Re: [PATCH v4 0/2] fix & prevent the missing preemption disabling
From: 王贇 <hidden>
Date: 2021-10-26 02:52:51
Also in:
linux-riscv, live-patching, lkml
From: 王贇 <hidden>
Date: 2021-10-26 02:52:51
Also in:
linux-riscv, live-patching, lkml
On 2021/10/26 上午10:42, Steven Rostedt wrote:
On Tue, 26 Oct 2021 10:09:12 +0800 王贇 [off-list ref] wrote:quoted
Just a ping, to see if there are any more comments :-PI guess you missed what went into mainline (and your name found a bug in my perl script for importing patches ;-) https://lore.kernel.org/all/20211019091344.65629198@gandalf.local.home/ (local)
Cool~ Missing some chinese font maybe, that's fine :-)
Which means patch 1 needs to change:quoted
+ /* + * Disable preemption to fulfill the promise. + * + * Don't worry about the bit 0 cases, they indicate + * the disabling behaviour has already been done by + * internal call previously. + */ + preempt_disable_notrace(); + return bit + 1; } +/* + * Preemption will be enabled (if it was previously enabled). + */ static __always_inline void trace_clear_recursion(int bit) { if (!bit) return; + if (bit > 0) + preempt_enable_notrace(); +Where this wont work anymore. Need to preempt disable and enable always.
Yup, will rebase on the latest changes~ Regards, Michael Wang
-- Stevequoted
barrier(); bit--; trace_recursion_clear(bit);@@ -209,7 +227,7 @@ static __always_inline void trace_clear_recursion(int bit) * tracing recursed in the same context (normal vs interrupt), *