Eric W. Biederman 526c3ddb6a signal/arm64: Document conflicts with SI_USER and SIGFPE,SIGTRAP,SIGBUS ... 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, BUS_FIXME, TRAP_FIXME siginfo_layout will now return SIL_FAULT and the appropriate fields will be reliably copied. But folks this is a new and unique kind of bad. This is massively untested code bad. This is inventing new and unique was to get siginfo wrong bad. This is don't even think about Posix or what siginfo means bad. This is lots of eyeballs all missing the fact that the code does the wrong thing bad. This is getting stuck and keep making the same mistake bad. I really hope we can find a non userspace breaking fix for this on a port as new as arm64. Possible ABI fixes include: - 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: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Tyler Baicar <tbaicar@codeaurora.org> Cc: James Morse <james.morse@arm.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Nicolas Pitre <nico@linaro.org> Cc: Olof Johansson <olof@lixom.net> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-arm-kernel@lists.infradead.org Ref: 53631b54c8 ("arm64: Floating point and SIMD") Ref: 32015c2356 ("arm64: exception: handle Synchronous External Abort") Ref: 1d18c47c73 ("arm64: MMU fault handling and page table management") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>		2018-01-12 14:21:05 -06:00
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auxvec.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00
bitsperlong.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00
bpf_perf_event.h	arm64/bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type	2017-12-05 15:02:41 +01:00
byteorder.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00
fcntl.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00
hwcap.h	arm64 updates for 4.15	2017-11-15 10:56:56 -08:00
Kbuild	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
kvm.h	First batch of KVM changes for 4.15	2017-11-16 13:00:24 -08:00
param.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00
perf_regs.h	License cleanup: add SPDX license identifier to uapi header files with no license	2017-11-02 11:19:54 +01:00
posix_types.h	License cleanup: add SPDX license identifier to uapi header files with no license	2017-11-02 11:19:54 +01:00
ptrace.h	arm64 updates for 4.15	2017-11-15 10:56:56 -08:00
setup.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00
sigcontext.h	arm64 updates for 4.15	2017-11-15 10:56:56 -08:00
siginfo.h	signal/arm64: Document conflicts with SI_USER and SIGFPE,SIGTRAP,SIGBUS	2018-01-12 14:21:05 -06:00
signal.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00
stat.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00
statfs.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00
ucontext.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00
unistd.h	License cleanup: add SPDX license identifier to uapi header files with a license	2017-11-02 11:20:11 +01:00