From: Joe Simmons-Talbott <josimmon@redhat.com>
To: libc-alpha@sourceware.org
Cc: Joe Simmons-Talbott <josimmon@redhat.com>
Subject: [PATCH v3] mips: dl-machine-reject-phdr: Get rid of alloca.
Date: Mon, 26 Jun 2023 09:16:21 -0400 [thread overview]
Message-ID: <20230626131621.763381-1-josimmon@redhat.com> (raw)
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 reply other threads:[~2023-06-26 13:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-26 13:16 Joe Simmons-Talbott [this message]
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
2023-10-02 11:52 ` Joe Simmons-Talbott
2023-10-02 12:13 ` Adhemerval Zanella Netto
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