From: mengqinggang <mengqinggang@loongson.cn>
To: binutils@sourceware.org
Cc: xuchenghua@loongson.cn, chenglulu@loongson.cn,
liuzhensong@loongson.cn, xry111@xry111.site, i.swmail@xen0n.name,
maskray@google.com, hejinyang@loongson.cn,
mengqinggang <mengqinggang@loongson.cn>
Subject: [PATCH 2/2] LoongArch: Fix immediate overflow check bug
Date: Mon, 17 Jul 2023 16:22:29 +0800 [thread overview]
Message-ID: <20230717082229.2149099-2-mengqinggang@loongson.cn> (raw)
In-Reply-To: <20230717082229.2149099-1-mengqinggang@loongson.cn>
For B16/B21/B26/PCREL20_S2 relocations, if immediate overflow check after
rightshift, and the mask need to include sign bit.
Now, the immediate overflow check before rightshift for easier understand.
bfd/ChangeLog:
* elfxx-loongarch.c (reloc_bits_pcrel20_s2): Delete.
(reloc_bits_b16): Delete.
(reloc_bits_b21): Delete.
(reloc_bits_b26): Delete.
(reloc_sign_bits): New.
---
bfd/elfxx-loongarch.c | 160 +++++++++---------------------------------
1 file changed, 32 insertions(+), 128 deletions(-)
diff --git a/bfd/elfxx-loongarch.c b/bfd/elfxx-loongarch.c
index da440d55c3c..2d299050c12 100644
--- a/bfd/elfxx-loongarch.c
+++ b/bfd/elfxx-loongarch.c
@@ -54,13 +54,7 @@ typedef struct loongarch_reloc_howto_type_struct
static bool
reloc_bits (bfd *abfd, reloc_howto_type *howto, bfd_vma *val);
static bool
-reloc_bits_pcrel20_s2 (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val);
-static bool
-reloc_bits_b16 (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val);
-static bool
-reloc_bits_b21 (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val);
-static bool
-reloc_bits_b26 (bfd *abfd, reloc_howto_type *howto, bfd_vma *val);
+reloc_sign_bits (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val);
static bfd_reloc_status_type
loongarch_elf_add_sub_reloc (bfd *, arelent *, asymbol *, void *,
@@ -457,7 +451,7 @@ static loongarch_reloc_howto_type loongarch_howto_table[] =
0x3fffc00, /* dst_mask */
false, /* pcrel_offset */
BFD_RELOC_LARCH_SOP_POP_32_S_10_16_S2, /* bfd_reloc_code_real_type */
- reloc_bits_b16, /* adjust_reloc_bits */
+ reloc_sign_bits, /* adjust_reloc_bits */
NULL), /* larch_reloc_type_name */
LOONGARCH_HOWTO (R_LARCH_SOP_POP_32_S_5_20, /* type (43). */
@@ -493,7 +487,7 @@ static loongarch_reloc_howto_type loongarch_howto_table[] =
false, /* pcrel_offset */
BFD_RELOC_LARCH_SOP_POP_32_S_0_5_10_16_S2,
/* bfd_reloc_code_real_type */
- reloc_bits_b21, /* adjust_reloc_bits */
+ reloc_sign_bits, /* adjust_reloc_bits */
NULL), /* larch_reloc_type_name */
LOONGARCH_HOWTO (R_LARCH_SOP_POP_32_S_0_10_10_16_S2, /* type (45). */
@@ -511,7 +505,7 @@ static loongarch_reloc_howto_type loongarch_howto_table[] =
false, /* pcrel_offset */
BFD_RELOC_LARCH_SOP_POP_32_S_0_10_10_16_S2,
/* bfd_reloc_code_real_type */
- reloc_bits_b26, /* adjust_reloc_bits */
+ reloc_sign_bits, /* adjust_reloc_bits */
NULL), /* larch_reloc_type_name */
LOONGARCH_HOWTO (R_LARCH_SOP_POP_32_U, /* type (46). */
@@ -766,7 +760,7 @@ static loongarch_reloc_howto_type loongarch_howto_table[] =
0x3fffc00, /* dst_mask. */
false, /* pcrel_offset. */
BFD_RELOC_LARCH_B16, /* bfd_reloc_code_real_type. */
- reloc_bits_b16, /* adjust_reloc_bits. */
+ reloc_sign_bits, /* adjust_reloc_bits. */
"b16"), /* larch_reloc_type_name. */
LOONGARCH_HOWTO (R_LARCH_B21, /* type (65). */
@@ -783,7 +777,7 @@ static loongarch_reloc_howto_type loongarch_howto_table[] =
0x3fffc1f, /* dst_mask. */
false, /* pcrel_offset. */
BFD_RELOC_LARCH_B21, /* bfd_reloc_code_real_type. */
- reloc_bits_b21, /* adjust_reloc_bits. */
+ reloc_sign_bits, /* adjust_reloc_bits. */
"b21"), /* larch_reloc_type_name. */
LOONGARCH_HOWTO (R_LARCH_B26, /* type (66). */
@@ -800,7 +794,7 @@ static loongarch_reloc_howto_type loongarch_howto_table[] =
0x03ffffff, /* dst_mask. */
false, /* pcrel_offset. */
BFD_RELOC_LARCH_B26, /* bfd_reloc_code_real_type. */
- reloc_bits_b26, /* adjust_reloc_bits. */
+ reloc_sign_bits, /* adjust_reloc_bits. */
"b26"), /* larch_reloc_type_name. */
LOONGARCH_HOWTO (R_LARCH_ABS_HI20, /* type (67). */
@@ -1436,7 +1430,7 @@ static loongarch_reloc_howto_type loongarch_howto_table[] =
0x1ffffe0, /* dst_mask. */
false, /* pcrel_offset. */
BFD_RELOC_LARCH_PCREL20_S2, /* bfd_reloc_code_real_type. */
- reloc_bits_pcrel20_s2, /* adjust_reloc_bits. */
+ reloc_sign_bits, /* adjust_reloc_bits. */
NULL), /* larch_reloc_type_name. */
/* Canonical Frame Address. */
@@ -1677,12 +1671,14 @@ reloc_bits (bfd *abfd ATTRIBUTE_UNUSED,
}
static bool
-reloc_bits_pcrel20_s2 (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val)
+reloc_sign_bits (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val)
{
+ if (howto->complain_on_overflow != complain_overflow_signed)
+ return false;
+
bfd_signed_vma val = (bfd_signed_vma)(*fix_val);
- bfd_signed_vma mask = ((bfd_signed_vma)0x1 << howto->bitsize) - 1;
- /* Check rightshift. */
+ /* Check alignment. FIXME: if rightshift is not alingment. */
if (howto->rightshift
&& (val & ((((bfd_signed_vma) 1) << howto->rightshift) - 1)))
{
@@ -1692,8 +1688,12 @@ reloc_bits_pcrel20_s2 (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val)
return false;
}
- val = val >> howto->rightshift;
+ bfd_signed_vma mask = ((bfd_signed_vma)0x1 << (howto->bitsize
+ + howto->rightshift - 1)) - 1;
+ /* Positive number: high part is all 0;
+ Negative number: if high part is not all 0, high part must be all 1.
+ high part: from sign bit to highest bit. */
if ((val & ~mask) && ((val & ~mask) != ~mask))
{
(*_bfd_error_handler) (_("%pB: relocation %s overflow 0x%lx"),
@@ -1702,123 +1702,27 @@ reloc_bits_pcrel20_s2 (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val)
return false;
}
- /* Perform insn bits field. */
- val = val & mask;
- val <<= howto->bitpos;
-
- *fix_val = (bfd_vma)val;
-
- return true;
-}
-
-
-/* Adjust val to perform insn
- R_LARCH_SOP_POP_32_S_10_16_S2
- R_LARCH_B16. */
-static bool
-reloc_bits_b16 (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val)
-{
- bfd_signed_vma val = *fix_val;
- bfd_signed_vma mask = ((bfd_signed_vma)0x1 << howto->bitsize) - 1;
-
- if (howto->complain_on_overflow != complain_overflow_signed)
- return false;
-
- /* Judge whether 4 bytes align. */
- if (val & ((0x1UL << howto->rightshift) - 1))
- return false;
-
- val = val >> howto->rightshift;
-
- if ((val & ~mask) && ((val & ~mask) != ~mask))
- {
- (*_bfd_error_handler) (_("%pB: relocation %s overflow 0x%lx"),
- abfd, howto->name, (long) val);
- bfd_set_error (bfd_error_bad_value);
- return false;
- }
-
- /* Perform insn bits field. */
- val = val & mask;
- val <<= howto->bitpos;
-
- *fix_val = val;
-
- return true;
-}
-
-/* Reloc type :
- R_LARCH_SOP_POP_32_S_0_5_10_16_S2
- R_LARCH_B21. */
-static bool
-reloc_bits_b21 (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val)
-{
- bfd_signed_vma val = *fix_val;
- bfd_signed_vma mask = ((bfd_signed_vma)0x1 << howto->bitsize) - 1;
-
- if (howto->complain_on_overflow != complain_overflow_signed)
- return false;
-
- /* Judge whether 4 bytes align. */
- if (val & ((0x1UL << howto->rightshift) - 1))
- return false;
-
val = val >> howto->rightshift;
-
- if ((val & ~mask) && ((val & ~mask) != ~mask))
- {
- (*_bfd_error_handler) (_("%pB: relocation %s overflow 0x%lx"),
- abfd, howto->name, (long) val);
- bfd_set_error (bfd_error_bad_value);
- return false;
- }
-
- /* Perform insn bits field. */
+ /* can delete? */
+ mask = ((bfd_signed_vma)0x1 << howto->bitsize) - 1;
val = val & mask;
- /* Perform insn bits field. 15:0<<10, 20:16>>16. */
- val = ((val & 0xffff) << 10) | ((val >> 16) & 0x1f);
-
- *fix_val = val;
-
- return true;
-}
-
-/* Reloc type:
- R_LARCH_SOP_POP_32_S_0_10_10_16_S2
- R_LARCH_B26. */
-static bool
-reloc_bits_b26 (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val)
-{
- bfd_signed_vma val = *fix_val;
- bfd_signed_vma mask = ((bfd_signed_vma)0x1 << howto->bitsize) - 1;
-
- if (howto->complain_on_overflow != complain_overflow_signed)
- return false;
-
- /* Judge whether 4 bytes align. */
- if (val & ((0x1UL << howto->rightshift) - 1))
- return false;
-
- val = val >> howto->rightshift;
-
- if ((val & ~mask) && ((val & ~mask) != ~mask))
+ switch (howto->type)
{
- (*_bfd_error_handler) (_("%pB: relocation %s overflow 0x%lx"),
- abfd, howto->name, (long) val);
- bfd_set_error (bfd_error_bad_value);
- return false;
+ case R_LARCH_SOP_POP_32_S_0_10_10_16_S2:
+ case R_LARCH_B26:
+ /* Perform insn bits field. 25:16>>16, 15:0<<10. */
+ val = ((val & 0xffff) << 10) | ((val >> 16) & 0x3ff);
+ break;
+ case R_LARCH_B21:
+ val = ((val & 0xffff) << 10) | ((val >> 16) & 0x1f);
+ break;
+ default:
+ val <<= howto->bitpos;
+ break;
}
-
- /* Perform insn bits field. */
- val = val & mask;
-
- /* Perform insn bits field. 25:16>>16, 15:0<<10. */
- val = ((val & 0xffff) << 10) | ((val >> 16) & 0x3ff);
-
*fix_val = val;
-
return true;
}
--
2.36.0
next prev parent reply other threads:[~2023-07-17 8:22 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-17 8:22 [PATCH 1/2] LoongArch: Fix instruction immediate bug caused by sign-extend mengqinggang
2023-07-17 8:22 ` mengqinggang [this message]
2023-07-21 3:56 ` [PATCH 2/2] LoongArch: Fix immediate overflow check bug mengqinggang
2023-07-22 7:47 ` Xi Ruoyao
2023-07-22 7:52 ` Xi Ruoyao
2023-07-22 8:23 ` Jinyang He
2023-07-24 9:14 ` Nick Clifton
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