svn commit: r338486 - in head/libexec/rtld-elf: . aarch64 arm mips powerpc powerpc64 riscv
Brooks Davis
brooks at FreeBSD.org
Wed Sep 5 23:23:18 UTC 2018
Author: brooks
Date: Wed Sep 5 23:23:16 2018
New Revision: 338486
URL: https://svnweb.freebsd.org/changeset/base/338486
Log:
Rework rtld's TLS Variant I implementation to match r326794
The above commit fixed handling overaligned TLS segments in libc's
TLS Variant I implementation, but rtld provides its own implementation
for dynamically-linked executables which lacks these fixes. Thus,
port these changes to rtld.
This was previously commited as r337978 and reverted in r338149 due to
exposing a bug the ARM rtld. This bug was fixed in r338317 by mmel.
Submitted by: James Clarke
Approved by: re (kib)
Reviewed by: kbowling
Testing by: kbowling (powerpc64), br (riscv), kevans (armv7)
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D16510
Modified:
head/libexec/rtld-elf/aarch64/rtld_machdep.h
head/libexec/rtld-elf/arm/rtld_machdep.h
head/libexec/rtld-elf/mips/rtld_machdep.h
head/libexec/rtld-elf/powerpc/rtld_machdep.h
head/libexec/rtld-elf/powerpc64/rtld_machdep.h
head/libexec/rtld-elf/riscv/rtld_machdep.h
head/libexec/rtld-elf/rtld.c
Modified: head/libexec/rtld-elf/aarch64/rtld_machdep.h
==============================================================================
--- head/libexec/rtld-elf/aarch64/rtld_machdep.h Wed Sep 5 21:47:22 2018 (r338485)
+++ head/libexec/rtld-elf/aarch64/rtld_machdep.h Wed Sep 5 23:23:16 2018 (r338486)
@@ -69,6 +69,8 @@ Elf_Addr reloc_jmpslot(Elf_Addr *where, Elf_Addr targe
#define calculate_tls_offset(prev_offset, prev_size, size, align) \
round(prev_offset + prev_size, align)
#define calculate_tls_end(off, size) ((off) + (size))
+#define calculate_tls_post_size(align) \
+ round(TLS_TCB_SIZE, align) - TLS_TCB_SIZE
#define TLS_TCB_SIZE 16
typedef struct {
Modified: head/libexec/rtld-elf/arm/rtld_machdep.h
==============================================================================
--- head/libexec/rtld-elf/arm/rtld_machdep.h Wed Sep 5 21:47:22 2018 (r338485)
+++ head/libexec/rtld-elf/arm/rtld_machdep.h Wed Sep 5 23:23:16 2018 (r338486)
@@ -69,6 +69,8 @@ typedef struct {
#define calculate_tls_offset(prev_offset, prev_size, size, align) \
round(prev_offset + prev_size, align)
#define calculate_tls_end(off, size) ((off) + (size))
+#define calculate_tls_post_size(align) \
+ round(TLS_TCB_SIZE, align) - TLS_TCB_SIZE
extern void *__tls_get_addr(tls_index *ti);
Modified: head/libexec/rtld-elf/mips/rtld_machdep.h
==============================================================================
--- head/libexec/rtld-elf/mips/rtld_machdep.h Wed Sep 5 21:47:22 2018 (r338485)
+++ head/libexec/rtld-elf/mips/rtld_machdep.h Wed Sep 5 23:23:16 2018 (r338486)
@@ -64,10 +64,11 @@ typedef struct {
#define round(size, align) \
(((size) + (align) - 1) & ~((align) - 1))
#define calculate_first_tls_offset(size, align) \
- round(TLS_TCB_SIZE, align)
+ TLS_TCB_SIZE
#define calculate_tls_offset(prev_offset, prev_size, size, align) \
round(prev_offset + prev_size, align)
#define calculate_tls_end(off, size) ((off) + (size))
+#define calculate_tls_post_size(align) 0
extern void *__tls_get_addr(tls_index *ti);
Modified: head/libexec/rtld-elf/powerpc/rtld_machdep.h
==============================================================================
--- head/libexec/rtld-elf/powerpc/rtld_machdep.h Wed Sep 5 21:47:22 2018 (r338485)
+++ head/libexec/rtld-elf/powerpc/rtld_machdep.h Wed Sep 5 23:23:16 2018 (r338486)
@@ -74,10 +74,11 @@ void _rtld_powerpc_pltcall(void);
#define round(size, align) \
(((size) + (align) - 1) & ~((align) - 1))
#define calculate_first_tls_offset(size, align) \
- round(8, align)
+ TLS_TCB_SIZE
#define calculate_tls_offset(prev_offset, prev_size, size, align) \
round(prev_offset + prev_size, align)
#define calculate_tls_end(off, size) ((off) + (size))
+#define calculate_tls_post_size(align) 0
typedef struct {
unsigned long ti_module;
Modified: head/libexec/rtld-elf/powerpc64/rtld_machdep.h
==============================================================================
--- head/libexec/rtld-elf/powerpc64/rtld_machdep.h Wed Sep 5 21:47:22 2018 (r338485)
+++ head/libexec/rtld-elf/powerpc64/rtld_machdep.h Wed Sep 5 23:23:16 2018 (r338486)
@@ -66,10 +66,11 @@ Elf_Addr reloc_jmpslot(Elf_Addr *where, Elf_Addr targe
#define round(size, align) \
(((size) + (align) - 1) & ~((align) - 1))
#define calculate_first_tls_offset(size, align) \
- round(16, align)
+ TLS_TCB_SIZE
#define calculate_tls_offset(prev_offset, prev_size, size, align) \
round(prev_offset + prev_size, align)
#define calculate_tls_end(off, size) ((off) + (size))
+#define calculate_tls_post_size(align) 0
typedef struct {
unsigned long ti_module;
Modified: head/libexec/rtld-elf/riscv/rtld_machdep.h
==============================================================================
--- head/libexec/rtld-elf/riscv/rtld_machdep.h Wed Sep 5 21:47:22 2018 (r338485)
+++ head/libexec/rtld-elf/riscv/rtld_machdep.h Wed Sep 5 23:23:16 2018 (r338486)
@@ -89,10 +89,11 @@ Elf_Addr reloc_jmpslot(Elf_Addr *where, Elf_Addr targe
#define round(size, align) \
(((size) + (align) - 1) & ~((align) - 1))
#define calculate_first_tls_offset(size, align) \
- round(16, align)
+ TLS_TCB_SIZE
#define calculate_tls_offset(prev_offset, prev_size, size, align) \
round(prev_offset + prev_size, align)
#define calculate_tls_end(off, size) ((off) + (size))
+#define calculate_tls_post_size(align) 0
typedef struct {
unsigned long ti_module;
Modified: head/libexec/rtld-elf/rtld.c
==============================================================================
--- head/libexec/rtld-elf/rtld.c Wed Sep 5 21:47:22 2018 (r338485)
+++ head/libexec/rtld-elf/rtld.c Wed Sep 5 23:23:16 2018 (r338486)
@@ -4693,47 +4693,87 @@ tls_get_addr_common(Elf_Addr **dtvp, int index, size_t
defined(__powerpc__) || defined(__riscv)
/*
+ * Return pointer to allocated TLS block
+ */
+static void *
+get_tls_block_ptr(void *tcb, size_t tcbsize)
+{
+ size_t extra_size, post_size, pre_size, tls_block_size;
+ size_t tls_init_align;
+
+ tls_init_align = MAX(obj_main->tlsalign, 1);
+
+ /* Compute fragments sizes. */
+ extra_size = tcbsize - TLS_TCB_SIZE;
+ post_size = calculate_tls_post_size(tls_init_align);
+ tls_block_size = tcbsize + post_size;
+ pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size;
+
+ return ((char *)tcb - pre_size - extra_size);
+}
+
+/*
* Allocate Static TLS using the Variant I method.
+ *
+ * For details on the layout, see lib/libc/gen/tls.c.
+ *
+ * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as
+ * it is based on tls_last_offset, and TLS offsets here are really TCB
+ * offsets, whereas libc's tls_static_space is just the executable's static
+ * TLS segment.
*/
void *
allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
{
Obj_Entry *obj;
- char *tcb;
- Elf_Addr **tls;
- Elf_Addr *dtv;
+ char *tls_block;
+ Elf_Addr *dtv, **tcb;
Elf_Addr addr;
int i;
+ size_t extra_size, maxalign, post_size, pre_size, tls_block_size;
+ size_t tls_init_align;
if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
return (oldtcb);
assert(tcbsize >= TLS_TCB_SIZE);
- tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize);
- tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
+ maxalign = MAX(tcbalign, tls_static_max_align);
+ tls_init_align = MAX(obj_main->tlsalign, 1);
+ /* Compute fragmets sizes. */
+ extra_size = tcbsize - TLS_TCB_SIZE;
+ post_size = calculate_tls_post_size(tls_init_align);
+ tls_block_size = tcbsize + post_size;
+ pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size;
+ tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size;
+
+ /* Allocate whole TLS block */
+ tls_block = malloc_aligned(tls_block_size, maxalign);
+ tcb = (Elf_Addr **)(tls_block + pre_size + extra_size);
+
if (oldtcb != NULL) {
- memcpy(tls, oldtcb, tls_static_space);
- free(oldtcb);
+ memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize),
+ tls_static_space);
+ free_aligned(get_tls_block_ptr(oldtcb, tcbsize));
/* Adjust the DTV. */
- dtv = tls[0];
+ dtv = tcb[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;
+ dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb;
}
}
} else {
dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
- tls[0] = dtv;
+ tcb[0] = dtv;
dtv[0] = tls_dtv_generation;
dtv[1] = tls_max_index;
for (obj = globallist_curr(objs); obj != NULL;
obj = globallist_next(obj)) {
if (obj->tlsoffset > 0) {
- addr = (Elf_Addr)tls + obj->tlsoffset;
+ addr = (Elf_Addr)tcb + obj->tlsoffset;
if (obj->tlsinitsize > 0)
memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
if (obj->tlssize > obj->tlsinitsize)
@@ -4752,14 +4792,19 @@ free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
{
Elf_Addr *dtv;
Elf_Addr tlsstart, tlsend;
- int dtvsize, i;
+ size_t post_size;
+ size_t dtvsize, i, tls_init_align;
assert(tcbsize >= TLS_TCB_SIZE);
+ tls_init_align = MAX(obj_main->tlsalign, 1);
- tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE;
- tlsend = tlsstart + tls_static_space;
+ /* Compute fragments sizes. */
+ post_size = calculate_tls_post_size(tls_init_align);
- dtv = *(Elf_Addr **)tlsstart;
+ tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size;
+ tlsend = (Elf_Addr)tcb + tls_static_space;
+
+ dtv = *(Elf_Addr **)tcb;
dtvsize = dtv[1];
for (i = 0; i < dtvsize; i++) {
if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
@@ -4767,7 +4812,7 @@ free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
}
}
free(dtv);
- free(tcb);
+ free_aligned(get_tls_block_ptr(tcb, tcbsize));
}
#endif
More information about the svn-src-all
mailing list