mirror_ubuntu-kernels/arch/x86
Eric W. Biederman add0b32ef9 siginfo: Move si_trapno inside the union inside _si_fault
It turns out that linux uses si_trapno very sparingly, and as such it
can be considered extra information for a very narrow selection of
signals, rather than information that is present with every fault
reported in siginfo.

As such move si_trapno inside the union inside of _si_fault.  This
results in no change in placement, and makes it eaiser
to extend _si_fault in the future as this reduces the number of
special cases.  In particular with si_trapno included in the union it
is no longer a concern that the union must be pointer aligned on most
architectures because the union follows immediately after si_addr
which is a pointer.

This change results in a difference in siginfo field placement on
sparc and alpha for the fields si_addr_lsb, si_lower, si_upper,
si_pkey, and si_perf.  These architectures do not implement the
signals that would use si_addr_lsb, si_lower, si_upper, si_pkey, and
si_perf.  Further these architecture have not yet implemented the
userspace that would use si_perf.

The point of this change is in fact to correct these placement issues
before sparc or alpha grow userspace that cares.  This change was
discussed[1] and the agreement is that this change is currently safe.

[1]: https://lkml.kernel.org/r/CAK8P3a0+uKYwL1NhY6Hvtieghba2hKYGD6hcKx5n8=4Gtt+pHA@mail.gmail.com
Acked-by: Marco Elver <elver@google.com>
v1: https://lkml.kernel.org/r/m1tunns7yf.fsf_-_@fess.ebiederm.org
v2: https://lkml.kernel.org/r/20210505141101.11519-5-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20210517195748.8880-1-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-05-18 16:17:03 -05:00
..
boot - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
configs module: remove EXPORT_UNUSED_SYMBOL* 2021-02-08 12:28:07 +01:00
crypto Objtool updates in this cycle were: 2021-04-28 12:53:24 -07:00
entry - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
events Perf events changes in this cycle were: 2021-04-28 13:03:44 -07:00
hyperv hyperv-next for 5.13 2021-04-26 10:44:16 -07:00
ia32 x86/ia32_signal: Propagate __user annotation properly 2020-12-11 19:44:31 +01:00
include Perf events changes in this cycle were: 2021-04-28 13:03:44 -07:00
kernel siginfo: Move si_trapno inside the union inside _si_fault 2021-05-18 16:17:03 -05:00
kvm Merge branch 'for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2021-04-27 18:47:42 -07:00
lib - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
math-emu x86/fpu/math-emu: Fix function cast warning 2021-03-23 00:08:02 +01:00
mm Trivial cleanups and fixes all over the place. 2021-04-26 09:25:47 -07:00
net - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
pci x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
platform - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
power - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
purgatory crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
ras
realmode x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
tools x86/tools/insn_sanity: Convert to insn_decode() 2021-03-15 12:21:11 +01:00
um um: remove process stub VMA 2021-02-12 21:37:38 +01:00
video
xen - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
.gitignore
Kbuild
Kconfig - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
Kconfig.assembler
Kconfig.cpu
Kconfig.debug x86, libnvdimm/test: Remove COPY_MC_TEST 2020-10-26 18:08:35 +01:00
Makefile - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
Makefile_32.cpu
Makefile.um