| Message ID | 20211129142849.3056714-1-mark.rutland@arm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | arm64: stacktrace: unify unwind code | expand |
On Mon, 29 Nov 2021 14:28:40 +0000, Mark Rutland wrote: > For historical reasons arm64 has a number of open-coded unwind functions. We'd > like to unify these to reduce the amount of unwind code we have to expose, and > to make it easier for subsequent patches to rework the unwind code for > RELIABLE_STACKTRACE. > > These patches unify the various unwinders using arch_stack_walk(). So that we > can use arch_stack_walk() without having to expose /proc/${PID}/stack, I've > picked Peter's patch decoupling ARCH_STACKWALK from STACKTRACE, which was > previously posted at: > > [...] Applied to arm64 (for-next/stacktrace), thanks! [1/9] arch: Make ARCH_STACKWALK independent of STACKTRACE https://git.kernel.org/arm64/c/1614b2b11fab [2/9] arm64: Add comment for stack_info::kr_cur https://git.kernel.org/arm64/c/1e5428b2b7e8 [3/9] arm64: Mark __switch_to() as __sched https://git.kernel.org/arm64/c/86bcbafcb726 [4/9] arm64: Make perf_callchain_kernel() use arch_stack_walk() https://git.kernel.org/arm64/c/ed876d35a1dc [5/9] arm64: Make __get_wchan() use arch_stack_walk() https://git.kernel.org/arm64/c/4f62bb7cb165 [6/9] arm64: Make return_address() use arch_stack_walk() https://git.kernel.org/arm64/c/39ef362d2d45 [7/9] arm64: Make profile_pc() use arch_stack_walk() https://git.kernel.org/arm64/c/22ecd975b61d [8/9] arm64: Make dump_backtrace() use arch_stack_walk() https://git.kernel.org/arm64/c/2dad6dc17bd0 [9/9] arm64: Make some stacktrace functions private https://git.kernel.org/arm64/c/d2d1d2645cfd
For historical reasons arm64 has a number of open-coded unwind functions. We'd like to unify these to reduce the amount of unwind code we have to expose, and to make it easier for subsequent patches to rework the unwind code for RELIABLE_STACKTRACE. These patches unify the various unwinders using arch_stack_walk(). So that we can use arch_stack_walk() without having to expose /proc/${PID}/stack, I've picked Peter's patch decoupling ARCH_STACKWALK from STACKTRACE, which was previously posted at: https://lore.kernel.org/lkml/20211022152104.356586621@infradead.org/ As the direction of travel seems to be to not unify the get_wchan() implementations, Peter suggested I pick the patch for now. This is the only patch in the series touching other architectures. The bulk of the series was perviously posted in Madhavan's series adding reliability checks to the unwinder: https://lore.kernel.org/linux-arm-kernel/20211015025847.17694-1-madvenka@linux.microsoft.com/ I have made some minor tweaks and updated each commit message to explain why the transformation is safe. Largely the changes should have no functional effect, but in a couple of cases there is a (benign and/or desirable) functional change, which is described in the relevant commit message. To make it possible for get_wchan() to use arch_stack_walk(), and to correct the expected behaviour of stack_trace_consume_entry_nosched() and stack_trace_save_tsk(), we need to mark arm64's __switch_to() as __sched, for which I've added a preparatory patch. Since v1 [1]: * Add necessary includes of <linux/stacktrace.h> * Remove unnecessary includes of <asm/stacktrace.h> * Rebase to v5.16-rc3 [1] https://lore.kernel.org/r/20211117140737.44420-1-mark.rutland@arm.com/ Thanks, Mark. Madhavan T. Venkataraman (5): arm64: Make perf_callchain_kernel() use arch_stack_walk() arm64: Make __get_wchan() use arch_stack_walk() arm64: Make return_address() use arch_stack_walk() arm64: Make profile_pc() use arch_stack_walk() arm64: Make dump_backtrace() use arch_stack_walk() Mark Rutland (3): arm64: Add comment for stack_info::kr_cur arm64: Mark __switch_to() as __sched arm64: Make some stacktrace functions private Peter Zijlstra (1): arch: Make ARCH_STACKWALK independent of STACKTRACE arch/arm64/include/asm/stacktrace.h | 10 ++--- arch/arm64/kernel/perf_callchain.c | 15 ++------ arch/arm64/kernel/process.c | 45 +++++++++++++--------- arch/arm64/kernel/return_address.c | 8 +--- arch/arm64/kernel/stacktrace.c | 60 +++++++---------------------- arch/arm64/kernel/time.c | 25 ++++++------ arch/powerpc/kernel/Makefile | 3 +- arch/riscv/kernel/stacktrace.c | 4 -- arch/s390/kernel/Makefile | 3 +- arch/x86/kernel/Makefile | 2 +- include/linux/stacktrace.h | 35 +++++++++-------- 11 files changed, 83 insertions(+), 127 deletions(-)