On Thu, May 24, 2018 at 1:47 PM, H.J. Lu <hjl.to...@gmail.com> wrote: > On Wed, May 23, 2018 at 8:35 AM, H.J. Lu <hjl.to...@gmail.com> wrote: >> On Wed, May 23, 2018 at 8:11 AM, Jan Hubicka <hubi...@ucw.cz> wrote: >>>> On Wed, May 23, 2018 at 2:01 AM, Jan Hubicka <hubi...@ucw.cz> wrote: >>>> >> On Tue, May 22, 2018 at 9:21 AM, Jan Hubicka <hubi...@ucw.cz> wrote: >>>> >> >> >>>>> > class ipa_opt_pass_d; >>>> >> >> >>>>> > typedef ipa_opt_pass_d *ipa_opt_pass; >>>> >> >> >>>>> > @@ -2894,7 +2896,8 @@ >>>> >> >> >>>>> > cgraph_node::only_called_directly_or_aliased_p (void) >>>> >> >> >>>>> > && !DECL_STATIC_CONSTRUCTOR (decl) >>>> >> >> >>>>> > && !DECL_STATIC_DESTRUCTOR (decl) >>>> >> >> >>>>> > && !used_from_object_file_p () >>>> >> >> >>>>> > - && !externally_visible); >>>> >> >> >>>>> > + && !externally_visible >>>> >> >> >>>>> > + && !lookup_attribute ("ifunc", DECL_ATTRIBUTES >>>> >> >> >>>>> > (decl))); >>>> >> >> >>>>> >>>> >> >> >>>>> How's it handled for our own generated resolver functions? >>>> >> >> >>>>> That is, >>>> >> >> >>>>> isn't there sth cheaper than doing a lookup_attribute here? I >>>> >> >> >>>>> see >>>> >> >> >>>>> that make_dispatcher_decl nor >>>> >> >> >>>>> ix86_get_function_versions_dispatcher >>>> >> >> >>>>> adds the 'ifunc' attribute (though they are TREE_PUBLIC there). >>>> >> >> >>>> >>>> >> >> >>>> Is there any drawback of setting force_output flag? >>>> >> >> >>>> Honza >>>> >> >> >>> >>>> >> >> >>> Setting force_output may prevent some optimizations. Can we add >>>> >> >> >>> a bit >>>> >> >> >>> for IFUNC resolver? >>>> >> >> >>> >>>> >> >> >> >>>> >> >> >> Here is the patch to add ifunc_resolver to cgraph_node. Tested on >>>> >> >> >> x86-64 >>>> >> >> >> and i686. Any comments? >>>> >> >> >> >>>> >> >> > >>>> >> >> > PING: >>>> >> >> > >>>> >> >> > https://gcc.gnu.org/ml/gcc-patches/2018-04/msg00647.html >>>> >> >> > >>>> >> >> >>>> >> >> PING. >>>> >> > OK, but please extend the verifier that ifunc_resolver flag is >>>> >> > equivalent to >>>> >> > lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)) >>>> >> > so we are sure things stays in sync. >>>> >> > >>>> >> >>>> >> Like this >>>> >> >>>> >> diff --git a/gcc/symtab.c b/gcc/symtab.c >>>> >> index 80f6f910c3b..954920b6dff 100644 >>>> >> --- a/gcc/symtab.c >>>> >> +++ b/gcc/symtab.c >>>> >> @@ -998,6 +998,13 @@ symtab_node::verify_base (void) >>>> >> error ("function symbol is not function"); >>>> >> error_found = true; >>>> >> } >>>> >> + else if ((lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)) >>>> >> + != NULL) >>>> >> + != dyn_cast <cgraph_node *> (this)->ifunc_resolver) >>>> >> + { >>>> >> + error ("inconsistent `ifunc' attribute"); >>>> >> + error_found = true; >>>> >> + } >>>> >> } >>>> >> else if (is_a <varpool_node *> (this)) >>>> >> { >>>> >> >>>> >> >>>> >> Thanks. >>>> > Yes, thanks! >>>> > Honza >>>> >>>> I'd like to also fix it on GCC 8 branch for CET. Should I backport my >>>> patch to GCC 8 after a few days or use the simple patch for GCC 8: >>>> >>>> https://gcc.gnu.org/ml/gcc-patches/2018-04/msg00588.html >>> >>> I would backport this one so we don't unnecesarily diverge. >>> Thanks! >>> Honza >> >> This is the backport which I will check into GCC 8 branch next week. >> > > This is the updated backport which I will check into GCC 8 branch next week. >
This is the updated backport which I will check into GCC 8 branch next week. -- H.J.
From 5ebddef01e810c1684ed0927c0dbb1239cf3c178 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" <hjl.to...@gmail.com> Date: Wed, 11 Apr 2018 12:31:21 -0700 Subject: [PATCH] Don't mark IFUNC resolver as only called directly Since IFUNC resolver is called indirectly, don't mark IFUNC resolver as only called directly. This patch adds ifunc_resolver to cgraph_node, sets ifunc_resolver for ifunc attribute and checks ifunc_resolver instead of looking up ifunc attribute. gcc/ Backport from mainline 2018-05-26 H.J. Lu <hongjiu...@intel.com> PR target/85900 PR target/85345 * varasm.c (assemble_alias): Lookup ifunc attribute on error. 2018-05-24 H.J. Lu <hongjiu...@intel.com> PR target/85900 PR target/85345 * varasm.c (assemble_alias): Check ifunc_resolver only on FUNCTION_DECL. 2018-05-22 H.J. Lu <hongjiu...@intel.com> PR target/85345 * cgraph.h (cgraph_node::create): Set ifunc_resolver for ifunc attribute. (cgraph_node::create_alias): Likewise. (cgraph_node::get_availability): Check ifunc_resolver instead of looking up ifunc attribute. * cgraphunit.c (maybe_diag_incompatible_alias): Likewise. * varasm.c (do_assemble_alias): Likewise. (assemble_alias): Likewise. (default_binds_local_p_3): Likewise. * cgraph.h (cgraph_node): Add ifunc_resolver. (cgraph_node::only_called_directly_or_aliased_p): Return false for IFUNC resolver. * lto-cgraph.c (input_node): Set ifunc_resolver for ifunc attribute. * symtab.c (symtab_node::verify_base): Verify that ifunc_resolver is equivalent to lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)). (symtab_node::binds_to_current_def_p): Check ifunc_resolver instead of looking up ifunc attribute. gcc/testsuite/ Backport from mainline 2018-05-24 Rainer Orth <r...@cebitec.uni-bielefeld.de> * gcc.target/i386/pr85345.c: Require ifunc support. 2018-05-22 H.J. Lu <hongjiu...@intel.com> PR target/85345 * gcc.target/i386/pr85345.c: New test. --- gcc/cgraph.c | 7 +++- gcc/cgraph.h | 4 +++ gcc/cgraphunit.c | 2 +- gcc/lto-cgraph.c | 2 ++ gcc/symtab.c | 11 ++++-- gcc/testsuite/gcc.target/i386/pr85345.c | 45 +++++++++++++++++++++++++ gcc/varasm.c | 10 ++++-- 7 files changed, 74 insertions(+), 7 deletions(-) create mode 100644 gcc/testsuite/gcc.target/i386/pr85345.c diff --git a/gcc/cgraph.c b/gcc/cgraph.c index 9a7d54d7cee..9f3a2929f6b 100644 --- a/gcc/cgraph.c +++ b/gcc/cgraph.c @@ -517,6 +517,9 @@ cgraph_node::create (tree decl) g->have_offload = true; } + if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl))) + node->ifunc_resolver = true; + node->register_symbol (); if (DECL_CONTEXT (decl) && TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL) @@ -575,6 +578,8 @@ cgraph_node::create_alias (tree alias, tree target) alias_node->alias = true; if (lookup_attribute ("weakref", DECL_ATTRIBUTES (alias)) != NULL) alias_node->transparent_alias = alias_node->weakref = true; + if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (alias))) + alias_node->ifunc_resolver = true; return alias_node; } @@ -2299,7 +2304,7 @@ cgraph_node::get_availability (symtab_node *ref) avail = AVAIL_AVAILABLE; else if (transparent_alias) ultimate_alias_target (&avail, ref); - else if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)) + else if (ifunc_resolver || lookup_attribute ("noipa", DECL_ATTRIBUTES (decl))) avail = AVAIL_INTERPOSABLE; else if (!externally_visible) diff --git a/gcc/cgraph.h b/gcc/cgraph.h index ee7ebb41c24..afb2745a841 100644 --- a/gcc/cgraph.h +++ b/gcc/cgraph.h @@ -530,6 +530,9 @@ public: /* Set when symbol can be streamed into bytecode for offloading. */ unsigned offloadable : 1; + /* Set when symbol is an IFUNC resolver. */ + unsigned ifunc_resolver : 1; + /* Ordering of all symtab entries. */ int order; @@ -2886,6 +2889,7 @@ cgraph_node::only_called_directly_or_aliased_p (void) { gcc_assert (!global.inlined_to); return (!force_output && !address_taken + && !ifunc_resolver && !used_from_other_partition && !DECL_VIRTUAL_P (decl) && !DECL_STATIC_CONSTRUCTOR (decl) diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c index e418ec04149..212ee7b8340 100644 --- a/gcc/cgraphunit.c +++ b/gcc/cgraphunit.c @@ -1307,7 +1307,7 @@ maybe_diag_incompatible_alias (tree alias, tree target) tree altype = TREE_TYPE (alias); tree targtype = TREE_TYPE (target); - bool ifunc = lookup_attribute ("ifunc", DECL_ATTRIBUTES (alias)); + bool ifunc = cgraph_node::get (alias)->ifunc_resolver; tree funcptr = altype; if (ifunc) diff --git a/gcc/lto-cgraph.c b/gcc/lto-cgraph.c index dcd5391012c..40baf858ca5 100644 --- a/gcc/lto-cgraph.c +++ b/gcc/lto-cgraph.c @@ -1257,6 +1257,8 @@ input_node (struct lto_file_decl_data *file_data, of ipa passes is done. Alays forcingly create a fresh node. */ node = symtab->create_empty (); node->decl = fn_decl; + if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (fn_decl))) + node->ifunc_resolver = 1; node->register_symbol (); } diff --git a/gcc/symtab.c b/gcc/symtab.c index c1533083573..954920b6dff 100644 --- a/gcc/symtab.c +++ b/gcc/symtab.c @@ -998,6 +998,13 @@ symtab_node::verify_base (void) error ("function symbol is not function"); error_found = true; } + else if ((lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)) + != NULL) + != dyn_cast <cgraph_node *> (this)->ifunc_resolver) + { + error ("inconsistent `ifunc' attribute"); + error_found = true; + } } else if (is_a <varpool_node *> (this)) { @@ -2253,13 +2260,13 @@ symtab_node::binds_to_current_def_p (symtab_node *ref) if (transparent_alias) return definition && get_alias_target()->binds_to_current_def_p (ref); - if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl))) + cgraph_node *cnode = dyn_cast <cgraph_node *> (this); + if (cnode && cnode->ifunc_resolver) return false; if (decl_binds_to_current_def_p (decl)) return true; /* Inline clones always binds locally. */ - cgraph_node *cnode = dyn_cast <cgraph_node *> (this); if (cnode && cnode->global.inlined_to) return true; diff --git a/gcc/testsuite/gcc.target/i386/pr85345.c b/gcc/testsuite/gcc.target/i386/pr85345.c new file mode 100644 index 00000000000..4ad9c01a974 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr85345.c @@ -0,0 +1,45 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fcf-protection" } */ +/* { dg-require-ifunc "" } */ +/* { dg-final { scan-assembler-times {\mendbr} 4 } } */ + +int resolver_fn = 0; +int resolved_fn = 0; + +static inline void +do_it_right_at_runtime_A (void) +{ + resolved_fn++; +} + +static inline void +do_it_right_at_runtime_B (void) +{ + resolved_fn++; +} + +static inline void do_it_right_at_runtime (void); + +void do_it_right_at_runtime (void) + __attribute__ ((ifunc ("resolve_do_it_right_at_runtime"))); + +extern int r; +static void (*resolve_do_it_right_at_runtime (void)) (void) +{ + resolver_fn++; + + typeof(do_it_right_at_runtime) *func; + if (r & 1) + func = do_it_right_at_runtime_A; + else + func = do_it_right_at_runtime_B; + + return (void *) func; +} + +int +main () +{ + do_it_right_at_runtime (); + return 0; +} diff --git a/gcc/varasm.c b/gcc/varasm.c index d24bac4ad8f..58efbc6441b 100644 --- a/gcc/varasm.c +++ b/gcc/varasm.c @@ -5821,7 +5821,8 @@ do_assemble_alias (tree decl, tree target) globalize_decl (decl); maybe_assemble_visibility (decl); } - if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl))) + if (TREE_CODE (decl) == FUNCTION_DECL + && cgraph_node::get (decl)->ifunc_resolver) { #if defined (ASM_OUTPUT_TYPE_DIRECTIVE) if (targetm.has_ifunc_p ()) @@ -5904,7 +5905,9 @@ assemble_alias (tree decl, tree target) # else if (!DECL_WEAK (decl)) { - if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl))) + /* NB: ifunc_resolver isn't set when an error is detected. */ + if (TREE_CODE (decl) == FUNCTION_DECL + && lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl))) error_at (DECL_SOURCE_LOCATION (decl), "ifunc is not supported in this configuration"); else @@ -7024,7 +7027,8 @@ default_binds_local_p_3 (const_tree exp, bool shlib, bool weak_dominate, weakref alias. */ if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)) || (TREE_CODE (exp) == FUNCTION_DECL - && lookup_attribute ("ifunc", DECL_ATTRIBUTES (exp)))) + && cgraph_node::get (exp) + && cgraph_node::get (exp)->ifunc_resolver)) return false; /* Static variables are always local. */ -- 2.17.0