From: Thomas Preud'homme Date: Thu, 2 Aug 2018 11:16:05 +0000 (+0000) Subject: Revert "[ARM] Fix PR85434: spilling of stack protector guard's address on ARM" X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=a8b2130aee62d3ac499938be26c9ae23c89d25c9;p=gcc.git Revert "[ARM] Fix PR85434: spilling of stack protector guard's address on ARM" This reverts commit r263245. From-SVN: r263252 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 23450e63e99..fdb93f85266 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -89,44 +89,6 @@ (process_file): Move functions processing to process_all_functions. -2018-08-02 Thomas Preud'homme - - PR target/85434 - * target-insns.def (stack_protect_combined_set): Define new standard - pattern name. - (stack_protect_combined_test): Likewise. - * cfgexpand.c (stack_protect_prologue): Try new - stack_protect_combined_set pattern first. - * function.c (stack_protect_epilogue): Try new - stack_protect_combined_test pattern first. - * config/arm/arm.c (require_pic_register): Add pic_reg and compute_now - parameters to control which register to use as PIC register and force - reloading PIC register respectively. Insert in the stream of insns if - possible. - (legitimize_pic_address): Expose above new parameters in prototype and - adapt recursive calls accordingly. - (arm_legitimize_address): Adapt to new legitimize_pic_address - prototype. - (thumb_legitimize_address): Likewise. - (arm_emit_call_insn): Adapt to new require_pic_register prototype. - * config/arm/arm-protos.h (legitimize_pic_address): Adapt to prototype - change. - * config/arm/arm.md (movsi expander): Adapt to legitimize_pic_address - prototype change. - (stack_protect_combined_set): New insn_and_split pattern. - (stack_protect_set): New insn pattern. - (stack_protect_combined_test): New insn_and_split pattern. - (stack_protect_test): New insn pattern. - * config/arm/unspecs.md (UNSPEC_SP_SET): New unspec. - (UNSPEC_SP_TEST): Likewise. - * doc/md.texi (stack_protect_combined_set): Document new standard - pattern name. - (stack_protect_set): Clarify that the operand for guard's address is - legal. - (stack_protect_combined_test): Document new standard pattern name. - (stack_protect_test): Clarify that the operand for guard's address is - legal. - 2018-08-02 David Malcolm * dumpfile.c (dump_user_location_t::dump_user_location_t): Add diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c index 0a73ac754cf..7353d5dce12 100644 --- a/gcc/cfgexpand.c +++ b/gcc/cfgexpand.c @@ -6105,18 +6105,8 @@ stack_protect_prologue (void) { tree guard_decl = targetm.stack_protect_guard (); rtx x, y; - struct expand_operand ops[2]; x = expand_normal (crtl->stack_protect_guard); - create_fixed_operand (&ops[0], x); - create_fixed_operand (&ops[1], DECL_RTL (guard_decl)); - /* Allow the target to compute address of Y and copy it to X without - leaking Y into a register. This combined address + copy pattern allows - the target to prevent spilling of any intermediate results by splitting - it after register allocator. */ - if (maybe_expand_insn (targetm.code_for_stack_protect_combined_set, 2, ops)) - return; - if (guard_decl) y = expand_normal (guard_decl); else diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h index 100844e659c..8537262ce64 100644 --- a/gcc/config/arm/arm-protos.h +++ b/gcc/config/arm/arm-protos.h @@ -67,7 +67,7 @@ extern int const_ok_for_dimode_op (HOST_WIDE_INT, enum rtx_code); extern int arm_split_constant (RTX_CODE, machine_mode, rtx, HOST_WIDE_INT, rtx, rtx, int); extern int legitimate_pic_operand_p (rtx); -extern rtx legitimize_pic_address (rtx, machine_mode, rtx, rtx, bool); +extern rtx legitimize_pic_address (rtx, machine_mode, rtx); extern rtx legitimize_tls_address (rtx, rtx); extern bool arm_legitimate_address_p (machine_mode, rtx, bool); extern int arm_legitimate_address_outer_p (machine_mode, rtx, RTX_CODE, int); diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index 87c728e0eea..f5eece4f152 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -7369,26 +7369,20 @@ legitimate_pic_operand_p (rtx x) } /* Record that the current function needs a PIC register. Initialize - cfun->machine->pic_reg if we have not already done so. - - A new pseudo register is used for the PIC register if possible, otherwise - PIC_REG must be non NULL and is used instead. COMPUTE_NOW forces the PIC - register to be loaded, irregardless of whether it was loaded previously. */ + cfun->machine->pic_reg if we have not already done so. */ static void -require_pic_register (rtx pic_reg, bool compute_now) +require_pic_register (void) { /* A lot of the logic here is made obscure by the fact that this routine gets called as part of the rtx cost estimation process. We don't want those calls to affect any assumptions about the real function; and further, we can't call entry_of_function() until we start the real expansion process. */ - if (!crtl->uses_pic_offset_table || compute_now) + if (!crtl->uses_pic_offset_table) { - gcc_assert (can_create_pseudo_p () - || (pic_reg != NULL_RTX && GET_MODE (pic_reg) == Pmode)); + gcc_assert (can_create_pseudo_p ()); if (arm_pic_register != INVALID_REGNUM - && can_create_pseudo_p () && !(TARGET_THUMB1 && arm_pic_register > LAST_LO_REGNUM)) { if (!cfun->machine->pic_reg) @@ -7405,8 +7399,7 @@ require_pic_register (rtx pic_reg, bool compute_now) rtx_insn *seq, *insn; if (!cfun->machine->pic_reg) - cfun->machine->pic_reg = - can_create_pseudo_p () ? gen_reg_rtx (Pmode) : pic_reg; + cfun->machine->pic_reg = gen_reg_rtx (Pmode); /* Play games to avoid marking the function as needing pic if we are being called as part of the cost-estimation @@ -7417,8 +7410,7 @@ require_pic_register (rtx pic_reg, bool compute_now) start_sequence (); if (TARGET_THUMB1 && arm_pic_register != INVALID_REGNUM - && arm_pic_register > LAST_LO_REGNUM - && can_create_pseudo_p ()) + && arm_pic_register > LAST_LO_REGNUM) emit_move_insn (cfun->machine->pic_reg, gen_rtx_REG (Pmode, arm_pic_register)); else @@ -7435,29 +7427,15 @@ require_pic_register (rtx pic_reg, bool compute_now) we can't yet emit instructions directly in the final insn stream. Queue the insns on the entry edge, they will be committed after everything else is expanded. */ - if (currently_expanding_to_rtl) - insert_insn_on_edge (seq, - single_succ_edge - (ENTRY_BLOCK_PTR_FOR_FN (cfun))); - else - emit_insn (seq); + insert_insn_on_edge (seq, + single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun))); } } } } -/* Legitimize PIC load to ORIG into REG. If REG is NULL, a new pseudo is - created to hold the result of the load. If not NULL, PIC_REG indicates - which register to use as PIC register, otherwise it is decided by register - allocator. COMPUTE_NOW forces the PIC register to be loaded at the current - location in the instruction stream, irregardless of whether it was loaded - previously. - - Returns the register REG into which the PIC load is performed. */ - rtx -legitimize_pic_address (rtx orig, machine_mode mode, rtx reg, rtx pic_reg, - bool compute_now) +legitimize_pic_address (rtx orig, machine_mode mode, rtx reg) { if (GET_CODE (orig) == SYMBOL_REF || GET_CODE (orig) == LABEL_REF) @@ -7491,7 +7469,7 @@ legitimize_pic_address (rtx orig, machine_mode mode, rtx reg, rtx pic_reg, rtx mem; /* If this function doesn't have a pic register, create one now. */ - require_pic_register (pic_reg, compute_now); + require_pic_register (); pat = gen_calculate_pic_address (reg, cfun->machine->pic_reg, orig); @@ -7542,11 +7520,9 @@ legitimize_pic_address (rtx orig, machine_mode mode, rtx reg, rtx pic_reg, gcc_assert (GET_CODE (XEXP (orig, 0)) == PLUS); - base = legitimize_pic_address (XEXP (XEXP (orig, 0), 0), Pmode, reg, - pic_reg, compute_now); + base = legitimize_pic_address (XEXP (XEXP (orig, 0), 0), Pmode, reg); offset = legitimize_pic_address (XEXP (XEXP (orig, 0), 1), Pmode, - base == reg ? 0 : reg, pic_reg, - compute_now); + base == reg ? 0 : reg); if (CONST_INT_P (offset)) { @@ -8731,8 +8707,7 @@ arm_legitimize_address (rtx x, rtx orig_x, machine_mode mode) { /* We need to find and carefully transform any SYMBOL and LABEL references; so go back to the original address expression. */ - rtx new_x = legitimize_pic_address (orig_x, mode, NULL_RTX, NULL_RTX, - false /*compute_now*/); + rtx new_x = legitimize_pic_address (orig_x, mode, NULL_RTX); if (new_x != orig_x) x = new_x; @@ -8800,8 +8775,7 @@ thumb_legitimize_address (rtx x, rtx orig_x, machine_mode mode) { /* We need to find and carefully transform any SYMBOL and LABEL references; so go back to the original address expression. */ - rtx new_x = legitimize_pic_address (orig_x, mode, NULL_RTX, NULL_RTX, - false /*compute_now*/); + rtx new_x = legitimize_pic_address (orig_x, mode, NULL_RTX); if (new_x != orig_x) x = new_x; @@ -18085,7 +18059,7 @@ arm_emit_call_insn (rtx pat, rtx addr, bool sibcall) ? !targetm.binds_local_p (SYMBOL_REF_DECL (addr)) : !SYMBOL_REF_LOCAL_P (addr))) { - require_pic_register (NULL_RTX, false /*compute_now*/); + require_pic_register (); use_reg (&CALL_INSN_FUNCTION_USAGE (insn), cfun->machine->pic_reg); } diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md index 130531d4eb6..ca2a2f5469f 100644 --- a/gcc/config/arm/arm.md +++ b/gcc/config/arm/arm.md @@ -6021,8 +6021,7 @@ operands[1] = legitimize_pic_address (operands[1], SImode, (!can_create_pseudo_p () ? operands[0] - : NULL_RTX), NULL_RTX, - false /*compute_now*/); + : 0)); } " ) @@ -8635,95 +8634,6 @@ (set_attr "conds" "clob")] ) -;; Named patterns for stack smashing protection. -(define_insn_and_split "stack_protect_combined_set" - [(set (match_operand:SI 0 "memory_operand" "=m") - (unspec:SI [(match_operand:SI 1 "memory_operand" "X")] - UNSPEC_SP_SET)) - (match_scratch:SI 2 "=r") - (match_scratch:SI 3 "=r")] - "" - "#" - "reload_completed" - [(parallel [(set (match_dup 0) (unspec:SI [(mem:SI (match_dup 2))] - UNSPEC_SP_SET)) - (clobber (match_dup 2))])] - " -{ - rtx addr = XEXP (operands[1], 0); - if (flag_pic) - { - /* Forces recomputing of GOT base now. */ - operands[1] = legitimize_pic_address (addr, SImode, operands[2], - operands[3], true /*compute_now*/); - } - else - { - if (!address_operand (addr, SImode)) - operands[1] = force_const_mem (SImode, addr); - emit_move_insn (operands[2], operands[1]); - } -}" -) - -(define_insn "stack_protect_set" - [(set (match_operand:SI 0 "memory_operand" "=m") - (unspec:SI [(mem:SI (match_operand:SI 1 "register_operand" "r"))] - UNSPEC_SP_SET)) - (clobber (match_dup 1))] - "" - "ldr\\t%1, [%1]\;str\\t%1, %0\;mov\t%1,0" - [(set_attr "length" "12") - (set_attr "type" "multiple")]) - -(define_insn_and_split "stack_protect_combined_test" - [(set (pc) - (if_then_else - (eq (match_operand:SI 0 "memory_operand" "m") - (unspec:SI [(match_operand:SI 1 "memory_operand" "X")] - UNSPEC_SP_TEST)) - (label_ref (match_operand 2)) - (pc))) - (match_scratch:SI 3 "=r") - (match_scratch:SI 4 "=r")] - "" - "#" - "reload_completed" - [(const_int 0)] -{ - rtx eq, addr; - - addr = XEXP (operands[1], 0); - if (flag_pic) - { - /* Forces recomputing of GOT base now. */ - operands[1] = legitimize_pic_address (addr, SImode, operands[3], - operands[4], - true /*compute_now*/); - } - else - { - if (!address_operand (addr, SImode)) - operands[1] = force_const_mem (SImode, addr); - emit_move_insn (operands[3], operands[1]); - } - emit_insn (gen_stack_protect_test (operands[4], operands[0], operands[3])); - eq = gen_rtx_EQ (VOIDmode, operands[4], const0_rtx); - emit_jump_insn (gen_cbranchsi4 (eq, operands[4], const0_rtx, operands[2])); - DONE; -}) - -(define_insn "stack_protect_test" - [(set (match_operand:SI 0 "register_operand" "=r") - (unspec:SI [(match_operand:SI 1 "memory_operand" "m") - (mem:SI (match_operand:SI 2 "register_operand" "r"))] - UNSPEC_SP_TEST)) - (clobber (match_dup 2))] - "" - "ldr\t%0, [%2]\;ldr\t%2, %1\;eor\t%0, %2, %0" - [(set_attr "length" "12") - (set_attr "type" "multiple")]) - (define_expand "casesi" [(match_operand:SI 0 "s_register_operand" "") ; index to jump on (match_operand:SI 1 "const_int_operand" "") ; lower bound diff --git a/gcc/config/arm/unspecs.md b/gcc/config/arm/unspecs.md index 8f9dbcb08dc..19416736ef9 100644 --- a/gcc/config/arm/unspecs.md +++ b/gcc/config/arm/unspecs.md @@ -86,9 +86,6 @@ UNSPEC_PROBE_STACK ; Probe stack memory reference UNSPEC_NONSECURE_MEM ; Represent non-secure memory in ARMv8-M with ; security extension - UNSPEC_SP_SET ; Represent the setting of stack protector's canary - UNSPEC_SP_TEST ; Represent the testing of stack protector's canary - ; against the guard. ]) (define_c_enum "unspec" [ diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi index e5851a6711d..02f9e1e4320 100644 --- a/gcc/doc/md.texi +++ b/gcc/doc/md.texi @@ -7388,61 +7388,22 @@ builtins. The get/set patterns have a single output/input operand respectively, with @var{mode} intended to be @code{Pmode}. -@cindex @code{stack_protect_combined_set} instruction pattern -@item @samp{stack_protect_combined_set} -This pattern, if defined, moves a @code{ptr_mode} value from an address -whose declaration RTX is given in operand 1 to the memory in operand 0 -without leaving the value in a register afterward. If several -instructions are needed by the target to perform the operation (eg. to -load the address from a GOT entry then load the @code{ptr_mode} value -and finally store it), it is the backend's responsibility to ensure no -intermediate result gets spilled. This is to avoid leaking the value -some place that an attacker might use to rewrite the stack guard slot -after having clobbered it. - -If this pattern is not defined, then the address declaration is -expanded first in the standard way and a @code{stack_protect_set} -pattern is then generated to move the value from that address to the -address in operand 0. - @cindex @code{stack_protect_set} instruction pattern @item @samp{stack_protect_set} -This pattern, if defined, moves a @code{ptr_mode} value from the valid -memory location in operand 1 to the memory in operand 0 without leaving -the value in a register afterward. This is to avoid leaking the value -some place that an attacker might use to rewrite the stack guard slot -after having clobbered it. - -Note: on targets where the addressing modes do not allow to load -directly from stack guard address, the address is expanded in a standard -way first which could cause some spills. +This pattern, if defined, moves a @code{ptr_mode} value from the memory +in operand 1 to the memory in operand 0 without leaving the value in +a register afterward. This is to avoid leaking the value some place +that an attacker might use to rewrite the stack guard slot after +having clobbered it. If this pattern is not defined, then a plain move pattern is generated. -@cindex @code{stack_protect_combined_test} instruction pattern -@item @samp{stack_protect_combined_test} -This pattern, if defined, compares a @code{ptr_mode} value from an -address whose declaration RTX is given in operand 1 with the memory in -operand 0 without leaving the value in a register afterward and -branches to operand 2 if the values were equal. If several -instructions are needed by the target to perform the operation (eg. to -load the address from a GOT entry then load the @code{ptr_mode} value -and finally store it), it is the backend's responsibility to ensure no -intermediate result gets spilled. This is to avoid leaking the value -some place that an attacker might use to rewrite the stack guard slot -after having clobbered it. - -If this pattern is not defined, then the address declaration is -expanded first in the standard way and a @code{stack_protect_test} -pattern is then generated to compare the value from that address to the -value at the memory in operand 0. - @cindex @code{stack_protect_test} instruction pattern @item @samp{stack_protect_test} This pattern, if defined, compares a @code{ptr_mode} value from the -valid memory location in operand 1 with the memory in operand 0 without -leaving the value in a register afterward and branches to operand 2 if -the values were equal. +memory in operand 1 with the memory in operand 0 without leaving the +value in a register afterward and branches to operand 2 if the values +were equal. If this pattern is not defined, then a plain compare pattern and conditional branch pattern is used. diff --git a/gcc/function.c b/gcc/function.c index a95d2f890cd..dee303cdbdd 100644 --- a/gcc/function.c +++ b/gcc/function.c @@ -4893,33 +4893,20 @@ stack_protect_epilogue (void) rtx_code_label *label = gen_label_rtx (); rtx x, y; rtx_insn *seq; - struct expand_operand ops[3]; x = expand_normal (crtl->stack_protect_guard); - create_fixed_operand (&ops[0], x); - create_fixed_operand (&ops[1], DECL_RTL (guard_decl)); - create_fixed_operand (&ops[2], label); - /* Allow the target to compute address of Y and compare it with X without - leaking Y into a register. This combined address + compare pattern allows - the target to prevent spilling of any intermediate results by splitting - it after register allocator. */ - if (!maybe_expand_jump_insn (targetm.code_for_stack_protect_combined_test, - 3, ops)) - { - if (guard_decl) - y = expand_normal (guard_decl); - else - y = const0_rtx; - - /* Allow the target to compare Y with X without leaking either into - a register. */ - if (targetm.have_stack_protect_test () - && ((seq = targetm.gen_stack_protect_test (x, y, label)) - != NULL_RTX)) - emit_insn (seq); - else - emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label); - } + if (guard_decl) + y = expand_normal (guard_decl); + else + y = const0_rtx; + + /* Allow the target to compare Y with X without leaking either into + a register. */ + if (targetm.have_stack_protect_test () + && ((seq = targetm.gen_stack_protect_test (x, y, label)) != NULL_RTX)) + emit_insn (seq); + else + emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label); /* The noreturn predictor has been moved to the tree level. The rtl-level predictors estimate this branch about 20%, which isn't enough to get diff --git a/gcc/target-insns.def b/gcc/target-insns.def index d39889b3522..9a552c3d11c 100644 --- a/gcc/target-insns.def +++ b/gcc/target-insns.def @@ -96,9 +96,7 @@ DEF_TARGET_INSN (sibcall_value, (rtx x0, rtx x1, rtx opt2, rtx opt3, DEF_TARGET_INSN (simple_return, (void)) DEF_TARGET_INSN (split_stack_prologue, (void)) DEF_TARGET_INSN (split_stack_space_check, (rtx x0, rtx x1)) -DEF_TARGET_INSN (stack_protect_combined_set, (rtx x0, rtx x1)) DEF_TARGET_INSN (stack_protect_set, (rtx x0, rtx x1)) -DEF_TARGET_INSN (stack_protect_combined_test, (rtx x0, rtx x1, rtx x2)) DEF_TARGET_INSN (stack_protect_test, (rtx x0, rtx x1, rtx x2)) DEF_TARGET_INSN (store_multiple, (rtx x0, rtx x1, rtx x2)) DEF_TARGET_INSN (tablejump, (rtx x0, rtx x1)) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index b5a46b47353..cd413d3b02e 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -15,11 +15,6 @@ PR target/86014 * gcc.target/aarch64/ldp_stp_13.c: New test. -2018-08-02 Thomas Preud'homme - - PR target/85434 - * gcc.target/arm/pr85434.c: New test. - 2018-08-01 Martin Sebor PR tree-optimization/86650 diff --git a/gcc/testsuite/gcc.target/arm/pr85434.c b/gcc/testsuite/gcc.target/arm/pr85434.c deleted file mode 100644 index 4143a861f7c..00000000000 --- a/gcc/testsuite/gcc.target/arm/pr85434.c +++ /dev/null @@ -1,200 +0,0 @@ -/* { dg-do compile } */ -/* { dg-require-effective-target fstack_protector }*/ -/* { dg-require-effective-target fpic }*/ -/* { dg-additional-options "-Os -fpic -fstack-protector-strong" } */ - -#include -#include - - -static const unsigned char base64_enc_map[64] = -{ - 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', - 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', - 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', - 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', - 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', - 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', - '8', '9', '+', '/' -}; - -#define BASE64_SIZE_T_MAX ( (size_t) -1 ) /* SIZE_T_MAX is not standard */ - - -void doSmth(void *x); - -#include - - -void check(int n) { - - if (!(n % 2 && n % 3 && n % 5)) { - __asm__ ( "add r8, r8, #1;" ); - } -} - -uint32_t test( - uint32_t a1, - uint32_t a2, - size_t a3, - size_t a4, - size_t a5, - size_t a6) -{ - uint32_t nResult = 0; - uint8_t* h = 0L; - uint8_t X[128]; - uint8_t mac[64]; - size_t len; - - doSmth(&a1); - doSmth(&a2); - doSmth(&a3); - doSmth(&a4); - doSmth(&a5); - doSmth(&a6); - - if (a1 && a2 && a3 && a4 && a5 && a6) { - nResult = 1; - h = (void*)X; - len = sizeof(X); - memset(X, a2, len); - len -= 64; - memcpy(mac ,X, len); - *(h + len) = a6; - - { - - - unsigned char *dst = X; - size_t dlen = a3; - size_t *olen = &a6; - const unsigned char *src = mac; - size_t slen = a4; - size_t i, n; - int C1, C2, C3; - unsigned char *p; - - if( slen == 0 ) - { - *olen = 0; - return( 0 ); - } - - n = slen / 3 + ( slen % 3 != 0 ); - - if( n > ( BASE64_SIZE_T_MAX - 1 ) / 4 ) - { - *olen = BASE64_SIZE_T_MAX; - return( 0 ); - } - - n *= 4; - - if( ( dlen < n + 1 ) || ( NULL == dst ) ) - { - *olen = n + 1; - return( 0 ); - } - - n = ( slen / 3 ) * 3; - - for( i = 0, p = dst; i < n; i += 3 ) - { - C1 = *src++; - C2 = *src++; - C3 = *src++; - - check(i); - - *p++ = base64_enc_map[(C1 >> 2) & 0x3F]; - *p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F]; - *p++ = base64_enc_map[(((C2 & 15) << 2) + (C3 >> 6)) & 0x3F]; - *p++ = base64_enc_map[C3 & 0x3F]; - } - - if( i < slen ) - { - C1 = *src++; - C2 = ( ( i + 1 ) < slen ) ? *src++ : 0; - - *p++ = base64_enc_map[(C1 >> 2) & 0x3F]; - *p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F]; - - if( ( i + 1 ) < slen ) - *p++ = base64_enc_map[((C2 & 15) << 2) & 0x3F]; - else *p++ = '='; - - *p++ = '='; - } - - *olen = p - dst; - *p = 0; - -} - - __asm__ ("mov r8, %0;" : "=r" ( nResult )); - } - else - { - nResult = 2; - } - - doSmth(X); - doSmth(mac); - - - return nResult; -} - -/* The pattern below catches sequences of instructions that were generated - for ARM and Thumb-2 before the fix for this PR. They are of the form: - - ldr rX, - - ldr rY, - ldr rZ, [rX] - - cmp rY, rZ - - bl __stack_chk_fail - - Ideally the optional block would check for the various rX, rY and rZ - registers not being set but this is not possible due to back references - being illegal in lookahead expression in Tcl, thus preventing to use the - only construct that allow to negate a regexp from using the backreferences - to those registers. Instead we go for the heuristic of allowing non ldr/cmp - instructions with the assumptions that (i) those are not part of the stack - protector sequences and (ii) they would only be scheduled here if they don't - conflict with registers used by stack protector. - - Note on the regexp logic: - Allowing non X instructions (where X is ldr or cmp) is done by looking for - some non newline spaces, followed by something which is not X, followed by - an alphanumeric character followed by anything but a newline and ended by a - newline the whole thing an undetermined number of times. The alphanumeric - character is there to force the match of the negative lookahead for X to - only happen after all the initial spaces and thus to check the mnemonic. - This prevents it to match one of the initial space. */ -/* { dg-final { scan-assembler-not {ldr[ \t]+([^,]+), \[(?:sp|fp)[^]]*\](?:\n[ \t]+(?!ldr)\w[^\n]*)*\n[ \t]+ldr[ \t]+([^,]+), \[(?:sp|fp)[^]]*\]\n[ \t]+ldr[ \t]+([^,]+), \[\1\](?:\n[ \t]+(?!ldr)\w[^\n]*)*\n[ \t]+cmp[ \t]+\2, \3(?:\n[ \t]+(?!cmp)\w[^\n]*)*\n[ \t]+bl[ \t]+__stack_chk_fail} } } */ - -/* Likewise for Thumb-1 sequences of instructions prior to the fix for this PR - which had the form: - - ldr rS, - - ldr rT, - - ldr rX, [rS, rT] - - ldr rY, - ldr rZ, [rX] - - cmp rY, rZ - - bl __stack_chk_fail - - Note on the regexp logic: - PC relative offset is checked by looking for a source operand that does not - contain [ or ]. */ -/* { dg-final { scan-assembler-not {ldr[ \t]+([^,]+), \[(?:sp|fp)[^]]*\](?:\n[ \t]+(?!ldr)\w[^\n]*)*\n[ \t]+ldr[ \t]+([^,]+), [^][\n]*(?:\n[ \t]+(?!ldr)\w[^\n]*)*\n[ \t]+ldr[ \t]+([^,]+), \[\1, \2\](?:\n[ \t]+(?!ldr)\w[^\n]*)*\n[ \t]+ldr[ \t]+([^,]+), \[(?:sp|fp)[^]]*\]\n[ \t]+ldr[ \t]+([^,]+), \[\3\](?:\n[ \t]+(?!ldr)\w[^\n]*)*\n[ \t]+cmp[ \t]+\4, \5(?:\n[ \t]+(?!cmp)\w[^\n]*)*\n[ \t]+bl[ \t]+__stack_chk_fail} } } */