* [binutils-gdb] LoongArch: Add tls transition support.
@ 2023-12-25 3:47 liu & zhensong
0 siblings, 0 replies; only message in thread
From: liu & zhensong @ 2023-12-25 3:47 UTC (permalink / raw)
To: bfd-cvs
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=3898e04b8e4be8744f876ba475b5b2a07ca61ee6
commit 3898e04b8e4be8744f876ba475b5b2a07ca61ee6
Author: Lulu Cai <cailulu@loongson.cn>
Date: Sun Nov 26 14:25:26 2023 +0800
LoongArch: Add tls transition support.
Transitions between DESC->IE/LE and IE->LE are supported now.
1. For DESC -> LE:
pcalau12i $a0,%desc_pc_hi20(var) => lu12i.w $a0,%le_hi20(var)
addi.d $a0,$a0,%desc_pc_lo12(var) => ori $a0,$a0,%le_lo12(var)
ld.d $a1,$a0,%desc_ld(var) => NOP
jirl $ra,$a1,%desc_call(var) => NOP
add.d $a0,$a0,$tp
2. For DESC -> IE:
pcalau12i $a0,%desc_pc_hi20(var) => pcalau12i $a0,%ie_pc_hi20(var)
addi.d $a0,$a0,%desc_pc_lo12(var) => ld.d $a0,$a0,%ie_pc_lo12(var)
ld.d $a1,$a0,%desc_ld(var) => NOP
jirl $ra,$a1,%desc_call(var) => NOP
add.d $a0,$a0,$tp
3. For IE -> LE:
pcalau12i $a0,%ie_pc_hi20(var) => lu12i.w $a0,%le_hi20(var)
ld.d $a0,$a0,%ie_pc_lo12(var) => ori $a0,$a0,%le_lo12(var)
add.d $a0,$a0,$tp
4. When a tls variable is accessed using both DESC and IE, DESC transitions
to IE and uses the same GOT entry as IE.
Diff:
---
bfd/elfnn-loongarch.c | 216 ++++++++++++++++++++++++++++++++++++++++++++-
include/opcode/loongarch.h | 6 ++
2 files changed, 221 insertions(+), 1 deletion(-)
diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
index 95a39148f73..1347d13d2e2 100644
--- a/bfd/elfnn-loongarch.c
+++ b/bfd/elfnn-loongarch.c
@@ -145,6 +145,16 @@ struct loongarch_elf_link_hash_table
#define elf_backend_rela_normal 1
#define elf_backend_default_execstack 0
+#define IS_LOONGARCH_TLS_DESC_RELOC(R_TYPE) \
+ ((R_TYPE) == R_LARCH_TLS_DESC_PC_HI20 \
+ || (R_TYPE) == R_LARCH_TLS_DESC_PC_LO12 \
+ || (R_TYPE) == R_LARCH_TLS_DESC_LD \
+ || (R_TYPE) == R_LARCH_TLS_DESC_CALL)
+
+#define IS_LOONGARCH_TLS_IE_RELOC(R_TYPE) \
+ ((R_TYPE) == R_LARCH_TLS_IE_PC_HI20 \
+ || (R_TYPE) == R_LARCH_TLS_IE_PC_LO12)
+
/* Generate a PLT header. */
static bool
@@ -593,6 +603,10 @@ loongarch_elf_record_tls_and_got_reference (bfd *abfd,
char *new_tls_type = &_bfd_loongarch_elf_tls_type (abfd, h, symndx);
*new_tls_type |= tls_type;
+
+ /* If a symbol is accessed by both IE and DESC, relax DESC to IE. */
+ if ((*new_tls_type & GOT_TLS_IE) && (*new_tls_type & GOT_TLS_GDESC))
+ *new_tls_type &= ~ (GOT_TLS_GDESC);
if ((*new_tls_type & GOT_NORMAL) && (*new_tls_type & ~GOT_NORMAL))
{
_bfd_error_handler (_("%pB: `%s' accessed both as normal and "
@@ -605,6 +619,104 @@ loongarch_elf_record_tls_and_got_reference (bfd *abfd,
return true;
}
+static unsigned int
+loongarch_reloc_got_type (unsigned int r_type)
+{
+ switch (r_type)
+ {
+ case R_LARCH_TLS_DESC_PC_HI20:
+ case R_LARCH_TLS_DESC_PC_LO12:
+ case R_LARCH_TLS_DESC_LD:
+ case R_LARCH_TLS_DESC_CALL:
+ return GOT_TLS_GDESC;
+
+ case R_LARCH_TLS_IE_PC_HI20:
+ case R_LARCH_TLS_IE_PC_LO12:
+ return GOT_TLS_IE;
+
+ default:
+ break;
+ }
+ return GOT_UNKNOWN;
+}
+
+/* Return true if tls type transition can be performed. */
+static bool
+loongarch_can_relax_tls (struct bfd_link_info *info, unsigned int r_type,
+ struct elf_link_hash_entry *h, bfd *input_bfd,
+ unsigned long r_symndx)
+{
+ char symbol_tls_type;
+ unsigned int reloc_got_type;
+
+ if (! (IS_LOONGARCH_TLS_DESC_RELOC (r_type)
+ || IS_LOONGARCH_TLS_IE_RELOC (r_type)))
+ return false;
+
+ symbol_tls_type = _bfd_loongarch_elf_tls_type (input_bfd, h, r_symndx);
+ reloc_got_type = loongarch_reloc_got_type (r_type);
+
+ if (symbol_tls_type == GOT_TLS_IE && GOT_TLS_GD_ANY_P (reloc_got_type))
+ return true;
+
+ if (! bfd_link_executable (info))
+ return false;
+
+ if (h && h->root.type == bfd_link_hash_undefweak)
+ return false;
+
+ return true;
+}
+
+/* The type of relocation that can be transitioned. */
+static unsigned int
+loongarch_tls_transition_without_check (struct bfd_link_info *info,
+ unsigned int r_type,
+ struct elf_link_hash_entry *h)
+{
+ bool local_exec = bfd_link_executable (info)
+ && SYMBOL_REFERENCES_LOCAL (info, h);
+
+ switch (r_type)
+ {
+ case R_LARCH_TLS_DESC_PC_HI20:
+ return (local_exec
+ ? R_LARCH_TLS_LE_HI20
+ : R_LARCH_TLS_IE_PC_HI20);
+
+ case R_LARCH_TLS_DESC_PC_LO12:
+ return (local_exec
+ ? R_LARCH_TLS_LE_LO12
+ : R_LARCH_TLS_IE_PC_LO12);
+
+ case R_LARCH_TLS_DESC_LD:
+ case R_LARCH_TLS_DESC_CALL:
+ return R_LARCH_NONE;
+
+ case R_LARCH_TLS_IE_PC_HI20:
+ return local_exec ? R_LARCH_TLS_LE_HI20 : r_type;
+
+ case R_LARCH_TLS_IE_PC_LO12:
+ return local_exec ? R_LARCH_TLS_LE_LO12 : r_type;
+
+ default:
+ break;
+ }
+
+ return r_type;
+}
+
+static unsigned int
+loongarch_tls_transition (struct bfd_link_info *info, unsigned int r_type,
+ struct elf_link_hash_entry *h, bfd *input_bfd,
+ unsigned long r_symndx)
+{
+ if (! loongarch_can_relax_tls (info, r_type, h, input_bfd,r_symndx))
+ return r_type;
+
+ return loongarch_tls_transition_without_check (info, r_type, h);
+}
+
/* Look through the relocs for a section during the first phase, and
allocate space in the global offset table or procedure linkage
table. */
@@ -706,6 +818,7 @@ loongarch_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
int need_dynreloc = 0;
int only_need_pcrel = 0;
+ r_type = loongarch_tls_transition (info, r_type, h, abfd, r_symndx);
switch (r_type)
{
case R_LARCH_GOT_PC_HI20:
@@ -2403,6 +2516,96 @@ loongarch_reloc_is_fatal (struct bfd_link_info *info,
relocation += 0x100000000; \
})
+/* Transition instruction sequence to relax instruction sequence. */
+static bool
+loongarch_tls_relax (bfd *abfd, asection *sec, Elf_Internal_Rela *rel,
+ int r_type, struct elf_link_hash_entry *h,
+ struct bfd_link_info *info)
+{
+ bool local_exec = bfd_link_executable (info)
+ && SYMBOL_REFERENCES_LOCAL (info, h);
+ bfd_byte *contents = elf_section_data (sec)->this_hdr.contents;
+ unsigned long insn;
+
+ switch (r_type)
+ {
+ case R_LARCH_TLS_DESC_PC_HI20:
+ if (local_exec)
+ /* DESC -> LE relaxation:
+ pcalalau12i $a0,%desc_pc_hi20(var) =>
+ lu12i.w $a0,%le_hi20(var)
+ */
+ bfd_put (32, abfd, LARCH_LU12I_W | LARCH_RD_A0,
+ contents + rel->r_offset);
+
+ /* DESC -> IE relaxation:
+ pcalalau12i $a0,%desc_pc_hi20(var) =>
+ pcalalau12i $a0,%ie_pc_hi20(var)
+ */
+ return true;
+
+ case R_LARCH_TLS_DESC_PC_LO12:
+ if (local_exec)
+ {
+ /* DESC -> LE relaxation:
+ addi.d $a0,$a0,%desc_pc_lo12(var) =>
+ ori $a0,$a0,le_lo12(var)
+ */
+ insn = LARCH_ORI | LARCH_RD_RJ_A0;
+ bfd_put (32, abfd, LARCH_ORI | LARCH_RD_RJ_A0,
+ contents + rel->r_offset);
+ }
+ else
+ {
+ /* DESC -> IE relaxation:
+ addi.d $a0,$a0,%desc_pc_lo12(var) =>
+ ld.d $a0,$a0,%%ie_pc_lo12
+ */
+ bfd_put (32, abfd, LARCH_LD_D | LARCH_RD_RJ_A0,
+ contents + rel->r_offset);
+ }
+ return true;
+
+ case R_LARCH_TLS_DESC_LD:
+ case R_LARCH_TLS_DESC_CALL:
+ /* DESC -> LE/IE relaxation:
+ ld.d $ra,$a0,%desc_ld(var) => NOP
+ jirl $ra,$ra,%desc_call(var) => NOP
+ */
+ bfd_put (32, abfd, LARCH_NOP, contents + rel->r_offset);
+ return true;
+
+ case R_LARCH_TLS_IE_PC_HI20:
+ if (local_exec)
+ {
+ /* IE -> LE relaxation:
+ pcalalau12i $rd,%ie_pc_hi20(var) =>
+ lu12i.w $rd,%le_hi20(var)
+ */
+ insn = bfd_getl32 (contents + rel->r_offset);
+ bfd_put (32, abfd, LARCH_LU12I_W | (insn & 0x1f),
+ contents + rel->r_offset);
+ }
+ return true;
+
+ case R_LARCH_TLS_IE_PC_LO12:
+ if (local_exec)
+ {
+ /* IE -> LE relaxation:
+ ld.d $rd,$rj,%%ie_pc_lo12 =>
+ ori $rd,$rj,le_lo12(var)
+ */
+ insn = bfd_getl32 (contents + rel->r_offset);
+ bfd_put (32, abfd, LARCH_ORI | (insn & 0x3ff),
+ contents + rel->r_offset);
+ }
+ return true;
+ }
+
+ return false;
+}
+
+
static int
loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
bfd *input_bfd, asection *input_section,
@@ -2426,7 +2629,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
relend = relocs + input_section->reloc_count;
for (rel = relocs; rel < relend; rel++)
{
- int r_type = ELFNN_R_TYPE (rel->r_info);
+ unsigned int r_type = ELFNN_R_TYPE (rel->r_info);
unsigned long r_symndx = ELFNN_R_SYM (rel->r_info);
bfd_vma pc = sec_addr (input_section) + rel->r_offset;
reloc_howto_type *howto = NULL;
@@ -2436,6 +2639,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
const char *name;
bfd_reloc_status_type r = bfd_reloc_ok;
bool is_ie, is_desc, is_undefweak, unresolved_reloc, defined_local;
+ unsigned int relaxed_r_type;
bool resolved_local, resolved_dynly, resolved_to_const;
char tls_type;
bfd_vma relocation, off, ie_off, desc_off;
@@ -2567,6 +2771,16 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
BFD_ASSERT (!resolved_local || defined_local);
+ relaxed_r_type = loongarch_tls_transition (info, r_type, h, input_bfd, r_symndx);
+ if (relaxed_r_type != r_type)
+ {
+ howto = loongarch_elf_rtype_to_howto (input_bfd, relaxed_r_type);
+ BFD_ASSERT (howto != NULL);
+
+ if (loongarch_tls_relax (input_bfd, input_section, rel, r_type, h, info))
+ r_type = relaxed_r_type;
+ }
+
is_desc = false;
is_ie = false;
switch (r_type)
diff --git a/include/opcode/loongarch.h b/include/opcode/loongarch.h
index da936f7945a..32ff4d8a0f1 100644
--- a/include/opcode/loongarch.h
+++ b/include/opcode/loongarch.h
@@ -42,6 +42,12 @@ extern "C"
((value) < (-(1 << ((bits) - 1) << align)) \
|| (value) > ((((1 << ((bits) - 1)) - 1) << align)))
+ #define LARCH_LU12I_W 0x14000000
+ #define LARCH_ORI 0x03800000
+ #define LARCH_LD_D 0x28c00000
+ #define LARCH_RD_A0 0x04
+ #define LARCH_RD_RJ_A0 0x084
+
typedef uint32_t insn_t;
struct loongarch_opcode
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2023-12-25 3:47 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-12-25 3:47 [binutils-gdb] LoongArch: Add tls transition support liu & zhensong
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).