From: Joe Simmons-Talbott <josimmon@redhat.com>
To: libc-alpha@sourceware.org
Subject: Re: [PATCH v3] mips: dl-machine-reject-phdr: Get rid of alloca.
Date: Thu, 7 Sep 2023 08:25:50 -0400 [thread overview]
Message-ID: <20230907122550.GL3849957@oak> (raw)
In-Reply-To: <20230829193019.GD3849957@oak>
Ping for review.
On Tue, Aug 29, 2023 at 03:30:19PM -0400, Joe Simmons-Talbott via Libc-alpha wrote:
> Ping.
>
> On Mon, Jun 26, 2023 at 09:16:21AM -0400, Joe Simmons-Talbott wrote:
> > Read directly into the mips_abiflags struct rather than reading the
> > entire segment and using alloca when the passed buffer is not big enough.
> >
> > Checked with build-many-glibcs.py on mips-linux-gnu
> > ---
> > Changes to v2:
> > * Rather than use a scratch buffer use the mips_abiflags struct itself
> > for reading since we're now just reading that much data and not the
> > whole segment.
> >
> > sysdeps/mips/dl-machine-reject-phdr.h | 26 ++++++++++----------------
> > 1 file changed, 10 insertions(+), 16 deletions(-)
> >
> > diff --git a/sysdeps/mips/dl-machine-reject-phdr.h b/sysdeps/mips/dl-machine-reject-phdr.h
> > index 104b590661..b784697fc1 100644
> > --- a/sysdeps/mips/dl-machine-reject-phdr.h
> > +++ b/sysdeps/mips/dl-machine-reject-phdr.h
> > @@ -161,7 +161,7 @@ elf_machine_reject_phdr_p (const ElfW(Phdr) *phdr, unsigned int phnum,
> > Lmid_t nsid;
> > int in_abi = -1;
> > struct abi_req in_req;
> > - Elf_MIPS_ABIFlags_v0 *mips_abiflags = NULL;
> > + Elf_MIPS_ABIFlags_v0 mips_abiflags;
> > bool perfect_match = false;
> > #if _MIPS_SIM == _ABIO32
> > unsigned int cur_mode = -1;
> > @@ -176,25 +176,19 @@ elf_machine_reject_phdr_p (const ElfW(Phdr) *phdr, unsigned int phnum,
> > /* Read the attributes section. */
> > if (ph != NULL)
> > {
> > - ElfW(Addr) size = ph->p_filesz;
> > + ElfW(Addr) size = sizeof (Elf_MIPS_ABIFlags_v0);
> >
> > - if (ph->p_offset + size <= len)
> > - mips_abiflags = (Elf_MIPS_ABIFlags_v0 *) (buf + ph->p_offset);
> > - else
> > - {
> > - mips_abiflags = alloca (size);
> > - __lseek (fd, ph->p_offset, SEEK_SET);
> > - if (__libc_read (fd, (void *) mips_abiflags, size) != size)
> > - REJECT (" unable to read PT_MIPS_ABIFLAGS\n");
> > - }
> > -
> > - if (size < sizeof (Elf_MIPS_ABIFlags_v0))
> > + if (ph->p_filesz < size)
> > REJECT (" contains malformed PT_MIPS_ABIFLAGS\n");
> >
> > - if (__glibc_unlikely (mips_abiflags->flags2 != 0))
> > - REJECT (" unknown MIPS.abiflags flags2: %u\n", mips_abiflags->flags2);
> > + __lseek (fd, ph->p_offset, SEEK_SET);
> > + if (__libc_read (fd, (void *) &mips_abiflags, size) != size)
> > + REJECT (" unable to read PT_MIPS_ABIFLAGS\n");
> > +
> > + if (__glibc_unlikely (mips_abiflags.flags2 != 0))
> > + REJECT (" unknown MIPS.abiflags flags2: %u\n", mips_abiflags.flags2);
> >
> > - in_abi = mips_abiflags->fp_abi;
> > + in_abi = mips_abiflags.fp_abi;
> > }
> >
> > /* ANY is compatible with anything. */
> > --
> > 2.39.2
> >
>
next prev parent reply other threads:[~2023-09-07 12:25 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-26 13:16 Joe Simmons-Talbott
2023-08-29 19:30 ` Joe Simmons-Talbott
2023-08-30 8:18 ` Ying Huang
2023-08-30 12:29 ` Joe Simmons-Talbott
2023-09-04 1:12 ` Ying Huang
2023-09-07 12:25 ` Joe Simmons-Talbott [this message]
2023-09-21 11:52 ` Joe Simmons-Talbott
2023-10-02 11:52 ` Joe Simmons-Talbott
2023-10-02 12:13 ` Adhemerval Zanella Netto
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