c4c95c5...
by
Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
posix: Remove dynamic memory allocation from execl{e,p}
GLIBC execl{e,p} implementation might use malloc if the total number of i
arguments exceed initial assumption size (1024). This might lead to
issue in two situations:
1. execl/execle is stated to be async-signal-safe by POSIX [1]. However
if execl is used in a signal handler with a large argument set (that
may call malloc internally) and the resulting call fails, it might
lead malloc in the program in a bad state.
2. If the functions are used in a vfork/clone(VFORK) situation it also
might issue malloc internal bad state.
This patch fixes it by using stack allocation instead. It also fixes
BZ#19534.
Tested on x86_64.
Changes from previous version:
- Remove arbitrary limit on stack allocation for argument handling
(it is arbitrary and does no impose any limit since it does not
consider current stack size neither stack size limit).
Fix MIPS mmap negative offset handling for consistency (bug 19550).
The handling of negative offsets in MIPS mmap is inconsistent with
other architectures, as shown by failure of the test
posix/tst-mmap-offset for o32 and n32. The MIPS mmap syscall uses a
signed argument and does a signed arithmetic shift on it, whereas the
glibc semantics expected by that test are for the offset to be
considered as a large positive offset. This patch makes MIPS
consistent with other architectures as far as possible by using the
mmap2 syscall on o32 (#including the generic implementation), and
making mmap not an alias for mmap64 for n32, with a custom
implementation for n32 that zero-extends the offset argument to 64-bit
before calling the mmap syscall.
Tested for MIPS64 (o32, n32, n64).
[BZ #19550]
* sysdeps/unix/sysv/linux/mips/mips32/mmap.c: New file.
* sysdeps/unix/sysv/linux/mips/mips64/mmap64.c: Move to ....
* sysdeps/unix/sysv/linux/mips/mips64/n64/mmap64.c: ... here.
* sysdeps/unix/sysv/linux/mips/mips64/n32/mmap.c: New file.
* sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list (mmap64):
New syscall entry.
* sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list (mmap):
New syscall entry.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (mmap): Remove
syscall entry.
elf/elf.h: Add new 386 and X86_64 relocations from binutils.
The following new 386 and X86_64 were added to binutils. They are
non-dynamic relocations, so don't need direct handling in glibc.
But other programs, like elfutils, use the glibc elf.h definitions
for the names and numbers when inspecting ET_REL files.
