diff options
Diffstat (limited to 'lib/libkvm/kvm_pcpu.c')
| -rw-r--r-- | lib/libkvm/kvm_pcpu.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/lib/libkvm/kvm_pcpu.c b/lib/libkvm/kvm_pcpu.c index e4f8909..484d2ea 100644 --- a/lib/libkvm/kvm_pcpu.c +++ b/lib/libkvm/kvm_pcpu.c @@ -1,8 +1,15 @@ /*- + * Copyright (c) 2010 Juniper Networks, Inc. + * Copyright (c) 2009 Robert N. M. Watson + * Copyright (c) 2009 Bjoern A. Zeeb <bz@FreeBSD.org> * Copyright (c) 2008 Yahoo!, Inc. * All rights reserved. + * * Written by: John Baldwin <jhb@FreeBSD.org> * + * This software was developed by Robert N. M. Watson under contract + * to Juniper Networks, Inc. + * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: @@ -49,6 +56,10 @@ static struct nlist kvm_pcpu_nl[] = { /* * Kernel per-CPU data state. We cache this stuff on the first * access. + * + * XXXRW: Possibly, this (and kvmpcpu_nl) should be per-kvm_t, in case the + * consumer has multiple handles in flight to differently configured + * kernels/crashdumps. */ static void **pcpu_data; static int maxcpu; @@ -150,3 +161,132 @@ kvm_getmaxcpu(kvm_t *kd) return (-1); return (maxcpu); } + +static int +_kvm_dpcpu_setcpu(kvm_t *kd, u_int cpu, int report_error) +{ + + if (!kd->dpcpu_initialized) { + if (report_error) + _kvm_err(kd, kd->program, "%s: not initialized", + __func__); + return (-1); + } + if (cpu >= kd->dpcpu_maxcpus) { + if (report_error) + _kvm_err(kd, kd->program, "%s: CPU %u too big", + __func__, cpu); + return (-1); + } + if (kd->dpcpu_off[cpu] == 0) { + if (report_error) + _kvm_err(kd, kd->program, "%s: CPU %u not found", + __func__, cpu); + return (-1); + } + kd->dpcpu_curcpu = cpu; + kd->dpcpu_curoff = kd->dpcpu_off[cpu]; + return (0); +} + +/* + * Set up libkvm to handle dynamic per-CPU memory. + */ +static int +_kvm_dpcpu_init(kvm_t *kd) +{ + struct nlist nl[] = { +#define NLIST_START_SET_PCPU 0 + { "___start_set_pcpu" }, +#define NLIST_STOP_SET_PCPU 1 + { "___stop_set_pcpu" }, +#define NLIST_DPCPU_OFF 2 + { "_dpcpu_off" }, +#define NLIST_MP_MAXCPUS 3 + { "_mp_maxcpus" }, + { NULL }, + }; + uintptr_t *dpcpu_off_buf; + size_t len; + u_int dpcpu_maxcpus; + + /* + * Locate and cache locations of important symbols using the internal + * version of _kvm_nlist, turning off initialization to avoid + * recursion in case of unresolveable symbols. + */ + if (_kvm_nlist(kd, nl, 0) != 0) + return (-1); + if (kvm_read(kd, nl[NLIST_MP_MAXCPUS].n_value, &dpcpu_maxcpus, + sizeof(dpcpu_maxcpus)) != sizeof(dpcpu_maxcpus)) + return (-1); + len = dpcpu_maxcpus * sizeof(*dpcpu_off_buf); + dpcpu_off_buf = malloc(len); + if (dpcpu_off_buf == NULL) + return (-1); + if (kvm_read(kd, nl[NLIST_DPCPU_OFF].n_value, dpcpu_off_buf, len) != + len) { + free(dpcpu_off_buf); + return (-1); + } + kd->dpcpu_start = nl[NLIST_START_SET_PCPU].n_value; + kd->dpcpu_stop = nl[NLIST_STOP_SET_PCPU].n_value; + kd->dpcpu_maxcpus = dpcpu_maxcpus; + kd->dpcpu_off = dpcpu_off_buf; + kd->dpcpu_initialized = 1; + (void)_kvm_dpcpu_setcpu(kd, 0, 0); + return (0); +} + +/* + * Check whether the dpcpu module has been initialized sucessfully or not, + * initialize it if permitted. + */ +int +_kvm_dpcpu_initialized(kvm_t *kd, int intialize) +{ + + if (kd->dpcpu_initialized || !intialize) + return (kd->dpcpu_initialized); + + (void)_kvm_dpcpu_init(kd); + + return (kd->dpcpu_initialized); +} + +/* + * Check whether the value is within the dpcpu symbol range and only if so + * adjust the offset relative to the current offset. + */ +uintptr_t +_kvm_dpcpu_validaddr(kvm_t *kd, uintptr_t value) +{ + + if (value == 0) + return (value); + + if (!kd->dpcpu_initialized) + return (value); + + if (value < kd->dpcpu_start || value >= kd->dpcpu_stop) + return (value); + + return (kd->dpcpu_curoff + value); +} + +int +kvm_dpcpu_setcpu(kvm_t *kd, u_int cpu) +{ + int ret; + + if (!kd->dpcpu_initialized) { + ret = _kvm_dpcpu_init(kd); + if (ret != 0) { + _kvm_err(kd, kd->program, "%s: init failed", + __func__); + return (ret); + } + } + + return (_kvm_dpcpu_setcpu(kd, cpu, 1)); +} |
