From: Xi Ruoyao <xry111@xry111.site>
To: mengqinggang <mengqinggang@loongson.cn>,
binutils@sourceware.org, Nick Clifton <nickc@redhat.com>
Cc: xuchenghua@loongson.cn, chenglulu@loongson.cn,
liuzhensong@loongson.cn, i.swmail@xen0n.name,
maskray@google.com, hejinyang@loongson.cn
Subject: Re: [PATCH 2/2] LoongArch: Fix immediate overflow check bug
Date: Sat, 22 Jul 2023 15:47:59 +0800 [thread overview]
Message-ID: <971354976c344d5ec087e8cce962cdbe7710faff.camel@xry111.site> (raw)
In-Reply-To: <9f523a9f-8414-49d2-b3db-303171bcc389@loongson.cn>
On Fri, 2023-07-21 at 11:56 +0800, mengqinggang wrote:
> Hi
>
> These two patches also need to be merged into the 2.41 branch. Thanks.
+Nick too.
For 1/2 it should be OK to backport. For 2/2 the subject and the commit
message do not add up: the subject says "Fix immediate overflow check
bug", but the message says "for easier understand". So does 2/2 really
fix a bug? If true we should backport it, otherwise we should not.
> 在 2023/7/17 下午4:22, mengqinggang 写道:
> > 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;
> > }
> >
>
--
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University
next prev parent reply other threads:[~2023-07-22 7:49 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 ` [PATCH 2/2] LoongArch: Fix immediate overflow check bug mengqinggang
2023-07-21 3:56 ` mengqinggang
2023-07-22 7:47 ` Xi Ruoyao [this message]
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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