The current handling of compat_siginfo_t is a mess: each architecture has its
own implementation, all of which are incorrect in different ways. This patch
series replaces all of the arch-specific versions with a single generic one that
is guaranteed to produce the same results as a 32-bit kernel.
Most architectures are able to use the generic compat_siginfo_t, except x86 and
MIPS. MIPS uses a slightly different compat_siginfo_t structure for ABI reasons
but can still use the generic copy_siginfo_{to,from}_user32. x86 can't use the
generic versions because it needs special handling for __SI_CHLD for x32 tasks.
One issue that isn't resolved in this series is sending signals between a 32-bit
process and 64-bit process. Sending a si_int will work correctly, but a si_ptr
value will likely get corrupted due to the different layouts of the 32-bit and
64-bit siginfo_t structures.
signalfd_copyinfo was also modified to properly generate data for compat tasks.
In particular the ssi_ptr and ssi_data members need to be sign-extended to 64
bits rather than zero-extended, since that is the behavior in 32-bit kernels.
This series has been tested on x86_64 and arm64.
Changes since v1:
- Properly copy padding bytes and avoid leaking uninitialized data to userspace
- Fixed compile errors on mips and powerpc
- Fixed some compiler warnings
- Fixed some formatting issues
Amanieu d'Antras (20):
compat: Add generic compat_siginfo_t
compat: Add generic copy_siginfo_{to,from}_user32
x86: Update compat_siginfo_t to be closer to the generic version
x86: Rewrite copy_siginfo_{to,from}_user32
mips: Clean up compat_siginfo_t
mips: Use generic copy_siginfo_{to,from}_user32
arm64: Use generic compat_siginfo_t
arm64: Use generic copy_siginfo_{to,from}_user32
parisc: Use generic compat_siginfo_t
parsic: Use generic copy_siginfo_{to,from}_user32
s390: Use generic compat_siginfo_t
s390: Use generic copy_siginfo_{to,from}_user32
powerpc: Use generic compat_siginfo_t
powerpc: Use generic copy_siginfo_{to,from}_user32
tile: Use generic compat_siginfo_t
tile: Use generic copy_siginfo_{to,from}_user32
sparc: Use generic compat_siginfo_t
sparc: Use generic copy_siginfo_{to,from}_user32
signalfd: Fix some issues in signalfd_copyinfo
signal: Remove unnecessary zero-initialization of siginfo_t
arch/arm64/include/asm/compat.h | 59 --------
arch/arm64/kernel/signal32.c | 85 -----------
arch/mips/include/asm/compat.h | 63 ++++----
arch/mips/kernel/signal32.c | 62 --------
arch/parisc/include/asm/compat.h | 52 -------
arch/parisc/kernel/signal32.c | 102 -------------
arch/powerpc/include/asm/compat.h | 60 --------
arch/powerpc/kernel/signal_32.c | 72 +---------
arch/s390/include/asm/compat.h | 51 -------
arch/s390/kernel/compat_signal.c | 102 -------------
arch/sparc/include/asm/compat.h | 54 -------
arch/sparc/kernel/signal32.c | 69 ---------
arch/tile/include/asm/compat.h | 57 --------
arch/tile/kernel/compat_signal.c | 75 ----------
arch/x86/include/asm/compat.h | 39 +++--
arch/x86/kernel/signal_compat.c | 285 ++++++++++++++++++++++++++++---------
fs/signalfd.c | 58 +++++---
include/linux/compat.h | 66 ++++++++-
include/uapi/asm-generic/siginfo.h | 1 +
kernel/compat.c | 224 +++++++++++++++++++++++++++++
kernel/ptrace.c | 1 -
kernel/signal.c | 16 ++-
22 files changed, 615 insertions(+), 1038 deletions(-)
--
2.6.2
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