Changed comment, corrected formatting, and removed Init(SSP_TLS). Thanks!
=====
2013-04-12 Andrew Hsieh <andrewhsieh.google.com>
* config/i386/i386.opt: New option mstack-protector-guard=.
* config/i386/i386-opts.h: Add enum stack_protector_guard.
* config/i386/i386.h: Introduce TARGET_SSP_GLOBAL_GUARD and
TARGET_SSP_TLS_GUARD.
* config/i386/i386.c (ix86_option_override_internal): Default
to SSP_TLS unless it's bionic
* config/i386/i386.md: define_expand/insn "stack_protect_set/test..."
if TARGET_SSP_TLS_GUARD
* doc/invoke.texi (i386 Option): Document.
Index: gcc/config/i386/i386.opt
===================================================================
--- gcc/config/i386/i386.opt (revision 197837)
+++ gcc/config/i386/i386.opt (working copy)
@@ -626,3 +626,17 @@
mrtm
Target Report Mask(ISA_RTM) Var(ix86_isa_flags) Save
Support RTM built-in functions and code generation
+
+mstack-protector-guard=
+Target RejectNegative Joined Enum(stack_protector_guard)
Var(ix86_stack_protector_guard)
+Use given stack-protector guard
+
+Enum
+Name(stack_protector_guard) Type(enum stack_protector_guard)
+Known stack protector guard (for use with the -mstack-protector-guard= option):
+
+EnumValue
+Enum(stack_protector_guard) String(tls) Value(SSP_TLS)
+
+EnumValue
+Enum(stack_protector_guard) String(global) Value(SSP_GLOBAL)
Index: gcc/config/i386/i386.md
===================================================================
--- gcc/config/i386/i386.md (revision 197837)
+++ gcc/config/i386/i386.md (working copy)
@@ -17058,7 +17058,7 @@
(define_expand "stack_protect_set"
[(match_operand 0 "memory_operand")
(match_operand 1 "memory_operand")]
- "!TARGET_HAS_BIONIC"
+ "TARGET_SSP_TLS_GUARD"
{
rtx (*insn)(rtx, rtx);
@@ -17083,7 +17083,7 @@
UNSPEC_SP_SET))
(set (match_scratch:PTR 2 "=&r") (const_int 0))
(clobber (reg:CC FLAGS_REG))]
- "!TARGET_HAS_BIONIC"
+ "TARGET_SSP_TLS_GUARD"
"mov{<imodesuffix>}\t{%1, %2|%2, %1}\;mov{<imodesuffix>}\t{%2,
%0|%0, %2}\;xor{l}\t%k2, %k2"
[(set_attr "type" "multi")])
@@ -17101,7 +17101,7 @@
[(match_operand 0 "memory_operand")
(match_operand 1 "memory_operand")
(match_operand 2)]
- "!TARGET_HAS_BIONIC"
+ "TARGET_SSP_TLS_GUARD"
{
rtx flags = gen_rtx_REG (CCZmode, FLAGS_REG);
@@ -17131,7 +17131,7 @@
(match_operand:PTR 2 "memory_operand" "m")]
UNSPEC_SP_TEST))
(clobber (match_scratch:PTR 3 "=&r"))]
- "!TARGET_HAS_BIONIC"
+ "TARGET_SSP_TLS_GUARD"
"mov{<imodesuffix>}\t{%1, %3|%3, %1}\;xor{<imodesuffix>}\t{%2, %3|%3, %2}"
[(set_attr "type" "multi")])
Index: gcc/config/i386/i386-opts.h
===================================================================
--- gcc/config/i386/i386-opts.h (revision 197837)
+++ gcc/config/i386/i386-opts.h (working copy)
@@ -85,4 +85,9 @@
ix86_veclibabi_type_acml
};
+enum stack_protector_guard {
+ SSP_TLS, /* per-thread canary in TLS block */
+ SSP_GLOBAL /* global canary */
+};
+
#endif
Index: gcc/config/i386/i386.c
===================================================================
--- gcc/config/i386/i386.c (revision 197837)
+++ gcc/config/i386/i386.c (working copy)
@@ -3922,6 +3922,10 @@
if (main_args_p)
target_option_default_node = target_option_current_node
= build_target_option_node ();
+
+ /* Handle stack protector */
+ if (!global_options_set.x_ix86_stack_protector_guard)
+ ix86_stack_protector_guard = TARGET_HAS_BIONIC ? SSP_GLOBAL : SSP_TLS;
}
/* Implement the TARGET_OPTION_OVERRIDE hook. */
Index: gcc/config/i386/i386.h
===================================================================
--- gcc/config/i386/i386.h (revision 197837)
+++ gcc/config/i386/i386.h (working copy)
@@ -486,6 +486,9 @@
#define TARGET_TLS_DIRECT_SEG_REFS_DEFAULT 0
#endif
+#define TARGET_SSP_GLOBAL_GUARD (ix86_stack_protector_guard == SSP_GLOBAL)
+#define TARGET_SSP_TLS_GUARD (ix86_stack_protector_guard == SSP_TLS)
+
/* Fence to use after loop using storent. */
extern tree x86_mfence;
Index: gcc/doc/invoke.texi
===================================================================
--- gcc/doc/invoke.texi (revision 197837)
+++ gcc/doc/invoke.texi (working copy)
@@ -656,7 +656,8 @@
-mcmodel=@var{code-model} -mabi=@var{name} -maddress-mode=@var{mode} @gol
-m32 -m64 -mx32 -mlarge-data-threshold=@var{num} @gol
-msse2avx -mfentry -m8bit-idiv @gol
--mavx256-split-unaligned-load -mavx256-split-unaligned-store}
+-mavx256-split-unaligned-load -mavx256-split-unaligned-store @gol
+-mstack-protector-guard=@var{guard}}
@emph{i386 and x86-64 Windows Options}
@gccoptlist{-mconsole -mcygwin -mno-cygwin -mdll @gol
@@ -14521,6 +14522,13 @@
@opindex avx256-split-unaligned-store
Split 32-byte AVX unaligned load and store.
+@item -mstack-protector-guard=@var{guard}
+@opindex mstack-protector-guard=@var{guard}
+Generate stack protection code using canary at @var{guard}. Supported
+locations are @samp{global} or @samp{tls} per thread at %gs:20 (the default).
+This option has effect only when @option{-fstack-protector}
+or @option{-fstack-protector-all} is also specified.
+
@end table
These @samp{-m} switches are supported in addition to the above
On Fri, Apr 12, 2013 at 5:49 PM, Uros Bizjak <ubiz...@gmail.com> wrote:
> On Fri, Apr 12, 2013 at 10:43 AM, Andrew Hsieh <andrewhs...@google.com> wrote:
>> Introduced TARGET_SSP_GLOBAL_GUARD and TARGET_SSP_TLS_GUARD as suggested.
>> As for handling default in ix86_option_override_internal, is it
>> possible to achieve the same "default to SSP_GLOBAL if bionic"
>> entirely in i386.opt?
>
> No, AFAIK option system won't dynamically initialize a variable.
>
> +mstack-protector-guard=
> +Target RejectNegative Joined Enum(stack_protector_guard)
> Var(ix86_stack_protector_
> guard) Init(SSP_TLS)
> +Use given stack-protector guard
>
> So, you don't need Init in the code above ...
>
>> +
>> + /* Handle stack protector */
>> + if (!global_options_set.x_ix86_stack_protector_guard)
>> + {
>> + ix86_stack_protector_guard = TARGET_HAS_BIONIC? SSP_GLOBAL : SSP_TLS;
>> + }
>
> ... since you initialize it here.
>
> Please, remove the braces here.
>
> Also, as Jakub said, please also update the comment for 32bit case.
>
> The patch is OK with these changes.
>
> Thanks,
> Uros.
--
Thanks,
Andrew
