From 337126607ffdaf15cbc9ccf3a96e52d71333f191 Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Mon, 29 Jan 2018 10:25:58 -0800 Subject: [PATCH] RISC-V: Thread-Local Storage Support This patch implements TLS support for RISC-V. We support all four standard TLS addressing modes (LE, IE, LD, and GD) when running on Linux via NPTL. There is a draft psABI document that defines our TLS ABI here https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md#thread-local-storage 2018-01-29 Palmer Dabbelt * sysdeps/riscv/dl-tls.h: New file. * sysdeps/riscv/libc-tls.c: Likewise. * sysdeps/riscv/nptl/tcb-offsets.sym: Likewise. * sysdeps/riscv/nptl/tls.h: Likewise. * sysdeps/riscv/stackinfo.h: Likewise. --- ChangeLog | 5 + sysdeps/riscv/dl-tls.h | 48 ++++++++++ sysdeps/riscv/libc-tls.c | 32 +++++++ sysdeps/riscv/nptl/tcb-offsets.sym | 6 ++ sysdeps/riscv/nptl/tls.h | 145 +++++++++++++++++++++++++++++ sysdeps/riscv/stackinfo.h | 33 +++++++ 6 files changed, 269 insertions(+) create mode 100644 sysdeps/riscv/dl-tls.h create mode 100644 sysdeps/riscv/libc-tls.c create mode 100644 sysdeps/riscv/nptl/tcb-offsets.sym create mode 100644 sysdeps/riscv/nptl/tls.h create mode 100644 sysdeps/riscv/stackinfo.h diff --git a/ChangeLog b/ChangeLog index a7f4a36332..0ebb348bfd 100644 --- a/ChangeLog +++ b/ChangeLog @@ -22,6 +22,11 @@ * sysdeps/riscv/setjmp.S: Likewise. * sysdeps/riscv/sys/asm.h: Likewise. * sysdeps/riscv/tls-macros.h: Likewise. + * sysdeps/riscv/dl-tls.h: New file. + * sysdeps/riscv/libc-tls.c: Likewise. + * sysdeps/riscv/nptl/tcb-offsets.sym: Likewise. + * sysdeps/riscv/nptl/tls.h: Likewise. + * sysdeps/riscv/stackinfo.h: Likewise. 2018-01-29 Florian Weimer diff --git a/sysdeps/riscv/dl-tls.h b/sysdeps/riscv/dl-tls.h new file mode 100644 index 0000000000..ab2d860314 --- /dev/null +++ b/sysdeps/riscv/dl-tls.h @@ -0,0 +1,48 @@ +/* Thread-local storage handling in the ELF dynamic linker. RISC-V version. + Copyright (C) 2011-2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + . */ + + +/* Type used for the representation of TLS information in the GOT. */ +typedef struct +{ + unsigned long int ti_module; + unsigned long int ti_offset; +} tls_index; + +/* The thread pointer points to the first static TLS block. */ +#define TLS_TP_OFFSET 0 + +/* Dynamic thread vector pointers point 0x800 past the start of each + TLS block. */ +#define TLS_DTV_OFFSET 0x800 + +/* Compute the value for a GOTTPREL reloc. */ +#define TLS_TPREL_VALUE(sym_map, sym) \ + ((sym_map)->l_tls_offset + (sym)->st_value - TLS_TP_OFFSET) + +/* Compute the value for a DTPREL reloc. */ +#define TLS_DTPREL_VALUE(sym) \ + ((sym)->st_value - TLS_DTV_OFFSET) + +extern void *__tls_get_addr (tls_index *ti); + +#define GET_ADDR_OFFSET (ti->ti_offset + TLS_DTV_OFFSET) +#define __TLS_GET_ADDR(__ti) (__tls_get_addr (__ti) - TLS_DTV_OFFSET) + +/* Value used for dtv entries for which the allocation is delayed. */ +#define TLS_DTV_UNALLOCATED ((void *) -1l) diff --git a/sysdeps/riscv/libc-tls.c b/sysdeps/riscv/libc-tls.c new file mode 100644 index 0000000000..c72abc1d34 --- /dev/null +++ b/sysdeps/riscv/libc-tls.c @@ -0,0 +1,32 @@ +/* Thread-local storage handling in the ELF dynamic linker. RISC-V version. + Copyright (C) 2011-2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + . */ + +#include +#include + +/* On RISC-V, linker optimizations are not required, so __tls_get_addr + can be called even in statically linked binaries. In this case module + must be always 1 and PT_TLS segment exist in the binary, otherwise it + would not link. */ + +void * +__tls_get_addr (tls_index *ti) +{ + dtv_t *dtv = THREAD_DTV (); + return (char *) dtv[1].pointer.val + GET_ADDR_OFFSET; +} diff --git a/sysdeps/riscv/nptl/tcb-offsets.sym b/sysdeps/riscv/nptl/tcb-offsets.sym new file mode 100644 index 0000000000..ab4981f2e2 --- /dev/null +++ b/sysdeps/riscv/nptl/tcb-offsets.sym @@ -0,0 +1,6 @@ +#include +#include + +#define thread_offsetof(mem) (long)(offsetof (struct pthread, mem) - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE) + +MULTIPLE_THREADS_OFFSET thread_offsetof (header.multiple_threads) diff --git a/sysdeps/riscv/nptl/tls.h b/sysdeps/riscv/nptl/tls.h new file mode 100644 index 0000000000..4c92afc58b --- /dev/null +++ b/sysdeps/riscv/nptl/tls.h @@ -0,0 +1,145 @@ +/* Definition for thread-local data handling. NPTL/RISC-V version. + Copyright (C) 2011-2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + . */ + +#ifndef _RISCV_TLS_H +#define _RISCV_TLS_H 1 + +#include + +#ifndef __ASSEMBLER__ +# include +# include +# include +# include + +register void *__thread_self asm ("tp"); +# define READ_THREAD_POINTER() ({ __thread_self; }) + +/* Get system call information. */ +# include + +/* The TP points to the start of the thread blocks. */ +# define TLS_DTV_AT_TP 1 +# define TLS_TCB_AT_TP 0 + +/* Get the thread descriptor definition. */ +# include + +typedef struct +{ + dtv_t *dtv; + void *private; +} tcbhead_t; + +/* This is the size of the initial TCB. Because our TCB is before the thread + pointer, we don't need this. */ +# define TLS_INIT_TCB_SIZE 0 + +/* Alignment requirements for the initial TCB. */ +# define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread) + +/* This is the size of the TCB. Because our TCB is before the thread + pointer, we don't need this. */ +# define TLS_TCB_SIZE 0 + +/* Alignment requirements for the TCB. */ +# define TLS_TCB_ALIGN __alignof__ (struct pthread) + +/* This is the size we need before TCB - actually, it includes the TCB. */ +# define TLS_PRE_TCB_SIZE \ + (sizeof (struct pthread) \ + + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1))) + +/* The thread pointer tp points to the end of the TCB. + The pthread_descr structure is immediately in front of the TCB. */ +# define TLS_TCB_OFFSET 0 + +/* Install the dtv pointer. The pointer passed is to the element with + index -1 which contain the length. */ +# define INSTALL_DTV(tcbp, dtvp) \ + (((tcbhead_t *) (tcbp))[-1].dtv = (dtvp) + 1) + +/* Install new dtv for current thread. */ +# define INSTALL_NEW_DTV(dtv) \ + (THREAD_DTV() = (dtv)) + +/* Return dtv of given thread descriptor. */ +# define GET_DTV(tcbp) \ + (((tcbhead_t *) (tcbp))[-1].dtv) + +/* Code to initially initialize the thread pointer. */ +# define TLS_INIT_TP(tcbp) \ + ({ __thread_self = (char*)tcbp + TLS_TCB_OFFSET; NULL; }) + +/* Return the address of the dtv for the current thread. */ +# define THREAD_DTV() \ + (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv) + +/* Return the thread descriptor for the current thread. */ +# define THREAD_SELF \ + ((struct pthread *) (READ_THREAD_POINTER () \ + - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)) + +/* Value passed to 'clone' for initialization of the thread register. */ +# define TLS_DEFINE_INIT_TP(tp, pd) \ + void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE + +/* Magic for libthread_db to know how to do THREAD_SELF. */ +# define DB_THREAD_SELF \ + CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE) + +/* Access to data in the thread descriptor is easy. */ +# define THREAD_GETMEM(descr, member) \ + descr->member +# define THREAD_GETMEM_NC(descr, member, idx) \ + descr->member[idx] +# define THREAD_SETMEM(descr, member, value) \ + descr->member = (value) +# define THREAD_SETMEM_NC(descr, member, idx, value) \ + descr->member[idx] = (value) + +/* l_tls_offset == 0 is perfectly valid, so we have to use some different + value to mean unset l_tls_offset. */ +# define NO_TLS_OFFSET -1 + +/* Get and set the global scope generation counter in struct pthread. */ +# define THREAD_GSCOPE_FLAG_UNUSED 0 +# define THREAD_GSCOPE_FLAG_USED 1 +# define THREAD_GSCOPE_FLAG_WAIT 2 +# define THREAD_GSCOPE_RESET_FLAG() \ + do \ + { int __res \ + = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag, \ + THREAD_GSCOPE_FLAG_UNUSED); \ + if (__res == THREAD_GSCOPE_FLAG_WAIT) \ + lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \ + } \ + while (0) +# define THREAD_GSCOPE_SET_FLAG() \ + do \ + { \ + THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \ + atomic_write_barrier (); \ + } \ + while (0) +# define THREAD_GSCOPE_WAIT() \ + GL(dl_wait_lookup_done) () + +#endif /* __ASSEMBLER__ */ + +#endif /* tls.h */ diff --git a/sysdeps/riscv/stackinfo.h b/sysdeps/riscv/stackinfo.h new file mode 100644 index 0000000000..5b4f91c6a1 --- /dev/null +++ b/sysdeps/riscv/stackinfo.h @@ -0,0 +1,33 @@ +/* Stack environment definitions for RISC-V. + Copyright (C) 2011-2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + . */ + +/* This file contains a bit of information about the stack allocation + of the processor. */ + +#ifndef _STACKINFO_H +#define _STACKINFO_H 1 + +#include + +/* On RISC-V the stack grows down. */ +#define _STACK_GROWS_DOWN 1 + +/* Default to a non-executable stack. */ +#define DEFAULT_STACK_PERMS (PF_R | PF_W) + +#endif /* stackinfo.h */