From mboxrd@z Thu Jan 1 00:00:00 1970 From: srikar@linux.vnet.ibm.com (Srikar Dronamraju) Date: Wed, 17 Oct 2012 22:10:59 +0530 Subject: [PATCH 2/9] uprobes: check for single step support In-Reply-To: <1350242593-17761-2-git-send-email-rabin@rab.in> References: <1350242593-17761-1-git-send-email-rabin@rab.in> <1350242593-17761-2-git-send-email-rabin@rab.in> Message-ID: <20121017164059.GF11096@linux.vnet.ibm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * Rabin Vincent [2012-10-14 21:23:06]: > Check for single step support before calling user_enable_single_step(), > since user_enable_single_step() just BUG()s if support does not exist. > Needed by ARM. > > Signed-off-by: Rabin Vincent > --- > kernel/events/uprobes.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > index 98256bc..db4e3ab 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -1450,7 +1450,8 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) > > void __weak arch_uprobe_enable_step(struct arch_uprobe *arch) > { > - user_enable_single_step(current); > + if (arch_has_single_step()) > + user_enable_single_step(current); > } > > void __weak arch_uprobe_disable_step(struct arch_uprobe *arch) This change is fine. But I am wondering if should have a dummy arch_uprobe_enable_step / arch_uprobe_disable_step in uprobes ARM. If arch_uprobe_enable_step() wasnt a weak function, then the fix you suggested would have been the only way to go. Again, I am not against this change. But I am hoping that we get feedback on which option is prefered, having this check or having a dummy function in archs like ARM. -- Thanks and Regards Srikar