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-rw-r--r--arch/powerpc/include/asm/pgtable.h6
-rw-r--r--arch/powerpc/kernel/Makefile2
-rw-r--r--arch/powerpc/kernel/asm-offsets.c2
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S19
-rw-r--r--arch/powerpc/kernel/perf_callchain.c527
-rw-r--r--arch/powerpc/mm/slb.c37
-rw-r--r--arch/powerpc/mm/stab.c11
7 files changed, 588 insertions, 16 deletions
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index eb17da781128..2a5da069714e 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -104,8 +104,8 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
else
pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte));
-#elif defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT) && defined(CONFIG_SMP)
- /* Second case is 32-bit with 64-bit PTE in SMP mode. In this case, we
+#elif defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT)
+ /* Second case is 32-bit with 64-bit PTE. In this case, we
* can just store as long as we do the two halves in the right order
* with a barrier in between. This is possible because we take care,
* in the hash code, to pre-invalidate if the PTE was already hashed,
@@ -140,7 +140,7 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
#else
/* Anything else just stores the PTE normally. That covers all 64-bit
- * cases, and 32-bit non-hash with 64-bit PTEs in UP mode
+ * cases, and 32-bit non-hash with 32-bit PTEs.
*/
*ptep = pte;
#endif
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index b73396b93905..9619285f64e8 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -97,7 +97,7 @@ obj64-$(CONFIG_AUDIT) += compat_audit.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
-obj-$(CONFIG_PPC_PERF_CTRS) += perf_counter.o
+obj-$(CONFIG_PPC_PERF_CTRS) += perf_counter.o perf_callchain.o
obj64-$(CONFIG_PPC_PERF_CTRS) += power4-pmu.o ppc970-pmu.o power5-pmu.o \
power5+-pmu.o power6-pmu.o power7-pmu.o
obj32-$(CONFIG_PPC_PERF_CTRS) += mpc7450-pmu.o
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 561b64652311..197b15646eeb 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -67,6 +67,8 @@ int main(void)
DEFINE(MMCONTEXTID, offsetof(struct mm_struct, context.id));
#ifdef CONFIG_PPC64
DEFINE(AUDITCONTEXT, offsetof(struct task_struct, audit_context));
+ DEFINE(SIGSEGV, SIGSEGV);
+ DEFINE(NMI_MASK, NMI_MASK);
#else
DEFINE(THREAD_INFO, offsetof(struct task_struct, stack));
#endif /* CONFIG_PPC64 */
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index eb898112e577..8ac85e08ffae 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -729,6 +729,11 @@ BEGIN_FTR_SECTION
bne- do_ste_alloc /* If so handle it */
END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
+ clrrdi r11,r1,THREAD_SHIFT
+ 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 */
+
/*
* On iSeries, we soft-disable interrupts here, then
* hard-enable interrupts so that the hash_page code can spin on
@@ -833,6 +838,20 @@ handle_page_fault:
bl .low_hash_fault
b .ret_from_except
+/*
+ * We come here as a result of a DSI at a point where we don't want
+ * to call hash_page, such as when we are accessing memory (possibly
+ * user memory) inside a PMU interrupt that occurred while interrupts
+ * were soft-disabled. We want to invoke the exception handler for
+ * the access, or panic if there isn't a handler.
+ */
+77: bl .save_nvgprs
+ mr r4,r3
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ li r5,SIGSEGV
+ bl .bad_page_fault
+ b .ret_from_except
+
/* here we have a segment miss */
do_ste_alloc:
bl .ste_allocate /* try to insert stab entry */
diff --git a/arch/powerpc/kernel/perf_callchain.c b/arch/powerpc/kernel/perf_callchain.c
new file mode 100644
index 000000000000..f74b62c67511
--- /dev/null
+++ b/arch/powerpc/kernel/perf_callchain.c
@@ -0,0 +1,527 @@
+/*
+ * Performance counter callchain support - powerpc architecture code
+ *
+ * Copyright © 2009 Paul Mackerras, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/perf_counter.h>
+#include <linux/percpu.h>
+#include <linux/uaccess.h>
+#include <linux/mm.h>
+#include <asm/ptrace.h>
+#include <asm/pgtable.h>
+#include <asm/sigcontext.h>
+#include <asm/ucontext.h>
+#include <asm/vdso.h>
+#ifdef CONFIG_PPC64
+#include "ppc32.h"
+#endif
+
+/*
+ * Store another value in a callchain_entry.
+ */
+static inline void callchain_store(struct perf_callchain_entry *entry, u64 ip)
+{
+ unsigned int nr = entry->nr;
+
+ if (nr < PERF_MAX_STACK_DEPTH) {
+ entry->ip[nr] = ip;
+ entry->nr = nr + 1;
+ }
+}
+
+/*
+ * Is sp valid as the address of the next kernel stack frame after prev_sp?
+ * The next frame may be in a different stack area but should not go
+ * back down in the same stack area.
+ */
+static int valid_next_sp(unsigned long sp, unsigned long prev_sp)
+{
+ if (sp & 0xf)
+ return 0; /* must be 16-byte aligned */
+ if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD))
+ return 0;
+ if (sp >= prev_sp + STACK_FRAME_OVERHEAD)
+ return 1;
+ /*
+ * sp could decrease when we jump off an interrupt stack
+ * back to the regular process stack.
+ */
+ if ((sp & ~(THREAD_SIZE - 1)) != (prev_sp & ~(THREAD_SIZE - 1)))
+ return 1;
+ return 0;
+}
+
+static void perf_callchain_kernel(struct pt_regs *regs,
+ struct perf_callchain_entry *entry)
+{
+ unsigned long sp, next_sp;
+ unsigned long next_ip;
+ unsigned long lr;
+ long level = 0;
+ unsigned long *fp;
+
+ lr = regs->link;
+ sp = regs->gpr[1];
+ callchain_store(entry, PERF_CONTEXT_KERNEL);
+ callchain_store(entry, regs->nip);
+
+ if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD))
+ return;
+
+ for (;;) {
+ fp = (unsigned long *) sp;
+ next_sp = fp[0];
+
+ if (next_sp == sp + STACK_INT_FRAME_SIZE &&
+ fp[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
+ /*
+ * This looks like an interrupt frame for an
+ * interrupt that occurred in the kernel
+ */
+ regs = (struct pt_regs *)(sp + STACK_FRAME_OVERHEAD);
+ next_ip = regs->nip;
+ lr = regs->link;
+ level = 0;
+ callchain_store(entry, PERF_CONTEXT_KERNEL);
+
+ } else {
+ if (level == 0)
+ next_ip = lr;
+ else
+ next_ip = fp[STACK_FRAME_LR_SAVE];
+
+ /*
+ * We can't tell which of the first two addresses
+ * we get are valid, but we can filter out the
+ * obviously bogus ones here. We replace them
+ * with 0 rather than removing them entirely so
+ * that userspace can tell which is which.
+ */
+ if ((level == 1 && next_ip == lr) ||
+ (level <= 1 && !kernel_text_address(next_ip)))
+ next_ip = 0;
+
+ ++level;
+ }
+
+ callchain_store(entry, next_ip);
+ if (!valid_next_sp(next_sp, sp))
+ return;
+ sp = next_sp;
+ }
+}
+
+#ifdef CONFIG_PPC64
+
+#ifdef CONFIG_HUGETLB_PAGE
+#define is_huge_psize(pagesize) (HPAGE_SHIFT && mmu_huge_psizes[pagesize])
+#else
+#define is_huge_psize(pagesize) 0
+#endif
+
+/*
+ * On 64-bit we don't want to invoke hash_page on user addresses from
+ * interrupt context, so if the access faults, we read the page tables
+ * to find which page (if any) is mapped and access it directly.
+ */
+static int read_user_stack_slow(void __user *ptr, void *ret, int nb)
+{
+ pgd_t *pgdir;
+ pte_t *ptep, pte;
+ int pagesize;
+ unsigned long addr = (unsigned long) ptr;
+ unsigned long offset;
+ unsigned long pfn;
+ void *kaddr;
+
+ pgdir = current->mm->pgd;
+ if (!pgdir)
+ return -EFAULT;
+
+ pagesize = get_slice_psize(current->mm, addr);
+
+ /* align address to page boundary */
+ offset = addr & ((1ul << mmu_psize_defs[pagesize].shift) - 1);
+ addr -= offset;
+
+ if (is_huge_psize(pagesize))
+ ptep = huge_pte_offset(current->mm, addr);
+ else
+ ptep = find_linux_pte(pgdir, addr);
+
+ if (ptep == NULL)
+ return -EFAULT;
+ pte = *ptep;
+ if (!pte_present(pte) || !(pte_val(pte) & _PAGE_USER))
+ return -EFAULT;
+ pfn = pte_pfn(pte);
+ if (!page_is_ram(pfn))
+ return -EFAULT;
+
+ /* no highmem to worry about here */
+ kaddr = pfn_to_kaddr(pfn);
+ memcpy(ret, kaddr + offset, nb);
+ return 0;
+}
+
+static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret)
+{
+ if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned long) ||
+ ((unsigned long)ptr & 7))
+ return -EFAULT;
+
+ if (!__get_user_inatomic(*ret, ptr))
+ return 0;
+
+ return read_user_stack_slow(ptr, ret, 8);
+}
+
+static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
+{
+ if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
+ ((unsigned long)ptr & 3))
+ return -EFAULT;
+
+ if (!__get_user_inatomic(*ret, ptr))
+ return 0;
+
+ return read_user_stack_slow(ptr, ret, 4);
+}
+
+static inline int valid_user_sp(unsigned long sp, int is_64)
+{
+ if (!sp || (sp & 7) || sp > (is_64 ? TASK_SIZE : 0x100000000UL) - 32)
+ return 0;
+ return 1;
+}
+
+/*
+ * 64-bit user processes use the same stack frame for RT and non-RT signals.
+ */
+struct signal_frame_64 {
+ char dummy[__SIGNAL_FRAMESIZE];
+ struct ucontext uc;
+ unsigned long unused[2];
+ unsigned int tramp[6];
+ struct siginfo *pinfo;
+ void *puc;
+ struct siginfo info;
+ char abigap[288];
+};
+
+static int is_sigreturn_64_address(unsigned long nip, unsigned long fp)
+{
+ if (nip == fp + offsetof(struct signal_frame_64, tramp))
+ return 1;
+ if (vdso64_rt_sigtramp && current->mm->context.vdso_base &&
+ nip == current->mm->context.vdso_base + vdso64_rt_sigtramp)
+ return 1;
+ return 0;
+}
+
+/*
+ * Do some sanity checking on the signal frame pointed to by sp.
+ * We check the pinfo and puc pointers in the frame.
+ */
+static int sane_signal_64_frame(unsigned long sp)
+{
+ struct signal_frame_64 __user *sf;
+ unsigned long pinfo, puc;
+
+ sf = (struct signal_frame_64 __user *) sp;
+ if (read_user_stack_64((unsigned long __user *) &sf->pinfo, &pinfo) ||
+ read_user_stack_64((unsigned long __user *) &sf->puc, &puc))
+ return 0;
+ return pinfo == (unsigned long) &sf->info &&
+ puc == (unsigned long) &sf->uc;
+}
+
+static void perf_callchain_user_64(struct pt_regs *regs,
+ struct perf_callchain_entry *entry)
+{
+ unsigned long sp, next_sp;
+ unsigned long next_ip;
+ unsigned long lr;
+ long level = 0;
+ struct signal_frame_64 __user *sigframe;
+ unsigned long __user *fp, *uregs;
+
+ next_ip = regs->nip;
+ lr = regs->link;
+ sp = regs->gpr[1];
+ callchain_store(entry, PERF_CONTEXT_USER);
+ callchain_store(entry, next_ip);
+
+ for (;;) {
+ fp = (unsigned long __user *) sp;
+ if (!valid_user_sp(sp, 1) || read_user_stack_64(fp, &next_sp))
+ return;
+ if (level > 0 && read_user_stack_64(&fp[2], &next_ip))
+ return;
+
+ /*
+ * Note: the next_sp - sp >= signal frame size check
+ * is true when next_sp < sp, which can happen when
+ * transitioning from an alternate signal stack to the
+ * normal stack.
+ */
+ if (next_sp - sp >= sizeof(struct signal_frame_64) &&
+ (is_sigreturn_64_address(next_ip, sp) ||
+ (level <= 1 && is_sigreturn_64_address(lr, sp))) &&
+ sane_signal_64_frame(sp)) {
+ /*
+ * This looks like an signal frame
+ */
+ sigframe = (struct signal_frame_64 __user *) sp;
+ uregs = sigframe->uc.uc_mcontext.gp_regs;
+ if (read_user_stack_64(&uregs[PT_NIP], &next_ip) ||
+ read_user_stack_64(&uregs[PT_LNK], &lr) ||
+ read_user_stack_64(&uregs[PT_R1], &sp))
+ return;
+ level = 0;
+ callchain_store(entry, PERF_CONTEXT_USER);
+ callchain_store(entry, next_ip);
+ continue;
+ }
+
+ if (level == 0)
+ next_ip = lr;
+ callchain_store(entry, next_ip);
+ ++level;
+ sp = next_sp;
+ }
+}
+
+static inline int current_is_64bit(void)
+{
+ /*
+ * We can't use test_thread_flag() here because we may be on an
+ * interrupt stack, and the thread flags don't get copied over
+ * from the thread_info on the main stack to the interrupt stack.
+ */
+ return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
+}
+
+#else /* CONFIG_PPC64 */
+/*
+ * On 32-bit we just access the address and let hash_page create a
+ * HPTE if necessary, so there is no need to fall back to reading
+ * the page tables. Since this is called at interrupt level,
+ * do_page_fault() won't treat a DSI as a page fault.
+ */
+static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
+{
+ if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
+ ((unsigned long)ptr & 3))
+ return -EFAULT;
+
+ return __get_user_inatomic(*ret, ptr);
+}
+
+static inline void perf_callchain_user_64(struct pt_regs *regs,
+ struct perf_callchain_entry *entry)
+{
+}
+
+static inline int current_is_64bit(void)
+{
+ return 0;
+}
+
+static inline int valid_user_sp(unsigned long sp, int is_64)
+{
+ if (!sp || (sp & 7) || sp > TASK_SIZE - 32)
+ return 0;
+ return 1;
+}
+
+#define __SIGNAL_FRAMESIZE32 __SIGNAL_FRAMESIZE
+#define sigcontext32 sigcontext
+#define mcontext32 mcontext
+#define ucontext32 ucontext
+#define compat_siginfo_t struct siginfo
+
+#endif /* CONFIG_PPC64 */
+
+/*
+ * Layout for non-RT signal frames
+ */
+struct signal_frame_32 {
+ char dummy[__SIGNAL_FRAMESIZE32];
+ struct sigcontext32 sctx;
+ struct mcontext32 mctx;
+ int abigap[56];
+};
+
+/*
+ * Layout for RT signal frames
+ */
+struct rt_signal_frame_32 {
+ char dummy[__SIGNAL_FRAMESIZE32 + 16];
+ compat_siginfo_t info;
+ struct ucontext32 uc;
+ int abigap[56];
+};
+
+static int is_sigreturn_32_address(unsigned int nip, unsigned int fp)
+{
+ if (nip == fp + offsetof(struct signal_frame_32, mctx.mc_pad))
+ return 1;
+ if (vdso32_sigtramp && current->mm->context.vdso_base &&
+ nip == current->mm->context.vdso_base + vdso32_sigtramp)
+ return 1;
+ return 0;
+}
+
+static int is_rt_sigreturn_32_address(unsigned int nip, unsigned int fp)
+{
+ if (nip == fp + offsetof(struct rt_signal_frame_32,
+ uc.uc_mcontext.mc_pad))
+ return 1;
+ if (vdso32_rt_sigtramp && current->mm->context.vdso_base &&
+ nip == current->mm->context.vdso_base + vdso32_rt_sigtramp)
+ return 1;
+ return 0;
+}
+
+static int sane_signal_32_frame(unsigned int sp)
+{
+ struct signal_frame_32 __user *sf;
+ unsigned int regs;
+
+ sf = (struct signal_frame_32 __user *) (unsigned long) sp;
+ if (read_user_stack_32((unsigned int __user *) &sf->sctx.regs, &regs))
+ return 0;
+ return regs == (unsigned long) &sf->mctx;
+}
+
+static int sane_rt_signal_32_frame(unsigned int sp)
+{
+ struct rt_signal_frame_32 __user *sf;
+ unsigned int regs;
+
+ sf = (struct rt_signal_frame_32 __user *) (unsigned long) sp;
+ if (read_user_stack_32((unsigned int __user *) &sf->uc.uc_regs, &regs))
+ return 0;
+ return regs == (unsigned long) &sf->uc.uc_mcontext;
+}
+
+static unsigned int __user *signal_frame_32_regs(unsigned int sp,
+ unsigned int next_sp, unsigned int next_ip)
+{
+ struct mcontext32 __user *mctx = NULL;
+ struct signal_frame_32 __user *sf;
+ struct rt_signal_frame_32 __user *rt_sf;
+
+ /*
+ * Note: the next_sp - sp >= signal frame size check
+ * is true when next_sp < sp, for example, when
+ * transitioning from an alternate signal stack to the
+ * normal stack.
+ */
+ if (next_sp - sp >= sizeof(struct signal_frame_32) &&
+ is_sigreturn_32_address(next_ip, sp) &&
+ sane_signal_32_frame(sp)) {
+ sf = (struct signal_frame_32 __user *) (unsigned long) sp;
+ mctx = &sf->mctx;
+ }
+
+ if (!mctx && next_sp - sp >= sizeof(struct rt_signal_frame_32) &&
+ is_rt_sigreturn_32_address(next_ip, sp) &&
+ sane_rt_signal_32_frame(sp)) {
+ rt_sf = (struct rt_signal_frame_32 __user *) (unsigned long) sp;
+ mctx = &rt_sf->uc.uc_mcontext;
+ }
+
+ if (!mctx)
+ return NULL;
+ return mctx->mc_gregs;
+}
+
+static void perf_callchain_user_32(struct pt_regs *regs,
+ struct perf_callchain_entry *entry)
+{
+ unsigned int sp, next_sp;
+ unsigned int next_ip;
+ unsigned int lr;
+ long level = 0;
+ unsigned int __user *fp, *uregs;
+
+ next_ip = regs->nip;
+ lr = regs->link;
+ sp = regs->gpr[1];
+ callchain_store(entry, PERF_CONTEXT_USER);
+ callchain_store(entry, next_ip);
+
+ while (entry->nr < PERF_MAX_STACK_DEPTH) {
+ fp = (unsigned int __user *) (unsigned long) sp;
+ if (!valid_user_sp(sp, 0) || read_user_stack_32(fp, &next_sp))
+ return;
+ if (level > 0 && read_user_stack_32(&fp[1], &next_ip))
+ return;
+
+ uregs = signal_frame_32_regs(sp, next_sp, next_ip);
+ if (!uregs && level <= 1)
+ uregs = signal_frame_32_regs(sp, next_sp, lr);
+ if (uregs) {
+ /*
+ * This looks like an signal frame, so restart
+ * the stack trace with the values in it.
+ */
+ if (read_user_stack_32(&uregs[PT_NIP], &next_ip) ||
+ read_user_stack_32(&uregs[PT_LNK], &lr) ||
+ read_user_stack_32(&uregs[PT_R1], &sp))
+ return;
+ level = 0;
+ callchain_store(entry, PERF_CONTEXT_USER);
+ callchain_store(entry, next_ip);
+ continue;
+ }
+
+ if (level == 0)
+ next_ip = lr;
+ callchain_store(entry, next_ip);
+ ++level;
+ sp = next_sp;
+ }
+}
+
+/*
+ * Since we can't get PMU interrupts inside a PMU interrupt handler,
+ * we don't need separate irq and nmi entries here.
+ */
+static DEFINE_PER_CPU(struct perf_callchain_entry, callchain);
+
+struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
+{
+ struct perf_callchain_entry *entry = &__get_cpu_var(callchain);
+
+ entry->nr = 0;
+
+ if (current->pid == 0) /* idle task? */
+ return entry;
+
+ if (!user_mode(regs)) {
+ perf_callchain_kernel(regs, entry);
+ if (current->mm)
+ regs = task_pt_regs(current);
+ else
+ regs = NULL;
+ }
+
+ if (regs) {
+ if (current_is_64bit())
+ perf_callchain_user_64(regs, entry);
+ else
+ perf_callchain_user_32(regs, entry);
+ }
+
+ return entry;
+}
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 5b7038f248b6..a685652effeb 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -92,15 +92,13 @@ static inline void create_shadowed_slbe(unsigned long ea, int ssize,
: "memory" );
}
-void slb_flush_and_rebolt(void)
+static void __slb_flush_and_rebolt(void)
{
/* If you change this make sure you change SLB_NUM_BOLTED
* appropriately too. */
unsigned long linear_llp, vmalloc_llp, lflags, vflags;
unsigned long ksp_esid_data, ksp_vsid_data;
- WARN_ON(!irqs_disabled());
-
linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp;
lflags = SLB_VSID_KERNEL | linear_llp;
@@ -117,12 +115,6 @@ void slb_flush_and_rebolt(void)
ksp_vsid_data = get_slb_shadow()->save_area[2].vsid;
}
- /*
- * We can't take a PMU exception in the following code, so hard
- * disable interrupts.
- */
- hard_irq_disable();
-
/* We need to do this all in asm, so we're sure we don't touch
* the stack between the slbia and rebolting it. */
asm volatile("isync\n"
@@ -139,6 +131,21 @@ void slb_flush_and_rebolt(void)
: "memory");
}
+void slb_flush_and_rebolt(void)
+{
+
+ WARN_ON(!irqs_disabled());
+
+ /*
+ * We can't take a PMU exception in the following code, so hard
+ * disable interrupts.
+ */
+ hard_irq_disable();
+
+ __slb_flush_and_rebolt();
+ get_paca()->slb_cache_ptr = 0;
+}
+
void slb_vmalloc_update(void)
{
unsigned long vflags;
@@ -180,12 +187,20 @@ static inline int esids_match(unsigned long addr1, unsigned long addr2)
/* Flush all user entries from the segment table of the current processor. */
void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
{
- unsigned long offset = get_paca()->slb_cache_ptr;
+ unsigned long offset;
unsigned long slbie_data = 0;
unsigned long pc = KSTK_EIP(tsk);
unsigned long stack = KSTK_ESP(tsk);
unsigned long unmapped_base;
+ /*
+ * We need interrupts hard-disabled here, not just soft-disabled,
+ * so that a PMU interrupt can't occur, which might try to access
+ * user memory (to get a stack trace) and possible cause an SLB miss
+ * which would update the slb_cache/slb_cache_ptr fields in the PACA.
+ */
+ hard_irq_disable();
+ offset = get_paca()->slb_cache_ptr;
if (!cpu_has_feature(CPU_FTR_NO_SLBIE_B) &&
offset <= SLB_CACHE_ENTRIES) {
int i;
@@ -200,7 +215,7 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
}
asm volatile("isync" : : : "memory");
} else {
- slb_flush_and_rebolt();
+ __slb_flush_and_rebolt();
}
/* Workaround POWER5 < DD2.1 issue */
diff --git a/arch/powerpc/mm/stab.c b/arch/powerpc/mm/stab.c
index 98cd1dc2ae75..ab5fb48b3e90 100644
--- a/arch/powerpc/mm/stab.c
+++ b/arch/powerpc/mm/stab.c
@@ -164,7 +164,7 @@ void switch_stab(struct task_struct *tsk, struct mm_struct *mm)
{
struct stab_entry *stab = (struct stab_entry *) get_paca()->stab_addr;
struct stab_entry *ste;
- unsigned long offset = __get_cpu_var(stab_cache_ptr);
+ unsigned long offset;
unsigned long pc = KSTK_EIP(tsk);
unsigned long stack = KSTK_ESP(tsk);
unsigned long unmapped_base;
@@ -172,6 +172,15 @@ void switch_stab(struct task_struct *tsk, struct mm_struct *mm)
/* Force previous translations to complete. DRENG */
asm volatile("isync" : : : "memory");
+ /*
+ * We need interrupts hard-disabled here, not just soft-disabled,
+ * so that a PMU interrupt can't occur, which might try to access
+ * user memory (to get a stack trace) and possible cause an STAB miss
+ * which would update the stab_cache/stab_cache_ptr per-cpu variables.
+ */
+ hard_irq_disable();
+
+ offset = __get_cpu_var(stab_cache_ptr);
if (offset <= NR_STAB_CACHE_ENTRIES) {
int i;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 21:40:03 +0000