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462 lines
16 KiB
462 lines
16 KiB
commit 5d7a77ede3e91948ee125bd82533d7e692543fff |
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Author: Jeff Law <law@redhat.com> |
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Date: Mon Oct 2 13:43:01 2017 -0600 |
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aarch64 support |
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diff --git a/gcc/config/aarch64/.aarch64.c.rej.swp b/gcc/config/aarch64/.aarch64.c.rej.swp |
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new file mode 100644 |
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index 00000000000..b899e21b855 |
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Binary files /dev/null and b/gcc/config/aarch64/.aarch64.c.rej.swp differ |
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diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c |
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index cadf193cfcf..e08632ffa88 100644 |
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--- a/gcc/config/aarch64/aarch64.c |
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+++ b/gcc/config/aarch64/aarch64.c |
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@@ -45,6 +45,8 @@ |
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#include "gimple.h" |
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#include "optabs.h" |
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#include "dwarf2.h" |
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+#include "params.h" |
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+#include "dumpfile.h" |
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|
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/* Classifies an address. |
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|
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@@ -1696,7 +1698,14 @@ aarch64_output_probe_stack_range (rtx reg1, rtx reg2) |
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output_asm_insn ("sub\t%0, %0, %1", xops); |
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|
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/* Probe at TEST_ADDR. */ |
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- output_asm_insn ("str\txzr, [%0]", xops); |
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+ if (flag_stack_clash_protection) |
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+ { |
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+ gcc_assert (xops[0] == stack_pointer_rtx); |
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+ xops[1] = GEN_INT (PROBE_INTERVAL - 8); |
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+ output_asm_insn ("str\txzr, [%0, %1]", xops); |
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+ } |
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+ else |
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+ output_asm_insn ("str\txzr, [%0]", xops); |
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|
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/* Test if TEST_ADDR == LAST_ADDR. */ |
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xops[1] = reg2; |
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@@ -2001,6 +2010,123 @@ aarch64_save_or_restore_callee_save_registers (HOST_WIDE_INT offset, |
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base_rtx, cfi_ops); |
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} |
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|
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+/* Allocate SIZE bytes of stack space using SCRATCH_REG as a scratch |
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+ register. */ |
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+ |
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+static void |
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+aarch64_allocate_and_probe_stack_space (int scratchreg, HOST_WIDE_INT size) |
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+{ |
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+ HOST_WIDE_INT probe_interval |
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+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL); |
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+ HOST_WIDE_INT guard_size |
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+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE); |
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+ HOST_WIDE_INT guard_used_by_caller = 1024; |
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+ |
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+ /* SIZE should be large enough to require probing here. ie, it |
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+ must be larger than GUARD_SIZE - GUARD_USED_BY_CALLER. |
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+ |
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+ We can allocate GUARD_SIZE - GUARD_USED_BY_CALLER as a single chunk |
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+ without any probing. */ |
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+ gcc_assert (size >= guard_size - guard_used_by_caller); |
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+ aarch64_sub_sp (scratchreg, guard_size - guard_used_by_caller, true); |
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+ HOST_WIDE_INT orig_size = size; |
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+ size -= (guard_size - guard_used_by_caller); |
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+ |
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+ HOST_WIDE_INT rounded_size = size & -probe_interval; |
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+ HOST_WIDE_INT residual = size - rounded_size; |
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+ |
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+ /* We can handle a small number of allocations/probes inline. Otherwise |
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+ punt to a loop. */ |
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+ if (rounded_size && rounded_size <= 4 * probe_interval) |
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+ { |
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+ /* We don't use aarch64_sub_sp here because we don't want to |
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+ repeatedly load SCRATCHREG. */ |
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+ rtx scratch_rtx = gen_rtx_REG (Pmode, scratchreg); |
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+ if (probe_interval > ARITH_FACTOR) |
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+ emit_move_insn (scratch_rtx, GEN_INT (-probe_interval)); |
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+ else |
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+ scratch_rtx = GEN_INT (-probe_interval); |
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+ |
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+ for (HOST_WIDE_INT i = 0; i < rounded_size; i += probe_interval) |
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+ { |
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+ rtx insn = emit_insn (gen_add2_insn (stack_pointer_rtx, scratch_rtx)); |
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+ add_reg_note (insn, REG_STACK_CHECK, const0_rtx); |
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+ |
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+ if (probe_interval > ARITH_FACTOR) |
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+ { |
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+ RTX_FRAME_RELATED_P (insn) = 1; |
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+ rtx adj = plus_constant (Pmode, stack_pointer_rtx, -probe_interval); |
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+ add_reg_note (insn, REG_CFA_ADJUST_CFA, |
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+ gen_rtx_SET (VOIDmode, stack_pointer_rtx, adj)); |
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+ } |
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+ |
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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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+ dump_stack_clash_frame_info (PROBE_INLINE, size != rounded_size); |
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+ } |
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+ else if (rounded_size) |
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+ { |
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+ /* Compute the ending address. */ |
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+ rtx temp = gen_rtx_REG (word_mode, scratchreg); |
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+ emit_move_insn (temp, GEN_INT (-rounded_size)); |
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+ rtx insn = emit_insn (gen_add3_insn (temp, stack_pointer_rtx, temp)); |
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+ |
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+ /* For the initial allocation, we don't have a frame pointer |
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+ set up, so we always need CFI notes. If we're doing the |
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+ final allocation, then we may have a frame pointer, in which |
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+ case it is the CFA, otherwise we need CFI notes. |
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+ |
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+ We can determine which allocation we are doing by looking at |
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+ the temporary register. IP0 is the initial allocation, IP1 |
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+ is the final allocation. */ |
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+ if (scratchreg == IP0_REGNUM || !frame_pointer_needed) |
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+ { |
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+ /* We want the CFA independent of the stack pointer for the |
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+ duration of the loop. */ |
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+ add_reg_note (insn, REG_CFA_DEF_CFA, |
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+ plus_constant (Pmode, temp, |
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+ (rounded_size + (orig_size - size)))); |
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+ RTX_FRAME_RELATED_P (insn) = 1; |
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+ } |
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+ |
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+ /* This allocates and probes the stack. |
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+ |
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+ It also probes at a 4k interval regardless of the value of |
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+ PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL. */ |
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+ insn = emit_insn (gen_probe_stack_range (stack_pointer_rtx, |
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+ stack_pointer_rtx, temp)); |
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+ |
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+ /* Now reset the CFA register if needed. */ |
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+ if (scratchreg == IP0_REGNUM || !frame_pointer_needed) |
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+ { |
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+ add_reg_note (insn, REG_CFA_DEF_CFA, |
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+ plus_constant (Pmode, stack_pointer_rtx, |
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+ (rounded_size + (orig_size - size)))); |
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+ RTX_FRAME_RELATED_P (insn) = 1; |
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+ } |
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+ |
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+ emit_insn (gen_blockage ()); |
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+ dump_stack_clash_frame_info (PROBE_LOOP, size != rounded_size); |
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+ } |
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+ else |
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+ dump_stack_clash_frame_info (PROBE_INLINE, size != rounded_size); |
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+ |
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+ /* Handle any residuals. |
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+ Note that any residual must be probed. */ |
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+ if (residual) |
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+ { |
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+ aarch64_sub_sp (scratchreg, residual, true); |
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+ add_reg_note (get_last_insn (), REG_STACK_CHECK, const0_rtx); |
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+ emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx, |
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+ (residual - GET_MODE_SIZE (word_mode)))); |
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+ emit_insn (gen_blockage ()); |
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+ } |
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+ return; |
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+} |
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+ |
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/* AArch64 stack frames generated by this compiler look like: |
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+-------------------------------+ |
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@@ -2073,6 +2199,44 @@ aarch64_expand_prologue (void) |
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- original_frame_size |
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- cfun->machine->frame.saved_regs_size); |
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|
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+ /* We do not fully protect aarch64 against stack clash style attacks |
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+ as doing so would be prohibitively expensive with less utility over |
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+ time as newer compilers are deployed. |
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+ |
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+ We assume the guard is at least 64k. Furthermore, we assume that |
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+ the caller has not pushed the stack pointer more than 1k into |
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+ the guard. A caller that pushes the stack pointer than 1k into |
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+ the guard is considered invalid. |
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+ |
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+ Note that the caller's ability to push the stack pointer into the |
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+ guard is a function of the number and size of outgoing arguments and/or |
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+ dynamic stack allocations due to the mandatory save of the link register |
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+ in the caller's frame. |
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+ |
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+ With those assumptions the callee can allocate up to 63k of stack |
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+ space without probing. |
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+ |
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+ When probing is needed, we emit a probe at the start of the prologue |
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+ and every PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL bytes thereafter. |
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+ |
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+ We have to track how much space has been allocated, but we do not |
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+ track stores into the stack as implicit probes except for the |
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+ fp/lr store. */ |
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+ HOST_WIDE_INT guard_size |
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+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE); |
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+ HOST_WIDE_INT guard_used_by_caller = 1024; |
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+ HOST_WIDE_INT final_adjust = crtl->outgoing_args_size; |
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+ HOST_WIDE_INT initial_adjust = frame_size; |
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+ |
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+ if (flag_stack_clash_protection) |
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+ { |
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+ if (initial_adjust == 0) |
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+ dump_stack_clash_frame_info (NO_PROBE_NO_FRAME, false); |
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+ else if (offset < guard_size - guard_used_by_caller |
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+ && final_adjust < guard_size - guard_used_by_caller) |
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+ dump_stack_clash_frame_info (NO_PROBE_SMALL_FRAME, true); |
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+ } |
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+ |
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/* Store pairs and load pairs have a range only -512 to 504. */ |
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if (offset >= 512) |
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{ |
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@@ -2089,7 +2253,10 @@ aarch64_expand_prologue (void) |
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frame_size -= (offset + crtl->outgoing_args_size); |
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fp_offset = 0; |
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- if (frame_size >= 0x1000000) |
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+ if (flag_stack_clash_protection |
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+ && frame_size >= guard_size - guard_used_by_caller) |
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+ aarch64_allocate_and_probe_stack_space (IP0_REGNUM, frame_size); |
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+ else if (frame_size >= 0x1000000) |
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{ |
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rtx op0 = gen_rtx_REG (Pmode, IP0_REGNUM); |
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emit_move_insn (op0, GEN_INT (-frame_size)); |
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@@ -2206,10 +2373,30 @@ aarch64_expand_prologue (void) |
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{ |
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if (crtl->outgoing_args_size > 0) |
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{ |
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- insn = emit_insn (gen_add2_insn |
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- (stack_pointer_rtx, |
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- GEN_INT (- crtl->outgoing_args_size))); |
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- RTX_FRAME_RELATED_P (insn) = 1; |
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+ if (flag_stack_clash_protection) |
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+ { |
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+ /* First probe if the final adjustment is larger than the |
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+ guard size less the amount of guard reserved for use by |
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+ the caller's outgoing args. */ |
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+ if (final_adjust >= guard_size - guard_used_by_caller) |
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+ aarch64_allocate_and_probe_stack_space (IP1_REGNUM, |
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+ final_adjust); |
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+ else |
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+ aarch64_sub_sp (IP1_REGNUM, final_adjust, !frame_pointer_needed); |
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+ |
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+ /* We must also probe if the final adjustment is larger than the |
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+ guard that is assumed used by the caller. This may be |
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+ sub-optimal. */ |
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+ if (final_adjust >= guard_used_by_caller) |
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+ { |
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+ if (dump_file) |
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+ fprintf (dump_file, |
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+ "Stack clash aarch64 large outgoing arg, probing\n"); |
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+ emit_stack_probe (stack_pointer_rtx); |
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+ } |
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+ } |
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+ else |
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+ aarch64_sub_sp (IP1_REGNUM, final_adjust, !frame_pointer_needed); |
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} |
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} |
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} |
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@@ -5088,6 +5275,12 @@ aarch64_override_options (void) |
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#endif |
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} |
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+ /* We assume the guard page is 64k. */ |
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+ maybe_set_param_value (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE, |
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+ 16, |
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+ global_options.x_param_values, |
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+ global_options_set.x_param_values); |
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+ |
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aarch64_override_options_after_change (); |
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} |
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@@ -8161,6 +8354,28 @@ aarch64_vectorize_vec_perm_const_ok (enum machine_mode vmode, |
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return ret; |
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} |
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|
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+/* It has been decided that to allow up to 1kb of outgoing argument |
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+ space to be allocated w/o probing. If more than 1kb of outgoing |
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+ argment space is allocated, then it must be probed and the last |
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+ probe must occur no more than 1kbyte away from the end of the |
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+ allocated space. |
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+ |
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+ This implies that the residual part of an alloca allocation may |
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+ need probing in cases where the generic code might not otherwise |
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+ think a probe is needed. |
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+ |
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+ This target hook returns TRUE when allocating RESIDUAL bytes of |
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+ alloca space requires an additional probe, otherwise FALSE is |
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+ returned. */ |
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+ |
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+static bool |
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+aarch64_stack_clash_protection_final_dynamic_probe (rtx residual) |
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+{ |
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+ return (residual == CONST0_RTX (Pmode) |
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+ || GET_CODE (residual) != CONST_INT |
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+ || INTVAL (residual) >= 1024); |
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+} |
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+ |
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#undef TARGET_ADDRESS_COST |
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#define TARGET_ADDRESS_COST aarch64_address_cost |
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@@ -8378,6 +8593,10 @@ aarch64_vectorize_vec_perm_const_ok (enum machine_mode vmode, |
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#undef TARGET_FIXED_CONDITION_CODE_REGS |
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#define TARGET_FIXED_CONDITION_CODE_REGS aarch64_fixed_condition_code_regs |
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+#undef TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE |
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+#define TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE \ |
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+ aarch64_stack_clash_protection_final_dynamic_probe |
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+ |
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struct gcc_target targetm = TARGET_INITIALIZER; |
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#include "gt-aarch64.h" |
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diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md |
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index a085c6acaf5..5485a5f70b1 100644 |
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--- a/gcc/config/aarch64/aarch64.md |
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+++ b/gcc/config/aarch64/aarch64.md |
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@@ -3401,7 +3401,7 @@ |
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) |
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(define_insn "probe_stack_range" |
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- [(set (match_operand:DI 0 "register_operand" "=r") |
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+ [(set (match_operand:DI 0 "register_operand" "=rk") |
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(unspec_volatile:DI [(match_operand:DI 1 "register_operand" "0") |
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(match_operand:DI 2 "register_operand" "r")] |
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UNSPECV_PROBE_STACK_RANGE))] |
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diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-12.c b/gcc/testsuite/gcc.target/aarch64/stack-check-12.c |
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new file mode 100644 |
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index 00000000000..2ce38483b6b |
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--- /dev/null |
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+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-12.c |
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@@ -0,0 +1,20 @@ |
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+/* { dg-do compile } */ |
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+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */ |
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+/* { dg-require-effective-target supports_stack_clash_protection } */ |
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+ |
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+extern void arf (unsigned long int *, unsigned long int *); |
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+void |
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+frob () |
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+{ |
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+ unsigned long int num[1000]; |
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+ unsigned long int den[1000]; |
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+ arf (den, num); |
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+} |
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+ |
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+/* This verifies that the scheduler did not break the dependencies |
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+ by adjusting the offsets within the probe and that the scheduler |
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+ did not reorder around the stack probes. */ |
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+/* { dg-final { scan-assembler-times "sub\\tsp, sp, #4096\\n\\tstr\\txzr, .sp, 4088." 3 } } */ |
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+ |
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+ |
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+ |
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diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-13.c b/gcc/testsuite/gcc.target/aarch64/stack-check-13.c |
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new file mode 100644 |
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index 00000000000..d8886835989 |
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--- /dev/null |
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+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-13.c |
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@@ -0,0 +1,28 @@ |
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+/* { dg-do compile } */ |
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+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */ |
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+/* { dg-require-effective-target supports_stack_clash_protection } */ |
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+ |
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+#define ARG32(X) X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X |
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+#define ARG192(X) ARG32(X),ARG32(X),ARG32(X),ARG32(X),ARG32(X),ARG32(X) |
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+void out1(ARG192(__int128)); |
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+int t1(int); |
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+ |
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+int t3(int x) |
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+{ |
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+ if (x < 1000) |
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+ return t1 (x) + 1; |
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+ |
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+ out1 (ARG192(1)); |
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+ return 0; |
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+} |
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+ |
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+ |
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+ |
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+/* This test creates a large (> 1k) outgoing argument area that needs |
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+ to be probed. We don't test the exact size of the space or the |
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+ exact offset to make the test a little less sensitive to trivial |
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+ output changes. */ |
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+/* { dg-final { scan-assembler-times "sub\\tsp, sp, #....\\n\\tstr\\txzr, \\\[sp" 1 } } */ |
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+ |
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+ |
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+ |
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diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-14.c b/gcc/testsuite/gcc.target/aarch64/stack-check-14.c |
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new file mode 100644 |
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index 00000000000..59ffe01376d |
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--- /dev/null |
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+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-14.c |
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@@ -0,0 +1,25 @@ |
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+/* { dg-do compile } */ |
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+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */ |
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+/* { dg-require-effective-target supports_stack_clash_protection } */ |
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+ |
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+int t1(int); |
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+ |
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+int t2(int x) |
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+{ |
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+ char *p = __builtin_alloca (4050); |
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+ x = t1 (x); |
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+ return p[x]; |
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+} |
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+ |
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+ |
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+/* This test has a constant sized alloca that is smaller than the |
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+ probe interval. But it actually requires two probes instead |
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+ of one because of the optimistic assumptions we made in the |
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+ aarch64 prologue code WRT probing state. |
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+ |
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+ The form can change quite a bit so we just check for two |
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+ probes without looking at the actual address. */ |
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+/* { dg-final { scan-assembler-times "str\\txzr," 2 } } */ |
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+ |
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+ |
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+ |
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diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-15.c b/gcc/testsuite/gcc.target/aarch64/stack-check-15.c |
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new file mode 100644 |
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index 00000000000..e06db6dc2f0 |
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--- /dev/null |
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+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-15.c |
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@@ -0,0 +1,24 @@ |
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+/* { dg-do compile } */ |
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+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */ |
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+/* { dg-require-effective-target supports_stack_clash_protection } */ |
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+ |
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+int t1(int); |
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+ |
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+int t2(int x) |
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+{ |
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+ char *p = __builtin_alloca (x); |
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+ x = t1 (x); |
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+ return p[x]; |
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+} |
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+ |
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+ |
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+/* This test has a variable sized alloca. It requires 3 probes. |
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+ One in the loop, one for the residual and at the end of the |
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+ alloca area. |
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+ |
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+ The form can change quite a bit so we just check for two |
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+ probes without looking at the actual address. */ |
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+/* { dg-final { scan-assembler-times "str\\txzr," 3 } } */ |
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+ |
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+ |
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+ |
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diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp |
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index aba99513ed0..a8451c98b08 100644 |
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--- a/gcc/testsuite/lib/target-supports.exp |
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+++ b/gcc/testsuite/lib/target-supports.exp |
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@@ -5420,14 +5420,9 @@ proc check_effective_target_autoincdec { } { |
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# |
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proc check_effective_target_supports_stack_clash_protection { } { |
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|
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- # Temporary until the target bits are fully ACK'd. |
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-# if { [istarget aarch*-*-*] } { |
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-# return 1 |
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-# } |
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- |
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if { [istarget x86_64-*-*] || [istarget i?86-*-*] |
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|| [istarget powerpc*-*-*] || [istarget rs6000*-*-*] |
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- || [istarget s390*-*-*] } { |
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+ || [istarget aarch64*-**] || [istarget s390*-*-*] } { |
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return 1 |
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} |
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return 0
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