From 11a3b9034935080b9996caf07fca6353309006f1 Mon Sep 17 00:00:00 2001 From: hjl Date: Mon, 15 Jan 2018 11:27:24 +0000 Subject: [PATCH 1/9] i386: Move struct ix86_frame to machine_function Make ix86_frame available to i386 code generation. This is needed to backport the patch set of -mindirect-branch= to mitigate variant #2 of the speculative execution vulnerabilities on x86 processors identified by CVE-2017-5715, aka Spectre. Backport from mainline * config/i386/i386.c (ix86_frame): Moved to ... * config/i386/i386.h (ix86_frame): Here. (machine_function): Add frame. * config/i386/i386.c (ix86_compute_frame_layout): Repace the frame argument with &cfun->machine->frame. (ix86_can_use_return_insn_p): Don't pass &frame to ix86_compute_frame_layout. Copy frame from cfun->machine->frame. (ix86_can_eliminate): Likewise. (ix86_expand_prologue): Likewise. (ix86_expand_epilogue): Likewise. (ix86_expand_split_stack_prologue): Likewise. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-7-branch@256691 138bc75d-0d04-0410-961f-82ee72b054a4 --- src/gcc/config/i386/i386.c | 68 ++++++++------------------------------------- src/gcc/config/i386/i386.h | 53 ++++++++++++++++++++++++++++++++++- 2 files changed, 65 insertions(+), 56 deletions(-) Index: b/src/gcc/config/i386/i386.c =================================================================== --- a/src/gcc/config/i386/i386.c +++ b/src/gcc/config/i386/i386.c @@ -2306,53 +2306,6 @@ struct GTY(()) stack_local_entry { struct stack_local_entry *next; }; -/* Structure describing stack frame layout. - Stack grows downward: - - [arguments] - <- ARG_POINTER - saved pc - - saved static chain if ix86_static_chain_on_stack - - saved frame pointer if frame_pointer_needed - <- HARD_FRAME_POINTER - [saved regs] - <- regs_save_offset - [padding0] - - [saved SSE regs] - <- sse_regs_save_offset - [padding1] | - | <- FRAME_POINTER - [va_arg registers] | - | - [frame] | - | - [padding2] | = to_allocate - <- STACK_POINTER - */ -struct ix86_frame -{ - int nsseregs; - int nregs; - int va_arg_size; - int red_zone_size; - int outgoing_arguments_size; - - /* The offsets relative to ARG_POINTER. */ - HOST_WIDE_INT frame_pointer_offset; - HOST_WIDE_INT hard_frame_pointer_offset; - HOST_WIDE_INT stack_pointer_offset; - HOST_WIDE_INT hfp_save_offset; - HOST_WIDE_INT reg_save_offset; - HOST_WIDE_INT sse_reg_save_offset; - - /* When save_regs_using_mov is set, emit prologue using - move instead of push instructions. */ - bool save_regs_using_mov; -}; - /* Which cpu are we scheduling for. */ enum attr_cpu ix86_schedule; @@ -2443,7 +2396,7 @@ static unsigned int ix86_function_arg_bo const_tree); static rtx ix86_static_chain (const_tree, bool); static int ix86_function_regparm (const_tree, const_tree); -static void ix86_compute_frame_layout (struct ix86_frame *); +static void ix86_compute_frame_layout (void); static bool ix86_expand_vector_init_one_nonzero (bool, machine_mode, rtx, rtx, int); static void ix86_add_new_builtins (HOST_WIDE_INT); @@ -9664,7 +9617,8 @@ ix86_can_use_return_insn_p (void) if (crtl->args.pops_args && crtl->args.size >= 32768) return 0; - ix86_compute_frame_layout (&frame); + ix86_compute_frame_layout (); + frame = cfun->machine->frame; return (frame.stack_pointer_offset == UNITS_PER_WORD && (frame.nregs + frame.nsseregs) == 0); } @@ -10073,8 +10027,8 @@ ix86_can_eliminate (const int from, cons HOST_WIDE_INT ix86_initial_elimination_offset (int from, int to) { - struct ix86_frame frame; - ix86_compute_frame_layout (&frame); + ix86_compute_frame_layout (); + struct ix86_frame frame = cfun->machine->frame; if (from == ARG_POINTER_REGNUM && to == HARD_FRAME_POINTER_REGNUM) return frame.hard_frame_pointer_offset; @@ -10113,8 +10067,9 @@ ix86_builtin_setjmp_frame_value (void) /* Fill structure ix86_frame about frame of currently computed function. */ static void -ix86_compute_frame_layout (struct ix86_frame *frame) +ix86_compute_frame_layout (void) { + struct ix86_frame *frame = &cfun->machine->frame; unsigned HOST_WIDE_INT stack_alignment_needed; HOST_WIDE_INT offset; unsigned HOST_WIDE_INT preferred_alignment; @@ -11417,7 +11372,8 @@ ix86_expand_prologue (void) m->fs.sp_offset = INCOMING_FRAME_SP_OFFSET; m->fs.sp_valid = true; - ix86_compute_frame_layout (&frame); + ix86_compute_frame_layout (); + frame = m->frame; if (!TARGET_64BIT && ix86_function_ms_hook_prologue (current_function_decl)) { @@ -12083,7 +12039,8 @@ ix86_expand_epilogue (int style) bool using_drap; ix86_finalize_stack_realign_flags (); - ix86_compute_frame_layout (&frame); + ix86_compute_frame_layout (); + frame = m->frame; m->fs.sp_valid = (!frame_pointer_needed || (crtl->sp_is_unchanging @@ -12546,7 +12503,8 @@ ix86_expand_split_stack_prologue (void) gcc_assert (flag_split_stack && reload_completed); ix86_finalize_stack_realign_flags (); - ix86_compute_frame_layout (&frame); + ix86_compute_frame_layout (); + frame = cfun->machine->frame; allocate = frame.stack_pointer_offset - INCOMING_FRAME_SP_OFFSET; /* This is the label we will branch to if we have enough stack Index: b/src/gcc/config/i386/i386.h =================================================================== --- a/src/gcc/config/i386/i386.h +++ b/src/gcc/config/i386/i386.h @@ -2409,9 +2409,56 @@ enum avx_u128_state #define FASTCALL_PREFIX '@' +#ifndef USED_FOR_TARGET +/* Structure describing stack frame layout. + Stack grows downward: + + [arguments] + <- ARG_POINTER + saved pc + + saved static chain if ix86_static_chain_on_stack + + saved frame pointer if frame_pointer_needed + <- HARD_FRAME_POINTER + [saved regs] + <- regs_save_offset + [padding0] + + [saved SSE regs] + <- sse_regs_save_offset + [padding1] | + | <- FRAME_POINTER + [va_arg registers] | + | + [frame] | + | + [padding2] | = to_allocate + <- STACK_POINTER + */ +struct GTY(()) ix86_frame +{ + int nsseregs; + int nregs; + int va_arg_size; + int red_zone_size; + int outgoing_arguments_size; + + /* The offsets relative to ARG_POINTER. */ + HOST_WIDE_INT frame_pointer_offset; + HOST_WIDE_INT hard_frame_pointer_offset; + HOST_WIDE_INT stack_pointer_offset; + HOST_WIDE_INT hfp_save_offset; + HOST_WIDE_INT reg_save_offset; + HOST_WIDE_INT sse_reg_save_offset; + + /* When save_regs_using_mov is set, emit prologue using + move instead of push instructions. */ + bool save_regs_using_mov; +}; + /* Machine specific frame tracking during prologue/epilogue generation. */ -#ifndef USED_FOR_TARGET struct GTY(()) machine_frame_state { /* This pair tracks the currently active CFA as reg+offset. When reg @@ -2457,6 +2504,9 @@ struct GTY(()) machine_function { int varargs_fpr_size; int optimize_mode_switching[MAX_386_ENTITIES]; + /* Cached initial frame layout for the current function. */ + struct ix86_frame frame; + /* Number of saved registers USE_FAST_PROLOGUE_EPILOGUE has been computed for. */ int use_fast_prologue_epilogue_nregs; @@ -2524,6 +2574,7 @@ struct GTY(()) machine_function { #define ix86_current_function_calls_tls_descriptor \ (ix86_tls_descriptor_calls_expanded_in_cfun && df_regs_ever_live_p (SP_REG)) #define ix86_static_chain_on_stack (cfun->machine->static_chain_on_stack) +#define ix86_red_zone_size (cfun->machine->frame.red_zone_size) /* Control behavior of x86_file_start. */ #define X86_FILE_START_VERSION_DIRECTIVE false