1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #define ATRACE_TAG ATRACE_TAG_DALVIK
18 
19 #include "palette/palette.h"
20 
21 #include <errno.h>
22 #include <sys/resource.h>
23 #include <sys/time.h>
24 #include <unistd.h>
25 
26 #include <mutex>
27 
28 #include <android-base/file.h>
29 #include <android-base/logging.h>
30 #include <android-base/macros.h>
31 #include <cutils/sched_policy.h>
32 #include <cutils/trace.h>
33 #include <log/event_tag_map.h>
34 #include <tombstoned/tombstoned.h>
35 #include <utils/Thread.h>
36 
37 #include "palette_system.h"
38 
PaletteGetVersion(int32_t * version)39 enum PaletteStatus PaletteGetVersion(int32_t* version) {
40   *version = art::palette::kPaletteVersion;
41   return PaletteStatus::kOkay;
42 }
43 
44 // Conversion map for "nice" values.
45 //
46 // We use Android thread priority constants to be consistent with the rest
47 // of the system.  In some cases adjacent entries may overlap.
48 //
49 static const int kNiceValues[art::palette::kNumManagedThreadPriorities] = {
50   ANDROID_PRIORITY_LOWEST,                // 1 (MIN_PRIORITY)
51   ANDROID_PRIORITY_BACKGROUND + 6,
52   ANDROID_PRIORITY_BACKGROUND + 3,
53   ANDROID_PRIORITY_BACKGROUND,
54   ANDROID_PRIORITY_NORMAL,                // 5 (NORM_PRIORITY)
55   ANDROID_PRIORITY_NORMAL - 2,
56   ANDROID_PRIORITY_NORMAL - 4,
57   ANDROID_PRIORITY_URGENT_DISPLAY + 3,
58   ANDROID_PRIORITY_URGENT_DISPLAY + 2,
59   ANDROID_PRIORITY_URGENT_DISPLAY         // 10 (MAX_PRIORITY)
60 };
61 
PaletteSchedSetPriority(int32_t tid,int32_t managed_priority)62 enum PaletteStatus PaletteSchedSetPriority(int32_t tid, int32_t managed_priority) {
63   if (managed_priority < art::palette::kMinManagedThreadPriority ||
64       managed_priority > art::palette::kMaxManagedThreadPriority) {
65     return PaletteStatus::kInvalidArgument;
66   }
67   int new_nice = kNiceValues[managed_priority - art::palette::kMinManagedThreadPriority];
68 
69   // TODO: b/18249098 The code below is broken. It uses getpriority() as a proxy for whether a
70   // thread is already in the SP_FOREGROUND cgroup. This is not necessarily true for background
71   // processes, where all threads are in the SP_BACKGROUND cgroup. This means that callers will
72   // have to call setPriority twice to do what they want :
73   //
74   //     Thread.setPriority(Thread.MIN_PRIORITY);  // no-op wrt to cgroups
75   //     Thread.setPriority(Thread.MAX_PRIORITY);  // will actually change cgroups.
76   if (new_nice >= ANDROID_PRIORITY_BACKGROUND) {
77     set_sched_policy(tid, SP_BACKGROUND);
78   } else if (getpriority(PRIO_PROCESS, tid) >= ANDROID_PRIORITY_BACKGROUND) {
79     set_sched_policy(tid, SP_FOREGROUND);
80   }
81 
82   if (setpriority(PRIO_PROCESS, tid, new_nice) != 0) {
83     return PaletteStatus::kCheckErrno;
84   }
85   return PaletteStatus::kOkay;
86 }
87 
PaletteSchedGetPriority(int32_t tid,int32_t * managed_priority)88 enum PaletteStatus PaletteSchedGetPriority(int32_t tid, /*out*/int32_t* managed_priority) {
89   errno = 0;
90   int native_priority = getpriority(PRIO_PROCESS, tid);
91   if (native_priority == -1 && errno != 0) {
92     *managed_priority = art::palette::kNormalManagedThreadPriority;
93     return PaletteStatus::kCheckErrno;
94   }
95 
96   for (int p = art::palette::kMinManagedThreadPriority;
97        p <= art::palette::kMaxManagedThreadPriority;
98        p = p + 1) {
99     int index = p - art::palette::kMinManagedThreadPriority;
100     if (native_priority >= kNiceValues[index]) {
101       *managed_priority = p;
102       return PaletteStatus::kOkay;
103     }
104   }
105   *managed_priority = art::palette::kMaxManagedThreadPriority;
106   return PaletteStatus::kOkay;
107 }
108 
PaletteWriteCrashThreadStacks(const char * stacks,size_t stacks_len)109 enum PaletteStatus PaletteWriteCrashThreadStacks(/*in*/const char* stacks, size_t stacks_len) {
110   android::base::unique_fd tombstone_fd;
111   android::base::unique_fd output_fd;
112 
113   if (!tombstoned_connect(getpid(), &tombstone_fd, &output_fd, kDebuggerdJavaBacktrace)) {
114     // Failure here could be due to file descriptor resource exhaustion
115     // so write the stack trace message to the log in case it helps
116     // debug that.
117     LOG(INFO) << std::string_view(stacks, stacks_len);
118     // tombstoned_connect() logs failure reason.
119     return PaletteStatus::kFailedCheckLog;
120   }
121 
122   PaletteStatus status = PaletteStatus::kOkay;
123   if (!android::base::WriteFully(output_fd, stacks, stacks_len)) {
124     PLOG(ERROR) << "Failed to write tombstoned output";
125     TEMP_FAILURE_RETRY(ftruncate(output_fd, 0));
126     status = PaletteStatus::kFailedCheckLog;
127   }
128 
129   if (TEMP_FAILURE_RETRY(fdatasync(output_fd)) == -1 && errno != EINVAL) {
130     // Ignore EINVAL so we don't report failure if we just tried to flush a pipe
131     // or socket.
132     if (status == PaletteStatus::kOkay) {
133       PLOG(ERROR) << "Failed to fsync tombstoned output";
134       status = PaletteStatus::kFailedCheckLog;
135     }
136     TEMP_FAILURE_RETRY(ftruncate(output_fd, 0));
137     TEMP_FAILURE_RETRY(fdatasync(output_fd));
138   }
139 
140   if (close(output_fd.release()) == -1 && errno != EINTR) {
141     if (status == PaletteStatus::kOkay) {
142       PLOG(ERROR) << "Failed to close tombstoned output";
143       status = PaletteStatus::kFailedCheckLog;
144     }
145   }
146 
147   if (!tombstoned_notify_completion(tombstone_fd)) {
148     // tombstoned_notify_completion() logs failure.
149     status = PaletteStatus::kFailedCheckLog;
150   }
151 
152   return status;
153 }
154 
PaletteTraceEnabled(int32_t * enabled)155 enum PaletteStatus PaletteTraceEnabled(/*out*/int32_t* enabled) {
156   *enabled = (ATRACE_ENABLED() != 0) ? 1 : 0;
157   return PaletteStatus::kOkay;
158 }
159 
PaletteTraceBegin(const char * name)160 enum PaletteStatus PaletteTraceBegin(const char* name) {
161   ATRACE_BEGIN(name);
162   return PaletteStatus::kOkay;
163 }
164 
PaletteTraceEnd()165 enum PaletteStatus PaletteTraceEnd() {
166   ATRACE_END();
167   return PaletteStatus::kOkay;
168 }
169 
PaletteTraceIntegerValue(const char * name,int32_t value)170 enum PaletteStatus PaletteTraceIntegerValue(const char* name, int32_t value) {
171   ATRACE_INT(name, value);
172   return PaletteStatus::kOkay;
173 }
174