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-rw-r--r--arch/powerpc/include/asm/atomic.h2
-rw-r--r--arch/powerpc/include/asm/dtl.h52
-rw-r--r--arch/powerpc/include/asm/lppaca.h44
-rw-r--r--arch/powerpc/include/asm/paca.h2
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S14
-rw-r--r--arch/powerpc/kernel/time.c2
-rw-r--r--arch/powerpc/kvm/book3s_hv.c1
-rw-r--r--arch/powerpc/mm/book3s64/hash_utils.c25
-rw-r--r--arch/powerpc/perf/core-book3s.c6
-rw-r--r--arch/powerpc/platforms/pseries/dtl.c1
-rw-r--r--arch/powerpc/platforms/pseries/lpar.c1
-rw-r--r--arch/powerpc/platforms/pseries/setup.c1
-rw-r--r--arch/powerpc/platforms/pseries/svm.c1
13 files changed, 102 insertions, 50 deletions
diff --git a/arch/powerpc/include/asm/atomic.h b/arch/powerpc/include/asm/atomic.h
index 498785ffc25f..0311c3c42960 100644
--- a/arch/powerpc/include/asm/atomic.h
+++ b/arch/powerpc/include/asm/atomic.h
@@ -11,8 +11,6 @@
#include <asm/cmpxchg.h>
#include <asm/barrier.h>
-#define ATOMIC_INIT(i) { (i) }
-
/*
* Since *_return_relaxed and {cmp}xchg_relaxed are implemented with
* a "bne-" instruction at the end, so an isync is enough as a acquire barrier
diff --git a/arch/powerpc/include/asm/dtl.h b/arch/powerpc/include/asm/dtl.h
new file mode 100644
index 000000000000..1625888f27ef
--- /dev/null
+++ b/arch/powerpc/include/asm/dtl.h
@@ -0,0 +1,52 @@
+#ifndef _ASM_POWERPC_DTL_H
+#define _ASM_POWERPC_DTL_H
+
+#include <asm/lppaca.h>
+#include <linux/spinlock_types.h>
+
+/*
+ * Layout of entries in the hypervisor's dispatch trace log buffer.
+ */
+struct dtl_entry {
+ u8 dispatch_reason;
+ u8 preempt_reason;
+ __be16 processor_id;
+ __be32 enqueue_to_dispatch_time;
+ __be32 ready_to_enqueue_time;
+ __be32 waiting_to_ready_time;
+ __be64 timebase;
+ __be64 fault_addr;
+ __be64 srr0;
+ __be64 srr1;
+};
+
+#define DISPATCH_LOG_BYTES 4096 /* bytes per cpu */
+#define N_DISPATCH_LOG (DISPATCH_LOG_BYTES / sizeof(struct dtl_entry))
+
+/*
+ * Dispatch trace log event enable mask:
+ * 0x1: voluntary virtual processor waits
+ * 0x2: time-slice preempts
+ * 0x4: virtual partition memory page faults
+ */
+#define DTL_LOG_CEDE 0x1
+#define DTL_LOG_PREEMPT 0x2
+#define DTL_LOG_FAULT 0x4
+#define DTL_LOG_ALL (DTL_LOG_CEDE | DTL_LOG_PREEMPT | DTL_LOG_FAULT)
+
+extern struct kmem_cache *dtl_cache;
+extern rwlock_t dtl_access_lock;
+
+/*
+ * When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE = y, the cpu accounting code controls
+ * reading from the dispatch trace log. If other code wants to consume
+ * DTL entries, it can set this pointer to a function that will get
+ * called once for each DTL entry that gets processed.
+ */
+extern void (*dtl_consumer)(struct dtl_entry *entry, u64 index);
+
+extern void register_dtl_buffer(int cpu);
+extern void alloc_dtl_buffers(unsigned long *time_limit);
+extern long hcall_vphn(unsigned long cpu, u64 flags, __be32 *associativity);
+
+#endif /* _ASM_POWERPC_DTL_H */
diff --git a/arch/powerpc/include/asm/lppaca.h b/arch/powerpc/include/asm/lppaca.h
index 3b4b305796ae..c390ec377bae 100644
--- a/arch/powerpc/include/asm/lppaca.h
+++ b/arch/powerpc/include/asm/lppaca.h
@@ -42,7 +42,6 @@
*/
#include <linux/cache.h>
#include <linux/threads.h>
-#include <linux/spinlock_types.h>
#include <asm/types.h>
#include <asm/mmu.h>
#include <asm/firmware.h>
@@ -146,49 +145,6 @@ struct slb_shadow {
} save_area[SLB_NUM_BOLTED];
} ____cacheline_aligned;
-/*
- * Layout of entries in the hypervisor's dispatch trace log buffer.
- */
-struct dtl_entry {
- u8 dispatch_reason;
- u8 preempt_reason;
- __be16 processor_id;
- __be32 enqueue_to_dispatch_time;
- __be32 ready_to_enqueue_time;
- __be32 waiting_to_ready_time;
- __be64 timebase;
- __be64 fault_addr;
- __be64 srr0;
- __be64 srr1;
-};
-
-#define DISPATCH_LOG_BYTES 4096 /* bytes per cpu */
-#define N_DISPATCH_LOG (DISPATCH_LOG_BYTES / sizeof(struct dtl_entry))
-
-/*
- * Dispatch trace log event enable mask:
- * 0x1: voluntary virtual processor waits
- * 0x2: time-slice preempts
- * 0x4: virtual partition memory page faults
- */
-#define DTL_LOG_CEDE 0x1
-#define DTL_LOG_PREEMPT 0x2
-#define DTL_LOG_FAULT 0x4
-#define DTL_LOG_ALL (DTL_LOG_CEDE | DTL_LOG_PREEMPT | DTL_LOG_FAULT)
-
-extern struct kmem_cache *dtl_cache;
-extern rwlock_t dtl_access_lock;
-
-/*
- * When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE = y, the cpu accounting code controls
- * reading from the dispatch trace log. If other code wants to consume
- * DTL entries, it can set this pointer to a function that will get
- * called once for each DTL entry that gets processed.
- */
-extern void (*dtl_consumer)(struct dtl_entry *entry, u64 index);
-
-extern void register_dtl_buffer(int cpu);
-extern void alloc_dtl_buffers(unsigned long *time_limit);
extern long hcall_vphn(unsigned long cpu, u64 flags, __be32 *associativity);
#endif /* CONFIG_PPC_BOOK3S */
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 45a839a7c6cf..84b2564cf5a4 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -29,7 +29,6 @@
#include <asm/hmi.h>
#include <asm/cpuidle.h>
#include <asm/atomic.h>
-#include <asm/rtas-types.h>
#include <asm-generic/mmiowb_types.h>
@@ -53,6 +52,7 @@ extern unsigned int debug_smp_processor_id(void); /* from linux/smp.h */
#define get_slb_shadow() (get_paca()->slb_shadow_ptr)
struct task_struct;
+struct rtas_args;
/*
* Defines the layout of the paca.
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 0fc8bad878b2..446e54c3f71e 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -3072,10 +3072,18 @@ do_hash_page:
ori r0,r0,DSISR_BAD_FAULT_64S@l
and. r0,r5,r0 /* weird error? */
bne- handle_page_fault /* if not, try to insert a HPTE */
+
+ /*
+ * If we are in an "NMI" (e.g., an interrupt when soft-disabled), then
+ * don't call hash_page, just fail the fault. This is required to
+ * prevent re-entrancy problems in the hash code, namely perf
+ * interrupts hitting while something holds H_PAGE_BUSY, and taking a
+ * hash fault. See the comment in hash_preload().
+ */
ld r11, PACA_THREAD_INFO(r13)
- lwz r0,TI_PREEMPT(r11) /* If we're in an "NMI" */
- andis. r0,r0,NMI_MASK@h /* (i.e. an irq when soft-disabled) */
- bne 77f /* then don't call hash_page now */
+ lwz r0,TI_PREEMPT(r11)
+ andis. r0,r0,NMI_MASK@h
+ bne 77f
/*
* r3 contains the trap number
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 6fcae436ae51..f85539ebb513 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -183,6 +183,8 @@ static inline unsigned long read_spurr(unsigned long tb)
#ifdef CONFIG_PPC_SPLPAR
+#include <asm/dtl.h>
+
/*
* Scan the dispatch trace log and count up the stolen time.
* Should be called with interrupts disabled.
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 6bf66649ab92..ebb04f331ad3 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -74,6 +74,7 @@
#include <asm/hw_breakpoint.h>
#include <asm/kvm_book3s_uvmem.h>
#include <asm/ultravisor.h>
+#include <asm/dtl.h>
#include "book3s.h"
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 468169e33c86..9b9f92ad0e7a 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1559,6 +1559,7 @@ static void hash_preload(struct mm_struct *mm, pte_t *ptep, unsigned long ea,
pgd_t *pgdir;
int rc, ssize, update_flags = 0;
unsigned long access = _PAGE_PRESENT | _PAGE_READ | (is_exec ? _PAGE_EXEC : 0);
+ unsigned long flags;
BUG_ON(get_region_id(ea) != USER_REGION_ID);
@@ -1592,6 +1593,28 @@ static void hash_preload(struct mm_struct *mm, pte_t *ptep, unsigned long ea,
return;
#endif /* CONFIG_PPC_64K_PAGES */
+ /*
+ * __hash_page_* must run with interrupts off, as it sets the
+ * H_PAGE_BUSY bit. It's possible for perf interrupts to hit at any
+ * time and may take a hash fault reading the user stack, see
+ * read_user_stack_slow() in the powerpc/perf code.
+ *
+ * If that takes a hash fault on the same page as we lock here, it
+ * will bail out when seeing H_PAGE_BUSY set, and retry the access
+ * leading to an infinite loop.
+ *
+ * Disabling interrupts here does not prevent perf interrupts, but it
+ * will prevent them taking hash faults (see the NMI test in
+ * do_hash_page), then read_user_stack's copy_from_user_nofault will
+ * fail and perf will fall back to read_user_stack_slow(), which
+ * walks the Linux page tables.
+ *
+ * Interrupts must also be off for the duration of the
+ * mm_is_thread_local test and update, to prevent preempt running the
+ * mm on another CPU (XXX: this may be racy vs kthread_use_mm).
+ */
+ local_irq_save(flags);
+
/* Is that local to this CPU ? */
if (mm_is_thread_local(mm))
update_flags |= HPTE_LOCAL_UPDATE;
@@ -1614,6 +1637,8 @@ static void hash_preload(struct mm_struct *mm, pte_t *ptep, unsigned long ea,
mm_ctx_user_psize(&mm->context),
mm_ctx_user_psize(&mm->context),
pte_val(*ptep));
+
+ local_irq_restore(flags);
}
/*
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index cd6a742ac6ef..01d70280d287 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -2179,6 +2179,12 @@ static void __perf_event_interrupt(struct pt_regs *regs)
perf_read_regs(regs);
+ /*
+ * If perf interrupts hit in a local_irq_disable (soft-masked) region,
+ * we consider them as NMIs. This is required to prevent hash faults on
+ * user addresses when reading callchains. See the NMI test in
+ * do_hash_page.
+ */
nmi = perf_intr_is_nmi(regs);
if (nmi)
nmi_enter();
diff --git a/arch/powerpc/platforms/pseries/dtl.c b/arch/powerpc/platforms/pseries/dtl.c
index eab8aa293743..982f069e4c31 100644
--- a/arch/powerpc/platforms/pseries/dtl.c
+++ b/arch/powerpc/platforms/pseries/dtl.c
@@ -12,6 +12,7 @@
#include <asm/smp.h>
#include <linux/uaccess.h>
#include <asm/firmware.h>
+#include <asm/dtl.h>
#include <asm/lppaca.h>
#include <asm/debugfs.h>
#include <asm/plpar_wrappers.h>
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index fd26f3d21d7b..f71ff2c94efe 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -40,6 +40,7 @@
#include <asm/fadump.h>
#include <asm/asm-prototypes.h>
#include <asm/debugfs.h>
+#include <asm/dtl.h>
#include "pseries.h"
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 2db8469e475f..27094c872fd6 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -70,6 +70,7 @@
#include <asm/idle.h>
#include <asm/swiotlb.h>
#include <asm/svm.h>
+#include <asm/dtl.h>
#include "pseries.h"
#include "../../../../drivers/pci/pci.h"
diff --git a/arch/powerpc/platforms/pseries/svm.c b/arch/powerpc/platforms/pseries/svm.c
index 40c0637203d5..e6d7a344d9f2 100644
--- a/arch/powerpc/platforms/pseries/svm.c
+++ b/arch/powerpc/platforms/pseries/svm.c
@@ -11,6 +11,7 @@
#include <asm/svm.h>
#include <asm/swiotlb.h>
#include <asm/ultravisor.h>
+#include <asm/dtl.h>
static int __init init_svm(void)
{
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-05 23:48:22 +0000