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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-11 17:48:14 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-11 17:48:14 -0800
commit140cd7fb04a4a2bc09a30980bc8104cc89e09330 (patch)
tree776d57c7508f946d592de4334d4d3cb50fd36220 /arch/powerpc/kernel/ftrace.c
parent27afc5dbda52ee3dbcd0bda7375c917c6936b470 (diff)
parent56548fc0e86cb9156af7a7e1f15ba78f251dafaf (diff)
downloadop-kernel-dev-140cd7fb04a4a2bc09a30980bc8104cc89e09330.zip
op-kernel-dev-140cd7fb04a4a2bc09a30980bc8104cc89e09330.tar.gz
Merge tag 'powerpc-3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux
Pull powerpc updates from Michael Ellerman: "Some nice cleanups like removing bootmem, and removal of __get_cpu_var(). There is one patch to mm/gup.c. This is the generic GUP implementation, but is only used by us and arm(64). We have an ack from Steve Capper, and although we didn't get an ack from Andrew he told us to take the patch through the powerpc tree. There's one cxl patch. This is in drivers/misc, but Greg said he was happy for us to manage fixes for it. There is an infrastructure patch to support an IPMI driver for OPAL. There is also an RTC driver for OPAL. We weren't able to get any response from the RTC maintainer, Alessandro Zummo, so in the end we just merged the driver. The usual batch of Freescale updates from Scott" * tag 'powerpc-3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (101 commits) powerpc/powernv: Return to cpu offline loop when finished in KVM guest powerpc/book3s: Fix partial invalidation of TLBs in MCE code. powerpc/mm: don't do tlbie for updatepp request with NO HPTE fault powerpc/xmon: Cleanup the breakpoint flags powerpc/xmon: Enable HW instruction breakpoint on POWER8 powerpc/mm/thp: Use tlbiel if possible powerpc/mm/thp: Remove code duplication powerpc/mm/hugetlb: Sanity check gigantic hugepage count powerpc/oprofile: Disable pagefaults during user stack read powerpc/mm: Check for matching hpte without taking hpte lock powerpc: Drop useless warning in eeh_init() powerpc/powernv: Cleanup unused MCE definitions/declarations. powerpc/eeh: Dump PHB diag-data early powerpc/eeh: Recover EEH error on ownership change for BCM5719 powerpc/eeh: Set EEH_PE_RESET on PE reset powerpc/eeh: Refactor eeh_reset_pe() powerpc: Remove more traces of bootmem powerpc/pseries: Initialise nvram_pstore_info's buf_lock cxl: Name interrupts in /proc/interrupt cxl: Return error to PSL if IRQ demultiplexing fails & print clearer warning ...
Diffstat (limited to 'arch/powerpc/kernel/ftrace.c')
-rw-r--r--arch/powerpc/kernel/ftrace.c73
1 files changed, 15 insertions, 58 deletions
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index e66af6d..44d4d8e 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -510,79 +510,36 @@ int ftrace_disable_ftrace_graph_caller(void)
}
#endif /* CONFIG_DYNAMIC_FTRACE */
-#ifdef CONFIG_PPC64
-extern void mod_return_to_handler(void);
-#endif
-
/*
* Hook the return address and push it in the stack of return addrs
- * in current thread info.
+ * in current thread info. Return the address we want to divert to.
*/
-void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
+unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
{
- unsigned long old;
- int faulted;
struct ftrace_graph_ent trace;
- unsigned long return_hooker = (unsigned long)&return_to_handler;
+ unsigned long return_hooker;
if (unlikely(ftrace_graph_is_dead()))
- return;
+ goto out;
if (unlikely(atomic_read(&current->tracing_graph_pause)))
- return;
-
-#ifdef CONFIG_PPC64
- /* non core kernel code needs to save and restore the TOC */
- if (REGION_ID(self_addr) != KERNEL_REGION_ID)
- return_hooker = (unsigned long)&mod_return_to_handler;
-#endif
-
- return_hooker = ppc_function_entry((void *)return_hooker);
+ goto out;
- /*
- * Protect against fault, even if it shouldn't
- * happen. This tool is too much intrusive to
- * ignore such a protection.
- */
- asm volatile(
- "1: " PPC_LL "%[old], 0(%[parent])\n"
- "2: " PPC_STL "%[return_hooker], 0(%[parent])\n"
- " li %[faulted], 0\n"
- "3:\n"
-
- ".section .fixup, \"ax\"\n"
- "4: li %[faulted], 1\n"
- " b 3b\n"
- ".previous\n"
-
- ".section __ex_table,\"a\"\n"
- PPC_LONG_ALIGN "\n"
- PPC_LONG "1b,4b\n"
- PPC_LONG "2b,4b\n"
- ".previous"
-
- : [old] "=&r" (old), [faulted] "=r" (faulted)
- : [parent] "r" (parent), [return_hooker] "r" (return_hooker)
- : "memory"
- );
-
- if (unlikely(faulted)) {
- ftrace_graph_stop();
- WARN_ON(1);
- return;
- }
+ return_hooker = ppc_function_entry(return_to_handler);
- trace.func = self_addr;
+ trace.func = ip;
trace.depth = current->curr_ret_stack + 1;
/* Only trace if the calling function expects to */
- if (!ftrace_graph_entry(&trace)) {
- *parent = old;
- return;
- }
+ if (!ftrace_graph_entry(&trace))
+ goto out;
+
+ if (ftrace_push_return_trace(parent, ip, &trace.depth, 0) == -EBUSY)
+ goto out;
- if (ftrace_push_return_trace(old, self_addr, &trace.depth, 0) == -EBUSY)
- *parent = old;
+ parent = return_hooker;
+out:
+ return parent;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
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