Date: Sun, 14 May 2006 01:38:10 GMT From: John Birrell <jb@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 97122 for review Message-ID: <200605140138.k4E1cAkU082504@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=97122 Change 97122 by jb@jb_freebsd2 on 2006/05/14 01:38:10 On Solaris the kernel always seems to be called 'genunix'. On FreeBSD a hardcoded kernel module name will often end in tears because it is so easy for an admin to use a different kernel other than '/boot/kernel/kernel'. Part of this difference comes from the fact that DTrace on Solaris accesses modules via the object file system (objfs) whereas on FreeBSD the kldstat(1) syscall returns the exact name of the file loaded as the module. So, on FreeBSD, DTrace needs to take care to determine the kernel module name by using the 'kern.bootfile' sysctl. Then it needs to convert that file name to a DTrace module name by converting slashes to underscores to get around the DTrace module name parser. Finally those global variables which apply to the kernel, like 'curthread', need to be formatted using the actual kernel boot file. There are more global variables which need to be converted, but we're out on a ledge so let's do one at a time and deal with the tests that use that one. Affected files ... .. //depot/projects/dtrace/src/contrib/opensolaris/lib/libdtrace/common/dt_open.c#11 edit Differences ... ==== //depot/projects/dtrace/src/contrib/opensolaris/lib/libdtrace/common/dt_open.c#11 (text) ==== @@ -119,6 +119,13 @@ }; /* + * Global varaiables that are formatted on FreeBSD based on the kernel file name. + */ +#if !defined(sun) +static char curthread_str[MAXPATHLEN]; +#endif + +/* * Table of global identifiers. This is used to populate the global identifier * hash when a new dtrace client open occurs. For more info see dt_ident.h. * The global identifiers that represent functions use the dt_idops_func ops @@ -192,7 +199,11 @@ { "curthread", DT_IDENT_SCALAR, 0, DIF_VAR_CURTHREAD, { DTRACE_STABILITY_STABLE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_COMMON }, DT_VERS_1_0, +#if defined(sun) &dt_idops_type, "genunix`kthread_t *" }, +#else + &dt_idops_type, curthread_str }, +#endif { "ddi_pathname", DT_IDENT_FUNC, 0, DIF_SUBR_DDI_PATHNAME, DT_ATTR_EVOLCMN, DT_VERS_1_0, &dt_idops_func, "string(void *, int64_t)" }, @@ -1075,6 +1086,36 @@ else bcopy(_dtrace_ints_64, dtp->dt_ints, sizeof (_dtrace_ints_64)); + /* + * On FreeBSD the kernel module name can't be hard-coded. The + * 'kern.bootfile' sysctl value tells us exactly which file is being + * used as the kernel. + */ +#if !defined(sun) + { + char bootfile[MAXPATHLEN]; + int i; + size_t len = sizeof(bootfile); + + /* This call shouldn't fail, but use a default just in case. */ + if (sysctlbyname("kern.bootfile", bootfile, &len, NULL, 0) != 0) + strlcpy(bootfile, "_boot_kernel_kernel", sizeof(bootfile)); + + /* + * Convert the kernel file name to a DTrace module name because DTrace + * doesn't like slashes in module names. + */ + for (i = 0; i < len; i++) + if (bootfile[i] == '/') + bootfile[i] = '_'; + + /* + * Format the global variables based on the kernel module name. + */ + snprintf(curthread_str, sizeof(curthread_str), "%s`struct thread *",bootfile); + } +#endif + dtp->dt_macros = dt_idhash_create("macro", NULL, 0, UINT_MAX); dtp->dt_aggs = dt_idhash_create("aggregation", NULL, DTRACE_AGGVARIDNONE + 1, UINT_MAX);
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