patches for 4.4

Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/queue-4.4/drivers-core-remove-glue-dirs-from-sysfs-earlier.patch b/queue-4.4/drivers-core-remove-glue-dirs-from-sysfs-earlier.patch
new file mode 100644 (file)
index 0000000..3cb0fe2
--- /dev/null
+++ b/queue-4.4/drivers-core-remove-glue-dirs-from-sysfs-earlier.patch
@@ -0,0 +1,93 @@
+From e26a9797c0a2aedfabe42b6ddecb49408e09604c Mon Sep 17 00:00:00 2001
+From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
+Date: Mon, 28 Jan 2019 09:31:30 -0800
+Subject: drivers: core: Remove glue dirs from sysfs earlier
+
+commit 726e41097920a73e4c7c33385dcc0debb1281e18 upstream
+
+For devices with a class, we create a "glue" directory between
+the parent device and the new device with the class name.
+
+This directory is never "explicitely" removed when empty however,
+this is left to the implicit sysfs removal done by kobject_release()
+when the object loses its last reference via kobject_put().
+
+This is problematic because as long as it's not been removed from
+sysfs, it is still present in the class kset and in sysfs directory
+structure.
+
+The presence in the class kset exposes a use after free bug fixed
+by the previous patch, but the presence in sysfs means that until
+the kobject is released, which can take a while (especially with
+kobject debugging), any attempt at re-creating such as binding a
+new device for that class/parent pair, will result in a sysfs
+duplicate file name error.
+
+This fixes it by instead doing an explicit kobject_del() when
+the glue dir is empty, by keeping track of the number of
+child devices of the gluedir.
+
+This is made easy by the fact that all glue dir operations are
+done with a global mutex, and there's already a function
+(cleanup_glue_dir) called in all the right places taking that
+mutex that can be enhanced for this. It appears that this was
+in fact the intent of the function, but the implementation was
+wrong.
+
+Backport Note: kref_read() is not present in 4.4. Hence,
+use atomic_read(&kref.refcount) instead of kref_read(&kref).
+
+Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
+Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Zubin Mithra <zsm@chromium.org>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/base/core.c     |  2 ++
+ include/linux/kobject.h | 17 +++++++++++++++++
+ 2 files changed, 19 insertions(+)
+
+diff --git a/drivers/base/core.c b/drivers/base/core.c
+index 049ccc070ce5..cb5718d2669e 100644
+--- a/drivers/base/core.c
++++ b/drivers/base/core.c
+@@ -862,6 +862,8 @@ static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
+               return;
+ 
+       mutex_lock(&gdp_mutex);
++      if (!kobject_has_children(glue_dir))
++              kobject_del(glue_dir);
+       kobject_put(glue_dir);
+       mutex_unlock(&gdp_mutex);
+ }
+diff --git a/include/linux/kobject.h b/include/linux/kobject.h
+index e6284591599e..5957c6a3fd7f 100644
+--- a/include/linux/kobject.h
++++ b/include/linux/kobject.h
+@@ -113,6 +113,23 @@ extern void kobject_put(struct kobject *kobj);
+ extern const void *kobject_namespace(struct kobject *kobj);
+ extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
+ 
++/**
++ * kobject_has_children - Returns whether a kobject has children.
++ * @kobj: the object to test
++ *
++ * This will return whether a kobject has other kobjects as children.
++ *
++ * It does NOT account for the presence of attribute files, only sub
++ * directories. It also assumes there is no concurrent addition or
++ * removal of such children, and thus relies on external locking.
++ */
++static inline bool kobject_has_children(struct kobject *kobj)
++{
++      WARN_ON_ONCE(atomic_read(&kobj->kref.refcount) == 0);
++
++      return kobj->sd && kobj->sd->dir.subdirs;
++}
++
+ struct kobj_type {
+       void (*release)(struct kobject *kobj);
+       const struct sysfs_ops *sysfs_ops;
+-- 
+2.19.1
+

diff --git a/queue-4.4/perf-unwind-take-pgoff-into-account-when-reporting-e.patch b/queue-4.4/perf-unwind-take-pgoff-into-account-when-reporting-e.patch
new file mode 100644 (file)
index 0000000..c694bdd
--- /dev/null
+++ b/queue-4.4/perf-unwind-take-pgoff-into-account-when-reporting-e.patch
@@ -0,0 +1,197 @@
+From b7faeae5fd5e58d5de5215e023813743fd79dbf8 Mon Sep 17 00:00:00 2001
+From: Milian Wolff <milian.wolff@kdab.com>
+Date: Mon, 29 Oct 2018 15:16:44 +0100
+Subject: perf unwind: Take pgoff into account when reporting elf to libdwfl
+
+[ Upstream commit 1fe627da30331024f453faef04d500079b901107 ]
+
+libdwfl parses an ELF file itself and creates mappings for the
+individual sections. perf on the other hand sees raw mmap events which
+represent individual sections. When we encounter an address pointing
+into a mapping with pgoff != 0, we must take that into account and
+report the file at the non-offset base address.
+
+This fixes unwinding with libdwfl in some cases. E.g. for a file like:
+
+```
+
+using namespace std;
+
+mutex g_mutex;
+
+double worker()
+{
+    lock_guard<mutex> guard(g_mutex);
+    uniform_real_distribution<double> uniform(-1E5, 1E5);
+    default_random_engine engine;
+    double s = 0;
+    for (int i = 0; i < 1000; ++i) {
+        s += norm(complex<double>(uniform(engine), uniform(engine)));
+    }
+    cout << s << endl;
+    return s;
+}
+
+int main()
+{
+    vector<std::future<double>> results;
+    for (int i = 0; i < 10000; ++i) {
+        results.push_back(async(launch::async, worker));
+    }
+    return 0;
+}
+```
+
+Compile it with `g++ -g -O2 -lpthread cpp-locking.cpp  -o cpp-locking`,
+then record it with `perf record --call-graph dwarf -e
+sched:sched_switch`.
+
+When you analyze it with `perf script` and libunwind, you should see:
+
+```
+cpp-locking 20038 [005] 54830.236589: sched:sched_switch: prev_comm=cpp-locking prev_pid=20038 prev_prio=120 prev_state=T ==> next_comm=swapper/5 next_pid=0 next_prio=120
+        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb1670208 schedule+0x28 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb16737cc rwsem_down_read_failed+0xec (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb1665e04 call_rwsem_down_read_failed+0x14 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb1672a03 down_read+0x13 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb106bd85 __do_page_fault+0x445 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb18015f5 page_fault+0x45 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+            7f38e4252591 new_heap+0x101 (/usr/lib/libc-2.28.so)
+            7f38e4252d0b arena_get2.part.4+0x2fb (/usr/lib/libc-2.28.so)
+            7f38e4255b1c tcache_init.part.6+0xec (/usr/lib/libc-2.28.so)
+            7f38e42569e5 __GI___libc_malloc+0x115 (inlined)
+            7f38e4241790 __GI__IO_file_doallocate+0x90 (inlined)
+            7f38e424fbbf __GI__IO_doallocbuf+0x4f (inlined)
+            7f38e424ee47 __GI__IO_file_overflow+0x197 (inlined)
+            7f38e424df36 _IO_new_file_xsputn+0x116 (inlined)
+            7f38e4242bfb __GI__IO_fwrite+0xdb (inlined)
+            7f38e463fa6d std::basic_streambuf<char, std::char_traits<char> >::sputn(char const*, long)+0x1cd (inlined)
+            7f38e463fa6d std::ostreambuf_iterator<char, std::char_traits<char> >::_M_put(char const*, long)+0x1cd (inlined)
+            7f38e463fa6d std::ostreambuf_iterator<char, std::char_traits<char> > std::__write<char>(std::ostreambuf_iterator<char, std::char_traits<char> >, char const*, int)+0x1cd (inlined)
+            7f38e463fa6d std::ostreambuf_iterator<char, std::char_traits<char> > std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::_M_insert_float<double>(std::ostreambuf_iterator<c>
+            7f38e464bd70 std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, double) const+0x90 (inl>
+            7f38e464bd70 std::ostream& std::ostream::_M_insert<double>(double)+0x90 (/usr/lib/libstdc++.so.6.0.25)
+            563b9cb502f7 std::ostream::operator<<(double)+0xb7 (inlined)
+            563b9cb502f7 worker()+0xb7 (/ssd/milian/projects/kdab/rnd/hotspot/build/tests/test-clients/cpp-locking/cpp-locking)
+            563b9cb506fb double std::__invoke_impl<double, double (*)()>(std::__invoke_other, double (*&&)())+0x2b (inlined)
+            563b9cb506fb std::__invoke_result<double (*)()>::type std::__invoke<double (*)()>(double (*&&)())+0x2b (inlined)
+            563b9cb506fb decltype (__invoke((_S_declval<0ul>)())) std::thread::_Invoker<std::tuple<double (*)()> >::_M_invoke<0ul>(std::_Index_tuple<0ul>)+0x2b (inlined)
+            563b9cb506fb std::thread::_Invoker<std::tuple<double (*)()> >::operator()()+0x2b (inlined)
+            563b9cb506fb std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<double>, std::__future_base::_Result_base::_Deleter>, std::thread::_Invoker<std::tuple<double (*)()> >, dou>
+            563b9cb506fb std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_>
+            563b9cb507e8 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const+0x28 (inlined)
+            563b9cb507e8 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*)+0x28 (/ssd/milian/>
+            7f38e46d24fe __pthread_once_slow+0xbe (/usr/lib/libpthread-2.28.so)
+            563b9cb51149 __gthread_once+0xe9 (inlined)
+            563b9cb51149 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*)>
+            563b9cb51149 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool)+0xe9 (inlined)
+            563b9cb51149 std::__future_base::_Async_state_impl<std::thread::_Invoker<std::tuple<double (*)()> >, double>::_Async_state_impl(std::thread::_Invoker<std::tuple<double (*)()> >&&)::{lambda()#1}::op>
+            563b9cb51149 void std::__invoke_impl<void, std::__future_base::_Async_state_impl<std::thread::_Invoker<std::tuple<double (*)()> >, double>::_Async_state_impl(std::thread::_Invoker<std::tuple<double>
+            563b9cb51149 std::__invoke_result<std::__future_base::_Async_state_impl<std::thread::_Invoker<std::tuple<double (*)()> >, double>::_Async_state_impl(std::thread::_Invoker<std::tuple<double (*)()> >>
+            563b9cb51149 decltype (__invoke((_S_declval<0ul>)())) std::thread::_Invoker<std::tuple<std::__future_base::_Async_state_impl<std::thread::_Invoker<std::tuple<double (*)()> >, double>::_Async_state_>
+            563b9cb51149 std::thread::_Invoker<std::tuple<std::__future_base::_Async_state_impl<std::thread::_Invoker<std::tuple<double (*)()> >, double>::_Async_state_impl(std::thread::_Invoker<std::tuple<dou>
+            563b9cb51149 std::thread::_State_impl<std::thread::_Invoker<std::tuple<std::__future_base::_Async_state_impl<std::thread::_Invoker<std::tuple<double (*)()> >, double>::_Async_state_impl(std::thread>
+            7f38e45f0062 execute_native_thread_routine+0x12 (/usr/lib/libstdc++.so.6.0.25)
+            7f38e46caa9c start_thread+0xfc (/usr/lib/libpthread-2.28.so)
+            7f38e42ccb22 __GI___clone+0x42 (inlined)
+```
+
+Before this patch, using libdwfl, you would see:
+
+```
+cpp-locking 20038 [005] 54830.236589: sched:sched_switch: prev_comm=cpp-locking prev_pid=20038 prev_prio=120 prev_state=T ==> next_comm=swapper/5 next_pid=0 next_prio=120
+        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb1670208 schedule+0x28 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb16737cc rwsem_down_read_failed+0xec (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb1665e04 call_rwsem_down_read_failed+0x14 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb1672a03 down_read+0x13 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb106bd85 __do_page_fault+0x445 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb18015f5 page_fault+0x45 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+            7f38e4252591 new_heap+0x101 (/usr/lib/libc-2.28.so)
+        a041161e77950c5c [unknown] ([unknown])
+```
+
+With this patch applied, we get a bit further in unwinding:
+
+```
+cpp-locking 20038 [005] 54830.236589: sched:sched_switch: prev_comm=cpp-locking prev_pid=20038 prev_prio=120 prev_state=T ==> next_comm=swapper/5 next_pid=0 next_prio=120
+        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb1670208 schedule+0x28 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb16737cc rwsem_down_read_failed+0xec (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb1665e04 call_rwsem_down_read_failed+0x14 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb1672a03 down_read+0x13 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb106bd85 __do_page_fault+0x445 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+        ffffffffb18015f5 page_fault+0x45 (/lib/modules/4.14.78-1-lts/build/vmlinux)
+            7f38e4252591 new_heap+0x101 (/usr/lib/libc-2.28.so)
+            7f38e4252d0b arena_get2.part.4+0x2fb (/usr/lib/libc-2.28.so)
+            7f38e4255b1c tcache_init.part.6+0xec (/usr/lib/libc-2.28.so)
+            7f38e42569e5 __GI___libc_malloc+0x115 (inlined)
+            7f38e4241790 __GI__IO_file_doallocate+0x90 (inlined)
+            7f38e424fbbf __GI__IO_doallocbuf+0x4f (inlined)
+            7f38e424ee47 __GI__IO_file_overflow+0x197 (inlined)
+            7f38e424df36 _IO_new_file_xsputn+0x116 (inlined)
+            7f38e4242bfb __GI__IO_fwrite+0xdb (inlined)
+            7f38e463fa6d std::basic_streambuf<char, std::char_traits<char> >::sputn(char const*, long)+0x1cd (inlined)
+            7f38e463fa6d std::ostreambuf_iterator<char, std::char_traits<char> >::_M_put(char const*, long)+0x1cd (inlined)
+            7f38e463fa6d std::ostreambuf_iterator<char, std::char_traits<char> > std::__write<char>(std::ostreambuf_iterator<char, std::char_traits<char> >, char const*, int)+0x1cd (inlined)
+            7f38e463fa6d std::ostreambuf_iterator<char, std::char_traits<char> > std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::_M_insert_float<double>(std::ostreambuf_iterator<c>
+            7f38e464bd70 std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, double) const+0x90 (inl>
+            7f38e464bd70 std::ostream& std::ostream::_M_insert<double>(double)+0x90 (/usr/lib/libstdc++.so.6.0.25)
+            563b9cb502f7 std::ostream::operator<<(double)+0xb7 (inlined)
+            563b9cb502f7 worker()+0xb7 (/ssd/milian/projects/kdab/rnd/hotspot/build/tests/test-clients/cpp-locking/cpp-locking)
+        6eab825c1ee3e4ff [unknown] ([unknown])
+```
+
+Note that the backtrace is still stopping too early, when compared to
+the nice results obtained via libunwind. It's unclear so far what the
+reason for that is.
+
+Committer note:
+
+Further comment by Milian on the thread started on the Link: tag below:
+
+ ---
+The remaining issue is due to a bug in elfutils:
+
+https://sourceware.org/ml/elfutils-devel/2018-q4/msg00089.html
+
+With both patches applied, libunwind and elfutils produce the same output for
+the above scenario.
+ ---
+
+Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
+Acked-by: Jiri Olsa <jolsa@kernel.org>
+Link: http://lkml.kernel.org/r/20181029141644.3907-1-milian.wolff@kdab.com
+Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ tools/perf/util/unwind-libdw.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
+index 880e8db32484..bf5ee8906fb2 100644
+--- a/tools/perf/util/unwind-libdw.c
++++ b/tools/perf/util/unwind-libdw.c
+@@ -41,13 +41,13 @@ static int __report_module(struct addr_location *al, u64 ip,
+               Dwarf_Addr s;
+ 
+               dwfl_module_info(mod, NULL, &s, NULL, NULL, NULL, NULL, NULL);
+-              if (s != al->map->start)
++              if (s != al->map->start - al->map->pgoff)
+                       mod = 0;
+       }
+ 
+       if (!mod)
+               mod = dwfl_report_elf(ui->dwfl, dso->short_name,
+-                                    (dso->symsrc_filename ? dso->symsrc_filename : dso->long_name), -1, al->map->start,
++                                    (dso->symsrc_filename ? dso->symsrc_filename : dso->long_name), -1, al->map->start - al->map->pgoff,
+                                     false);
+ 
+       return mod && dwfl_addrmodule(ui->dwfl, ip) == mod ? 0 : -1;
+-- 
+2.19.1
+

diff --git a/queue-4.4/perf-unwind-unwind-with-libdw-doesn-t-take-symfs-int.patch b/queue-4.4/perf-unwind-unwind-with-libdw-doesn-t-take-symfs-int.patch
new file mode 100644 (file)
index 0000000..e6829d6
--- /dev/null
+++ b/queue-4.4/perf-unwind-unwind-with-libdw-doesn-t-take-symfs-int.patch
@@ -0,0 +1,42 @@
+From fb065cd70aba33ad4f57b58b0ef7c0b0c7506057 Mon Sep 17 00:00:00 2001
+From: Martin Vuille <jpmv27@aim.com>
+Date: Sun, 11 Feb 2018 16:24:20 -0500
+Subject: perf unwind: Unwind with libdw doesn't take symfs into account
+
+[ Upstream commit 3d20c6246690219881786de10d2dda93f616d0ac ]
+
+Path passed to libdw for unwinding doesn't include symfs path
+if specified, so unwinding fails because ELF file is not found.
+
+Similar to unwinding with libunwind, pass symsrc_filename instead
+of long_name. If there is no symsrc_filename, fallback to long_name.
+
+Signed-off-by: Martin Vuille <jpmv27@aim.com>
+Cc: Adrian Hunter <adrian.hunter@intel.com>
+Cc: David Ahern <dsahern@gmail.com>
+Cc: Jiri Olsa <jolsa@kernel.org>
+Cc: Namhyung Kim <namhyung@kernel.org>
+Cc: Wang Nan <wangnan0@huawei.com>
+Link: http://lkml.kernel.org/r/20180211212420.18388-1-jpmv27@aim.com
+Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ tools/perf/util/unwind-libdw.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
+index 60edec383281..880e8db32484 100644
+--- a/tools/perf/util/unwind-libdw.c
++++ b/tools/perf/util/unwind-libdw.c
+@@ -47,7 +47,7 @@ static int __report_module(struct addr_location *al, u64 ip,
+ 
+       if (!mod)
+               mod = dwfl_report_elf(ui->dwfl, dso->short_name,
+-                                    dso->long_name, -1, al->map->start,
++                                    (dso->symsrc_filename ? dso->symsrc_filename : dso->long_name), -1, al->map->start,
+                                     false);
+ 
+       return mod && dwfl_addrmodule(ui->dwfl, ip) == mod ? 0 : -1;
+-- 
+2.19.1
+

diff --git a/queue-4.4/series b/queue-4.4/series
index ff45f52248f2a6f60e26f757cd548ac1380cd720..2422f7f93dde4349ec3486b6770e94d006519b7b 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -21,3 +21,6 @@ x86-kaslr-fix-incorrect-i8254-outb-parameters.patch
 can-dev-__can_get_echo_skb-fix-bogous-check-for-non-existing-skb-by-removing-it.patch
 can-bcm-check-timer-values-before-ktime-conversion.patch
 vt-invoke-notifier-on-screen-size-change.patch
+perf-unwind-unwind-with-libdw-doesn-t-take-symfs-int.patch
+perf-unwind-take-pgoff-into-account-when-reporting-e.patch
+drivers-core-remove-glue-dirs-from-sysfs-earlier.patch