aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/ptrace.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/ptrace.c')
-rw-r--r--arch/x86/kernel/ptrace.c384
1 files changed, 1 insertions, 383 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 2e9b55027b7e..70c4872cd8aa 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -2,9 +2,6 @@
2/* 2/*
3 * Pentium III FXSR, SSE support 3 * Pentium III FXSR, SSE support
4 * Gareth Hughes <gareth@valinux.com>, May 2000 4 * Gareth Hughes <gareth@valinux.com>, May 2000
5 *
6 * BTS tracing
7 * Markus Metzger <markus.t.metzger@intel.com>, Dec 2007
8 */ 5 */
9 6
10#include <linux/kernel.h> 7#include <linux/kernel.h>
@@ -22,7 +19,6 @@
22#include <linux/audit.h> 19#include <linux/audit.h>
23#include <linux/seccomp.h> 20#include <linux/seccomp.h>
24#include <linux/signal.h> 21#include <linux/signal.h>
25#include <linux/workqueue.h>
26#include <linux/perf_event.h> 22#include <linux/perf_event.h>
27#include <linux/hw_breakpoint.h> 23#include <linux/hw_breakpoint.h>
28 24
@@ -36,7 +32,6 @@
36#include <asm/desc.h> 32#include <asm/desc.h>
37#include <asm/prctl.h> 33#include <asm/prctl.h>
38#include <asm/proto.h> 34#include <asm/proto.h>
39#include <asm/ds.h>
40#include <asm/hw_breakpoint.h> 35#include <asm/hw_breakpoint.h>
41 36
42#include "tls.h" 37#include "tls.h"
@@ -693,7 +688,7 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
693 struct perf_event_attr attr; 688 struct perf_event_attr attr;
694 689
695 if (!t->ptrace_bps[nr]) { 690 if (!t->ptrace_bps[nr]) {
696 hw_breakpoint_init(&attr); 691 ptrace_breakpoint_init(&attr);
697 /* 692 /*
698 * Put stub len and type to register (reserve) an inactive but 693 * Put stub len and type to register (reserve) an inactive but
699 * correct bp 694 * correct bp
@@ -789,342 +784,6 @@ static int ioperm_get(struct task_struct *target,
789 0, IO_BITMAP_BYTES); 784 0, IO_BITMAP_BYTES);
790} 785}
791 786
792#ifdef CONFIG_X86_PTRACE_BTS
793/*
794 * A branch trace store context.
795 *
796 * Contexts may only be installed by ptrace_bts_config() and only for
797 * ptraced tasks.
798 *
799 * Contexts are destroyed when the tracee is detached from the tracer.
800 * The actual destruction work requires interrupts enabled, so the
801 * work is deferred and will be scheduled during __ptrace_unlink().
802 *
803 * Contexts hold an additional task_struct reference on the traced
804 * task, as well as a reference on the tracer's mm.
805 *
806 * Ptrace already holds a task_struct for the duration of ptrace operations,
807 * but since destruction is deferred, it may be executed after both
808 * tracer and tracee exited.
809 */
810struct bts_context {
811 /* The branch trace handle. */
812 struct bts_tracer *tracer;
813
814 /* The buffer used to store the branch trace and its size. */
815 void *buffer;
816 unsigned int size;
817
818 /* The mm that paid for the above buffer. */
819 struct mm_struct *mm;
820
821 /* The task this context belongs to. */
822 struct task_struct *task;
823
824 /* The signal to send on a bts buffer overflow. */
825 unsigned int bts_ovfl_signal;
826
827 /* The work struct to destroy a context. */
828 struct work_struct work;
829};
830
831static int alloc_bts_buffer(struct bts_context *context, unsigned int size)
832{
833 void *buffer = NULL;
834 int err = -ENOMEM;
835
836 err = account_locked_memory(current->mm, current->signal->rlim, size);
837 if (err < 0)
838 return err;
839
840 buffer = kzalloc(size, GFP_KERNEL);
841 if (!buffer)
842 goto out_refund;
843
844 context->buffer = buffer;
845 context->size = size;
846 context->mm = get_task_mm(current);
847
848 return 0;
849
850 out_refund:
851 refund_locked_memory(current->mm, size);
852 return err;
853}
854
855static inline void free_bts_buffer(struct bts_context *context)
856{
857 if (!context->buffer)
858 return;
859
860 kfree(context->buffer);
861 context->buffer = NULL;
862
863 refund_locked_memory(context->mm, context->size);
864 context->size = 0;
865
866 mmput(context->mm);
867 context->mm = NULL;
868}
869
870static void free_bts_context_work(struct work_struct *w)
871{
872 struct bts_context *context;
873
874 context = container_of(w, struct bts_context, work);
875
876 ds_release_bts(context->tracer);
877 put_task_struct(context->task);
878 free_bts_buffer(context);
879 kfree(context);
880}
881
882static inline void free_bts_context(struct bts_context *context)
883{
884 INIT_WORK(&context->work, free_bts_context_work);
885 schedule_work(&context->work);
886}
887
888static inline struct bts_context *alloc_bts_context(struct task_struct *task)
889{
890 struct bts_context *context = kzalloc(sizeof(*context), GFP_KERNEL);
891 if (context) {
892 context->task = task;
893 task->bts = context;
894
895 get_task_struct(task);
896 }
897
898 return context;
899}
900
901static int ptrace_bts_read_record(struct task_struct *child, size_t index,
902 struct bts_struct __user *out)
903{
904 struct bts_context *context;
905 const struct bts_trace *trace;
906 struct bts_struct bts;
907 const unsigned char *at;
908 int error;
909
910 context = child->bts;
911 if (!context)
912 return -ESRCH;
913
914 trace = ds_read_bts(context->tracer);
915 if (!trace)
916 return -ESRCH;
917
918 at = trace->ds.top - ((index + 1) * trace->ds.size);
919 if ((void *)at < trace->ds.begin)
920 at += (trace->ds.n * trace->ds.size);
921
922 if (!trace->read)
923 return -EOPNOTSUPP;
924
925 error = trace->read(context->tracer, at, &bts);
926 if (error < 0)
927 return error;
928
929 if (copy_to_user(out, &bts, sizeof(bts)))
930 return -EFAULT;
931
932 return sizeof(bts);
933}
934
935static int ptrace_bts_drain(struct task_struct *child,
936 long size,
937 struct bts_struct __user *out)
938{
939 struct bts_context *context;
940 const struct bts_trace *trace;
941 const unsigned char *at;
942 int error, drained = 0;
943
944 context = child->bts;
945 if (!context)
946 return -ESRCH;
947
948 trace = ds_read_bts(context->tracer);
949 if (!trace)
950 return -ESRCH;
951
952 if (!trace->read)
953 return -EOPNOTSUPP;
954
955 if (size < (trace->ds.top - trace->ds.begin))
956 return -EIO;
957
958 for (at = trace->ds.begin; (void *)at < trace->ds.top;
959 out++, drained++, at += trace->ds.size) {
960 struct bts_struct bts;
961
962 error = trace->read(context->tracer, at, &bts);
963 if (error < 0)
964 return error;
965
966 if (copy_to_user(out, &bts, sizeof(bts)))
967 return -EFAULT;
968 }
969
970 memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
971
972 error = ds_reset_bts(context->tracer);
973 if (error < 0)
974 return error;
975
976 return drained;
977}
978
979static int ptrace_bts_config(struct task_struct *child,
980 long cfg_size,
981 const struct ptrace_bts_config __user *ucfg)
982{
983 struct bts_context *context;
984 struct ptrace_bts_config cfg;
985 unsigned int flags = 0;
986
987 if (cfg_size < sizeof(cfg))
988 return -EIO;
989
990 if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
991 return -EFAULT;
992
993 context = child->bts;
994 if (!context)
995 context = alloc_bts_context(child);
996 if (!context)
997 return -ENOMEM;
998
999 if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
1000 if (!cfg.signal)
1001 return -EINVAL;
1002
1003 return -EOPNOTSUPP;
1004 context->bts_ovfl_signal = cfg.signal;
1005 }
1006
1007 ds_release_bts(context->tracer);
1008 context->tracer = NULL;
1009
1010 if ((cfg.flags & PTRACE_BTS_O_ALLOC) && (cfg.size != context->size)) {
1011 int err;
1012
1013 free_bts_buffer(context);
1014 if (!cfg.size)
1015 return 0;
1016
1017 err = alloc_bts_buffer(context, cfg.size);
1018 if (err < 0)
1019 return err;
1020 }
1021
1022 if (cfg.flags & PTRACE_BTS_O_TRACE)
1023 flags |= BTS_USER;
1024
1025 if (cfg.flags & PTRACE_BTS_O_SCHED)
1026 flags |= BTS_TIMESTAMPS;
1027
1028 context->tracer =
1029 ds_request_bts_task(child, context->buffer, context->size,
1030 NULL, (size_t)-1, flags);
1031 if (unlikely(IS_ERR(context->tracer))) {
1032 int error = PTR_ERR(context->tracer);
1033
1034 free_bts_buffer(context);
1035 context->tracer = NULL;
1036 return error;
1037 }
1038
1039 return sizeof(cfg);
1040}
1041
1042static int ptrace_bts_status(struct task_struct *child,
1043 long cfg_size,
1044 struct ptrace_bts_config __user *ucfg)
1045{
1046 struct bts_context *context;
1047 const struct bts_trace *trace;
1048 struct ptrace_bts_config cfg;
1049
1050 context = child->bts;
1051 if (!context)
1052 return -ESRCH;
1053
1054 if (cfg_size < sizeof(cfg))
1055 return -EIO;
1056
1057 trace = ds_read_bts(context->tracer);
1058 if (!trace)
1059 return -ESRCH;
1060
1061 memset(&cfg, 0, sizeof(cfg));
1062 cfg.size = trace->ds.end - trace->ds.begin;
1063 cfg.signal = context->bts_ovfl_signal;
1064 cfg.bts_size = sizeof(struct bts_struct);
1065
1066 if (cfg.signal)
1067 cfg.flags |= PTRACE_BTS_O_SIGNAL;
1068
1069 if (trace->ds.flags & BTS_USER)
1070 cfg.flags |= PTRACE_BTS_O_TRACE;
1071
1072 if (trace->ds.flags & BTS_TIMESTAMPS)
1073 cfg.flags |= PTRACE_BTS_O_SCHED;
1074
1075 if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
1076 return -EFAULT;
1077
1078 return sizeof(cfg);
1079}
1080
1081static int ptrace_bts_clear(struct task_struct *child)
1082{
1083 struct bts_context *context;
1084 const struct bts_trace *trace;
1085
1086 context = child->bts;
1087 if (!context)
1088 return -ESRCH;
1089
1090 trace = ds_read_bts(context->tracer);
1091 if (!trace)
1092 return -ESRCH;
1093
1094 memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
1095
1096 return ds_reset_bts(context->tracer);
1097}
1098
1099static int ptrace_bts_size(struct task_struct *child)
1100{
1101 struct bts_context *context;
1102 const struct bts_trace *trace;
1103
1104 context = child->bts;
1105 if (!context)
1106 return -ESRCH;
1107
1108 trace = ds_read_bts(context->tracer);
1109 if (!trace)
1110 return -ESRCH;
1111
1112 return (trace->ds.top - trace->ds.begin) / trace->ds.size;
1113}
1114
1115/*
1116 * Called from __ptrace_unlink() after the child has been moved back
1117 * to its original parent.
1118 */
1119void ptrace_bts_untrace(struct task_struct *child)
1120{
1121 if (unlikely(child->bts)) {
1122 free_bts_context(child->bts);
1123 child->bts = NULL;
1124 }
1125}
1126#endif /* CONFIG_X86_PTRACE_BTS */
1127
1128/* 787/*
1129 * Called by kernel/ptrace.c when detaching.. 788 * Called by kernel/ptrace.c when detaching..
1130 * 789 *
@@ -1252,39 +911,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
1252 break; 911 break;
1253#endif 912#endif
1254 913
1255 /*
1256 * These bits need more cooking - not enabled yet:
1257 */
1258#ifdef CONFIG_X86_PTRACE_BTS
1259 case PTRACE_BTS_CONFIG:
1260 ret = ptrace_bts_config
1261 (child, data, (struct ptrace_bts_config __user *)addr);
1262 break;
1263
1264 case PTRACE_BTS_STATUS:
1265 ret = ptrace_bts_status
1266 (child, data, (struct ptrace_bts_config __user *)addr);
1267 break;
1268
1269 case PTRACE_BTS_SIZE:
1270 ret = ptrace_bts_size(child);
1271 break;
1272
1273 case PTRACE_BTS_GET:
1274 ret = ptrace_bts_read_record
1275 (child, data, (struct bts_struct __user *) addr);
1276 break;
1277
1278 case PTRACE_BTS_CLEAR:
1279 ret = ptrace_bts_clear(child);
1280 break;
1281
1282 case PTRACE_BTS_DRAIN:
1283 ret = ptrace_bts_drain
1284 (child, data, (struct bts_struct __user *) addr);
1285 break;
1286#endif /* CONFIG_X86_PTRACE_BTS */
1287
1288 default: 914 default:
1289 ret = ptrace_request(child, request, addr, data); 915 ret = ptrace_request(child, request, addr, data);
1290 break; 916 break;
@@ -1544,14 +1170,6 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1544 1170
1545 case PTRACE_GET_THREAD_AREA: 1171 case PTRACE_GET_THREAD_AREA:
1546 case PTRACE_SET_THREAD_AREA: 1172 case PTRACE_SET_THREAD_AREA:
1547#ifdef CONFIG_X86_PTRACE_BTS
1548 case PTRACE_BTS_CONFIG:
1549 case PTRACE_BTS_STATUS:
1550 case PTRACE_BTS_SIZE:
1551 case PTRACE_BTS_GET:
1552 case PTRACE_BTS_CLEAR:
1553 case PTRACE_BTS_DRAIN:
1554#endif /* CONFIG_X86_PTRACE_BTS */
1555 return arch_ptrace(child, request, addr, data); 1173 return arch_ptrace(child, request, addr, data);
1556 1174
1557 default: 1175 default:
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-15 14:53:48 -0500