SIGBUS si_code 12

[Paul Floyd]

A bit more on this.

The code in question is in trap.c:

			if (signo == SIGSEGV) {
				ucode = SEGV_MAPERR;
			} else if (prot_fault_translation == 0) {
				/*
				 * Autodetect.  This check also covers
				 * the images without the ABI-tag ELF
				 * note.
				 */
				if (SV_CURPROC_ABI() == SV_ABI_FREEBSD &&
				    p->p_osrel >= P_OSREL_SIGSEGV) {
					signo = SIGSEGV;
					ucode = SEGV_ACCERR;
				} else {
					signo = SIGBUS;
					ucode = T_PAGEFLT;
				}
			} else if (prot_fault_translation == 1) {
				/*
				 * Always compat mode.
				 */
				signo = SIGBUS;
				ucode = T_PAGEFLT;
			} else {
				/*
				 * Always SIGSEGV mode.
				 */
				signo = SIGSEGV;
				ucode = SEGV_ACCERR;
			}


I have machte.prot_fault_translation set to 0 (the default I believe) so this enters the first ‘else if’ branch.

The value of p_osrel looks like it comes from retold.c. I see two mechanisms - passed via auxv AT_OSRELDATE (with a backup of using a sysctl) and reading the NT_FREEBSD_ABI_TAG note - I’m not sure which is used in this case.

The auxv value seems to be sent and I can’t see why either should be failing.

A+
Paul