diff mbox series

[1/2,V2] Implement hwasan target_hook.

Message ID 20221130052114.10229-1-hongtao.liu@intel.com
State New
Headers show
Series [1/2,V2] Implement hwasan target_hook. | expand

Commit Message

liuhongt Nov. 30, 2022, 5:21 a.m. UTC
Update in V2:
Add documentation for -mlam={none,u48,u57} to x86 options in invoke.texi.

gcc/ChangeLog:

	* doc/invoke.texi (x86 options): Document
	-mlam={none,u48,u57}.
	* config/i386/i386-opts.h (enum lam_type): New enum.
	* config/i386/i386.c (ix86_memtag_can_tag_addresses): New.
	(ix86_memtag_set_tag): Ditto.
	(ix86_memtag_extract_tag): Ditto.
	(ix86_memtag_add_tag): Ditto.
	(ix86_memtag_tag_size): Ditto.
	(ix86_memtag_untagged_pointer): Ditto.
	(TARGET_MEMTAG_CAN_TAG_ADDRESSES): New.
	(TARGET_MEMTAG_ADD_TAG): Ditto.
	(TARGET_MEMTAG_SET_TAG): Ditto.
	(TARGET_MEMTAG_EXTRACT_TAG): Ditto.
	(TARGET_MEMTAG_UNTAGGED_POINTER): Ditto.
	(TARGET_MEMTAG_TAG_SIZE): Ditto.
	(IX86_HWASAN_SHIFT): Ditto.
	(IX86_HWASAN_TAG_SIZE): Ditto.
	* config/i386/i386-expand.c (ix86_expand_call): Untag code
	pointer.
	* config/i386/i386-options.c (ix86_option_override_internal):
	Error when enable -mlam=[u48|u57] for 32-bit code.
	* config/i386/i386.opt: Add -mlam=[none|u48|u57].
	* config/i386/i386-protos.h (ix86_memtag_untagged_pointer):
	Declare.
	(ix86_memtag_can_tag_addresses): Ditto.
---
 gcc/config/i386/i386-expand.cc  |  12 ++++
 gcc/config/i386/i386-options.cc |   3 +
 gcc/config/i386/i386-opts.h     |   6 ++
 gcc/config/i386/i386-protos.h   |   2 +
 gcc/config/i386/i386.cc         | 123 ++++++++++++++++++++++++++++++++
 gcc/config/i386/i386.opt        |  16 +++++
 gcc/doc/invoke.texi             |   9 ++-
 7 files changed, 170 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index d26e7e41445..0e94782165a 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -92,6 +92,7 @@  along with GCC; see the file COPYING3.  If not see
 #include "i386-options.h"
 #include "i386-builtins.h"
 #include "i386-expand.h"
+#include "asan.h"
 
 /* Split one or more double-mode RTL references into pairs of half-mode
    references.  The RTL can be REG, offsettable MEM, integer constant, or
@@ -9438,6 +9439,17 @@  ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
       fnaddr = gen_rtx_MEM (QImode, copy_to_mode_reg (word_mode, fnaddr));
     }
 
+  /* PR100665: Hwasan may tag code pointer which is not supported by LAM,
+     mask off code pointers here.
+     TODO: also need to handle indirect jump.  */
+  if (ix86_memtag_can_tag_addresses () && !fndecl
+      && sanitize_flags_p (SANITIZE_HWADDRESS))
+    {
+      rtx untagged_addr = ix86_memtag_untagged_pointer (XEXP (fnaddr, 0),
+							NULL_RTX);
+      fnaddr = gen_rtx_MEM (QImode, untagged_addr);
+    }
+
   call = gen_rtx_CALL (VOIDmode, fnaddr, callarg1);
 
   if (retval)
diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
index 44dcccb0a73..25f21ac2a49 100644
--- a/gcc/config/i386/i386-options.cc
+++ b/gcc/config/i386/i386-options.cc
@@ -2033,6 +2033,9 @@  ix86_option_override_internal (bool main_args_p,
   if (TARGET_UINTR && !TARGET_64BIT)
     error ("%<-muintr%> not supported for 32-bit code");
 
+  if (ix86_lam_type && !TARGET_LP64)
+    error ("%<-mlam=%> option: [u48|u57] not supported for 32-bit code");
+
   if (!opts->x_ix86_arch_string)
     opts->x_ix86_arch_string
       = TARGET_64BIT_P (opts->x_ix86_isa_flags)
diff --git a/gcc/config/i386/i386-opts.h b/gcc/config/i386/i386-opts.h
index 8f71e89fa9a..d3bfeed0af2 100644
--- a/gcc/config/i386/i386-opts.h
+++ b/gcc/config/i386/i386-opts.h
@@ -128,4 +128,10 @@  enum harden_sls {
   harden_sls_all = harden_sls_return | harden_sls_indirect_jmp
 };
 
+enum lam_type {
+  lam_none = 0,
+  lam_u48 = 1,
+  lam_u57
+};
+
 #endif
diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
index e136f6ec175..abd123c9efc 100644
--- a/gcc/config/i386/i386-protos.h
+++ b/gcc/config/i386/i386-protos.h
@@ -228,6 +228,8 @@  extern void ix86_expand_atomic_fetch_op_loop (rtx, rtx, rtx, enum rtx_code,
 extern void ix86_expand_cmpxchg_loop (rtx *, rtx, rtx, rtx, rtx, rtx,
 				      bool, rtx_code_label *);
 extern rtx ix86_expand_fast_convert_bf_to_sf (rtx);
+extern rtx ix86_memtag_untagged_pointer (rtx, rtx);
+extern bool ix86_memtag_can_tag_addresses (void);
 
 #ifdef TREE_CODE
 extern void init_cumulative_args (CUMULATIVE_ARGS *, tree, rtx, tree, int);
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 95babd93c9d..518cc9ffd1f 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -24274,6 +24274,111 @@  ix86_push_rounding (poly_int64 bytes)
   return ROUND_UP (bytes, UNITS_PER_WORD);
 }
 
+/* Use 8 bits metadata start from bit48 for LAM_U48,
+   6 bits metadat start from bit57 for LAM_U57.  */
+#define IX86_HWASAN_SHIFT (ix86_lam_type == lam_u48		\
+			   ? 48					\
+			   : (ix86_lam_type == lam_u57 ? 57 : 0))
+#define IX86_HWASAN_TAG_SIZE (ix86_lam_type == lam_u48		\
+			      ? 8				\
+			      : (ix86_lam_type == lam_u57 ? 6 : 0))
+
+/* Implement TARGET_MEMTAG_CAN_TAG_ADDRESSES.  */
+bool
+ix86_memtag_can_tag_addresses ()
+{
+  return ix86_lam_type != lam_none && TARGET_LP64;
+}
+
+/* Implement TARGET_MEMTAG_TAG_SIZE.  */
+unsigned char
+ix86_memtag_tag_size ()
+{
+  return IX86_HWASAN_TAG_SIZE;
+}
+
+/* Implement TARGET_MEMTAG_SET_TAG.  */
+rtx
+ix86_memtag_set_tag (rtx untagged, rtx tag, rtx target)
+{
+  /* default_memtag_insert_random_tag may
+     generate tag with value more than 6 bits.  */
+  if (ix86_lam_type == lam_u57)
+    {
+      unsigned HOST_WIDE_INT and_imm
+	= (HOST_WIDE_INT_1U << IX86_HWASAN_TAG_SIZE) - 1;
+
+      emit_insn (gen_andqi3 (tag, tag, GEN_INT (and_imm)));
+    }
+  tag = expand_simple_binop (Pmode, ASHIFT, tag,
+			     GEN_INT (IX86_HWASAN_SHIFT), NULL_RTX,
+			     /* unsignedp = */1, OPTAB_WIDEN);
+  rtx ret = expand_simple_binop (Pmode, IOR, untagged, tag, target,
+				 /* unsignedp = */1, OPTAB_DIRECT);
+  return ret;
+}
+
+/* Implement TARGET_MEMTAG_EXTRACT_TAG.  */
+rtx
+ix86_memtag_extract_tag (rtx tagged_pointer, rtx target)
+{
+  rtx tag = expand_simple_binop (Pmode, LSHIFTRT, tagged_pointer,
+				 GEN_INT (IX86_HWASAN_SHIFT), target,
+				 /* unsignedp = */0,
+				 OPTAB_DIRECT);
+  rtx ret = gen_reg_rtx (QImode);
+  /* Mask off bit63 when LAM_U57.  */
+  if (ix86_lam_type == lam_u57)
+    {
+      unsigned HOST_WIDE_INT and_imm
+	= (HOST_WIDE_INT_1U << IX86_HWASAN_TAG_SIZE) - 1;
+      emit_insn (gen_andqi3 (ret, gen_lowpart (QImode, tag),
+			     gen_int_mode (and_imm, QImode)));
+    }
+  else
+    emit_move_insn (ret, gen_lowpart (QImode, tag));
+  return ret;
+}
+
+/* The default implementation of TARGET_MEMTAG_UNTAGGED_POINTER.  */
+rtx
+ix86_memtag_untagged_pointer (rtx tagged_pointer, rtx target)
+{
+  /* Leave bit63 alone.  */
+  rtx tag_mask = gen_int_mode (((HOST_WIDE_INT_1U << IX86_HWASAN_SHIFT)
+				+ (HOST_WIDE_INT_1U << 63) - 1),
+			       Pmode);
+  rtx untagged_base = expand_simple_binop (Pmode, AND, tagged_pointer,
+					   tag_mask, target, true,
+					   OPTAB_DIRECT);
+  gcc_assert (untagged_base);
+  return untagged_base;
+}
+
+/* Implement TARGET_MEMTAG_ADD_TAG.  */
+rtx
+ix86_memtag_add_tag (rtx base, poly_int64 offset, unsigned char tag_offset)
+{
+  rtx base_tag = gen_reg_rtx (QImode);
+  rtx base_addr = gen_reg_rtx (Pmode);
+  rtx tagged_addr = gen_reg_rtx (Pmode);
+  rtx new_tag = gen_reg_rtx (QImode);
+  unsigned HOST_WIDE_INT and_imm
+    = (HOST_WIDE_INT_1U << IX86_HWASAN_SHIFT) - 1;
+
+  /* When there's "overflow" in tag adding,
+     need to mask the most significant bit off.  */
+  emit_move_insn (base_tag, ix86_memtag_extract_tag (base, NULL_RTX));
+  emit_move_insn (base_addr,
+		  ix86_memtag_untagged_pointer (base, NULL_RTX));
+  emit_insn (gen_add2_insn (base_tag, gen_int_mode (tag_offset, QImode)));
+  emit_move_insn (new_tag, base_tag);
+  emit_insn (gen_andqi3 (new_tag, new_tag, gen_int_mode (and_imm, QImode)));
+  emit_move_insn (tagged_addr,
+		  ix86_memtag_set_tag (base_addr, new_tag, NULL_RTX));
+  return plus_constant (Pmode, tagged_addr, offset);
+}
+
 /* Target-specific selftests.  */
 
 #if CHECKING_P
@@ -25068,6 +25173,24 @@  ix86_libgcc_floating_mode_supported_p
 # define TARGET_ASM_RELOC_RW_MASK ix86_reloc_rw_mask
 #endif
 
+#undef TARGET_MEMTAG_CAN_TAG_ADDRESSES
+#define TARGET_MEMTAG_CAN_TAG_ADDRESSES ix86_memtag_can_tag_addresses
+
+#undef TARGET_MEMTAG_ADD_TAG
+#define TARGET_MEMTAG_ADD_TAG ix86_memtag_add_tag
+
+#undef TARGET_MEMTAG_SET_TAG
+#define TARGET_MEMTAG_SET_TAG ix86_memtag_set_tag
+
+#undef TARGET_MEMTAG_EXTRACT_TAG
+#define TARGET_MEMTAG_EXTRACT_TAG ix86_memtag_extract_tag
+
+#undef TARGET_MEMTAG_UNTAGGED_POINTER
+#define TARGET_MEMTAG_UNTAGGED_POINTER ix86_memtag_untagged_pointer
+
+#undef TARGET_MEMTAG_TAG_SIZE
+#define TARGET_MEMTAG_TAG_SIZE ix86_memtag_tag_size
+
 static bool ix86_libc_has_fast_function (int fcode ATTRIBUTE_UNUSED)
 {
 #ifdef OPTION_GLIBC
diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index aa8574e6b71..fb4e57ada7c 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -1250,3 +1250,19 @@  Support RAOINT built-in functions and code generation.
 munroll-only-small-loops
 Target Var(ix86_unroll_only_small_loops) Init(0) Save
 Enable conservative small loop unrolling.
+
+mlam=
+Target RejectNegative Joined Enum(lam_type) Var(ix86_lam_type) Init(lam_none)
+-mlam=[none|u48|u57] Instrument meta data position in user data pointers.
+
+Enum
+Name(lam_type) Type(enum lam_type) UnknownError(unknown lam type %qs)
+
+EnumValue
+Enum(lam_type) String(none) Value(lam_none)
+
+EnumValue
+Enum(lam_type) String(u48) Value(lam_u48)
+
+EnumValue
+Enum(lam_type) String(u57) Value(lam_u57)
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index e312b5cef3d..dcecf6849b0 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -1448,7 +1448,7 @@  See RS/6000 and PowerPC Options.
 -mindirect-branch=@var{choice}  -mfunction-return=@var{choice} @gol
 -mindirect-branch-register -mharden-sls=@var{choice} @gol
 -mindirect-branch-cs-prefix -mneeded -mno-direct-extern-access @gol
--munroll-only-small-loops}
+-munroll-only-small-loops -mlam=@var{choice}}
 
 @emph{x86 Windows Options}
 @gccoptlist{-mconsole  -mcygwin  -mno-cygwin  -mdll @gol
@@ -33857,6 +33857,13 @@  Controls conservative small loop unrolling. It is default enabled by
 O2, and unrolls loop with less than 4 insns by 1 time. Explicit
 -f[no-]unroll-[all-]loops would disable this flag to avoid any
 unintended unrolling behavior that user does not want.
+
+@item -mlam=@var{choice}
+@opindex mlam
+LAM(linear-address masking) allows special bits in the pointer to be used
+for metadata. The default is @samp{none}. With @samp{u48}, pointer bits in
+positions 62:48 can be used for metadata; With @samp{u57}, pointer bits in
+positions 62:57 can be used for metadata.
 @end table
 
 @node x86 Windows Options