user/sven/linux.git/kernel/trace, branch v5.9.1

Merge tag 'trace-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2020-10-01T16:41:02Z

Pull tracing fixes from Steven Rostedt: "Two tracing fixes: - Fix temp buffer accounting that caused a WARNING for ftrace_dump_on_opps() - Move the recursion check in one of the function callback helpers to the beginning of the function, as if the rcu_is_watching() gets traced, it will cause a recursive loop that will crash the kernel" * tag 'trace-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Move RCU is watching check after recursion check tracing: Fix trace_find_next_entry() accounting of temp buffer size

ftrace: Move RCU is watching check after recursion check

2020-09-29T17:05:10Z

The first thing that the ftrace function callback helper functions should do is to check for recursion. Peter Zijlstra found that when "rcu_is_watching()" had its notrace removed, it caused perf function tracing to crash. This is because the call of rcu_is_watching() is tested before function recursion is checked and and if it is traced, it will cause an infinite recursion loop. rcu_is_watching() should still stay notrace, but to prevent this should never had crashed in the first place. The recursion prevention must be the first thing done in callback functions. Link: https://lore.kernel.org/r/20200929112541.GM2628@hirez.programming.kicks-ass.net Cc: stable@vger.kernel.org Cc: Paul McKenney Fixes: c68c0fa293417 ("ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too") Acked-by: Peter Zijlstra (Intel) Reported-by: Peter Zijlstra (Intel) Signed-off-by: Steven Rostedt (VMware)

tracing: Fix trace_find_next_entry() accounting of temp buffer size

2020-09-29T16:46:22Z

The temp buffer size variable for trace_find_next_entry() was incorrectly being updated when the size did not change. The temp buffer size should only be updated when it is reallocated. This is mostly an issue when used with ftrace_dump(). That's because ftrace_dump() can not allocate a new buffer, and instead uses a temporary buffer with a fix size. But the variable that keeps track of that size is incorrectly updated with each call, and it could fall into the path that would try to reallocate the buffer and produce a warning. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1601 at kernel/trace/trace.c:3548 trace_find_next_entry+0xd0/0xe0 Modules linked in [..] CPU: 1 PID: 1601 Comm: bash Not tainted 5.9.0-rc5-test+ #521 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:trace_find_next_entry+0xd0/0xe0 Code: 40 21 00 00 4c 89 e1 31 d2 4c 89 ee 48 89 df e8 c6 9e ff ff 89 ab 54 21 00 00 5b 5d 41 5c 41 5d c3 48 63 d5 eb bf 31 c0 eb f0 <0f> 0b 48 63 d5 eb b4 66 0f 1f 84 00 00 00 00 00 53 48 8d 8f 60 21 RSP: 0018:ffff95a4f2e8bd70 EFLAGS: 00010046 RAX: ffffffff96679fc0 RBX: ffffffff97910de0 RCX: ffffffff96679fc0 RDX: ffff95a4f2e8bd98 RSI: ffff95a4ee321098 RDI: ffffffff97913000 RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000046 R12: ffff95a4f2e8bd98 R13: 0000000000000000 R14: ffff95a4ee321098 R15: 00000000009aa301 FS: 00007f8565484740(0000) GS:ffff95a55aa40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055876bd43d90 CR3: 00000000b76e6003 CR4: 00000000001706e0 Call Trace: trace_print_lat_context+0x58/0x2d0 ? cpumask_next+0x16/0x20 print_trace_line+0x1a4/0x4f0 ftrace_dump.cold+0xad/0x12c __handle_sysrq.cold+0x51/0x126 write_sysrq_trigger+0x3f/0x4a proc_reg_write+0x53/0x80 vfs_write+0xca/0x210 ksys_write+0x70/0xf0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f8565579487 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 RSP: 002b:00007ffd40707948 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f8565579487 RDX: 0000000000000002 RSI: 000055876bd74de0 RDI: 0000000000000001 RBP: 000055876bd74de0 R08: 000000000000000a R09: 0000000000000001 R10: 000055876bdec280 R11: 0000000000000246 R12: 0000000000000002 R13: 00007f856564a500 R14: 0000000000000002 R15: 00007f856564a700 irq event stamp: 109958 ---[ end trace 7aab5b7e51484b00 ]--- Not only fix the updating of the temp buffer, but also do not free the temp buffer before a new buffer is allocated (there's no reason to not continue to use the current temp buffer if an allocation fails). Cc: stable@vger.kernel.org Fixes: 8e99cf91b99bb ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic") Reported-by: Anna-Maria Behnsen Signed-off-by: Steven Rostedt (VMware)

Merge tag 'trace-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2020-09-22T16:08:33Z

Pull tracing fixes from Steven Rostedt: - Check kprobe is enabled before unregistering from ftrace as it isn't registered when disabled. - Remove kprobes enabled via command-line that is on init text when freed. - Add missing RCU synchronization for ftrace trampoline symbols removed from kallsyms. - Free trampoline on error path if ftrace_startup() fails. - Give more space for the longer PID numbers in trace output. - Fix a possible double free in the histogram code. - A couple of fixes that were discovered by sparse. * tag 'trace-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: bootconfig: init: make xbc_namebuf static kprobes: tracing/kprobes: Fix to kill kprobes on initmem after boot tracing: fix double free ftrace: Let ftrace_enable_sysctl take a kernel pointer buffer tracing: Make the space reserved for the pid wider ftrace: Fix missing synchronize_rcu() removing trampoline from kallsyms ftrace: Free the trampoline when ftrace_startup() fails kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()

Merge branch 'akpm' (patches from Andrew)

2020-09-20T01:18:37Z

Merge fixes from Andrew Morton: "15 patches. Subsystems affected by this patch series: mailmap, mm/hotfixes, mm/thp, mm/memory-hotplug, misc, kcsan" * emailed patches from Andrew Morton : kcsan: kconfig: move to menu 'Generic Kernel Debugging Instruments' fs/fs-writeback.c: adjust dirtytime_interval_handler definition to match prototype stackleak: let stack_erasing_sysctl take a kernel pointer buffer ftrace: let ftrace_enable_sysctl take a kernel pointer buffer mm/memory_hotplug: drain per-cpu pages again during memory offline selftests/vm: fix display of page size in map_hugetlb mm/thp: fix __split_huge_pmd_locked() for migration PMD kprobes: fix kill kprobe which has been marked as gone tmpfs: restore functionality of nr_inodes=0 mlock: fix unevictable_pgs event counts on THP mm: fix check_move_unevictable_pages() on THP mm: migration of hugetlbfs page skip memcg ksm: reinstate memcg charge on copied pages mailmap: add older email addresses for Kees Cook

ftrace: let ftrace_enable_sysctl take a kernel pointer buffer

2020-09-19T20:13:39Z

Commit 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") changed ctl_table.proc_handler to take a kernel pointer. Adjust the signature of ftrace_enable_sysctl to match ctl_table.proc_handler which fixes the following sparse warning: kernel/trace/ftrace.c:7544:43: warning: incorrect type in argument 3 (different address spaces) kernel/trace/ftrace.c:7544:43: expected void * kernel/trace/ftrace.c:7544:43: got void [noderef] __user *buffer Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") Signed-off-by: Tobias Klauser Signed-off-by: Andrew Morton Cc: Christoph Hellwig Cc: Al Viro Link: https://lkml.kernel.org/r/20200907093207.13540-1-tklauser@distanz.ch Signed-off-by: Linus Torvalds

tracing: fix double free

2020-09-18T17:16:40Z

clang static analyzer reports this problem trace_events_hist.c:3824:3: warning: Attempt to free released memory kfree(hist_data->attrs->var_defs.name[i]); In parse_var_defs() if there is a problem allocating var_defs.expr, the earlier var_defs.name is freed. This free is duplicated by free_var_defs() which frees the rest of the list. Because free_var_defs() has to run anyway, remove the second free fom parse_var_defs(). Link: https://lkml.kernel.org/r/20200907135845.15804-1-trix@redhat.com Cc: stable@vger.kernel.org Fixes: 30350d65ac56 ("tracing: Add variable support to hist triggers") Reviewed-by: Tom Zanussi Signed-off-by: Tom Rix Signed-off-by: Steven Rostedt (VMware)

ftrace: Let ftrace_enable_sysctl take a kernel pointer buffer

2020-09-18T17:15:56Z

Commit 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") changed ctl_table.proc_handler to take a kernel pointer. Adjust the signature of ftrace_enable_sysctl to match ctl_table.proc_handler which fixes the following sparse warning: kernel/trace/ftrace.c:7544:43: warning: incorrect type in argument 3 (different address spaces) kernel/trace/ftrace.c:7544:43: expected void * kernel/trace/ftrace.c:7544:43: got void [noderef] __user *buffer Link: https://lkml.kernel.org/r/20200907093207.13540-1-tklauser@distanz.ch Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") Cc: Andrew Morton Cc: Ingo Molnar Cc: Christoph Hellwig Cc: Al Viro Signed-off-by: Tobias Klauser Signed-off-by: Steven Rostedt (VMware)

tracing: Make the space reserved for the pid wider

2020-09-18T16:42:11Z

For 64bit CONFIG_BASE_SMALL=0 systems PID_MAX_LIMIT is set by default to 4194304. During boot the kernel sets a new value based on number of CPUs but no lower than 32768. It is 1024 per CPU so with 128 CPUs the default becomes 131072 which needs six digits. This value can be increased during run time but must not exceed the initial upper limit. Systemd sometime after v241 sets it to the upper limit during boot. The result is that when the pid exceeds five digits, the trace output is a little hard to read because it is no longer properly padded (same like on big iron with 98+ CPUs). Increase the pid padding to seven digits. Link: https://lkml.kernel.org/r/20200904082331.dcdkrr3bkn3e4qlg@linutronix.de Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware)

ftrace: Fix missing synchronize_rcu() removing trampoline from kallsyms

2020-09-18T16:22:42Z

Add synchronize_rcu() after list_del_rcu() in ftrace_remove_trampoline_from_kallsyms() to protect readers of ftrace_ops_trampoline_list (in ftrace_get_trampoline_kallsym) which is used when kallsyms is read. Link: https://lkml.kernel.org/r/20200901091617.31837-1-adrian.hunter@intel.com Fixes: fc0ea795f53c8d ("ftrace: Add symbols for ftrace trampolines") Signed-off-by: Adrian Hunter Signed-off-by: Steven Rostedt (VMware)