https://github.com/ClangBuiltLinux/linux/issues/1566

mc-request.i

typedef unsigned short __u16;
typedef __u16 u16;
enum { false, true };
typedef _Bool bool;
typedef struct qspinlock {
        struct {
                struct {
                        u16 tail;
                };
        };
} arch_spinlock_t;
typedef struct raw_spinlock {
        arch_spinlock_t raw_lock;
} raw_spinlock_t;
typedef struct spinlock {
        struct {
                struct raw_spinlock rlock;
        };
} spinlock_t;
struct bug_entry {};
void __attribute__(())
_raw_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags);
static inline __attribute__(()) __attribute__(()) __attribute__(())
__attribute__(()) void
spin_unlock_irqrestore(spinlock_t *lock)
{
        do
                _raw_spin_unlock_irqrestore(&lock->rlock, 0);

        while (0);
}
struct wait_queue_head {
        spinlock_t lock;
};
typedef struct wait_queue_head wait_queue_head_t;
typedef struct refcount_struct {
} refcount_t;
struct kref {
        refcount_t refcount;
};
static inline __attribute__(()) __attribute__(()) __attribute__(()) int
kref_put(struct kref *kref, void (*release)())
{
        if (refcount_dec_and_test(&kref->refcount))
                release(kref);
}
enum media_request_state {
        MEDIA_REQUEST_STATE_QUEUED,
};
struct media_request {
        struct media_device *mdev;
        struct kref kref;
        enum media_request_state state;
        unsigned int num_incomplete_objects;
        wait_queue_head_t poll_wait;
        spinlock_t lock;
};
struct media_request_object {
        struct media_request req;
};
extern void media_request_release();
struct media_request_object *media_request_object_complete_obj;
void media_request_object_complete(void)
{
        struct media_request *req = &media_request_object_complete_obj->req;

        bool completed = false;
        if (({
                    int __ret_warn_on = !!(!req->num_incomplete_objects);
                    if (__builtin_expect(!!(__ret_warn_on), 0))
                            do {
                                    asm(".byte 0x0f, 0x0b");
                                    asm(".Lreachable%=:\n\t"
                                        ".pushsection .discard.reachable\n\t"
                                        ".long .Lreachable%= - .\n\t"
                                        ".popsection\n\t" ::
                                                : "memory");
                            } while (0);
                    __builtin_expect(!!(__ret_warn_on), 0);
            }) ||
            ({
                    int __ret_warn_on =
                            !!(req->state != MEDIA_REQUEST_STATE_QUEUED);
                    if (__builtin_expect(!!(__ret_warn_on), 0))
                            do {
                                    asm(".byte 0x0f, 0x0b" ::"i"(
                                            sizeof(struct bug_entry)));
                                    asm(".Lreachable%=:\n\t"
                                        ".pushsection .discard.reachable\n\t"
                                        ".long .Lreachable%= - .\n\t"
                                        ".popsection\n\t" ::
                                                : "memory");
                            } while (0);
                    __builtin_expect(!!(__ret_warn_on), 0);
            }))
                goto unlock;
        if (!--req->num_incomplete_objects) {
                __wake_up(&req->poll_wait, 0x0001, 0, 0);
                completed = true;
        }
unlock:
        spin_unlock_irqrestore(&req->lock);
        if (completed)
                kref_put(&req->kref, media_request_release);
}

mc-request.s

        .file   "mc-request.i"
        .text
        .p2align 4
        .globl  media_request_object_complete
        .type   media_request_object_complete, @function
media_request_object_complete:
.LFB2:
        .cfi_startproc
        pushq   %rbp
        .cfi_def_cfa_offset 16
        .cfi_offset 6, -16
        pushq   %rbx
        .cfi_def_cfa_offset 24
        .cfi_offset 3, -24
        subq    $8, %rsp
        .cfi_def_cfa_offset 32
        movq    media_request_object_complete_obj(%rip), %rbx
        movl    12(%rbx), %eax
        leaq    18(%rbx), %rbp
        testl   %eax, %eax
        je      .L16
        movl    8(%rbx), %edx
        testl   %edx, %edx
        jne     .L17
        subl    $1, %eax
        movl    %eax, 12(%rbx)
        je      .L18
        addq    $8, %rsp
        .cfi_remember_state
        .cfi_def_cfa_offset 24
        movq    %rbp, %rdi
        xorl    %esi, %esi
        popq    %rbx
        .cfi_def_cfa_offset 16
        popq    %rbp
        .cfi_def_cfa_offset 8
        jmp     _raw_spin_unlock_irqrestore
        .p2align 4,,10
        .p2align 3
.L18:
        .cfi_restore_state
        xorl    %ecx, %ecx
        xorl    %edx, %edx
        leaq    16(%rbx), %rdi
        movl    $1, %esi
        xorl    %eax, %eax
        call    __wake_up
        movq    %rbp, %rdi
        xorl    %esi, %esi
        leaq    8(%rbx), %rbp
        call    _raw_spin_unlock_irqrestore
        xorl    %eax, %eax
        movq    %rbp, %rdi
        call    refcount_dec_and_test
        testl   %eax, %eax
        je      .L19
        addq    $8, %rsp
        .cfi_remember_state
        .cfi_def_cfa_offset 24
        movq    %rbp, %rdi
        xorl    %eax, %eax
        popq    %rbx
        .cfi_def_cfa_offset 16
        popq    %rbp
        .cfi_def_cfa_offset 8
        jmp     media_request_release
        .p2align 4,,10
        .p2align 3
.L19:
        .cfi_restore_state
        addq    $8, %rsp
        .cfi_remember_state
        .cfi_def_cfa_offset 24
        popq    %rbx
        .cfi_def_cfa_offset 16
        popq    %rbp
        .cfi_def_cfa_offset 8
        ret
        .p2align 4,,10
        .p2align 3
.L16:
        .cfi_restore_state
#APP
# 72 "mc-request.i" 1
        .byte 0x0f, 0x0b
# 0 "" 2
#NO_APP
.L13:
#APP
# 88 "mc-request.i" 1
        .Lreachable90:
        .pushsection .discard.reachable
        .long .Lreachable90 - .
        .popsection

# 0 "" 2
#NO_APP
        addq    $8, %rsp
        .cfi_remember_state
        .cfi_def_cfa_offset 24
        movq    %rbp, %rdi
        xorl    %esi, %esi
        popq    %rbx
        .cfi_def_cfa_offset 16
        popq    %rbp
        .cfi_def_cfa_offset 8
        jmp     _raw_spin_unlock_irqrestore
        .p2align 4,,10
        .p2align 3
.L17:
        .cfi_restore_state
#APP
# 86 "mc-request.i" 1
        .byte 0x0f, 0x0b
# 0 "" 2
#NO_APP
        jmp     .L13
        .cfi_endproc
.LFE2:
        .size   media_request_object_complete, .-media_request_object_complete
        .globl  media_request_object_complete_obj
        .bss
        .align 8
        .type   media_request_object_complete_obj, @object
        .size   media_request_object_complete_obj, 8
media_request_object_complete_obj:
        .zero   8
        .ident  "GCC: (Debian 11.2.0-12) 11.2.0"
        .section        .note.GNU-stack,"",@progbits

repro.sh

gcc -fno-PIE -O2 -c -o mc-request.o mc-request.i -w
tools/objtool/objtool orc generate --module  --no-fp   --retpoline  --uaccess  mc-request.o