diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/platforms/pseries/lpar.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index 5d3ea9f60dd7..ca5d5898d320 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -713,6 +713,13 @@ EXPORT_SYMBOL(arch_free_page); /* NB: reg/unreg are called while guarded with the tracepoints_mutex */ extern long hcall_tracepoint_refcount; +/* + * Since the tracing code might execute hcalls we need to guard against + * recursion. One example of this are spinlocks calling H_YIELD on + * shared processor partitions. + */ +static DEFINE_PER_CPU(unsigned int, hcall_trace_depth); + void hcall_tracepoint_regfunc(void) { hcall_tracepoint_refcount++; @@ -725,12 +732,42 @@ void hcall_tracepoint_unregfunc(void) void __trace_hcall_entry(unsigned long opcode, unsigned long *args) { + unsigned long flags; + unsigned int *depth; + + local_irq_save(flags); + + depth = &__get_cpu_var(hcall_trace_depth); + + if (*depth) + goto out; + + (*depth)++; trace_hcall_entry(opcode, args); + (*depth)--; + +out: + local_irq_restore(flags); } void __trace_hcall_exit(long opcode, unsigned long retval, unsigned long *retbuf) { + unsigned long flags; + unsigned int *depth; + + local_irq_save(flags); + + depth = &__get_cpu_var(hcall_trace_depth); + + if (*depth) + goto out; + + (*depth)++; trace_hcall_exit(opcode, retval, retbuf); + (*depth)--; + +out: + local_irq_restore(flags); } #endif |