From: Vincent Chen <vincent.chen@sifive.com>
To: libc-alpha@sourceware.org, palmer@dabbelt.com,
darius@bluespec.com, dj@redhat.com
Cc: vincent.chen@sifive.com, nelson.chu@sifive.com
Subject: [PATCH 1/2] riscv: Add support for GNU indirect function
Date: Tue, 1 Dec 2020 18:22:59 +0800 [thread overview]
Message-ID: <1606818180-17436-2-git-send-email-vincent.chen@sifive.com> (raw)
In-Reply-To: <1606818180-17436-1-git-send-email-vincent.chen@sifive.com>
Enable riscv Glibc to support GNU indirect function
---
libc-abis | 1 +
sysdeps/riscv/dl-irel.h | 53 ++++++++++++++++++++++++++++++++++++++
sysdeps/riscv/dl-machine.h | 22 ++++++++++++++++
3 files changed, 76 insertions(+)
create mode 100644 sysdeps/riscv/dl-irel.h
diff --git a/libc-abis b/libc-abis
index e702f6ae24..fb772499b2 100644
--- a/libc-abis
+++ b/libc-abis
@@ -46,5 +46,6 @@ IFUNC powerpc64-*-linux*
IFUNC powerpc-*-linux*
IFUNC sparc64-*-linux*
IFUNC sparc-*-linux*
+IFUNC riscv*-linux*
# Absolute (SHN_ABS) symbols working correctly.
ABSOLUTE
diff --git a/sysdeps/riscv/dl-irel.h b/sysdeps/riscv/dl-irel.h
new file mode 100644
index 0000000000..7dcfffae6a
--- /dev/null
+++ b/sysdeps/riscv/dl-irel.h
@@ -0,0 +1,53 @@
+/* Machine-dependent ELF indirect relocation inline functions.
+ RISC-V version.
+ Copyright (C) 2020 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
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef _DL_IREL_H
+#define _DL_IREL_H
+
+#include <stdio.h>
+#include <unistd.h>
+#include <ldsodefs.h>
+#include <sysdep.h>
+
+#define ELF_MACHINE_IRELA 1
+
+static inline ElfW(Addr)
+__attribute ((always_inline))
+elf_ifunc_invoke (ElfW(Addr) addr)
+{
+ return ((ElfW(Addr) (*) (uint64_t)) (addr)) (GLRO(dl_hwcap));
+}
+
+static inline void
+__attribute ((always_inline))
+elf_irela (const ElfW(Rela) *reloc)
+{
+ ElfW(Addr) *const reloc_addr = (void *) reloc->r_offset;
+ const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info);
+
+ if (__glibc_likely (r_type == R_RISCV_IRELATIVE))
+ {
+ ElfW(Addr) value = elf_ifunc_invoke (reloc->r_addend);
+ *reloc_addr = value;
+ }
+ else
+ __libc_fatal ("Unexpected reloc type in static binary.\n");
+}
+
+#endif
diff --git a/sysdeps/riscv/dl-machine.h b/sysdeps/riscv/dl-machine.h
index 511140864e..0ae45dd0c3 100644
--- a/sysdeps/riscv/dl-machine.h
+++ b/sysdeps/riscv/dl-machine.h
@@ -25,6 +25,7 @@
#include <elf/elf.h>
#include <sys/asm.h>
#include <dl-tls.h>
+#include <dl-irel.h>
#ifndef _RTLD_PROLOGUE
# define _RTLD_PROLOGUE(entry) \
@@ -176,6 +177,13 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
if (sym_map != NULL)
value = SYMBOL_ADDRESS (sym_map, sym, true) + reloc->r_addend;
+ if (sym != NULL
+ && __glibc_unlikely (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC)
+ && __glibc_likely (sym->st_shndx != SHN_UNDEF)
+ && __glibc_likely (!skip_ifunc))
+ value = elf_ifunc_invoke (value);
+
+
switch (r_type)
{
#ifndef RTLD_BOOTSTRAP
@@ -251,6 +259,13 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
}
#endif
+ case R_RISCV_IRELATIVE:
+ value = map->l_addr + reloc->r_addend;
+ if (__glibc_likely (!skip_ifunc))
+ value = elf_ifunc_invoke (value);
+ *addr_field = value;
+ break;
+
case R_RISCV_JUMP_SLOT:
case __WORDSIZE == 64 ? R_RISCV_64 : R_RISCV_32:
*addr_field = value;
@@ -292,6 +307,13 @@ elf_machine_lazy_rel (struct link_map *map, ElfW(Addr) l_addr,
else
*reloc_addr = map->l_mach.plt;
}
+ else if (__glibc_unlikely (r_type == R_RISCV_IRELATIVE))
+ {
+ ElfW(Addr) value = map->l_addr + reloc->r_addend;
+ if (__glibc_likely (!skip_ifunc))
+ value = elf_ifunc_invoke (value);
+ *reloc_addr = value;
+ }
else
_dl_reloc_bad_type (map, r_type, 1);
}
--
2.29.2
next prev parent reply other threads:[~2020-12-01 10:23 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-01 10:22 [PATCH 0/2] riscv: add " Vincent Chen
2020-12-01 10:22 ` Vincent Chen [this message]
2020-12-01 11:14 ` [PATCH 1/2] riscv: Add " Andreas Schwab
2020-12-01 11:42 ` Florian Weimer
2020-12-04 3:29 ` Vincent Chen
2020-12-04 5:57 ` Florian Weimer
2020-12-01 13:13 ` Szabolcs Nagy
2020-12-04 3:35 ` Vincent Chen
2020-12-01 10:23 ` [PATCH 2/2] riscv: Initialize $gp before resolving the IRELATIVE relocation Vincent Chen
2020-12-02 2:52 ` [PATCH 0/2] riscv: add support for GNU indirect function Jim Wilson
2020-12-07 21:36 ` Jim Wilson
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