diff options
| -rw-r--r-- | arch/arm/kernel/ftrace.c | 17 | ||||
| -rw-r--r-- | drivers/clk/clkdev.c | 11 |
2 files changed, 24 insertions, 4 deletions
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index a0b6d1e3812f..e61591f33a6c 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -232,11 +232,24 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, unsigned long old; if (unlikely(atomic_read(¤t->tracing_graph_pause))) +err_out: return; if (IS_ENABLED(CONFIG_UNWINDER_FRAME_POINTER)) { - /* FP points one word below parent's top of stack */ - frame_pointer += 4; + /* + * Usually, the stack frames are contiguous in memory but cases + * have been observed where the next stack frame does not live + * at 'frame_pointer + 4' as this code used to assume. + * + * Instead, dereference the field in the stack frame that + * stores the SP of the calling frame: to avoid unbounded + * recursion, this cannot involve any ftrace instrumented + * functions, so use the __get_kernel_nofault() primitive + * directly. + */ + __get_kernel_nofault(&frame_pointer, + (unsigned long *)(frame_pointer - 8), + unsigned long, err_out); } else { struct stackframe frame = { .fp = frame_pointer, diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 6a77d7e201a9..2f83fb97c6fb 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -204,8 +204,15 @@ fail: pr_err("%pV:%s: %s ID is greater than %zu\n", &vaf, con_id, failure, max_size); va_end(ap_copy); - kfree(cla); - return NULL; + + /* + * Don't fail in this case, but as the entry won't ever match just + * fill it with something that also won't match. + */ + strscpy(cla->con_id, "bad", sizeof(cla->con_id)); + strscpy(cla->dev_id, "bad", sizeof(cla->dev_id)); + + return &cla->cl; } static struct clk_lookup * |