I enabled the undefined behavior sanitizer, and built Linusâ master branch under Ubuntu 17.10 with gcc (Ubuntu 7.2.0-8ubuntu3) 7.2.0.
```
$ grep UBSAN /boot/config-4.15.0-rc3+
CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL=y
# CONFIG_ARCH_WANTS_UBSAN_NO_NULL is not set
CONFIG_UBSAN=y
CONFIG_UBSAN_SANITIZE_ALL=y
# CONFIG_UBSAN_ALIGNMENT is not set
CONFIG_UBSAN_NULL=y
```
Starting the system the messages below are printed.
```
[ÂÂÂ 0.758899] ================================================================================
[ÂÂÂ 0.758960] UBSAN: Undefined behaviour in drivers/acpi/sysfs.c:849:33
[ÂÂÂ 0.759008] shift exponent 64 is too large for 64-bit type 'long long unsigned int'
[ÂÂÂ 0.759064] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc3+ #12
[ÂÂÂ 0.759076] Hardware name: Notebook N24_25BU/N24_25BU, BIOS 5.12 07/07/2017
[ÂÂÂ 0.759088] Call Trace:
[ÂÂÂ 0.759118]Â ? ftrace_graph_caller+0x98/0x98
[ÂÂÂ 0.759133]Â dump_stack+0x70/0xae
[ÂÂÂ 0.759167]Â ubsan_epilogue+0x9/0x40
[ÂÂÂ 0.759188]Â __ubsan_handle_shift_out_of_bounds+0x12b/0x170
[ÂÂÂ 0.759214]Â ? ftrace_graph_caller+0x68/0x98
[ÂÂÂ 0.759293]Â ? acpi_gpe_apply_masked_gpes+0x50/0xa9
[ÂÂÂ 0.759314]Â acpi_gpe_apply_masked_gpes+0x50/0xa9
[ÂÂÂ 0.759348]Â ? ftrace_graph_caller+0x98/0x98
[ÂÂÂ 0.759363]Â acpi_scan_init+0x145/0x2e4
[ÂÂÂ 0.759385]Â ? acpi_sleep_proc_init+0x24/0x24
[ÂÂÂ 0.759413]Â ? acpi_sleep_proc_init+0x24/0x24
[ÂÂÂ 0.759429]Â ? ftrace_graph_caller+0x98/0x98
[ÂÂÂ 0.759444]Â acpi_init+0x340/0x3a0
[ÂÂÂ 0.759500]Â ? ftrace_graph_caller+0x98/0x98
[ÂÂÂ 0.759515]Â do_one_initcall+0x173/0x200
[ÂÂÂ 0.759553]Â ? acpi_sleep_proc_init+0x24/0x24
[ÂÂÂ 0.759573]Â ? do_one_initcall+0x5/0x200
[ÂÂÂ 0.759612]Â ? ftrace_graph_caller+0x98/0x98
[ÂÂÂ 0.759628]Â kernel_init_freeable+0x305/0x395
[ÂÂÂ 0.759653]Â ? rest_init+0xd0/0xd0
[ÂÂÂ 0.759689]Â kernel_init+0xb/0x119
[ÂÂÂ 0.759705]Â ? rest_init+0xd0/0xd0
[ÂÂÂ 0.759721]Â ret_from_fork+0x1f/0x30
[ÂÂÂ 0.759815] ================================================================================
```
Please tell me, if you need anything else to address this.
Attachment:
smime.p7s
Description: S/MIME Cryptographic Signature