Messages in this thread | | | Date | Wed, 07 Aug 2019 12:34:01 -0400 | From | Steven Rostedt <> | Subject | [PATCH 0/2] tracing/arm: Fix the stack tracer when LR is saved after local storage |
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As arm64 saves the link register after a function's local variables are stored, it causes the max stack tracer to be off by one in its output of which function has the bloated stack frame.
The first patch fixes this by creating a ARCH_RET_ADDR_BEFORE_LOCAL_VARS define that an achitecture (arm64) may set in asm/ftrace.h, and this will cause the stack tracer to make the shift.
As it has been proven that the stack tracer isn't the most trivial algorithm to understand by staring at the code, the second patch adds comments to the code to explain the algorithm with and without the ARCH_RET_ADDR_BEFORE_LOCAL_VARS.
Hmm, should this be sent to stable (and for inclusion now?)
-- Steve
Steven Rostedt (VMware) (2): tracing/arm64: Have max stack tracer handle the case of return address after data tracing: Document the stack trace algorithm in the comments
---- arch/arm64/include/asm/ftrace.h | 1 + kernel/trace/trace_stack.c | 112 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 113 insertions(+)
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