From: dave.long@linaro.org (David Long)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/5] arm64: Handle TRAP_HWBRKPT for user mode as well
Date: Tue, 6 Sep 2016 17:36:18 -0400 [thread overview]
Message-ID: <57CF36D2.4010404@linaro.org> (raw)
In-Reply-To: <20160906161139.GG19605@e104818-lin.cambridge.arm.com>
On 09/06/2016 12:11 PM, Catalin Marinas wrote:
> On Tue, Aug 02, 2016 at 11:00:07AM +0530, Pratyush Anand wrote:
>> --- a/arch/arm64/kernel/debug-monitors.c
>> +++ b/arch/arm64/kernel/debug-monitors.c
>> @@ -246,6 +246,8 @@ static void send_user_sigtrap(int si_code)
>> static int single_step_handler(unsigned long addr, unsigned int esr,
>> struct pt_regs *regs)
>> {
>> + bool handler_found = false;
>> +
>> /*
>> * If we are stepping a pending breakpoint, call the hw_breakpoint
>> * handler first.
>> @@ -253,7 +255,14 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
>> if (!reinstall_suspended_bps(regs))
>> return 0;
>>
>> - if (user_mode(regs)) {
>> +#ifdef CONFIG_KPROBES
>> + if (kprobe_single_step_handler(regs, esr) == DBG_HOOK_HANDLED)
>> + handler_found = true;
>> +#endif
>> + if (!handler_found && call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
>> + handler_found = true;
>> +
>> + if (!handler_found && user_mode(regs)) {
>> send_user_sigtrap(TRAP_HWBKPT);
>
> Could we register kprobe_single_step_handler() via register_set_hook()
> and only invoke call_step_hook() above?
>
I seem to recall a criticism of doing that in a much earlier kprobes64
patch of mine. The concern was that it would cause unnecessarily more
kernel functions to be kprobes-blacklisted. Hence the hardcoded check
and call.
-dl
next prev parent reply other threads:[~2016-09-06 21:36 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-02 5:30 [PATCH 0/5] ARM64: Uprobe support added Pratyush Anand
2016-08-02 5:30 ` [PATCH 1/5] arm64: kprobe: protect/rename few definitions to be reused by uprobe Pratyush Anand
2016-08-02 5:30 ` [PATCH 2/5] arm64: kgdb_step_brk_fn: ignore other's exception Pratyush Anand
2016-08-02 5:30 ` [PATCH 3/5] arm64: Handle TRAP_HWBRKPT for user mode as well Pratyush Anand
2016-09-06 16:11 ` Catalin Marinas
2016-09-06 21:36 ` David Long [this message]
2016-09-07 4:47 ` Pratyush Anand
2016-09-07 13:41 ` Catalin Marinas
2016-08-02 5:30 ` [PATCH 4/5] arm64: Handle TRAP_BRKPT " Pratyush Anand
2016-09-06 16:34 ` Catalin Marinas
2016-08-02 5:30 ` [PATCH 5/5] arm64: Add uprobe support Pratyush Anand
2016-08-09 18:49 ` Oleg Nesterov
2016-08-24 7:13 ` Pratyush Anand
2016-08-24 15:47 ` Oleg Nesterov
2016-08-24 15:56 ` Will Deacon
2016-08-25 13:33 ` Oleg Nesterov
2016-09-20 16:59 ` Catalin Marinas
2016-09-21 11:00 ` Pratyush Anand
2016-09-21 17:04 ` Catalin Marinas
2016-09-22 3:23 ` Pratyush Anand
2016-09-22 16:50 ` Catalin Marinas
2016-09-23 4:12 ` Pratyush Anand
2016-09-23 13:05 ` Catalin Marinas
2016-09-25 17:02 ` Pratyush Anand
2016-09-26 11:01 ` Catalin Marinas
2016-09-26 13:03 ` Pratyush Anand
2016-09-27 13:51 ` Catalin Marinas
2016-09-27 15:03 ` Pratyush Anand
2016-09-28 17:12 ` Catalin Marinas
2016-08-24 7:26 ` [PATCH 0/5] ARM64: Uprobe support added Pratyush Anand
2016-09-20 2:51 ` Pratyush Anand
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