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authorCupertino Miranda <cupertino.miranda@oracle.com>2023-03-16 08:39:52 +0000
committerCupertino Miranda <cupertino.miranda@oracle.com>2023-03-16 09:11:09 +0000
commit5e4c7a839d1c0d68a4a518cf2dc8e87925575e58 (patch)
treee063d731af82e3e76b3ed441fc0d46b505bbc213 /bfd/elf64-bpf.c
parent6752dd75f76457902729a5f03d09fa28ec5d68c3 (diff)
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BPF relocations review / refactoring
- Removed not needed relocations. - Renamed relocations to match llvm and linux kernel. Relocation changes: R_BPF_INSN_64 => R_BPF_64_64 R_BPF_INSN_DISP32 => R_BPF_64_32 R_BPF_DATA_32 => R_BPF_64_ABS32 R_BPF_DATA_64 => R_BPF_64_ABS64 ChangeLog: * bfd/bpf-reloc.def: Created file with BPF_HOWTO macro entries. * bfd/reloc.c: Removed non needed relocations. * bfd/bfd-in2.h: regenerated. * bfd/libbfd.h: regenerated. * bfd/elf64-bpf.c: Changed relocations. * include/elf/bpf.h: Adapted relocation values/names. * gas/config/tc-bpf.c: Changed relocation mapping.
Diffstat (limited to 'bfd/elf64-bpf.c')
-rw-r--r--bfd/elf64-bpf.c314
1 files changed, 47 insertions, 267 deletions
diff --git a/bfd/elf64-bpf.c b/bfd/elf64-bpf.c
index 4f9949b..ef34d62 100644
--- a/bfd/elf64-bpf.c
+++ b/bfd/elf64-bpf.c
@@ -34,214 +34,40 @@
static bfd_reloc_status_type bpf_elf_generic_reloc
(bfd *, arelent *, asymbol *, void *, asection *, bfd *, char **);
+#undef BPF_HOWTO
+#define BPF_HOWTO(type, right, size, bits, pcrel, left, ovf, func, name, \
+ inplace, src_mask, dst_mask, pcrel_off) \
+ type##_IDX,
+enum bpf_reloc_index {
+ R_BPF_INVALID_IDX = -1,
+#include "bpf-reloc.def"
+ R_BPF_SIZE
+};
+#undef BPF_HOWTO
+
/* Relocation tables. */
+#define BPF_HOWTO(...) HOWTO(__VA_ARGS__),
static reloc_howto_type bpf_elf_howto_table [] =
{
- /* This reloc does nothing. */
- HOWTO (R_BPF_NONE, /* type */
- 0, /* rightshift */
- 0, /* size */
- 0, /* bitsize */
- false, /* pc_relative */
- 0, /* bitpos */
- complain_overflow_dont, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_NONE", /* name */
- false, /* partial_inplace */
- 0, /* src_mask */
- 0, /* dst_mask */
- false), /* pcrel_offset */
-
- /* 64-immediate in LDDW instruction. */
- HOWTO (R_BPF_INSN_64, /* type */
- 0, /* rightshift */
- 8, /* size */
- 64, /* bitsize */
- false, /* pc_relative */
- 32, /* bitpos */
- complain_overflow_signed, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_INSN_64", /* name */
- true, /* partial_inplace */
- MINUS_ONE, /* src_mask */
- MINUS_ONE, /* dst_mask */
- true), /* pcrel_offset */
-
- /* 32-immediate in many instructions. */
- HOWTO (R_BPF_INSN_32, /* type */
- 0, /* rightshift */
- 4, /* size */
- 32, /* bitsize */
- false, /* pc_relative */
- 32, /* bitpos */
- complain_overflow_signed, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_INSN_32", /* name */
- true, /* partial_inplace */
- 0xffffffff, /* src_mask */
- 0xffffffff, /* dst_mask */
- true), /* pcrel_offset */
-
- /* 16-bit offsets in instructions. */
- HOWTO (R_BPF_INSN_16, /* type */
- 0, /* rightshift */
- 2, /* size */
- 16, /* bitsize */
- false, /* pc_relative */
- 16, /* bitpos */
- complain_overflow_signed, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_INSN_16", /* name */
- true, /* partial_inplace */
- 0x0000ffff, /* src_mask */
- 0x0000ffff, /* dst_mask */
- true), /* pcrel_offset */
-
- /* 16-bit PC-relative address in jump instructions. */
- HOWTO (R_BPF_INSN_DISP16, /* type */
- 0, /* rightshift */
- 2, /* size */
- 16, /* bitsize */
- true, /* pc_relative */
- 16, /* bitpos */
- complain_overflow_signed, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_INSN_DISP16", /* name */
- true, /* partial_inplace */
- 0xffff, /* src_mask */
- 0xffff, /* dst_mask */
- true), /* pcrel_offset */
-
- HOWTO (R_BPF_DATA_8_PCREL,
- 0, /* rightshift */
- 1, /* size */
- 8, /* bitsize */
- true, /* pc_relative */
- 0, /* bitpos */
- complain_overflow_signed, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_8_PCREL", /* name */
- true, /* partial_inplace */
- 0xff, /* src_mask */
- 0xff, /* dst_mask */
- true), /* pcrel_offset */
-
- HOWTO (R_BPF_DATA_16_PCREL,
- 0, /* rightshift */
- 2, /* size */
- 16, /* bitsize */
- true, /* pc_relative */
- 0, /* bitpos */
- complain_overflow_signed, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_16_PCREL", /* name */
- false, /* partial_inplace */
- 0xffff, /* src_mask */
- 0xffff, /* dst_mask */
- true), /* pcrel_offset */
-
- HOWTO (R_BPF_DATA_32_PCREL,
- 0, /* rightshift */
- 4, /* size */
- 32, /* bitsize */
- true, /* pc_relative */
- 0, /* bitpos */
- complain_overflow_signed, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_32_PCREL", /* name */
- false, /* partial_inplace */
- 0xffffffff, /* src_mask */
- 0xffffffff, /* dst_mask */
- true), /* pcrel_offset */
-
- HOWTO (R_BPF_DATA_8,
- 0, /* rightshift */
- 1, /* size */
- 8, /* bitsize */
- false, /* pc_relative */
- 0, /* bitpos */
- complain_overflow_unsigned, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_DATA_8", /* name */
- true, /* partial_inplace */
- 0xff, /* src_mask */
- 0xff, /* dst_mask */
- false), /* pcrel_offset */
-
- HOWTO (R_BPF_DATA_16,
- 0, /* rightshift */
- 2, /* size */
- 16, /* bitsize */
- false, /* pc_relative */
- 0, /* bitpos */
- complain_overflow_unsigned, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_DATA_16", /* name */
- false, /* partial_inplace */
- 0xffff, /* src_mask */
- 0xffff, /* dst_mask */
- false), /* pcrel_offset */
-
- /* 32-bit PC-relative address in call instructions. */
- HOWTO (R_BPF_INSN_DISP32, /* type */
- 0, /* rightshift */
- 4, /* size */
- 32, /* bitsize */
- true, /* pc_relative */
- 32, /* bitpos */
- complain_overflow_signed, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_INSN_DISP32", /* name */
- true, /* partial_inplace */
- 0xffffffff, /* src_mask */
- 0xffffffff, /* dst_mask */
- true), /* pcrel_offset */
-
- /* 32-bit data. */
- HOWTO (R_BPF_DATA_32, /* type */
- 0, /* rightshift */
- 4, /* size */
- 32, /* bitsize */
- false, /* pc_relative */
- 0, /* bitpos */
- complain_overflow_bitfield, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_DATA_32", /* name */
- false, /* partial_inplace */
- 0xffffffff, /* src_mask */
- 0xffffffff, /* dst_mask */
- true), /* pcrel_offset */
-
- /* 64-bit data. */
- HOWTO (R_BPF_DATA_64, /* type */
- 0, /* rightshift */
- 8, /* size */
- 64, /* bitsize */
- false, /* pc_relative */
- 0, /* bitpos */
- complain_overflow_bitfield, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_DATA_64", /* name */
- false, /* partial_inplace */
- 0, /* src_mask */
- MINUS_ONE, /* dst_mask */
- true), /* pcrel_offset */
-
- HOWTO (R_BPF_DATA_64_PCREL,
- 0, /* rightshift */
- 8, /* size */
- 64, /* bitsize */
- true, /* pc_relative */
- 0, /* bitpos */
- complain_overflow_signed, /* complain_on_overflow */
- bpf_elf_generic_reloc, /* special_function */
- "R_BPF_64_PCREL", /* name */
- false, /* partial_inplace */
- MINUS_ONE, /* src_mask */
- MINUS_ONE, /* dst_mask */
- true), /* pcrel_offset */
+ #include "bpf-reloc.def"
};
#undef AHOW
+#undef BPF_HOWTO
+
+#define BPF_HOWTO(type, right, size, bits, pcrel, left, ovf, func, name, \
+ inplace, src_mask, dst_mask, pcrel_off) \
+ case type: { return type##_IDX; }
+static enum bpf_reloc_index
+bpf_index_for_rtype(unsigned int r_type)
+{
+ switch(r_type) {
+#include "bpf-reloc.def"
+ default:
+ /* Unreachable code. */
+ BFD_ASSERT(0);
+ return -1;
+ };
+}
/* Map BFD reloc types to bpf ELF reloc types. */
@@ -249,44 +75,20 @@ static reloc_howto_type *
bpf_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED,
bfd_reloc_code_real_type code)
{
- /* Note that the bpf_elf_howto_table is indexed by the R_ constants.
- Thus, the order that the howto records appear in the table *must*
- match the order of the relocation types defined in
- include/elf/bpf.h. */
-
switch (code)
{
case BFD_RELOC_NONE:
- return &bpf_elf_howto_table[ (int) R_BPF_NONE];
-
- case BFD_RELOC_8_PCREL:
- return &bpf_elf_howto_table[ (int) R_BPF_DATA_8_PCREL];
- case BFD_RELOC_16_PCREL:
- return &bpf_elf_howto_table[ (int) R_BPF_DATA_16_PCREL];
- case BFD_RELOC_32_PCREL:
- return &bpf_elf_howto_table[ (int) R_BPF_DATA_32_PCREL];
- case BFD_RELOC_64_PCREL:
- return &bpf_elf_howto_table[ (int) R_BPF_DATA_64_PCREL];
-
- case BFD_RELOC_8:
- return &bpf_elf_howto_table[ (int) R_BPF_DATA_8];
- case BFD_RELOC_16:
- return &bpf_elf_howto_table[ (int) R_BPF_DATA_16];
+ return &bpf_elf_howto_table[ (int) R_BPF_NONE_IDX];
+
case BFD_RELOC_32:
- return &bpf_elf_howto_table[ (int) R_BPF_DATA_32];
+ return &bpf_elf_howto_table[ (int) R_BPF_64_ABS32_IDX];
case BFD_RELOC_64:
- return &bpf_elf_howto_table[ (int) R_BPF_DATA_64];
+ return &bpf_elf_howto_table[ (int) R_BPF_64_ABS64_IDX];
case BFD_RELOC_BPF_64:
- return &bpf_elf_howto_table[ (int) R_BPF_INSN_64];
- case BFD_RELOC_BPF_32:
- return &bpf_elf_howto_table[ (int) R_BPF_INSN_32];
- case BFD_RELOC_BPF_16:
- return &bpf_elf_howto_table[ (int) R_BPF_INSN_16];
- case BFD_RELOC_BPF_DISP16:
- return &bpf_elf_howto_table[ (int) R_BPF_INSN_DISP16];
+ return &bpf_elf_howto_table[ (int) R_BPF_64_64_IDX];
case BFD_RELOC_BPF_DISP32:
- return &bpf_elf_howto_table[ (int) R_BPF_INSN_DISP32];
+ return &bpf_elf_howto_table[ (int) R_BPF_64_32_IDX];
default:
/* Pacify gcc -Wall. */
@@ -302,7 +104,7 @@ bpf_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, const char *r_name)
{
unsigned int i;
- for (i = 0; i < ARRAY_SIZE (bpf_elf_howto_table); i++)
+ for (i = 0; i < R_BPF_SIZE; i++)
if (bpf_elf_howto_table[i].name != NULL
&& strcasecmp (bpf_elf_howto_table[i].name, r_name) == 0)
return &bpf_elf_howto_table[i];
@@ -317,9 +119,11 @@ bpf_info_to_howto (bfd *abfd, arelent *bfd_reloc,
Elf_Internal_Rela *elf_reloc)
{
unsigned int r_type;
-
+ unsigned int i;
r_type = ELF64_R_TYPE (elf_reloc->r_info);
- if (r_type >= (unsigned int) R_BPF_max)
+
+ i = bpf_index_for_rtype(r_type);
+ if (i == (unsigned int) -1)
{
/* xgettext:c-format */
_bfd_error_handler (_("%pB: unsupported relocation type %#x"),
@@ -328,7 +132,7 @@ bpf_info_to_howto (bfd *abfd, arelent *bfd_reloc,
return false;
}
- bfd_reloc->howto = &bpf_elf_howto_table [r_type];
+ bfd_reloc->howto = &bpf_elf_howto_table [i];
return true;
}
@@ -438,8 +242,7 @@ bpf_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED,
switch (howto->type)
{
- case R_BPF_INSN_DISP16:
- case R_BPF_INSN_DISP32:
+ case R_BPF_64_32:
{
/* Make the relocation PC-relative, and change its unit to
64-bit words. Note we need *signed* arithmetic
@@ -465,10 +268,8 @@ bpf_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED,
r = bfd_reloc_ok;
break;
}
- case R_BPF_DATA_8:
- case R_BPF_DATA_16:
- case R_BPF_DATA_32:
- case R_BPF_DATA_64:
+ case R_BPF_64_ABS64:
+ case R_BPF_64_ABS32:
{
addend = bfd_get (howto->bitsize, input_bfd, where);
relocation += addend;
@@ -477,28 +278,7 @@ bpf_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED,
r = bfd_reloc_ok;
break;
}
- case R_BPF_INSN_16:
- {
-
- addend = bfd_get_16 (input_bfd, where + 2);
- relocation += addend;
- bfd_put_16 (input_bfd, relocation, where + 2);
-
- r = bfd_reloc_ok;
- break;
- }
- case R_BPF_INSN_32:
- {
- /* Write relocated value */
-
- addend = bfd_get_32 (input_bfd, where + 4);
- relocation += addend;
- bfd_put_32 (input_bfd, relocation, where + 4);
-
- r = bfd_reloc_ok;
- break;
- }
- case R_BPF_INSN_64:
+ case R_BPF_64_64:
{
/*
LDDW instructions are 128 bits long, with a 64-bit immediate.
@@ -610,7 +390,7 @@ bpf_elf_generic_reloc (bfd *abfd, arelent *reloc_entry, asymbol *symbol,
/* Sanity check that the address is in range. */
bfd_size_type end = bfd_get_section_limit_octets (abfd, input_section);
bfd_size_type reloc_size;
- if (reloc_entry->howto->type == R_BPF_INSN_64)
+ if (reloc_entry->howto->type == R_BPF_64_64)
reloc_size = 16;
else
reloc_size = (reloc_entry->howto->bitsize
@@ -642,7 +422,7 @@ bpf_elf_generic_reloc (bfd *abfd, arelent *reloc_entry, asymbol *symbol,
return status;
/* Now finally install the relocation. */
- if (reloc_entry->howto->type == R_BPF_INSN_64)
+ if (reloc_entry->howto->type == R_BPF_64_64)
{
/* lddw is a 128-bit (!) instruction that allows loading a 64-bit
immediate into a register. the immediate is split in half, with the