Comment 0 for bug 1499838

strace shows you what is going on. The relevant code is in libfreeipmi/locate/ipmi-locate-dmidecode.c, where it is trolling through /dev/mem.

ubuntu@cvm1:~$ dmesg
ubuntu@cvm1:~$ sudo strace -f ipmi-locate
execve("/usr/sbin/ipmi-locate", ["ipmi-locate"], [/* 14 vars */]) = 0
brk(0) = 0xffffaea81000
faccessat(AT_FDCWD, "/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffff8a7ca000
faccessat(AT_FDCWD, "/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=39330, ...}) = 0
mmap(NULL, 39330, PROT_READ, MAP_PRIVATE, 3, 0) = 0xffff8a7c0000
close(3) = 0
faccessat(AT_FDCWD, "/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/libfreeipmi.so.12", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0\267\0\1\0\0\0\200\361\21\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=4443888, ...}) = 0
mmap(NULL, 4507696, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xffff8a356000
mprotect(0xffff8a5eb000, 65536, PROT_NONE) = 0
mmap(0xffff8a5fb000, 1736704, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x295000) = 0xffff8a5fb000
close(3) = 0
faccessat(AT_FDCWD, "/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/aarch64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0\267\0\1\0\0\0\250\16\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1275592, ...}) = 0
mmap(NULL, 1348480, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xffff8a20c000
mprotect(0xffff8a33d000, 61440, PROT_NONE) = 0
mmap(0xffff8a34c000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x130000) = 0xffff8a34c000
mmap(0xffff8a352000, 13184, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xffff8a352000
close(3) = 0
faccessat(AT_FDCWD, "/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/aarch64-linux-gnu/libgcrypt.so.11", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0\267\0\1\0\0\0\300~\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=474496, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffff8a7bf000
mmap(NULL, 473688, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xffff8a198000
mmap(0xffff8a208000, 16384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x70000) = 0xffff8a208000
close(3) = 0
faccessat(AT_FDCWD, "/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/aarch64-linux-gnu/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0\267\0\1\0\0\0\240R\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=588696, ...}) = 0
mmap(NULL, 651944, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xffff8a0f8000
mprotect(0xffff8a187000, 61440, PROT_NONE) = 0
mmap(0xffff8a196000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x8e000) = 0xffff8a196000
close(3) = 0
faccessat(AT_FDCWD, "/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/aarch64-linux-gnu/libgpg-error.so.0", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0\267\0\1\0\0\0\0\n\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=18312, ...}) = 0
mmap(NULL, 82008, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xffff8a0e3000
mprotect(0xffff8a0e6000, 65536, PROT_NONE) = 0
mmap(0xffff8a0f6000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0xffff8a0f6000
close(3) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffff8a7be000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffff8a0e2000
mprotect(0xffff8a34c000, 16384, PROT_READ) = 0
mprotect(0xffff8a0f6000, 4096, PROT_READ) = 0
mprotect(0xffff8a196000, 4096, PROT_READ) = 0
mprotect(0xffff8a208000, 4096, PROT_READ) = 0
mprotect(0xffff8a5fb000, 339968, PROT_READ) = 0
mprotect(0xffff8a7e4000, 4096, PROT_READ) = 0
mprotect(0xffff8a7ce000, 4096, PROT_READ) = 0
munmap(0xffff8a7c0000, 39330) = 0
brk(0) = 0xffffaea81000
brk(0xffffaeaa2000) = 0xffffaeaa2000
getrlimit(RLIMIT_CORE, {rlim_cur=0, rlim_max=RLIM64_INFINITY}) = 0
setrlimit(RLIMIT_CORE, {rlim_cur=0, rlim_max=RLIM64_INFINITY}) = 0
getuid() = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0
mmap(NULL, 65536, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffff8a0d2000
openat(AT_FDCWD, "/proc/efi/systab", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/sys/firmware/efi/systab", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0400, st_size=4096, ...}) = 0
mmap(NULL, 65536, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffff8a0c2000
read(3, "ACPI20=0xffea16000\n", 4096) = 19
read(3, "", 4096) = 0
close(3) = 0
munmap(0xffff8a0c2000, 65536) = 0
write(1, "Probing KCS device using DMIDECO"..., 45Probing KCS device using DMIDECODE... FAILED
) = 45
write(1, "\n", 1
) = 1
openat(AT_FDCWD, "/proc/efi/systab", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/sys/firmware/efi/systab", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0400, st_size=4096, ...}) = 0
mmap(NULL, 65536, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffff8a0c2000
read(3, "ACPI20=0xffea16000\n", 4096) = 19
read(3, "", 4096) = 0
close(3) = 0
munmap(0xffff8a0c2000, 65536) = 0
write(1, "Probing SMIC device using DMIDEC"..., 46Probing SMIC device using DMIDECODE... FAILED
) = 46
write(1, "\n", 1
) = 1
openat(AT_FDCWD, "/proc/efi/systab", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/sys/firmware/efi/systab", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0400, st_size=4096, ...}) = 0
mmap(NULL, 65536, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffff8a0c2000
read(3, "ACPI20=0xffea16000\n", 4096) = 19
read(3, "", 4096) = 0
close(3) = 0
munmap(0xffff8a0c2000, 65536) = 0
write(1, "Probing BT device using DMIDECOD"..., 44Probing BT device using DMIDECODE... FAILED
) = 44
write(1, "\n", 1
) = 1
openat(AT_FDCWD, "/proc/efi/systab", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/sys/firmware/efi/systab", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0400, st_size=4096, ...}) = 0
mmap(NULL, 65536, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffff8a0c2000
read(3, "ACPI20=0xffea16000\n", 4096) = 19
read(3, "", 4096) = 0
close(3) = 0
munmap(0xffff8a0c2000, 65536) = 0
write(1, "Probing SSIF device using DMIDEC"..., 46Probing SSIF device using DMIDECODE... FAILED
) = 46
write(1, "\n", 1
) = 1
openat(AT_FDCWD, "/dev/mem", O_RDONLY|O_SYNC) = 3
mmap(NULL, 65536, PROT_READ, MAP_PRIVATE, 3, 0xf0000) = 0xffff8a0c2000
close(3) = 0
--- SIGBUS {si_signo=SIGBUS, si_code=SI_USER, si_pid=18446744071730634752, si_uid=65535} ---
+++ killed by SIGBUS (core dumped) +++
ubuntu@cvm1:~$ dmesg
[61820.238001] Unhandled fault: synchronous external abort (0x92000210) at 0x0000ffff8a0c2000
ubuntu@cvm1:~$