add support for TLS variant I, presently needed for arm and mips

despite documentation that makes it sound a lot different, the only
ABI-constraint difference between TLS variants II and I seems to be
that variant II stores the initial TLS segment immediately below the
thread pointer (i.e. the thread pointer points to the end of it) and
variant I stores the initial TLS segment above the thread pointer,
requiring the thread descriptor to be stored below. the actual value
stored in the thread pointer register also tends to have per-arch
random offsets applied to it for silly micro-optimization purposes.

with these changes applied, TLS should be basically working on all
supported archs except microblaze. I'm still working on getting the
necessary information and a working toolchain that can build TLS
binaries for microblaze, but in theory, static-linked programs with
TLS and dynamic-linked programs where only the main executable uses
TLS should already work on microblaze.

alignment constraints have not yet been heavily tested, so it's
possible that this code does not always align TLS segments correctly
on archs that need TLS variant I.

diff --git a/arch/arm/pthread_arch.h b/arch/arm/pthread_arch.h
index 5f96f2b07d36c0162aa2545c44d9d03e3911166a..43a1c012f466dcd41bc6444edfd4c265c722f7cd 100644 (file)
--- a/arch/arm/pthread_arch.h
+++ b/arch/arm/pthread_arch.h
@@ -1,6 +1,9 @@
-typedef pthread_t (*__pthread_self_func_t)(void) __attribute__((const));
+typedef char *(*__ptr_func_t)(void) __attribute__((const));
 
-#define __pthread_self ((__pthread_self_func_t)0xffff0fe0)
+#define __pthread_self() \
+       ((pthread_t)(((__ptr_func_t)0xffff0fe0)()+8-sizeof(struct pthread)))
+
+#define TLS_ABOVE_TP
+#define TP_ADJ(p) ((char *)(p) + sizeof(struct pthread) - 8)
 
-#define CANCEL_REG_SP 16
 #define CANCEL_REG_IP 18

diff --git a/arch/arm/reloc.h b/arch/arm/reloc.h
index c37af07bb8d84f6cfdcb71f276bff12b79d3dc46..b41314de8bd8c55eadcb09585ba1ae8d0ff97120 100644 (file)
--- a/arch/arm/reloc.h
+++ b/arch/arm/reloc.h
@@ -34,8 +34,8 @@ static inline void do_single_reloc(
                break;
        case R_ARM_TLS_TPOFF32:
                *reloc_addr += def.sym
-                       ? def.sym->st_value - def.dso->tls_offset
-                       : 0 - self->tls_offset;
+                       ? def.sym->st_value + def.dso->tls_offset + 8
+                       : self->tls_offset + 8;
                break;
        }
 }

diff --git a/arch/i386/pthread_arch.h b/arch/i386/pthread_arch.h
index 0ea0aaca4253d362972148e1e7f30ef92fa02b80..1c06c7641df683b9ffe14c0e91f0b1da192abbe0 100644 (file)
--- a/arch/i386/pthread_arch.h
+++ b/arch/i386/pthread_arch.h
@@ -5,5 +5,6 @@ static inline struct pthread *__pthread_self()
        return self;
 }
 
-#define CANCEL_REG_SP 7
+#define TP_ADJ(p) (p)
+
 #define CANCEL_REG_IP 14

diff --git a/arch/microblaze/pthread_arch.h b/arch/microblaze/pthread_arch.h
index 6c0ab5ad5a1dd6a404250fd84752d8971f084106..259d3d615ab1fb30755d48a03730c1a5d3005eff 100644 (file)
--- a/arch/microblaze/pthread_arch.h
+++ b/arch/microblaze/pthread_arch.h
@@ -5,4 +5,6 @@ static inline struct pthread *__pthread_self()
        return self;
 }
 
+#define TP_ADJ(p) (p)
+
 #define CANCEL_REG_IP 32

diff --git a/arch/mips/pthread_arch.h b/arch/mips/pthread_arch.h
index 77b7330dacfd1445d4635d64bb0c6ece1a87897c..f8e35ae46377d5f89ed3eede40dcc1cff83c2747 100644 (file)
--- a/arch/mips/pthread_arch.h
+++ b/arch/mips/pthread_arch.h
@@ -1,12 +1,16 @@
 static inline struct pthread *__pthread_self()
 {
-       struct pthread *self;
 #ifdef __clang__
-       __asm__ __volatile__ (".word 0x7c03e83b ; move %0, $3" : "=r" (self) : : "$3" );
+       char *tp;
+       __asm__ __volatile__ (".word 0x7c03e83b ; move %0, $3" : "=r" (tp) : : "$3" );
 #else
-       __asm__ __volatile__ (".word 0x7c03e83b" : "=v" (self) );
+       register char *tp __asm__("$3");
+       __asm__ __volatile__ (".word 0x7c03e83b" : "=r" (tp) );
 #endif
-       return self;
+       return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
 }
 
+#define TLS_ABOVE_TP
+#define TP_ADJ(p) ((char *)(p) + sizeof(struct pthread) + 0x7000)
+
 #define CANCEL_REG_IP (3-(union {int __i; char __b;}){1}.__b)

diff --git a/arch/mips/reloc.h b/arch/mips/reloc.h
index 785489ed1077ec860e670aadb4836e16c7678f87..f5e9c77b0c63f4e9754b8fee95661d71c87e4b67 100644 (file)
--- a/arch/mips/reloc.h
+++ b/arch/mips/reloc.h
@@ -23,6 +23,17 @@ static inline void do_single_reloc(
        case R_MIPS_COPY:
                memcpy(reloc_addr, (void *)sym_val, sym_size);
                break;
+       case R_MIPS_TLS_DTPMOD32:
+               *reloc_addr = def.dso ? def.dso->tls_id : self->tls_id;
+               break;
+       case R_MIPS_TLS_DTPREL32:
+               *reloc_addr += def.sym->st_value;
+               break;
+       case R_MIPS_TLS_TPREL32:
+               *reloc_addr += def.sym
+                       ? def.sym->st_value + def.dso->tls_offset - 0x7000
+                       : self->tls_offset - 0x7000;
+               break;
        }
 }
 

diff --git a/arch/x86_64/pthread_arch.h b/arch/x86_64/pthread_arch.h
index 836187f5654ea4087c754c512f3543163e3738ff..77c8387c57b698118bbd1af0da452274ca0d710f 100644 (file)
--- a/arch/x86_64/pthread_arch.h
+++ b/arch/x86_64/pthread_arch.h
@@ -5,5 +5,6 @@ static inline struct pthread *__pthread_self()
        return self;
 }
 
-#define CANCEL_REG_SP 15
+#define TP_ADJ(p) (p)
+
 #define CANCEL_REG_IP 16

diff --git a/src/env/__init_tls.c b/src/env/__init_tls.c
index e70025d77a01b25176c2ffd0487cee103cf047a6..ab5992ce1c928eaccddc44bd8f301f2a5b98a981 100644 (file)
--- a/src/env/__init_tls.c
+++ b/src/env/__init_tls.c
@@ -15,11 +15,18 @@ void *__copy_tls(unsigned char *mem)
        if (!image) return mem;
        void **dtv = (void *)mem;
        dtv[0] = (void *)1;
+#ifdef TLS_ABOVE_TP
+       mem += sizeof(void *) * 2;
+       mem += -((uintptr_t)mem + sizeof(struct pthread)) & (align-1);
+       td = (pthread_t)mem;
+       mem += sizeof(struct pthread);
+#else
        mem += __libc.tls_size - sizeof(struct pthread);
        mem -= (uintptr_t)mem & (align-1);
        td = (pthread_t)mem;
        td->dtv = dtv;
        mem -= size;
+#endif
        dtv[1] = mem;
        memcpy(mem, image, len);
        return td;
@@ -33,7 +40,7 @@ void *__tls_get_addr(size_t *v)
 static void *simple(void *p)
 {
        *(void **)p = p;
-       return __set_thread_area(p) ? 0 : p;
+       return __set_thread_area(TP_ADJ(p)) ? 0 : p;
 }
 
 weak_alias(simple, __install_initial_tls);

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index 5353979e31b1ecf4b39b4db1ce3cad38b0613a3c..2ec8fb8c4985b92a782a3a692e3b3884178480f7 100644 (file)
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -539,10 +539,16 @@ static struct dso *load_library(const char *name)
                }
                p->tls_id = ++tls_cnt;
                tls_align = MAXP2(tls_align, p->tls_align);
+#ifdef TLS_ABOVE_TP
+               p->tls_offset = tls_offset + ( (tls_align-1) &
+                       -(tls_offset + (uintptr_t)p->tls_image) );
+               tls_offset += p->tls_size;
+#else
                tls_offset += p->tls_size + p->tls_align - 1;
                tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
                        & (p->tls_align-1);
                p->tls_offset = tls_offset;
+#endif
                p->new_dtv = (void *)(-sizeof(size_t) &
                        (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
                p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
@@ -697,6 +703,18 @@ void *__copy_tls(unsigned char *mem)
        void **dtv = (void *)mem;
        dtv[0] = (void *)tls_cnt;
 
+#ifdef TLS_ABOVE_TP
+       mem += sizeof(void *) * (tls_cnt+1);
+       mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
+       td = (pthread_t)mem;
+       mem += sizeof(struct pthread);
+
+       for (p=head; p; p=p->next) {
+               if (!p->tls_id) continue;
+               dtv[p->tls_id] = mem + p->tls_offset;
+               memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
+       }
+#else
        mem += libc.tls_size - sizeof(struct pthread);
        mem -= (uintptr_t)mem & (tls_align-1);
        td = (pthread_t)mem;
@@ -706,6 +724,7 @@ void *__copy_tls(unsigned char *mem)
                dtv[p->tls_id] = mem - p->tls_offset;
                memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
        }
+#endif
        td->dtv = dtv;
        return td;
 }
@@ -753,9 +772,12 @@ void *__tls_get_addr(size_t *v)
 
 static void update_tls_size()
 {
-       size_t below_tp = (1+tls_cnt) * sizeof(void *) + tls_offset;
-       size_t above_tp = sizeof(struct pthread) + tls_align;
-       libc.tls_size = ALIGN(below_tp + above_tp, tls_align);
+       libc.tls_size = ALIGN(
+               (1+tls_cnt) * sizeof(void *) +
+               tls_offset +
+               sizeof(struct pthread) +
+               tls_align * 2,
+       tls_align);
 }
 
 void *__dynlink(int argc, char **argv)
@@ -866,9 +888,16 @@ void *__dynlink(int argc, char **argv)
        }
        if (app->tls_size) {
                app->tls_id = tls_cnt = 1;
+#ifdef TLS_ABOVE_TP
+               app->tls_offset = 0;
+               tls_offset = app->tls_size
+                       + ( -((uintptr_t)app->tls_image + app->tls_size)
+                       & (app->tls_align-1) );
+#else
                tls_offset = app->tls_offset = app->tls_size
                        + ( -((uintptr_t)app->tls_image + app->tls_size)
                        & (app->tls_align-1) );
+#endif
                tls_align = MAXP2(tls_align, app->tls_align);
        }
        app->global = 1;

diff --git a/src/thread/arm/tls.s b/src/thread/arm/tls.s
new file mode 100644 (file)
index 0000000..59736ac
--- /dev/null
+++ b/src/thread/arm/tls.s
@@ -0,0 +1,4 @@
+.global __aeabi_read_tp
+.type __aeabi_read_tp,%function
+__aeabi_read_tp:
+       ldr pc,=0xffff0fe0

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index 627ff5fbbe087cea6782eb8a9703aa389061ff5e..e67616e7464475187a138017cc9a09d428453721 100644 (file)
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -147,7 +147,7 @@ int pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict attr,
        new->canary = self->canary;
 
        a_inc(&libc.threads_minus_1);
-       ret = __clone(start, stack, flags, new, &new->tid, new, &new->tid);
+       ret = __clone(start, stack, flags, new, &new->tid, TP_ADJ(new), &new->tid);
 
        __release_ptc();
 

diff --git a/src/thread/pthread_self.c b/src/thread/pthread_self.c
index a93d8129353103d5b0a63be15636bbe7b1d8a558..23dbaa5eb805ccbcf65d9e1772b9ab6cabb52853 100644 (file)
--- a/src/thread/pthread_self.c
+++ b/src/thread/pthread_self.c
@@ -10,7 +10,7 @@ static int init_main_thread()
 {
        __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK,
                SIGPT_SET, 0, __SYSCALL_SSLEN);
-       if (__set_thread_area(main_thread) < 0) return -1;
+       if (__set_thread_area(TP_ADJ(main_thread)) < 0) return -1;
        main_thread->canceldisable = libc.canceldisable;
        main_thread->tsd = (void **)__pthread_tsd_main;
        main_thread->errno_ptr = __errno_location();