On Thu, Sep 30, 2021 at 2:20 PM Marco Elver [off-list ref] wrote:

On Thu, Sep 30, 2021 at 03:50AM +0000, yanjun.zhu@linux.dev wrote:

quoted

quoted

quoted

-EXPORT_SYMBOL(__kasan_kmalloc);

Sorry, but this will break all users of kmalloc() with KASAN on if
!TRACING:

*module users.

An allmodconfig but with CONFIG_TRACING=n will probably show you the problem.

Follow your advice, I changed CONFIG_TRACING=n in .config. Then I run "make -jxx modules".
But CONFIG_TRACING is changed to y.
So what you mentioned does not appear.

CONFIG_TRACING is not user selectable but auto-selected, just have to
disable all those that select it. See .config, which breaks.

 Symbol: TRACING [=y]
  x Type  : bool
  x Defined at kernel/trace/Kconfig:114
  x Selects: RING_BUFFER [=y] && STACKTRACE [=y] && TRACEPOINTS [=y]
&& NOP_TRACER [=y] && BINARY_PRINTF [=y] && EVENT_TRACING [=y] &&
TRACE_CLOCK [=y]   x
  x Selected by [y]:
  x   - PREEMPTIRQ_TRACEPOINTS [=y] && (TRACE_PREEMPT_TOGGLE [=n] ||
TRACE_IRQFLAGS [=y])
  x   - GENERIC_TRACER [=y]
  x   - KPROBE_EVENTS [=y] && FTRACE [=y] && KPROBES [=y] &&
HAVE_REGS_AND_STACK_ACCESS_API [=y]
  x   - UPROBE_EVENTS [=y] && FTRACE [=y] && ARCH_SUPPORTS_UPROBES
[=y] && MMU [=y] && PERF_EVENTS [=y]
  x   - SYNTH_EVENTS [=y] && FTRACE [=y]
  x   - HIST_TRIGGERS [=y] && FTRACE [=y] &&
ARCH_HAVE_NMI_SAFE_CMPXCHG [=y]
  x Selected by [n]:
  x   - DRM_I915_TRACE_GEM [=n] && HAS_IOMEM [=y] && DRM_I915 [=m] &&
EXPERT [=y] && DRM_I915_DEBUG_GEM [=n]
  x   - DRM_I915_TRACE_GTT [=n] && HAS_IOMEM [=y] && DRM_I915 [=m] &&
EXPERT [=y] && DRM_I915_DEBUG_GEM [=n]
  x   - ENABLE_DEFAULT_TRACERS [=n] && FTRACE [=y] && !GENERIC_TRACER [=y]

From .config, I got the above. It seems that CONFIG_TRACING is
selected by a lot of things.

Is there any method to set CONFIG_TRACING=n?

Zhu Yanjun