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commit a3e2ba88eb09c1eed2f7ed6e17660b345464bb90
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Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
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Date:   Wed Sep 20 05:05:12 2017 +0000
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    2017-09-18  Jeff Law  <law@redhat.com>
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            * explow.c: Include "params.h" and "dumpfile.h".
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            (anti_adjust_stack_and_probe_stack_clash): New function.
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            (get_stack_check_protect): Likewise.
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            (compute_stack_clash_protection_loop_data): Likewise.
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            (emit_stack_clash_protection_loop_start): Likewise.
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            (emit_stack_clash_protection_loop_end): Likewise.
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            (allocate_dynamic_stack_space): Use get_stack_check_protect.
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            Use anti_adjust_stack_and_probe_stack_clash.
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            * explow.h (compute_stack_clash_protection_loop_data): Prototype.
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            (emit_stack_clash_protection_loop_start): Likewise.
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            (emit_stack_clash_protection_loop_end): Likewise.
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            * rtl.h (get_stack_check_protect): Prototype.
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            * target.def (stack_clash_protection_final_dynamic_probe): New hook.
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            * targhooks.c (default_stack_clash_protection_final_dynamic_probe): New.
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            * targhooks.h (default_stack_clash_protection_final_dynamic_probe):
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            Prototype.
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            * doc/tm.texi.in (TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE):
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            Add @hook.
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            * doc/tm.texi: Rebuilt.
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            * config/alpha/alpha.c (alpha_expand_prologue): Likewise.
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            * config/i386/i386.c (ix86_expand_prologue): Likewise.
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            * config/ia64/ia64.c (ia64_expand_prologue): Likewise.
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            * config/mips/mips.c (mips_expand_prologue): Likewise.
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            * config/rs6000/rs6000.c (rs6000_emit_prologue): Likewise.
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            * config/sparc/sparc.c (sparc_expand_prologue): Likewise.
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            (sparc_flat_expand_prologue): Likewise.
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            * gcc.dg/stack-check-3.c: New test.
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    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252995 138bc75d-0d04-0410-961f-82ee72b054a4
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diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c
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index 2874b8454a9..5402f5213d6 100644
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--- a/gcc/config/alpha/alpha.c
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+++ b/gcc/config/alpha/alpha.c
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@@ -7625,7 +7625,7 @@ alpha_expand_prologue (void)
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   probed_size = frame_size;
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   if (flag_stack_check)
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-    probed_size += STACK_CHECK_PROTECT;
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+    probed_size += get_stack_check_protect ();
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   if (probed_size <= 32768)
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     {
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diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
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index e36726ba722..d996fd160e8 100644
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--- a/gcc/config/i386/i386.c
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+++ b/gcc/config/i386/i386.c
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@@ -10544,12 +10544,12 @@ ix86_expand_prologue (void)
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 	  HOST_WIDE_INT size = allocate;
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 	  if (TARGET_64BIT && size >= (HOST_WIDE_INT) 0x80000000)
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-	    size = 0x80000000 - STACK_CHECK_PROTECT - 1;
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+	    size = 0x80000000 - get_stack_check_protect () - 1;
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 	  if (TARGET_STACK_PROBE)
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-	    ix86_emit_probe_stack_range (0, size + STACK_CHECK_PROTECT);
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+	    ix86_emit_probe_stack_range (0, size + get_stack_check_protect ());
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 	  else
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-	    ix86_emit_probe_stack_range (STACK_CHECK_PROTECT, size);
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+	    ix86_emit_probe_stack_range (get_stack_check_protect (), size);
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 	}
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     }
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diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
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index 50bbad6661c..390983936e8 100644
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--- a/gcc/config/ia64/ia64.c
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+++ b/gcc/config/ia64/ia64.c
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@@ -3435,7 +3435,7 @@ ia64_expand_prologue (void)
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     current_function_static_stack_size = current_frame_info.total_size;
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   if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
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-    ia64_emit_probe_stack_range (STACK_CHECK_PROTECT,
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+    ia64_emit_probe_stack_range (get_stack_check_protect (),
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 				 current_frame_info.total_size,
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 				 current_frame_info.n_input_regs
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 				   + current_frame_info.n_local_regs);
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diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
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index 41c5d6b6b1f..9b7eb678f19 100644
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--- a/gcc/config/mips/mips.c
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+++ b/gcc/config/mips/mips.c
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@@ -10746,7 +10746,7 @@ mips_expand_prologue (void)
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     current_function_static_stack_size = size;
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   if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK && size)
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-    mips_emit_probe_stack_range (STACK_CHECK_PROTECT, size);
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+    mips_emit_probe_stack_range (get_stack_check_protect (), size);
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   /* Save the registers.  Allocate up to MIPS_MAX_FIRST_STACK_STEP
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      bytes beforehand; this is enough to cover the register save area
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diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
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index 15583055895..a9052c6becf 100644
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--- a/gcc/config/rs6000/rs6000.c
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+++ b/gcc/config/rs6000/rs6000.c
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@@ -23214,7 +23214,8 @@ rs6000_emit_prologue (void)
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     current_function_static_stack_size = info->total_size;
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   if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK && info->total_size)
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-    rs6000_emit_probe_stack_range (STACK_CHECK_PROTECT, info->total_size);
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+    rs6000_emit_probe_stack_range (get_stack_check_protect (),
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+				   info->total_size);
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   if (TARGET_FIX_AND_CONTINUE)
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     {
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diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
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index e5d326cdf23..e5e93c80261 100644
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--- a/gcc/config/sparc/sparc.c
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+++ b/gcc/config/sparc/sparc.c
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@@ -5431,7 +5431,7 @@ sparc_expand_prologue (void)
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     current_function_static_stack_size = size;
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   if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK && size)
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-    sparc_emit_probe_stack_range (STACK_CHECK_PROTECT, size);
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+    sparc_emit_probe_stack_range (get_stack_check_protect (), size);
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   if (size == 0)
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     ; /* do nothing.  */
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@@ -5533,7 +5533,7 @@ sparc_flat_expand_prologue (void)
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     current_function_static_stack_size = size;
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   if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK && size)
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-    sparc_emit_probe_stack_range (STACK_CHECK_PROTECT, size);
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+    sparc_emit_probe_stack_range (get_stack_check_protect (), size);
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   if (sparc_save_local_in_regs_p)
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     emit_save_or_restore_local_in_regs (stack_pointer_rtx, SPARC_STACK_BIAS,
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diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
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index 6b18a2724bc..eeef757bf5b 100644
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--- a/gcc/doc/tm.texi
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+++ b/gcc/doc/tm.texi
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@@ -3571,6 +3571,10 @@ GCC computed the default from the values of the above macros and you will
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 normally not need to override that default.
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 @end defmac
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+@deftypefn {Target Hook} bool TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE (rtx @var{residual})
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+Some targets make optimistic assumptions about the state of stack probing when they emit their prologues.  On such targets a probe into the end of any dynamically allocated space is likely required for safety against stack clash style attacks.  Define this variable to return nonzero if such a probe is required or zero otherwise.  You need not define this macro if it would always have the value zero.
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+@end deftypefn
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+
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 @need 2000
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 @node Frame Registers
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 @subsection Registers That Address the Stack Frame
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diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
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index 7d0b3c73b2f..6707ca87236 100644
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--- a/gcc/doc/tm.texi.in
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+++ b/gcc/doc/tm.texi.in
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@@ -3539,6 +3539,8 @@ GCC computed the default from the values of the above macros and you will
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 normally not need to override that default.
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 @end defmac
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+@hook TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE
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+
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 @need 2000
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 @node Frame Registers
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 @subsection Registers That Address the Stack Frame
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diff --git a/gcc/explow.c b/gcc/explow.c
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index 7da8bc75f19..2526e8513b7 100644
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--- a/gcc/explow.c
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+++ b/gcc/explow.c
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@@ -40,8 +40,11 @@ along with GCC; see the file COPYING3.  If not see
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 #include "target.h"
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 #include "common/common-target.h"
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 #include "output.h"
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+#include "params.h"
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+#include "dumpfile.h"
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 static rtx break_out_memory_refs (rtx);
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+static void anti_adjust_stack_and_probe_stack_clash (rtx);
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 /* Truncate and perhaps sign-extend C as appropriate for MODE.  */
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@@ -1140,6 +1143,29 @@ update_nonlocal_goto_save_area (void)
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   emit_stack_save (SAVE_NONLOCAL, &r_save);
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 }
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+/* Return the number of bytes to "protect" on the stack for -fstack-check.
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+
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+   "protect" in the context of -fstack-check means how many bytes we
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+   should always ensure are available on the stack.  More importantly
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+   this is how many bytes are skipped when probing the stack.
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+
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+   On some targets we want to reuse the -fstack-check prologue support
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+   to give a degree of protection against stack clashing style attacks.
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+
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+   In that scenario we do not want to skip bytes before probing as that
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+   would render the stack clash protections useless.
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+
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+   So we never use STACK_CHECK_PROTECT directly.  Instead we indirect though
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+   this helper which allows us to provide different values for
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+   -fstack-check and -fstack-clash-protection.  */
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+HOST_WIDE_INT
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+get_stack_check_protect (void)
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+{
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+  if (flag_stack_clash_protection)
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+    return 0;
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+ return STACK_CHECK_PROTECT;
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+}
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+
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 /* Return an rtx representing the address of an area of memory dynamically
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    pushed on the stack.
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@@ -1393,7 +1419,7 @@ allocate_dynamic_stack_space (rtx size, unsigned size_align,
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     probe_stack_range (STACK_OLD_CHECK_PROTECT + STACK_CHECK_MAX_FRAME_SIZE,
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 		       size);
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   else if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
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-    probe_stack_range (STACK_CHECK_PROTECT, size);
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+    probe_stack_range (get_stack_check_protect (), size);
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   /* Don't let anti_adjust_stack emit notes.  */
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   suppress_reg_args_size = true;
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@@ -1451,6 +1477,8 @@ allocate_dynamic_stack_space (rtx size, unsigned size_align,
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       if (flag_stack_check && STACK_CHECK_MOVING_SP)
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 	anti_adjust_stack_and_probe (size, false);
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+      else if (flag_stack_clash_protection)
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+	anti_adjust_stack_and_probe_stack_clash (size);
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       else
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 	anti_adjust_stack (size);
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@@ -1712,6 +1740,219 @@ probe_stack_range (HOST_WIDE_INT first, rtx size)
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     }
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 }
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+/* Compute parameters for stack clash probing a dynamic stack
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+   allocation of SIZE bytes.
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+
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+   We compute ROUNDED_SIZE, LAST_ADDR, RESIDUAL and PROBE_INTERVAL.
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+
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+   Additionally we conditionally dump the type of probing that will
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+   be needed given the values computed.  */
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+
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+void
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+compute_stack_clash_protection_loop_data (rtx *rounded_size, rtx *last_addr,
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+					  rtx *residual,
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+					  HOST_WIDE_INT *probe_interval,
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+					  rtx size)
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+{
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+  /* Round SIZE down to STACK_CLASH_PROTECTION_PROBE_INTERVAL */
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+  *probe_interval
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+    = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL);
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+  *rounded_size = simplify_gen_binary (AND, Pmode, size,
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+				        GEN_INT (-*probe_interval));
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+
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+  /* Compute the value of the stack pointer for the last iteration.
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+     It's just SP + ROUNDED_SIZE.  */
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+  rtx rounded_size_op = force_operand (*rounded_size, NULL_RTX);
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+  *last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
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+					      stack_pointer_rtx,
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+					      rounded_size_op),
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+			      NULL_RTX);
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+
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+  /* Compute any residuals not allocated by the loop above.  Residuals
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+     are just the ROUNDED_SIZE - SIZE.  */
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+  *residual = simplify_gen_binary (MINUS, Pmode, size, *rounded_size);
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+
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+  /* Dump key information to make writing tests easy.  */
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+  if (dump_file)
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+    {
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+      if (*rounded_size == CONST0_RTX (Pmode))
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+	fprintf (dump_file,
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+		 "Stack clash skipped dynamic allocation and probing loop.\n");
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+      else if (GET_CODE (*rounded_size) == CONST_INT
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+	       && INTVAL (*rounded_size) <= 4 * *probe_interval)
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+	fprintf (dump_file,
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+		 "Stack clash dynamic allocation and probing inline.\n");
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+      else if (GET_CODE (*rounded_size) == CONST_INT)
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+	fprintf (dump_file,
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+		 "Stack clash dynamic allocation and probing in "
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+		 "rotated loop.\n");
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+      else
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+	fprintf (dump_file,
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+		 "Stack clash dynamic allocation and probing in loop.\n");
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+
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+      if (*residual != CONST0_RTX (Pmode))
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+	fprintf (dump_file,
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+		 "Stack clash dynamic allocation and probing residuals.\n");
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+      else
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+	fprintf (dump_file,
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+		 "Stack clash skipped dynamic allocation and "
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+		 "probing residuals.\n");
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+    }
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+}
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+
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+/* Emit the start of an allocate/probe loop for stack
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+   clash protection.
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+
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+   LOOP_LAB and END_LAB are returned for use when we emit the
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+   end of the loop.
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+
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+   LAST addr is the value for SP which stops the loop.  */
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+void
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+emit_stack_clash_protection_probe_loop_start (rtx *loop_lab,
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+					      rtx *end_lab,
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+					      rtx last_addr,
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+					      bool rotated)
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+{
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+  /* Essentially we want to emit any setup code, the top of loop
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+     label and the comparison at the top of the loop.  */
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+  *loop_lab = gen_label_rtx ();
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+  *end_lab = gen_label_rtx ();
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+
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+  emit_label (*loop_lab);
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+  if (!rotated)
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+    emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, EQ, NULL_RTX,
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+			     Pmode, 1, *end_lab);
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+}
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+
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+/* Emit the end of a stack clash probing loop.
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+
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+   This consists of just the jump back to LOOP_LAB and
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+   emitting END_LOOP after the loop.  */
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+
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+void
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+emit_stack_clash_protection_probe_loop_end (rtx loop_lab, rtx end_loop,
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+					    rtx last_addr, bool rotated)
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+{
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+  if (rotated)
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+    emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, NE, NULL_RTX,
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+			     Pmode, 1, loop_lab);
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+  else
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+    emit_jump (loop_lab);
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+
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+  emit_label (end_loop);
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+
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+}
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+
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+/* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
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+   while probing it.  This pushes when SIZE is positive.  SIZE need not
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+   be constant.
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+
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+   This is subtly different than anti_adjust_stack_and_probe to try and
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+   prevent stack-clash attacks
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+
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+     1. It must assume no knowledge of the probing state, any allocation
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+	must probe.
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+
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+	Consider the case of a 1 byte alloca in a loop.  If the sum of the
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+	allocations is large, then this could be used to jump the guard if
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+	probes were not emitted.
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+
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+     2. It never skips probes, whereas anti_adjust_stack_and_probe will
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+	skip probes on the first couple PROBE_INTERVALs on the assumption
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+	they're done elsewhere.
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+
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+     3. It only allocates and probes SIZE bytes, it does not need to
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+	allocate/probe beyond that because this probing style does not
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+	guarantee signal handling capability if the guard is hit.  */
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+
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+static void
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+anti_adjust_stack_and_probe_stack_clash (rtx size)
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+{
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+  /* First ensure SIZE is Pmode.  */
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+  if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
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+    size = convert_to_mode (Pmode, size, 1);
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+
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+  /* We can get here with a constant size on some targets.  */
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+  rtx rounded_size, last_addr, residual;
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+  HOST_WIDE_INT probe_interval;
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+  compute_stack_clash_protection_loop_data (&rounded_size, &last_addr,
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+					    &residual, &probe_interval, size);
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+
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+  if (rounded_size != CONST0_RTX (Pmode))
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+    {
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+      if (INTVAL (rounded_size) <= 4 * probe_interval)
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+	{
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+	  for (HOST_WIDE_INT i = 0;
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+	       i < INTVAL (rounded_size);
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+	       i += probe_interval)
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+	    {
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+	      anti_adjust_stack (GEN_INT (probe_interval));
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+
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+	      /* The prologue does not probe residuals.  Thus the offset
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+		 here to probe just beyond what the prologue had already
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+		 allocated.  */
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+	      emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
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+					       (probe_interval
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+						- GET_MODE_SIZE (word_mode))));
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+	      emit_insn (gen_blockage ());
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+	    }
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+	}
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+      else
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+	{
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+	  rtx loop_lab, end_loop;
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+	  bool rotate_loop = GET_CODE (rounded_size) == CONST_INT;
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+	  emit_stack_clash_protection_probe_loop_start (&loop_lab, &end_loop,
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+							last_addr, rotate_loop);
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+
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+	  anti_adjust_stack (GEN_INT (probe_interval));
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+
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+	  /* The prologue does not probe residuals.  Thus the offset here
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+	     to probe just beyond what the prologue had already allocated.  */
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+	  emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
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+					   (probe_interval
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+					    - GET_MODE_SIZE (word_mode))));
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+
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+	  emit_stack_clash_protection_probe_loop_end (loop_lab, end_loop,
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+						      last_addr, rotate_loop);
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+	  emit_insn (gen_blockage ());
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+	}
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+    }
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+
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+  if (residual != CONST0_RTX (Pmode))
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+    {
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+      rtx x = force_reg (Pmode, plus_constant (Pmode, residual,
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+					       -GET_MODE_SIZE (word_mode)));
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+      anti_adjust_stack (residual);
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+      emit_stack_probe (gen_rtx_PLUS (Pmode, stack_pointer_rtx, x));
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+      emit_insn (gen_blockage ());
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+    }
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+
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+  /* Some targets make optimistic assumptions in their prologues about
85359c
+     how the caller may have probed the stack.  Make sure we honor
85359c
+     those assumptions when needed.  */
85359c
+  if (size != CONST0_RTX (Pmode)
85359c
+      && targetm.stack_clash_protection_final_dynamic_probe (residual))
85359c
+    {
85359c
+      /* Ideally we would just probe at *sp.  However, if SIZE is not
85359c
+	 a compile-time constant, but is zero at runtime, then *sp
85359c
+	 might hold live data.  So probe at *sp if we know that
85359c
+	 an allocation was made, otherwise probe into the red zone
85359c
+	 which is obviously undesirable.  */
85359c
+      if (GET_CODE (size) == CONST_INT)
85359c
+	{
85359c
+	  emit_stack_probe (stack_pointer_rtx);
85359c
+	  emit_insn (gen_blockage ());
85359c
+	}
85359c
+      else
85359c
+	{
85359c
+	  emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
85359c
+					   -GET_MODE_SIZE (word_mode)));
85359c
+	  emit_insn (gen_blockage ());
85359c
+	}
85359c
+    }
85359c
+}
85359c
+
85359c
+
85359c
 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
85359c
    while probing it.  This pushes when SIZE is positive.  SIZE need not
85359c
    be constant.  If ADJUST_BACK is true, adjust back the stack pointer
85359c
diff --git a/gcc/rtl.h b/gcc/rtl.h
85359c
index 91f3387c701..ab8ec27418d 100644
85359c
--- a/gcc/rtl.h
85359c
+++ b/gcc/rtl.h
85359c
@@ -1756,6 +1756,17 @@ extern int currently_expanding_to_rtl;
85359c
 /* In explow.c */
85359c
 extern HOST_WIDE_INT trunc_int_for_mode	(HOST_WIDE_INT, enum machine_mode);
85359c
 extern rtx plus_constant (enum machine_mode, rtx, HOST_WIDE_INT);
85359c
+extern HOST_WIDE_INT get_stack_check_protect (void);
85359c
+
85359c
+/* Support for building allocation/probing loops for stack-clash
85359c
+   protection of dyamically allocated stack space.  */
85359c
+extern void compute_stack_clash_protection_loop_data (rtx *, rtx *, rtx *,
85359c
+						      HOST_WIDE_INT *, rtx);
85359c
+extern void emit_stack_clash_protection_probe_loop_start (rtx *, rtx *,
85359c
+							  rtx, bool);
85359c
+extern void emit_stack_clash_protection_probe_loop_end (rtx, rtx,
85359c
+							rtx, bool);
85359c
+
85359c
 
85359c
 /* In rtl.c */
85359c
 extern rtx rtx_alloc_stat (RTX_CODE MEM_STAT_DECL);
85359c
diff --git a/gcc/target.def b/gcc/target.def
85359c
index 4d6081c3121..eb2bd46f7a1 100644
85359c
--- a/gcc/target.def
85359c
+++ b/gcc/target.def
85359c
@@ -2580,6 +2580,13 @@ DEFHOOK
85359c
  void, (void),
85359c
  hook_void_void)
85359c
 
85359c
+DEFHOOK
85359c
+(stack_clash_protection_final_dynamic_probe,
85359c
+ "Some targets make optimistic assumptions about the state of stack probing when they emit their prologues.  On such targets a probe into the end of any dynamically allocated space is likely required for safety against stack clash style attacks.  Define this variable to return nonzero if such a probe is required or zero otherwise.  You need not define this macro if it would always have the value zero.",
85359c
+ bool, (rtx residual),
85359c
+ default_stack_clash_protection_final_dynamic_probe)
85359c
+
85359c
+
85359c
 /* Functions specific to the C family of frontends.  */
85359c
 #undef HOOK_PREFIX
85359c
 #define HOOK_PREFIX "TARGET_C_"
85359c
diff --git a/gcc/targhooks.c b/gcc/targhooks.c
85359c
index f6aa9907225..be23875538d 100644
85359c
--- a/gcc/targhooks.c
85359c
+++ b/gcc/targhooks.c
85359c
@@ -1557,4 +1557,10 @@ default_canonicalize_comparison (int *, rtx *, rtx *, bool)
85359c
 {
85359c
 }
85359c
 
85359c
+bool
85359c
+default_stack_clash_protection_final_dynamic_probe (rtx residual ATTRIBUTE_UNUSED)
85359c
+{
85359c
+  return 0;
85359c
+}
85359c
+
85359c
 #include "gt-targhooks.h"
85359c
diff --git a/gcc/targhooks.h b/gcc/targhooks.h
85359c
index b64274d3ff9..4acf33fae08 100644
85359c
--- a/gcc/targhooks.h
85359c
+++ b/gcc/targhooks.h
85359c
@@ -195,3 +195,4 @@ extern const char *default_pch_valid_p (const void *, size_t);
85359c
 extern void default_asm_output_ident_directive (const char*);
85359c
 
85359c
 extern bool default_member_type_forces_blk (const_tree, enum machine_mode);
85359c
+extern bool default_stack_clash_protection_final_dynamic_probe (rtx);
85359c
diff --git a/gcc/testsuite/gcc.dg/stack-check-3.c b/gcc/testsuite/gcc.dg/stack-check-3.c
85359c
new file mode 100644
85359c
index 00000000000..58fb65649ee
85359c
--- /dev/null
85359c
+++ b/gcc/testsuite/gcc.dg/stack-check-3.c
85359c
@@ -0,0 +1,86 @@
85359c
+/* The goal here is to ensure that dynamic allocations via vlas or
85359c
+   alloca calls receive probing.
85359c
+
85359c
+   Scanning the RTL or assembly code seems like insanity here as does
85359c
+   checking for particular allocation sizes and probe offsets.  For
85359c
+   now we just verify that there's an allocation + probe loop and
85359c
+   residual allocation + probe for f?.  */
85359c
+
85359c
+/* { dg-do compile } */
85359c
+/* { dg-options "-O2 -fstack-clash-protection -fdump-rtl-expand -fno-optimize-sibling-calls --param stack-clash-protection-probe-interval=4096 --param stack-clash-protection-guard-size=4096" } */
85359c
+/* { dg-require-effective-target supports_stack_clash_protection } */
85359c
+
85359c
+__attribute__((noinline, noclone)) void
85359c
+foo (char *p)
85359c
+{
85359c
+  asm volatile ("" : : "r" (p) : "memory");
85359c
+}
85359c
+
85359c
+/* Simple VLA, no other locals. */
85359c
+__attribute__((noinline, noclone)) void
85359c
+f0 (int x)
85359c
+{
85359c
+  char vla[x];
85359c
+  foo (vla);
85359c
+}
85359c
+
85359c
+/* Simple VLA, small local frame.  */
85359c
+__attribute__((noinline, noclone)) void
85359c
+f1 (int x)
85359c
+{
85359c
+  char locals[128];
85359c
+  char vla[x];
85359c
+  foo (vla);
85359c
+}
85359c
+
85359c
+/* Small constant alloca, no other locals. */
85359c
+__attribute__((noinline, noclone)) void
85359c
+f2 (int x)
85359c
+{
85359c
+  char *vla = __builtin_alloca (128);
85359c
+  foo (vla);
85359c
+}
85359c
+
85359c
+/* Big constant alloca, small local frame.  */
85359c
+__attribute__((noinline, noclone)) void
85359c
+f3 (int x)
85359c
+{
85359c
+  char locals[128];
85359c
+  char *vla = __builtin_alloca (16384);
85359c
+  foo (vla);
85359c
+}
85359c
+
85359c
+/* Big constant alloca, small local frame.  */
85359c
+__attribute__((noinline, noclone)) void
85359c
+f3a (int x)
85359c
+{
85359c
+  char locals[128];
85359c
+  char *vla = __builtin_alloca (32768);
85359c
+  foo (vla);
85359c
+}
85359c
+
85359c
+/* Nonconstant alloca, no other locals. */
85359c
+__attribute__((noinline, noclone)) void
85359c
+f4 (int x)
85359c
+{
85359c
+  char *vla = __builtin_alloca (x);
85359c
+  foo (vla);
85359c
+}
85359c
+
85359c
+/* Nonconstant alloca, small local frame.  */
85359c
+__attribute__((noinline, noclone)) void
85359c
+f5 (int x)
85359c
+{
85359c
+  char locals[128];
85359c
+  char *vla = __builtin_alloca (x);
85359c
+  foo (vla);
85359c
+}
85359c
+
85359c
+/* { dg-final { scan-rtl-dump-times "allocation and probing residuals" 7 "expand" } } */
85359c
+
85359c
+
85359c
+/* { dg-final { scan-rtl-dump-times "allocation and probing in loop" 7 "expand" { target callee_realigns_stack } } } */
85359c
+/* { dg-final { scan-rtl-dump-times "allocation and probing in loop" 4 "expand" { target { ! callee_realigns_stack } } } } */
85359c
+/* { dg-final { scan-rtl-dump-times "allocation and probing in rotated loop" 1 "expand" { target { ! callee_realigns_stack } } } } */
85359c
+/* { dg-final { scan-rtl-dump-times "allocation and probing inline" 1 "expand" { target { ! callee_realigns_stack } } } } */
85359c
+/* { dg-final { scan-rtl-dump-times "skipped dynamic allocation and probing loop" 1 "expand" { target { ! callee_realigns_stack } } } } */