xpcom/reflect/xptcall/src/md/unix/xptcinvoke_gcc_x86_unix.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Sat, 03 Jan 2015 20:18:00 +0100
branch
TOR_BUG_3246
changeset 7
129ffea94266
permissions
-rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

     1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
     2 /* This Source Code Form is subject to the terms of the Mozilla Public
     3  * License, v. 2.0. If a copy of the MPL was not distributed with this
     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
     6 /* Platform specific code to invoke XPCOM methods on native objects */
     8 #include "xptcprivate.h"
     9 #include "xptc_gcc_x86_unix.h"
    11 extern "C" {
    12 static void ATTRIBUTE_USED __attribute__ ((regparm(3)))
    13 invoke_copy_to_stack(uint32_t paramCount, nsXPTCVariant* s, uint32_t* d)
    14 {
    15     for(uint32_t i = paramCount; i >0; i--, d++, s++)
    16     {
    17         if(s->IsPtrData())
    18         {
    19             *((void**)d) = s->ptr;
    20             continue;
    21         }
    23         switch(s->type)
    24         {
    25         case nsXPTType::T_I64    : *((int64_t*) d) = s->val.i64; d++;    break;
    26         case nsXPTType::T_U64    : *((uint64_t*)d) = s->val.u64; d++;    break;
    27         case nsXPTType::T_DOUBLE : *((double*)  d) = s->val.d;   d++;    break;
    28         default                  : *((void**)d)    = s->val.p;           break;
    29         }
    30     }
    31 }
    32 } // extern "C"
    34 /*
    35   EXPORT_XPCOM_API(nsresult)
    36   NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex,
    37                    uint32_t paramCount, nsXPTCVariant* params);
    39   Each param takes at most two 4-byte words.
    40   It doesn't matter if we push too many words, and calculating the exact
    41   amount takes time.
    43   that        = ebp + 0x08
    44   methodIndex = ebp + 0x0c
    45   paramCount  = ebp + 0x10
    46   params      = ebp + 0x14
    48 */
    50 __asm__ (
    51 	".text\n\t"
    52 /* alignment here seems unimportant here; this was 16, now it's 2 which
    53    is what xptcstubs uses. */
    54 	".align 2\n\t"
    55 	".globl " SYMBOL_UNDERSCORE "NS_InvokeByIndex\n\t"
    56 #ifndef XP_MACOSX
    57 	".type  " SYMBOL_UNDERSCORE "NS_InvokeByIndex,@function\n"
    58 #endif
    59 	SYMBOL_UNDERSCORE "NS_InvokeByIndex:\n\t"
    60 	"pushl %ebp\n\t"
    61 	"movl  %esp, %ebp\n\t"
    62 	"movl  0x10(%ebp), %eax\n\t"
    63 	"leal  0(,%eax,8),%edx\n\t"
    65         /* set up call frame for method. */
    66 	"subl  %edx, %esp\n\t"       /* make room for params. */
    67 /* Align to maximum x86 data size: 128 bits == 16 bytes == XMM register size.
    68  * This is to avoid protection faults where SSE+ alignment of stack pointer
    69  * is assumed and required, e.g. by GCC4's -ftree-vectorize option.
    70  */
    71 	"andl  $0xfffffff0, %esp\n\t"   /* drop(?) stack ptr to 128-bit align */
    72 /* $esp should be aligned to a 16-byte boundary here (note we include an 
    73  * additional 4 bytes in a later push instruction). This will ensure $ebp 
    74  * in the function called below is aligned to a 0x8 boundary. SSE instructions 
    75  * like movapd/movdqa expect memory operand to be aligned on a 16-byte
    76  * boundary. The GCC compiler will generate the memory operand using $ebp
    77  * with an 8-byte offset.
    78  */
    79 	"subl  $0xc, %esp\n\t"          /* lower again; push/call below will re-align */
    80 	"movl  %esp, %ecx\n\t"          /* ecx = d */
    81 	"movl  8(%ebp), %edx\n\t"       /* edx = this */
    82 	"pushl %edx\n\t"                /* push this. esp % 16 == 0 */
    84 	"movl  0x14(%ebp), %edx\n\t"
    85 	"call  " SYMBOL_UNDERSCORE "invoke_copy_to_stack\n\t"
    86 	"movl  0x08(%ebp), %ecx\n\t"	/* 'that' */
    87 	"movl  (%ecx), %edx\n\t"
    88 	"movl  0x0c(%ebp), %eax\n\t"    /* function index */
    89 	"leal  (%edx,%eax,4), %edx\n\t"
    90 	"call  *(%edx)\n\t"
    91 	"movl  %ebp, %esp\n\t"
    92 	"popl  %ebp\n\t"
    93 	"ret\n"
    94 #ifndef XP_MACOSX
    95 	".size " SYMBOL_UNDERSCORE "NS_InvokeByIndex, . -" SYMBOL_UNDERSCORE "NS_InvokeByIndex\n\t"
    96 #endif
    97 );

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