diff options
Diffstat (limited to 'usr/src/lib/libkvm/common/kvm.c')
| -rw-r--r-- | usr/src/lib/libkvm/common/kvm.c | 89 |
1 files changed, 85 insertions, 4 deletions
diff --git a/usr/src/lib/libkvm/common/kvm.c b/usr/src/lib/libkvm/common/kvm.c index d3a5dbd81c..c71c4db31b 100644 --- a/usr/src/lib/libkvm/common/kvm.c +++ b/usr/src/lib/libkvm/common/kvm.c @@ -24,7 +24,9 @@ * Use is subject to license terms. */ -#pragma ident "%Z%%M% %I% %E% SMI" +/* + * Copyright (c) 2013, Joyent, Inc. All rights reserved. + */ #include <kvm.h> #include <stdio.h> @@ -34,6 +36,7 @@ #include <limits.h> #include <fcntl.h> #include <strings.h> +#include <errno.h> #include <sys/mem.h> #include <sys/stat.h> #include <sys/mman.h> @@ -55,12 +58,15 @@ struct _kvmd { proc_t *kvm_practive; pid_t kvm_pid; char kvm_namelist[MAXNAMELEN + 1]; + boolean_t kvm_namelist_core; proc_t kvm_proc; }; #define PREAD (ssize_t (*)(int, void *, size_t, offset_t))pread64 #define PWRITE (ssize_t (*)(int, void *, size_t, offset_t))pwrite64 +static int kvm_nlist_core(kvm_t *kd, struct nlist nl[], const char *err); + static kvm_t * fail(kvm_t *kd, const char *err, const char *message, ...) { @@ -164,9 +170,15 @@ kvm_open(const char *namelist, const char *corefile, const char *swapfile, (void) strncpy(kd->kvm_namelist, namelist, MAXNAMELEN); - if (kvm_nlist(kd, nl) == -1) - return (fail(kd, err, "%s is not a %d-bit kernel namelist", - namelist, DUMP_WORDSIZE)); + if (kvm_nlist(kd, nl) == -1) { + if (kd->kvm_corefd == -1) { + return (fail(kd, err, "%s is not a %d-bit " + "kernel namelist", namelist, DUMP_WORDSIZE)); + } + + if (kvm_nlist_core(kd, nl, err) == -1) + return (NULL); /* fail() already called */ + } kd->kvm_kas = (struct as *)nl[0].n_value; kd->kvm_practive = (proc_t *)nl[1].n_value; @@ -186,16 +198,85 @@ kvm_close(kvm_t *kd) (void) close(kd->kvm_kmemfd); if (kd->kvm_memfd != -1) (void) close(kd->kvm_memfd); + if (kd->kvm_namelist_core) + (void) unlink(kd->kvm_namelist); free(kd); return (0); } +const char * +kvm_namelist(kvm_t *kd) +{ + return (kd->kvm_namelist); +} + int kvm_nlist(kvm_t *kd, struct nlist nl[]) { return (nlist(kd->kvm_namelist, nl)); } +/* + * If we don't have a name list, try to dig it out of the kernel crash dump. + * (The symbols have been present in the dump, uncompressed, for nearly a + * decade as of this writing -- and it is frankly surprising that the archaic + * notion of a disjoint symbol table managed to survive that change.) + */ +static int +kvm_nlist_core(kvm_t *kd, struct nlist nl[], const char *err) +{ + dumphdr_t *dump = &kd->kvm_dump; + char *msg = "couldn't extract symbols from dump"; + char *template = "/tmp/.libkvm.kvm_nlist_core.pid%d.XXXXXX"; + int fd, rval; + + if (dump->dump_ksyms_size != dump->dump_ksyms_csize) { + (void) fail(kd, err, "%s: kernel symbols are compressed", msg); + return (-1); + } + + if (dump->dump_ksyms + dump->dump_ksyms_size > kd->kvm_coremapsize) { + (void) fail(kd, err, "%s: kernel symbols not mapped", msg); + return (-1); + } + + /* + * Beause this temporary file may be left as a turd if the caller + * does not properly call kvm_close(), we make sure that it clearly + * indicates its origins. + */ + (void) snprintf(kd->kvm_namelist, MAXNAMELEN, template, getpid()); + + if ((fd = mkstemp(kd->kvm_namelist)) == -1) { + (void) fail(kd, err, "%s: couldn't create temporary " + "symbols file: %s", msg, strerror(errno)); + return (-1); + } + + kd->kvm_namelist_core = B_TRUE; + + do { + rval = write(fd, (caddr_t)((uintptr_t)kd->kvm_core + + (uintptr_t)dump->dump_ksyms), dump->dump_ksyms_size); + } while (rval < dump->dump_ksyms_size && errno == EINTR); + + if (rval < dump->dump_ksyms_size) { + (void) fail(kd, err, "%s: couldn't write to temporary " + "symbols file: %s", msg, strerror(errno)); + (void) close(fd); + return (-1); + } + + (void) close(fd); + + if (kvm_nlist(kd, nl) == -1) { + (void) fail(kd, err, "%s: symbols not valid", msg); + return (-1); + } + + return (0); +} + static offset_t kvm_lookup(kvm_t *kd, struct as *as, uint64_t addr) { |