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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-16 12:47:46 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-16 12:47:46 -0800 |
commit | 5b0e2cb020085efe202123162502e0b551e49a0e (patch) | |
tree | 534bbb4c9f98c2ed9a520e11107029e5df38c3c2 /arch/powerpc/kernel/kprobes-ftrace.c | |
parent | 758f875848d78148cf9a9cdb3ff1ddf29b234056 (diff) | |
parent | 3ffa9d9e2a7c10127d8cbf91ea2be15390b450ed (diff) |
Merge tag 'powerpc-4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"A bit of a small release, I suspect in part due to me travelling for
KS. But my backlog of patches to review is smaller than usual, so I
think in part folks just didn't send as much this cycle.
Non-highlights:
- Five fixes for the >128T address space handling, both to fix bugs
in our implementation and to bring the semantics exactly into line
with x86.
Highlights:
- Support for a new OPAL call on bare metal machines which gives us a
true NMI (ie. is not masked by MSR[EE]=0) for debugging etc.
- Support for Power9 DD2 in the CXL driver.
- Improvements to machine check handling so that uncorrectable errors
can be reported into the generic memory_failure() machinery.
- Some fixes and improvements for VPHN, which is used under PowerVM
to notify the Linux partition of topology changes.
- Plumbing to enable TM (transactional memory) without suspend on
some Power9 processors (PPC_FEATURE2_HTM_NO_SUSPEND).
- Support for emulating vector loads form cache-inhibited memory, on
some Power9 revisions.
- Disable the fast-endian switch "syscall" by default (behind a
CONFIG), we believe it has never had any users.
- A major rework of the API drivers use when initiating and waiting
for long running operations performed by OPAL firmware, and changes
to the powernv_flash driver to use the new API.
- Several fixes for the handling of FP/VMX/VSX while processes are
using transactional memory.
- Optimisations of TLB range flushes when using the radix MMU on
Power9.
- Improvements to the VAS facility used to access coprocessors on
Power9, and related improvements to the way the NX crypto driver
handles requests.
- Implementation of PMEM_API and UACCESS_FLUSHCACHE for 64-bit.
Thanks to: Alexey Kardashevskiy, Alistair Popple, Allen Pais, Andrew
Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Balbir Singh, Benjamin
Herrenschmidt, Breno Leitao, Christophe Leroy, Christophe Lombard,
Cyril Bur, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven,
Guilherme G. Piccoli, Gustavo Romero, Haren Myneni, Joel Stanley,
Kamalesh Babulal, Kautuk Consul, Markus Elfring, Masami Hiramatsu,
Michael Bringmann, Michael Neuling, Michal Suchanek, Naveen N. Rao,
Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pedro Miraglia
Franco de Carvalho, Philippe Bergheaud, Sandipan Das, Seth Forshee,
Shriya, Stephen Rothwell, Stewart Smith, Sukadev Bhattiprolu, Tyrel
Datwyler, Vaibhav Jain, Vaidyanathan Srinivasan, and William A.
Kennington III"
* tag 'powerpc-4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (151 commits)
powerpc/64s: Fix Power9 DD2.0 workarounds by adding DD2.1 feature
powerpc/64s: Fix masking of SRR1 bits on instruction fault
powerpc/64s: mm_context.addr_limit is only used on hash
powerpc/64s/radix: Fix 128TB-512TB virtual address boundary case allocation
powerpc/64s/hash: Allow MAP_FIXED allocations to cross 128TB boundary
powerpc/64s/hash: Fix fork() with 512TB process address space
powerpc/64s/hash: Fix 128TB-512TB virtual address boundary case allocation
powerpc/64s/hash: Fix 512T hint detection to use >= 128T
powerpc: Fix DABR match on hash based systems
powerpc/signal: Properly handle return value from uprobe_deny_signal()
powerpc/fadump: use kstrtoint to handle sysfs store
powerpc/lib: Implement UACCESS_FLUSHCACHE API
powerpc/lib: Implement PMEM API
powerpc/powernv/npu: Don't explicitly flush nmmu tlb
powerpc/powernv/npu: Use flush_all_mm() instead of flush_tlb_mm()
powerpc/powernv/idle: Round up latency and residency values
powerpc/kprobes: refactor kprobe_lookup_name for safer string operations
powerpc/kprobes: Blacklist emulate_update_regs() from kprobes
powerpc/kprobes: Do not disable interrupts for optprobes and kprobes_on_ftrace
powerpc/kprobes: Disable preemption before invoking probe handler for optprobes
...
Diffstat (limited to 'arch/powerpc/kernel/kprobes-ftrace.c')
-rw-r--r-- | arch/powerpc/kernel/kprobes-ftrace.c | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerpc/kernel/kprobes-ftrace.c index 6c089d9757c9..7a1f99f1b47f 100644 --- a/arch/powerpc/kernel/kprobes-ftrace.c +++ b/arch/powerpc/kernel/kprobes-ftrace.c @@ -25,6 +25,21 @@ #include <linux/preempt.h> #include <linux/ftrace.h> +/* + * This is called from ftrace code after invoking registered handlers to + * disambiguate regs->nip changes done by jprobes and livepatch. We check if + * there is an active jprobe at the provided address (mcount location). + */ +int __is_active_jprobe(unsigned long addr) +{ + if (!preemptible()) { + struct kprobe *p = raw_cpu_read(current_kprobe); + return (p && (unsigned long)p->addr == addr) ? 1 : 0; + } + + return 0; +} + static nokprobe_inline int __skip_singlestep(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb, unsigned long orig_nip) @@ -60,11 +75,8 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip, { struct kprobe *p; struct kprobe_ctlblk *kcb; - unsigned long flags; - /* Disable irq for emulating a breakpoint and avoiding preempt */ - local_irq_save(flags); - hard_irq_disable(); + preempt_disable(); p = get_kprobe((kprobe_opcode_t *)nip); if (unlikely(!p) || kprobe_disabled(p)) @@ -86,13 +98,17 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip, kcb->kprobe_status = KPROBE_HIT_ACTIVE; if (!p->pre_handler || !p->pre_handler(p, regs)) __skip_singlestep(p, regs, kcb, orig_nip); - /* - * If pre_handler returns !0, it sets regs->nip and - * resets current kprobe. - */ + else { + /* + * If pre_handler returns !0, it sets regs->nip and + * resets current kprobe. In this case, we should not + * re-enable preemption. + */ + return; + } } end: - local_irq_restore(flags); + preempt_enable_no_resched(); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); |