From mboxrd@z Thu Jan 1 00:00:00 1970 From: ravi.bangoria@linux.ibm.com (Ravi Bangoria) Date: Wed, 4 Jul 2018 10:23:19 +0530 Subject: [PATCH v5 06/10] Uprobes: Support SDT markers having reference count (semaphore) In-Reply-To: <20180703172543.GC23144@redhat.com> References: <20180628052209.13056-1-ravi.bangoria@linux.ibm.com> <20180628052209.13056-7-ravi.bangoria@linux.ibm.com> <20180701210935.GA14404@redhat.com> <0c543791-f3b7-5a4b-f002-e1c76bb430c0@linux.ibm.com> <20180702180156.GA31400@redhat.com> <20180703163645.GA23144@redhat.com> <20180703172543.GC23144@redhat.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Oleg, On 07/03/2018 10:55 PM, Oleg Nesterov wrote: > On 07/03, Oleg Nesterov wrote: >> >> In short. There is a 1:1 relationship between uprobe_write_opcode(is_register => 1) >> and install_breakpoint(), and between uprobe_write_opcode(is_register => 0) and >> remove_breakpoint(). Whatever uprobe_write_opcode() can do if is_register == 1 can be >> done in install_breakpoint(), the same for is_register == 0 and remove_breakpont(). >> >> What have I missed? > > Ah. I missed the fact that uprobe_write_opcode() doesn't do update_ref_ctr() if > verify_opcode() returns false. > > Now I understand what did you mean by "for each consumer". So if we move this logic > into install/remove_breakpoint as I tried to suggest, we will also need another error > code for the case when verify_opcode() returns false. Ok so if we can use verify_opcode() inside install_breakpoint(), we can probably move implementation logic in install/remove_breakpoint(). Let me explore that more. Thanks, Ravi