[ANNOUNCE] v5.0.5-rt3

From: Sebastian Andrzej Siewior
Date: Thu Mar 28 2019 - 18:17:44 EST


Dear RT folks!

I'm pleased to announce the v5.0.5-rt3 patch set.

Changes since v5.0.5-rt2:

- Multiple fixes for build failures introduced by the printk series.
Reported by the kbuild test robot, patched by John Ogness.

- Various powerpc fixes:
- Reorder TIF bits so the assembly code compiles. Reported by kbuild
test robot.

- Avoid acquiring a sleeping lock during the bring of the secondary
CPU.

- Use a local_lock instead of disabling interrupts as protection in
pseries' iommu code.

- Turn show_lock into raw_lock which is used during a sysrq request in
ARM64. Patch by Julien Grall.

Known issues
- A warning triggered in "rcu_note_context_switch" originated from
SyS_timer_gettime(). The issue was always there, it is now
visible. Reported by Grygorii Strashko and Daniel Wagner.

- rcutorture is currently broken on -RT. Reported by Juri Lelli.

The delta patch against v5.0.5-rt2 is appended below and can be found here:

https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.0/incr/patch-5.0.5-rt2-rt3.patch.xz

You can get this release via the git tree at:

git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git v5.0.5-rt3

The RT patch against v5.0.5 can be found here:

https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.0/older/patch-5.0.5-rt3.patch.xz

The split quilt queue is available at:

https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.0/older/patches-5.0.5-rt3.tar.xz

Sebastian

diff --git a/arch/powerpc/include/asm/stackprotector.h b/arch/powerpc/include/asm/stackprotector.h
index 1c8460e235838..e764eb4b6c284 100644
--- a/arch/powerpc/include/asm/stackprotector.h
+++ b/arch/powerpc/include/asm/stackprotector.h
@@ -24,7 +24,11 @@ static __always_inline void boot_init_stack_canary(void)
unsigned long canary;

/* Try to get a semi random initial value. */
+#ifdef CONFIG_PREEMPT_RT_FULL
+ canary = (unsigned long)&canary;
+#else
canary = get_random_canary();
+#endif
canary ^= mftb();
canary ^= LINUX_VERSION_CODE;
canary &= CANARY_MASK;
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 7e542e729f131..f9132398566d9 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -90,7 +90,7 @@ void arch_setup_new_exec(void);
/*
* thread information flag bit numbers
*/
-#define TIF_NEED_RESCHED_LAZY 0 /* lazy rescheduling necessary */
+#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_SIGPENDING 1 /* signal pending */
#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
#define TIF_FSCHECK 3 /* Check FS is USER_DS on return */
@@ -101,11 +101,12 @@ void arch_setup_new_exec(void);
#define TIF_SINGLESTEP 8 /* singlestepping active */
#define TIF_NOHZ 9 /* in adaptive nohz mode */
#define TIF_SECCOMP 10 /* secure computing */
-#define TIF_RESTOREALL 11 /* Restore all regs (implies NOERROR) */
-#define TIF_NOERROR 12 /* Force successful syscall return */
+
+#define TIF_NEED_RESCHED_LAZY 11 /* lazy rescheduling necessary */
+#define TIF_SYSCALL_TRACEPOINT 12 /* syscall tracepoint instrumentation */
+
#define TIF_NOTIFY_RESUME 13 /* callback before returning to user */
#define TIF_UPROBE 14 /* breakpointed or single-stepping */
-#define TIF_SYSCALL_TRACEPOINT 15 /* syscall tracepoint instrumentation */
#define TIF_EMULATE_STACK_STORE 16 /* Is an instruction emulation
for stack store? */
#define TIF_MEMDIE 17 /* is terminating due to OOM killer */
@@ -114,7 +115,9 @@ void arch_setup_new_exec(void);
#endif
#define TIF_POLLING_NRFLAG 19 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_32BIT 20 /* 32 bit binary */
-#define TIF_SYSCALL_TRACE 21 /* syscall trace active */
+#define TIF_RESTOREALL 21 /* Restore all regs (implies NOERROR) */
+#define TIF_NOERROR 22 /* Force successful syscall return */
+

/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 553e1ad981c30..1b6c95d49cd23 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -393,7 +393,9 @@ _GLOBAL(DoSyscall)
MTMSRD(r10)
lwz r9,TI_FLAGS(r12)
li r8,-MAX_ERRNO
- andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
+ lis r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@h
+ ori r0,r0, (_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@l
+ and. r0,r9,r0
bne- syscall_exit_work
cmplw 0,r3,r8
blt+ syscall_exit_cont
@@ -511,13 +513,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
b syscall_dotrace_cont

syscall_exit_work:
- andi. r0,r9,_TIF_RESTOREALL
+ andis. r0,r9,_TIF_RESTOREALL@h
beq+ 0f
REST_NVGPRS(r1)
b 2f
0: cmplw 0,r3,r8
blt+ 1f
- andi. r0,r9,_TIF_NOERROR
+ andis. r0,r9,_TIF_NOERROR@h
bne- 1f
lwz r11,_CCR(r1) /* Load CR */
neg r3,r3
@@ -526,12 +528,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)

1: stw r6,RESULT(r1) /* Save result */
stw r3,GPR3(r1) /* Update return value */
-2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
+2: andis. r0,r9,(_TIF_PERSYSCALL_MASK)@h
beq 4f

/* Clear per-syscall TIF flags if any are set. */

- li r11,_TIF_PERSYSCALL_MASK
+ lis r11,_TIF_PERSYSCALL_MASK@h
addi r12,r12,TI_FLAGS
3: lwarx r8,0,r12
andc r8,r8,r11
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index fcf8fe69beb51..d857823e25b2f 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -253,7 +253,9 @@ system_call: /* label this so stack traces look sane */

ld r9,TI_FLAGS(r12)
li r11,-MAX_ERRNO
- andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
+ lis r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@h
+ ori r0,r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@l
+ and. r0,r9,r0
bne- .Lsyscall_exit_work

andi. r0,r8,MSR_FP
@@ -370,25 +372,25 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
/* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr.
If TIF_NOERROR is set, just save r3 as it is. */

- andi. r0,r9,_TIF_RESTOREALL
+ andis. r0,r9,_TIF_RESTOREALL@h
beq+ 0f
REST_NVGPRS(r1)
b 2f
0: cmpld r3,r11 /* r11 is -MAX_ERRNO */
blt+ 1f
- andi. r0,r9,_TIF_NOERROR
+ andis. r0,r9,_TIF_NOERROR@h
bne- 1f
ld r5,_CCR(r1)
neg r3,r3
oris r5,r5,0x1000 /* Set SO bit in CR */
std r5,_CCR(r1)
1: std r3,GPR3(r1)
-2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
+2: andis. r0,r9,(_TIF_PERSYSCALL_MASK)@h
beq 4f

/* Clear per-syscall TIF flags if any are set. */

- li r11,_TIF_PERSYSCALL_MASK
+ lis r11,(_TIF_PERSYSCALL_MASK)@h
addi r12,r12,TI_FLAGS
3: ldarx r10,0,r12
andc r10,r10,r11
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 7a1de34f38c85..314be8e39d1fd 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -174,7 +174,6 @@ extern void panic_flush_kmsg_start(void)

extern void panic_flush_kmsg_end(void)
{
- printk_safe_flush_on_panic();
kmsg_dump(KMSG_DUMP_PANIC);
bust_spinlocks(0);
debug_locks_off();
diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c
index 3c6ab22a0c4e3..bf98181c5b309 100644
--- a/arch/powerpc/kernel/watchdog.c
+++ b/arch/powerpc/kernel/watchdog.c
@@ -181,11 +181,6 @@ static void watchdog_smp_panic(int cpu, u64 tb)

wd_smp_unlock(&flags);

- printk_safe_flush();
- /*
- * printk_safe_flush() seems to require another print
- * before anything actually goes out to console.
- */
if (sysctl_hardlockup_all_cpu_backtrace)
trigger_allbutself_cpu_backtrace();

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 8fc8fe0b98485..14ecedbd8ff12 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -38,6 +38,7 @@
#include <linux/of.h>
#include <linux/iommu.h>
#include <linux/rculist.h>
+#include <linux/locallock.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/rtas.h>
@@ -191,6 +192,7 @@ static int tce_build_pSeriesLP(struct iommu_table *tbl, long tcenum,
}

static DEFINE_PER_CPU(__be64 *, tce_page);
+static DEFINE_LOCAL_IRQ_LOCK(tcp_page_lock);

static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
long npages, unsigned long uaddr,
@@ -211,7 +213,8 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
direction, attrs);
}

- local_irq_save(flags); /* to protect tcep and the page behind it */
+ /* to protect tcep and the page behind it */
+ local_lock_irqsave(tcp_page_lock, flags);

tcep = __this_cpu_read(tce_page);

@@ -222,7 +225,7 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
tcep = (__be64 *)__get_free_page(GFP_ATOMIC);
/* If allocation fails, fall back to the loop implementation */
if (!tcep) {
- local_irq_restore(flags);
+ local_unlock_irqrestore(tcp_page_lock, flags);
return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
direction, attrs);
}
@@ -256,7 +259,7 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
tcenum += limit;
} while (npages > 0 && !rc);

- local_irq_restore(flags);
+ local_unlock_irqrestore(tcp_page_lock, flags);

if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) {
ret = (int)rc;
@@ -414,13 +417,14 @@ static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn,
u64 rc = 0;
long l, limit;

- local_irq_disable(); /* to protect tcep and the page behind it */
+ /* to protect tcep and the page behind it */
+ local_lock_irq(tcp_page_lock);
tcep = __this_cpu_read(tce_page);

if (!tcep) {
tcep = (__be64 *)__get_free_page(GFP_ATOMIC);
if (!tcep) {
- local_irq_enable();
+ local_unlock_irq(tcp_page_lock);
return -ENOMEM;
}
__this_cpu_write(tce_page, tcep);
@@ -466,7 +470,7 @@ static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn,

/* error cleanup: caller will clear whole range */

- local_irq_enable();
+ local_unlock_irq(tcp_page_lock);
return rc;
}

diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index 1f03078ec3527..8473557c7ab2a 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -208,7 +208,7 @@ static struct sysrq_key_op sysrq_showlocks_op = {
#endif

#ifdef CONFIG_SMP
-static DEFINE_SPINLOCK(show_lock);
+static DEFINE_RAW_SPINLOCK(show_lock);

static void showacpu(void *dummy)
{
@@ -218,10 +218,10 @@ static void showacpu(void *dummy)
if (idle_cpu(smp_processor_id()))
return;

- spin_lock_irqsave(&show_lock, flags);
+ raw_spin_lock_irqsave(&show_lock, flags);
pr_info("CPU%d:\n", smp_processor_id());
show_stack(NULL, NULL);
- spin_unlock_irqrestore(&show_lock, flags);
+ raw_spin_unlock_irqrestore(&show_lock, flags);
}

static void sysrq_showregs_othercpus(struct work_struct *dummy)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 5cfd8ea445362..997d07b6bf975 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -370,6 +370,18 @@ static u64 clear_seq;
#define LOG_LEVEL(v) ((v) & 0x07)
#define LOG_FACILITY(v) ((v) >> 3 & 0xff)

+/* Return log buffer address */
+char *log_buf_addr_get(void)
+{
+ return printk_rb.buffer;
+}
+
+/* Return log buffer size */
+u32 log_buf_len_get(void)
+{
+ return (1 << printk_rb.size_bits);
+}
+
/* human readable text of the record */
static char *log_text(const struct printk_log *msg)
{
@@ -1910,7 +1922,7 @@ asmlinkage int vprintk_emit(int facility, int level,
}
EXPORT_SYMBOL(vprintk_emit);

-__printf(1, 0) int vprintk_func(const char *fmt, va_list args)
+static __printf(1, 0) int vprintk_func(const char *fmt, va_list args)
{
return vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args);
}
@@ -2684,7 +2696,7 @@ static int __init init_printk_kthread(void)
}
late_initcall(init_printk_kthread);

-int vprintk_deferred(const char *fmt, va_list args)
+static int vprintk_deferred(const char *fmt, va_list args)
{
return vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args);
}
diff --git a/lib/printk_ringbuffer.c b/lib/printk_ringbuffer.c
index ce33b5add5a17..9a31d7dbdc005 100644
--- a/lib/printk_ringbuffer.c
+++ b/lib/printk_ringbuffer.c
@@ -196,8 +196,14 @@ void prb_commit(struct prb_handle *h)

if (changed) {
atomic_long_inc(&rb->wq_counter);
- if (wq_has_sleeper(rb->wq))
+ if (wq_has_sleeper(rb->wq)) {
+#ifdef CONFIG_IRQ_WORK
irq_work_queue(rb->wq_work);
+#else
+ if (!in_nmi())
+ wake_up_interruptible_all(rb->wq);
+#endif
+ }
}
}

diff --git a/localversion-rt b/localversion-rt
index c3054d08a1129..1445cd65885cd 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt2
+-rt3