linux/arch/arm/vfp
Eric W. Biederman 7771c66457 signal/arm: Document conflicts with SI_USER and SIGFPE
Setting si_code to 0 results in a userspace seeing an si_code of 0.
This is the same si_code as SI_USER.  Posix and common sense requires
that SI_USER not be a signal specific si_code.  As such this use of 0
for the si_code is a pretty horribly broken ABI.

Further use of si_code == 0 guaranteed that copy_siginfo_to_user saw a
value of __SI_KILL and now sees a value of SIL_KILL with the result
that uid and pid fields are copied and which might copying the si_addr
field by accident but certainly not by design.  Making this a very
flakey implementation.

Utilizing FPE_FIXME, siginfo_layout will now return SIL_FAULT and the
appropriate fields will be reliably copied.

Possible ABI fixes includee:
- Send the signal without siginfo
- Don't generate a signal
- Possibly assign and use an appropriate si_code
- Don't handle cases which can't happen

Cc: Russell King <rmk@flint.arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Ref: 451436b7bbb2 ("[ARM] Add support code for ARM hardware vector floating point")
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-01-12 14:21:05 -06:00
..
Makefile ARM: vfp: use -mfloat-abi=soft to build vfp 2011-10-01 21:08:55 +02:00
entry.S ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ 2014-07-18 12:29:04 +01:00
vfp.h ARM: 8629/1: vfp: properly tag assembly function declarations in C code 2016-11-22 11:45:09 +00:00
vfpdouble.c ARM: 8026/1: Fix emulation of multiply accumulate instructions 2014-04-14 23:28:24 +01:00
vfphw.S ARM: 8195/1: vfp: Bounce undefined instructions in vectored mode 2014-11-17 20:53:57 +00:00
vfpinstr.h [ARM] 4583/1: ARMv7: Add VFPv3 support 2008-01-26 14:41:28 +00:00
vfpmodule.c signal/arm: Document conflicts with SI_USER and SIGFPE 2018-01-12 14:21:05 -06:00
vfpsingle.c ARM: convert printk(KERN_* to pr_* 2014-11-21 15:24:50 +00:00