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, 21 Sep 2023 07:52:35 -0400 [thread overview]
Message-ID: <20230921115235.GS3849957@oak> (raw)
In-Reply-To: <20230907122550.GL3849957@oak>
Ping.
On Thu, Sep 07, 2023 at 08:25:50AM -0400, Joe Simmons-Talbott wrote:
> 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:[~2023-09-21 11:52 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
2023-09-21 11:52 ` Joe Simmons-Talbott [this message]
2023-10-02 11:52 ` Joe Simmons-Talbott
2023-10-02 12:13 ` Adhemerval Zanella Netto
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230921115235.GS3849957@oak \
--to=josimmon@redhat.com \
--cc=libc-alpha@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).