2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
10 /* process.c - manage lwp context switches be means of setjmp/longjmp. */
12 #include <afsconfig.h>
13 #include <afs/param.h>
24 #if defined(AFS_OSF_ENV) || defined(AFS_S390_LINUX20_ENV)
25 extern int PRE_Block; /* used in lwp.c and process.s */
27 extern char PRE_Block; /* used in lwp.c and process.s */
30 #if defined(USE_UCONTEXT) && defined(HAVE_UCONTEXT_H)
33 savecontext(void (*ep) (void), struct lwp_context *savearea, char *newsp)
35 #if defined(AFS_LINUX20_ENV)
36 /* getcontext does not export stack info */
43 getcontext(&savearea->ucontext);
44 #if defined(AFS_LINUX20_ENV)
45 savearea->topstack = (char *)&stackvar;
47 savearea->topstack = savearea->ucontext.uc_stack.ss_sp;
49 switch (savearea->state) {
55 thread.uc_stack.ss_sp =
56 newsp - AFS_LWP_MINSTACKSIZE + sizeof(void *) +
58 thread.uc_stack.ss_size = AFS_LWP_MINSTACKSIZE - sizeof(void *);
59 makecontext(&thread, ep, 0);
71 returnto(struct lwp_context *savearea)
76 setcontext(&savearea->ucontext);
84 #if defined(AFS_SGI64_ENV)
90 #elif defined(AFS_HPUX_ENV) || defined(AFS_PARISC_LINUX24_ENV)
92 #elif defined(AFS_LINUX20_ENV)
93 #if defined(AFS_PPC_LINUX20_ENV) || defined(AFS_PPC64_LINUX20_ENV)
95 #elif defined(AFS_I386_LINUX20_ENV)
97 #elif defined(AFS_S390_LINUX20_ENV)
100 #elif defined(AFS_SPARC_LINUX20_ENV)
103 #elif defined(AFS_SPARC64_LINUX20_ENV) && defined(AFS_32BIT_USR_ENV)
106 #elif defined(AFS_ALPHA_LINUX20_ENV)
109 #elif defined(AFS_PARISC_LINUX24_ENV)
112 #error Unsupported linux LWP system type.
114 #elif defined(AFS_X86_FBSD_ENV)
116 #elif defined(AFS_DARWIN_ENV)
119 Need offset to SP in jmp_buf for this platform.
122 * On SGIs the type of the elements of the array passed to setjmp
123 * differs based on the ISA chosen. It is int for mips1 and mips2 and
124 * __uint64_t for mips3 and mips4
127 #if (_MIPS_ISA == _MIPS_ISA_MIPS3 || _MIPS_ISA == _MIPS_ISA_MIPS4)
128 typedef __uint64_t jmp_buf_type;
131 #if defined(AFS_ALPHA_LINUX20_ENV) || defined(AFS_PPC64_LINUX20_ENV)
132 typedef long jmp_buf_type;
134 typedef int jmp_buf_type;
135 #endif /*AFS_ALPHA_LINUX20_ENV */
138 static jmp_buf jmp_tmp;
139 static void (*EP) (void);
141 static jmp_buf_type *jmpBuffer;
143 /** Starting with Glibc 2.4 pointers in jmp_buf are mangled (XOR) for "protection".
144 * On Sparc ucontext functions are not implemented.
146 #define ptr_mangle(x) (x)
147 #ifdef AFS_LINUX20_ENV
150 #if (__GLIBC__ > 2) || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 3)
152 #if defined(AFS_SPARC64_LINUX24_ENV) || defined(AFS_SPARC_LINUX24_ENV)
153 /* technically we should use POINTER_GUARD
154 * ( == offsetof (tcbhead_t, pointer_guard) )
158 static int ptr_mangle(int p)
160 register char *tls_ptr __asm__("%g7");
161 return p ^ *(int*)(tls_ptr + 0x18);
164 #error need ptr_mangle support or use UCONTEXT
173 savecontext(void (*ep)(void), struct lwp_context *savearea, char *sp)
180 code = setjmp(savearea->setjmp_buffer);
181 jmpBuffer = (jmp_buf_type *) savearea->setjmp_buffer;
182 savearea->topstack = (char *) ptr_mangle(jmpBuffer[LWP_SP]);
186 int i, *ptr = (int *)savearea->setjmp_buffer;
187 printf("savecontext\n");
188 for (i = 0; i < 5; i++)
189 printf("(%d) 0x%x ", i, ptr[i]);
191 for (i = 5; i < 10; i++)
192 printf("(%d) 0x%x ", i, ptr[i]);
201 rc = setjmp(jmp_tmp);
204 jmpBuffer = (jmp_buf_type *) jmp_tmp;
205 jmpBuffer[LWP_SP] = ptr_mangle((jmp_buf_type) sp);
206 #if defined(AFS_S390_LINUX20_ENV) || defined(AFS_SPARC_LINUX20_ENV) || (defined(AFS_SPARC64_LINUX20_ENV) && defined(AFS_32BIT_USR_ENV))
207 jmpBuffer[LWP_FP] = ptr_mangle((jmp_buf_type) sp);
213 assert(0); /* never returns */
216 perror("Error in setjmp1\n");
221 case 2: /* restoring frame */
225 perror("Error in setjmp2 : restoring\n");
232 returnto(struct lwp_context * savearea)
235 int i, *ptr = savearea->setjmp_buffer;
237 printf("Returning to \n");
238 for (i = 0; i < 5; i++)
239 printf("(%d) 0x%x ", i, ptr[i]);
241 for (i = 5; i < 10; i++)
242 printf("(%d) 0x%x ", i, ptr[i]);
246 longjmp(savearea->setjmp_buffer, 2);