From 17911ff38aa58d3c95c07589dbf5d3564c4cf3c5 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Fri, 11 Oct 2019 17:22:50 -0400 Subject: tracing: Add locked_down checks to the open calls of files created for tracefs Added various checks on open tracefs calls to see if tracefs is in lockdown mode, and if so, to return -EPERM. Note, the event format files (which are basically standard on all machines) as well as the enabled_functions file (which shows what is currently being traced) are not lockde down. Perhaps they should be, but it seems counter intuitive to lockdown information to help you know if the system has been modified. Link: http://lkml.kernel.org/r/CAHk-=wj7fGPKUspr579Cii-w_y60PtRaiDgKuxVtBAMK0VNNkA@mail.gmail.com Suggested-by: Linus Torvalds Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_stack.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel/trace/trace_stack.c') diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index ec9a34a97129..4df9a209f7ca 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -5,6 +5,7 @@ */ #include #include +#include #include #include #include @@ -470,6 +471,12 @@ static const struct seq_operations stack_trace_seq_ops = { static int stack_trace_open(struct inode *inode, struct file *file) { + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + return seq_open(file, &stack_trace_seq_ops); } @@ -487,6 +494,7 @@ stack_trace_filter_open(struct inode *inode, struct file *file) { struct ftrace_ops *ops = inode->i_private; + /* Checks for tracefs lockdown */ return ftrace_regex_open(ops, FTRACE_ITER_FILTER, inode, file); } -- cgit v1.3-8-gc7d7 From b8299d362d0837ae39e87e9019ebe6b736e0f035 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Thu, 2 Jan 2020 22:02:41 -0500 Subject: tracing: Have stack tracer compile when MCOUNT_INSN_SIZE is not defined On some archs with some configurations, MCOUNT_INSN_SIZE is not defined, and this makes the stack tracer fail to compile. Just define it to zero in this case. Link: https://lore.kernel.org/r/202001020219.zvE3vsty%lkp@intel.com Cc: stable@vger.kernel.org Fixes: 4df297129f622 ("tracing: Remove most or all of stack tracer stack size from stack_max_size") Reported-by: kbuild test robot Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_stack.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/trace/trace_stack.c') diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 4df9a209f7ca..c557f42a9397 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -283,6 +283,11 @@ static void check_stack(unsigned long ip, unsigned long *stack) local_irq_restore(flags); } +/* Some archs may not define MCOUNT_INSN_SIZE */ +#ifndef MCOUNT_INSN_SIZE +# define MCOUNT_INSN_SIZE 0 +#endif + static void stack_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *pt_regs) -- cgit v1.3-8-gc7d7