Re: stable/linux-3.16.y build: 178 builds: 1 failed, 177 passed, 2 errors, 57 warnings (v3.16.52)

[Arnd Bergmann]

On Tue, Jan 2, 2018 at 12:48 PM, kernelci.org bot <bot@xxxxxxxxxxxx> wrote:

Hi Ben,

almost a clean build with kernelci!

> Errors summary:
> 1 drivers/scsi/mpt2sas/mpt2sas_base.c:3550:1: internal compiler error: in extract_constrain_insn, at recog.c:2190
> 1 drivers/scsi/mpt2sas/mpt2sas_base.c:3550:1: error: insn does not satisfy its constraints:

See earlier discussion https://www.spinics.net/lists/stable/msg195996.html

> Warnings summary:
> 54 include/linux/stddef.h:8:14: warning: 'return' with a value, in function returning void

This comes from an incorrect backport of commit
49e67dd17649 ("of: fdt: add missing allocation-failure check")

It's harmless, and stable/linux-3.18.y has the correct version:

--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -380,6 +380,6 @@ static void __unflatten_device_tree(void *blob,
        /* Allocate memory for the expanded device tree */
        mem = dt_alloc(size + 4, __alignof__(struct device_node));
        if (!mem)
-               return NULL;
+               return;

        memset(mem, 0, size);


> 2 ipc/sem.c:377:6: warning: '___p1' may be used uninitialized in this function [-Wmaybe-uninitialized]

This code was last touched in 3.16 by the backport of commit
5864a2fd3088 ("ipc/sem.c: fix complex_count vs. simple op race")

The warning is in "smp_load_acquire(&sma->complex_mode))", and I suspect
that commit 27d7be1801a4 ("ipc/sem.c: avoid using spin_unlock_wait()")
avoided the warning upstream by removing the smp_mb() before it.

The code is way too complex for a fly-by analysis, so I'm adding Manfred
to Cc here. It may be worth comparing the full list of backports that
went into ipc/sem.c in 3.16.y with those in 3.18.y and 4.1.y that don't
have the warning. Here is what I see in the git history:

$ git log --oneline v3.16..stable/linux-3.16.y ipc/sem.c
accb9f16adba ipc/sem.c: fix complex_count vs. simple op race
5b11c133308b ipc: remove use of seq_printf return value
08397b1a5cd4 sysv, ipc: fix security-layer leaking
35cfc2b3a9da ipc/sem.c: fully initialize sem_array before making it visible
69a9a86b645f ipc/sem.c: update/correct memory barriers
30f995ba77ca ipc/sem.c: change memory barrier in sem_lock() to smp_rmb()
76ce4fe19d6b ipc,sem: fix use after free on IPC_RMID after a task
using same semaphore set exits

$ git log --oneline v3.16..stable/linux-3.18.y ipc/sem.c
7dd90826dfba sysv, ipc: fix security-layer leaking
ff12efa03da1 ipc/sem.c: update/correct memory barriers
38b50c47c25e ipc,sem: fix use after free on IPC_RMID after a task
using same semaphore set exits
e8577d1f0329 ipc/sem.c: fully initialize sem_array before making it visible

$ git log --oneline v3.16..stable/linux-4.1.y ipc/sem.c
e2b438fdfa4d sysv, ipc: fix security-layer leaking
b6805da60f01 ipc/sem.c: update/correct memory barriers
7be83cf01024 ipc,sem: fix use after free on IPC_RMID after a task
using same semaphore set exits
7f032d6ef615 ipc: remove use of seq_printf return value
52644c9ab3fa ipc,sem: use current->state helpers
2e094abfd1f2 ipc/sem.c: change memory barrier in sem_lock() to smp_rmb()
e8577d1f0329 ipc/sem.c: fully initialize sem_array before making it visible

$ git log --oneline v3.16..stable/linux-4.4.y ipc/sem.c
f6031d95320d ipc/sem.c: fix complex_count vs. simple op race
62659f0b9ed7 sysv, ipc: fix security-layer leaking
3ed1f8a99d70 ipc/sem.c: update/correct memory barriers
a97955844807 ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()
602b8593d2b4 ipc,sem: fix use after free on IPC_RMID after a task
using same semaphore set exits
55b7ae50167e ipc: rename ipc_obtain_object
7f032d6ef615 ipc: remove use of seq_printf return value
52644c9ab3fa ipc,sem: use current->state helpers
2e094abfd1f2 ipc/sem.c: change memory barrier in sem_lock() to smp_rmb()
e8577d1f0329 ipc/sem.c: fully initialize sem_array before making it visible

$ git log --oneline v3.16..stable/linux-4.9.y ipc/sem.c
2a1613a586de ipc/sem.c: add cond_resched in exit_sme
5864a2fd3088 ipc/sem.c: fix complex_count vs. simple op race
9b24fef9f041 sysv, ipc: fix security-layer leaking
be3e78449803 locking/spinlock: Update spin_unlock_wait() users
33ac279677dc locking/barriers: Introduce smp_acquire__after_ctrl_dep()
a5f4db877177 ipc/sem: make semctl setting sempid consistent
1d5cfdb07628 tree wide: use kvfree() than conditional kfree()/vfree()
3ed1f8a99d70 ipc/sem.c: update/correct memory barriers
a97955844807 ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()
602b8593d2b4 ipc,sem: fix use after free on IPC_RMID after a task
using same semaphore set exits
55b7ae50167e ipc: rename ipc_obtain_object
7f032d6ef615 ipc: remove use of seq_printf return value
52644c9ab3fa ipc,sem: use current->state helpers
2e094abfd1f2 ipc/sem.c: change memory barrier in sem_lock() to smp_rmb()
e8577d1f0329 ipc/sem.c: fully initialize sem_array before making it visible

> 1 arch/arm/kernel/head-nommu.S:167: Warning: Use of r13 as a source register is deprecated when r15 is the destination register.

Fixed by backporting:

970d96f9a81b ("ARM: 8383/1: nommu: avoid deprecated source register on mov")

     Arnd