libutil-25.tar.gz

[apple/libutil.git] / reexec_to_match_kernel.c

diff --git a/reexec_to_match_kernel.c b/reexec_to_match_kernel.c
index a617c64378dba392c90d8b2a8340a905953c992a..d510fbcd8bc6b03f7a0369049435615cda530c09 100644 (file)
--- a/reexec_to_match_kernel.c
+++ b/reexec_to_match_kernel.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008 Apple Inc. All rights reserved.
+ * Copyright (c) 2008-2010 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
@@ -37,16 +37,17 @@
 
 static cpu_type_t current_program_arch(void);
 static cpu_type_t current_kernel_arch(void);
-static int reexec(cpu_type_t cputype);
+static int reexec(cpu_type_t cputype, const char *guardenv);
 
-#define kReExec "REEXEC_TO_MATCH_KERNEL"
+#define kReExecToMatchKernel "REEXEC_TO_MATCH_KERNEL"
+#define kReExecToMatchLP64 "REEXEC_TO_MATCH_LP64NESS"
 
 int reexec_to_match_kernel(void)
 {
        cpu_type_t kernarch, progarch;
        char *alreadyenv;
        
-       alreadyenv = getenv(kReExec);
+       alreadyenv = getenv(kReExecToMatchKernel);
        if (alreadyenv) {
                /* we've done this at least once, assume
                   another try won't help */
@@ -68,7 +69,43 @@ int reexec_to_match_kernel(void)
        }
 
        /* Now we need to re-exec */
-       return reexec(kernarch);
+       return reexec(kernarch, kReExecToMatchKernel);
+}
+
+int reexec_to_match_lp64ness(bool isLP64)
+{
+       cpu_type_t kernarch, progarch, targetarch;
+       char *alreadyenv;
+       
+       alreadyenv = getenv(kReExecToMatchLP64);
+       if (alreadyenv) {
+               /* we've done this at least once, assume
+                  another try won't help */
+               return 0;
+       }
+
+       kernarch = current_kernel_arch();
+       progarch = current_program_arch();
+
+       if (kernarch == 0) {
+               /* could not determine kernel arch */
+               errno = EINVAL;
+               return -1;
+       }
+
+       if (isLP64) {
+               targetarch = kernarch | CPU_ARCH_ABI64;
+       } else {
+               targetarch = kernarch & ~CPU_ARCH_ABI64;
+       }
+
+       if (targetarch == progarch) {
+               /* nothing to do here */
+               return 0;
+       }
+
+       /* Now we need to re-exec */
+       return reexec(targetarch, kReExecToMatchLP64);
 }
 
 static cpu_type_t current_program_arch(void)
@@ -114,7 +151,7 @@ static cpu_type_t current_kernel_arch(void)
        return current_arch;
 }
 
-static int reexec(cpu_type_t cputype)
+static int reexec(cpu_type_t cputype, const char *guardenv)
 {
        posix_spawnattr_t  attr;
        int                ret, envcount;
@@ -122,6 +159,7 @@ static int reexec(cpu_type_t cputype)
        char                       **argv, **oldenvp, **newenvp;
        char                       execpath[MAXPATHLEN+1];
        uint32_t                   execsize;
+       char               guardstr[32];
 
        argv = *_NSGetArgv();
        oldenvp = *_NSGetEnviron();
@@ -132,7 +170,9 @@ static int reexec(cpu_type_t cputype)
        for (envcount = 0; oldenvp[envcount]; envcount++) {
                newenvp[envcount] = oldenvp[envcount];
        }
-       newenvp[envcount++] = kReExec"=1";
+
+       snprintf(guardstr, sizeof(guardstr), "%s=1", guardenv);
+       newenvp[envcount++] = guardstr;
        newenvp[envcount] = NULL;
 
        execsize = (uint32_t)sizeof(execpath);
@@ -154,15 +194,16 @@ static int reexec(cpu_type_t cputype)
                return -1;
        }
 
-       /*
-       fprintf(stderr, "reexec: %s\n", execpath);
+#if 0
+       fprintf(stderr, "reexec: %s (arch=%d)\n", execpath, cputype);
        for (envcount=0; newenvp[envcount]; envcount++) {
                fprintf(stderr, "env[%d] = %s\n", envcount, newenvp[envcount]);
        }
        for (envcount=0; argv[envcount]; envcount++) {
                fprintf(stderr, "argv[%d] = %s\n", envcount, argv[envcount]);
        }
-       */
+#endif
+
        ret = posix_spawn(NULL, execpath, NULL, &attr, argv, newenvp);
        if (ret != 0) {
                errno = ret;