr* dtv;
int dtvsize, i;
Elf_Addr *dtv;
Elf_Addr tlsstart, tlsend;
int dtvsize, i;
/*
* Figure out the size of the initial TLS block so that we can
* find stuff which __tls_get_addr() allocated dynamically.
*/
size = tls_static_space;
assert(tcbsize >= TLS_TCB_SIZE);
dtv = ((Elf_Addr**)tls)[0];
tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE;
tlsend = tlsstart + tls_static_space;
dtv = *(Elf_Addr **)tlsstart;
dtvsize = dtv[1];
tlsstart = (Elf_Addr) tls;
tlsend = tlsstart + size;
for (i = 0; i < dtvsize; i++) {
if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) {
free((void*) dtv[i+2]);
if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
free((void*)dtv[i+2]);
}
}
free((void*) tlsstart);
free(dtv);
free(tcb);
}
#endif