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authorLinus Torvalds <torvalds@linux-foundation.org>2020-12-17 13:22:17 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-17 13:22:17 -0800
commit09c0796adf0c793462fda1d7c8c43324551405c7 (patch)
tree90893d337b215482f059dd7e522279b23ffa0961 /arch/s390
parent312dcaf967219effe0483785f24e4072a5bed9a5 (diff)
parentf6a694665f132cbf6e2222dd2f173dc35330a8aa (diff)
Merge tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt: "The major update to this release is that there's a new arch config option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. Currently, only x86_64 enables it. All the ftrace callbacks now take a struct ftrace_regs instead of a struct pt_regs. If the architecture has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will have enough information to read the arguments of the function being traced, as well as access to the stack pointer. This way, if a user (like live kernel patching) only cares about the arguments, then it can avoid using the heavier weight "regs" callback, that puts in enough information in the struct ftrace_regs to simulate a breakpoint exception (needed for kprobes). A new config option that audits the timestamps of the ftrace ring buffer at most every event recorded. Ftrace recursion protection has been cleaned up to move the protection to the callback itself (this saves on an extra function call for those callbacks). Perf now handles its own RCU protection and does not depend on ftrace to do it for it (saving on that extra function call). New debug option to add "recursed_functions" file to tracefs that lists all the places that triggered the recursion protection of the function tracer. This will show where things need to be fixed as recursion slows down the function tracer. The eval enum mapping updates done at boot up are now offloaded to a work queue, as it caused a noticeable pause on slow embedded boards. Various clean ups and last minute fixes" * tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) tracing: Offload eval map updates to a work queue Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS" ring-buffer: Add rb_check_bpage in __rb_allocate_pages ring-buffer: Fix two typos in comments tracing: Drop unneeded assignment in ring_buffer_resize() tracing: Disable ftrace selftests when any tracer is running seq_buf: Avoid type mismatch for seq_buf_init ring-buffer: Fix a typo in function description ring-buffer: Remove obsolete rb_event_is_commit() ring-buffer: Add test to validate the time stamp deltas ftrace/documentation: Fix RST C code blocks tracing: Clean up after filter logic rewriting tracing: Remove the useless value assignment in test_create_synth_event() livepatch: Use the default ftrace_ops instead of REGS when ARGS is available ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs MAINTAINERS: assign ./fs/tracefs to TRACING tracing: Fix some typos in comments ftrace: Remove unused varible 'ret' ring-buffer: Add recording of ring buffer recursion into recursed_functions ...
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/livepatch.h5
-rw-r--r--arch/s390/kernel/ftrace.c20
2 files changed, 20 insertions, 5 deletions
diff --git a/arch/s390/include/asm/livepatch.h b/arch/s390/include/asm/livepatch.h
index 818612b784cd..d578a8c76676 100644
--- a/arch/s390/include/asm/livepatch.h
+++ b/arch/s390/include/asm/livepatch.h
@@ -11,10 +11,13 @@
#ifndef ASM_LIVEPATCH_H
#define ASM_LIVEPATCH_H
+#include <linux/ftrace.h>
#include <asm/ptrace.h>
-static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
+static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)
{
+ struct pt_regs *regs = ftrace_get_regs(fregs);
+
regs->psw.addr = ip;
}
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index ebc1284a618b..c6ddeb5029b4 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -163,17 +163,26 @@ int ftrace_disable_ftrace_graph_caller(void)
#ifdef CONFIG_KPROBES_ON_FTRACE
void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ops, struct pt_regs *regs)
+ struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
struct kprobe_ctlblk *kcb;
- struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip);
+ struct pt_regs *regs;
+ struct kprobe *p;
+ int bit;
- if (unlikely(!p) || kprobe_disabled(p))
+ bit = ftrace_test_recursion_trylock(ip, parent_ip);
+ if (bit < 0)
return;
+ regs = ftrace_get_regs(fregs);
+ preempt_disable_notrace();
+ p = get_kprobe((kprobe_opcode_t *)ip);
+ if (unlikely(!p) || kprobe_disabled(p))
+ goto out;
+
if (kprobe_running()) {
kprobes_inc_nmissed_count(p);
- return;
+ goto out;
}
__this_cpu_write(current_kprobe, p);
@@ -193,6 +202,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
}
}
__this_cpu_write(current_kprobe, NULL);
+out:
+ preempt_enable_notrace();
+ ftrace_test_recursion_unlock(bit);
}
NOKPROBE_SYMBOL(kprobe_ftrace_handler);

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