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>
23 #if defined(AFS_OSF_ENV) || defined(AFS_S390_LINUX20_ENV)
24 extern int PRE_Block; /* used in lwp.c and process.s */
26 extern char PRE_Block; /* used in lwp.c and process.s */
29 #if defined(USE_UCONTEXT) && defined(HAVE_UCONTEXT_H)
32 savecontext(void (*ep) (void), struct lwp_context *savearea, char *newsp)
34 #if defined(AFS_LINUX20_ENV)
35 /* getcontext does not export stack info */
42 getcontext(&savearea->ucontext);
43 #if defined(AFS_LINUX20_ENV)
44 savearea->topstack = (char *)&stackvar;
46 savearea->topstack = savearea->ucontext.uc_stack.ss_sp;
48 switch (savearea->state) {
54 thread.uc_stack.ss_sp =
55 newsp - AFS_LWP_MINSTACKSIZE + sizeof(void *) +
57 thread.uc_stack.ss_size = AFS_LWP_MINSTACKSIZE - sizeof(void *);
58 makecontext(&thread, ep, 0);
70 returnto(struct lwp_context *savearea)
75 setcontext(&savearea->ucontext);
83 #if defined(AFS_SGI64_ENV)
89 #elif defined(AFS_HPUX_ENV) || defined(AFS_PARISC_LINUX24_ENV)
91 #elif defined(AFS_LINUX20_ENV)
92 #if defined(AFS_PPC_LINUX20_ENV) || defined(AFS_PPC64_LINUX20_ENV)
94 #elif defined(AFS_I386_LINUX20_ENV)
96 #elif defined(AFS_S390_LINUX20_ENV)
99 #elif defined(AFS_SPARC_LINUX20_ENV)
102 #elif defined(AFS_SPARC64_LINUX20_ENV) && defined(AFS_32BIT_USR_ENV)
105 #elif defined(AFS_ALPHA_LINUX20_ENV)
108 #elif defined(AFS_PARISC_LINUX24_ENV)
111 #error Unsupported linux LWP system type.
113 #elif defined(AFS_X86_FBSD_ENV)
115 #elif defined(AFS_DARWIN_ENV)
118 Need offset to SP in jmp_buf for this platform.
121 * On SGIs the type of the elements of the array passed to setjmp
122 * differs based on the ISA chosen. It is int for mips1 and mips2 and
123 * __uint64_t for mips3 and mips4
126 #if (_MIPS_ISA == _MIPS_ISA_MIPS3 || _MIPS_ISA == _MIPS_ISA_MIPS4)
127 typedef __uint64_t jmp_buf_type;
130 #if defined(AFS_ALPHA_LINUX20_ENV) || defined(AFS_PPC64_LINUX20_ENV)
131 typedef long jmp_buf_type;
133 typedef int jmp_buf_type;
134 #endif /*AFS_ALPHA_LINUX20_ENV */
137 static jmp_buf jmp_tmp;
138 static void (*EP) (void);
140 static jmp_buf_type *jmpBuffer;
142 /** Starting with Glibc 2.4 pointers in jmp_buf are mangled (XOR) for "protection".
143 * On Sparc ucontext functions are not implemented.
145 #define ptr_mangle(x) (x)
146 #ifdef AFS_LINUX20_ENV
149 #if (__GLIBC__ > 2) || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 3)
151 #if defined(AFS_SPARC64_LINUX24_ENV) || defined(AFS_SPARC_LINUX24_ENV)
152 /* technically we should use POINTER_GUARD
153 * ( == offsetof (tcbhead_t, pointer_guard) )
157 static int ptr_mangle(int p)
159 register char *tls_ptr __asm__("%g7");
160 return p ^ *(int*)(tls_ptr + 0x18);
163 #error need ptr_mangle support or use UCONTEXT
172 savecontext(void (*ep)(void), struct lwp_context *savearea, char *sp)
179 code = setjmp(savearea->setjmp_buffer);
180 jmpBuffer = (jmp_buf_type *) savearea->setjmp_buffer;
181 savearea->topstack = (char *) ptr_mangle(jmpBuffer[LWP_SP]);
185 int i, *ptr = (int *)savearea->setjmp_buffer;
186 printf("savecontext\n");
187 for (i = 0; i < 5; i++)
188 printf("(%d) 0x%x ", i, ptr[i]);
190 for (i = 5; i < 10; i++)
191 printf("(%d) 0x%x ", i, ptr[i]);
200 rc = setjmp(jmp_tmp);
203 jmpBuffer = (jmp_buf_type *) jmp_tmp;
204 jmpBuffer[LWP_SP] = ptr_mangle((jmp_buf_type) sp);
205 #if defined(AFS_S390_LINUX20_ENV) || defined(AFS_SPARC_LINUX20_ENV) || (defined(AFS_SPARC64_LINUX20_ENV) && defined(AFS_32BIT_USR_ENV))
206 jmpBuffer[LWP_FP] = ptr_mangle((jmp_buf_type) sp);
212 assert(0); /* never returns */
215 perror("Error in setjmp1\n");
220 case 2: /* restoring frame */
224 perror("Error in setjmp2 : restoring\n");
231 returnto(struct lwp_context * savearea)
234 int i, *ptr = savearea->setjmp_buffer;
236 printf("Returning to \n");
237 for (i = 0; i < 5; i++)
238 printf("(%d) 0x%x ", i, ptr[i]);
240 for (i = 5; i < 10; i++)
241 printf("(%d) 0x%x ", i, ptr[i]);
245 longjmp(savearea->setjmp_buffer, 2);