Fix the ABI change of the signal delivered on the access to the page

with insufficient protection mode.

For the i386 and amd64, create the tunable, machdep.prot_fault_translation,
with the following behaviour:
	0 = autodetect the signal to be delivered on KERN_PROTECTION_FAILURE
	    from vm_fault based on the ELF OSABI note:
		no note or __FreeBSD_version < 700004 - SIGBUS/BUS_PAGE_FAULT
		note, and __FreeBSD_version >= 700004 - SIGSEGV/SEGV_ACCERR
	1 = always SIGBUS/BUS_PAGE_FAULT
	2 = always SIGSEGV/SEGV_ACCERR

This would do mostly automatic correction of ABI breakage, with the exception
of the untaged binaries for 7-CURRENT/RELENG_7 before the note is fixed. For
them, sysctl would allow to run the binary with manual settings.

Discussed with:	portmgr (kris)
PR:		kern/118304
MFC after:	3 days

0 files changed, 0 insertions, 0 deletions