1/* ====================================================================
2 * Copyright (c) 2005 The OpenSSL Project. Rights for redistribution
3 * and usage in source and binary forms are granted according to the
4 * OpenSSL license.
5 */
6
7#include <stdio.h>
8#if defined(__DECC)
9# include <c_asm.h>
10# pragma __nostandard
11#endif
12
13#include "e_os.h"
14
15#if !defined(POINTER_TO_FUNCTION_IS_POINTER_TO_1ST_INSTRUCTION)
16# if	(defined(__sun) && (defined(__sparc) || defined(__sparcv9)))	|| \
17	(defined(__sgi) && (defined(__mips) || defined(mips)))		|| \
18	(defined(__osf__) && defined(__alpha))				|| \
19	(defined(__linux) && (defined(__arm) || defined(__arm__)))	|| \
20	(defined(__i386) || defined(__i386__))				|| \
21	(defined(__x86_64) || defined(__x86_64__))			|| \
22	defined(__ANDROID__)						|| \
23	(defined(vax) || defined(__vax__))
24#  define POINTER_TO_FUNCTION_IS_POINTER_TO_1ST_INSTRUCTION
25# endif
26#endif
27
28#if defined(__xlC__) && __xlC__>=0x600 && (defined(_POWER) || defined(_ARCH_PPC))
29static void *instruction_pointer_xlc(void);
30# pragma mc_func instruction_pointer_xlc {\
31	"7c0802a6"	/* mflr	r0  */	\
32	"48000005"	/* bl	$+4 */	\
33	"7c6802a6"	/* mflr	r3  */	\
34	"7c0803a6"	/* mtlr	r0  */	}
35# pragma reg_killed_by instruction_pointer_xlc gr0 gr3
36# define INSTRUCTION_POINTER_IMPLEMENTED(ret) (ret=instruction_pointer_xlc());
37#endif
38
39#ifdef FIPS_START
40#define FIPS_ref_point FIPS_text_start
41/* Some compilers put string literals into a separate segment. As we
42 * are mostly interested to hash AES tables in .rodata, we declare
43 * reference points accordingly. In case you wonder, the values are
44 * big-endian encoded variable names, just to prevent these arrays
45 * from being merged by linker. */
46const unsigned int FIPS_rodata_start[]=
47	{ 0x46495053, 0x5f726f64, 0x6174615f, 0x73746172 };
48#else
49#define FIPS_ref_point FIPS_text_end
50const unsigned int FIPS_rodata_end[]=
51	{ 0x46495053, 0x5f726f64, 0x6174615f, 0x656e645b };
52#endif
53
54/*
55 * I declare reference function as static in order to avoid certain
56 * pitfalls in -dynamic linker behaviour...
57 */
58static void *instruction_pointer(void)
59{ void *ret=NULL;
60/* These are ABI-neutral CPU-specific snippets. ABI-neutrality means
61 * that they are designed to work under any OS running on particular
62 * CPU, which is why you don't find any #ifdef THIS_OR_THAT_OS in
63 * this function. */
64#if	defined(INSTRUCTION_POINTER_IMPLEMENTED)
65    INSTRUCTION_POINTER_IMPLEMENTED(ret);
66#elif	defined(__GNUC__) && __GNUC__>=2
67# if	defined(__alpha) || defined(__alpha__)
68#   define INSTRUCTION_POINTER_IMPLEMENTED
69    __asm __volatile (	"br	%0,1f\n1:" : "=r"(ret) );
70# elif	defined(__i386) || defined(__i386__)
71#   define INSTRUCTION_POINTER_IMPLEMENTED
72    __asm __volatile (	"call 1f\n1:	popl %0" : "=r"(ret) );
73    ret = (void *)((size_t)ret&~3UL); /* align for better performance */
74# elif	defined(__ia64) || defined(__ia64__)
75#   define INSTRUCTION_POINTER_IMPLEMENTED
76    __asm __volatile (	"mov	%0=ip" : "=r"(ret) );
77# elif	defined(__hppa) || defined(__hppa__) || defined(__pa_risc)
78#   define INSTRUCTION_POINTER_IMPLEMENTED
79    __asm __volatile (	"blr	%%r0,%0\n\tnop" : "=r"(ret) );
80    ret = (void *)((size_t)ret&~3UL); /* mask privilege level */
81# elif	defined(__mips) || defined(__mips__)
82#   define INSTRUCTION_POINTER_IMPLEMENTED
83    void *scratch;
84    __asm __volatile (	"move	%1,$31\n\t"	/* save ra */
85			"bal	.+8; nop\n\t"
86			"move	%0,$31\n\t"
87			"move	$31,%1"		/* restore ra */
88			: "=r"(ret),"=r"(scratch) );
89# elif	defined(__ppc__) || defined(__powerpc) || defined(__powerpc__) || \
90	defined(__POWERPC__) || defined(_POWER) || defined(__PPC__) || \
91	defined(__PPC64__) || defined(__powerpc64__)
92#   define INSTRUCTION_POINTER_IMPLEMENTED
93    void *scratch;
94    __asm __volatile (	"mfspr	%1,8\n\t"	/* save lr */
95			"bl	$+4\n\t"
96			"mfspr	%0,8\n\t"	/* mflr ret */
97			"mtspr	8,%1"		/* restore lr */
98			: "=r"(ret),"=r"(scratch) );
99# elif	defined(__s390__) || defined(__s390x__)
100#   define INSTRUCTION_POINTER_IMPLEMENTED
101    __asm __volatile (	"bras	%0,1f\n1:" : "=r"(ret) );
102    ret = (void *)((size_t)ret&~3UL);
103# elif	defined(__sparc) || defined(__sparc__) || defined(__sparcv9)
104#   define INSTRUCTION_POINTER_IMPLEMENTED
105    void *scratch;
106    __asm __volatile (	"mov	%%o7,%1\n\t"
107			"call	.+8; nop\n\t"
108		  	"mov	%%o7,%0\n\t"
109			"mov	%1,%%o7"
110			: "=r"(ret),"=r"(scratch) );
111# elif	defined(__x86_64) || defined(__x86_64__)
112#   define INSTRUCTION_POINTER_IMPLEMENTED
113    __asm __volatile (	"leaq	0(%%rip),%0" : "=r"(ret) );
114    ret = (void *)((size_t)ret&~3UL); /* align for better performance */
115# endif
116#elif	defined(__DECC) && defined(__alpha)
117#   define INSTRUCTION_POINTER_IMPLEMENTED
118    ret = (void *)(size_t)asm("br %v0,1f\n1:");
119#elif   defined(_MSC_VER) && defined(_M_IX86)
120#   define INSTRUCTION_POINTER_IMPLEMENTED
121    void *scratch;
122    _asm {
123            call    self
124    self:   pop     eax
125            mov     scratch,eax
126         }
127    ret = (void *)((size_t)scratch&~3UL);
128#endif
129  return ret;
130}
131
132/*
133 * This function returns pointer to an instruction in the vicinity of
134 * its entry point, but not outside this object module. This guarantees
135 * that sequestered code is covered...
136 */
137void *FIPS_ref_point()
138{
139#if	defined(INSTRUCTION_POINTER_IMPLEMENTED)
140    return instruction_pointer();
141/* Below we essentially cover vendor compilers which do not support
142 * inline assembler... */
143#elif	defined(_AIX)
144    struct { void *ip,*gp,*env; } *p = (void *)instruction_pointer;
145    return p->ip;
146#elif	defined(_HPUX_SOURCE)
147# if	defined(__hppa) || defined(__hppa__)
148    struct { void *i[4]; } *p = (void *)FIPS_ref_point;
149
150    if (sizeof(p) == 8)	/* 64-bit */
151	return p->i[2];
152    else if ((size_t)p & 2)
153    {	p = (void *)((size_t)p&~3UL);
154	return p->i[0];
155    }
156    else
157	return (void *)p;
158# elif	defined(__ia64) || defined(__ia64__)
159    struct { unsigned long long ip,gp; } *p=(void *)instruction_pointer;
160    return (void *)(size_t)p->ip;
161# endif
162#elif	(defined(__VMS) || defined(VMS)) && !(defined(vax) || defined(__vax__))
163    /* applies to both alpha and ia64 */
164    struct { unsigned __int64 opaque,ip; } *p=(void *)instruction_pointer;
165    return (void *)(size_t)p->ip;
166#elif	defined(__VOS__)
167    /* applies to both pa-risc and ia32 */
168    struct { void *dp,*ip,*gp; } *p = (void *)instruction_pointer;
169    return p->ip;
170#elif	defined(_WIN32)
171# if	defined(_WIN64) && defined(_M_IA64)
172    struct { void *ip,*gp; } *p = (void *)FIPS_ref_point;
173    return p->ip;
174# else
175    return (void *)FIPS_ref_point;
176# endif
177/*
178 * In case you wonder why there is no #ifdef __linux. All Linux targets
179 * are GCC-based and therefore are covered by instruction_pointer above
180 * [well, some are covered by by the one below]...
181 */
182#elif	defined(POINTER_TO_FUNCTION_IS_POINTER_TO_1ST_INSTRUCTION)
183    return (void *)instruction_pointer;
184#else
185    return NULL;
186#endif
187}
188