https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77964
Bug ID: 77964
Summary: [7 Regression] Linux kernel firmware loader
miscompiled
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: trippels at gcc dot gnu.org
Target Milestone: ---
Created attachment 39803
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39803&action=edit
unreduced testcase
A Linux kernel build with gcc trunk crashes early during boot.
It happens during loading of builtin firmware.
RIP points to strcmp() in fw_get_builtin_firmware() on a bogus address.
markus@x4 linux % scripts/faddr2line ./vmlinux _request_firmware+0xa8
_request_firmware+0xa8/0xff:
fw_get_builtin_firmware at drivers/base/firmware_class.c:55
(inlined by) _request_firmware_prepare at drivers/base/firmware_class.c:1066
(inlined by) _request_firmware at drivers/base/firmware_class.c:1149
drivers/base/firmware_class.c:
49 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
50 void *buf, size_t size)
51 {
52 struct builtin_fw *b_fw;
53
54 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
{
55 if (strcmp(name, b_fw->name) == 0) {
56 fw->size = b_fw->size;
57 fw->data = b_fw->data;
58
59 if (buf && fw->size <= size)
60 memcpy(buf, fw->data, fw->size);
61 return true;
62 }
63 }
64
65 return false;
66 }
I have attached the firmware_class.i file.
The kernel crashes for -O1 -O2 and -Os. Strangely -O3 is fine.
Haven't looked deeper yet, but maybe someone sees what is going on?
