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Mon, 22 Jul 2019 14:05:13 +1000 (AEST) From: Michael Ellerman To: Nathan Chancellor , Tyrel Datwyler , Benjamin Herrenschmidt , Paul Mackerras Subject: Re: [PATCH v2] PCI: rpaphp: Avoid a sometimes-uninitialized warning In-Reply-To: <20190722024313.GB55142@archlinux-threadripper> References: <20190603174323.48251-1-natechancellor@gmail.com> <20190603221157.58502-1-natechancellor@gmail.com> <20190722024313.GB55142@archlinux-threadripper> Date: Mon, 22 Jul 2019 14:05:12 +1000 Message-ID: <87lfwq7lzb.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pci@vger.kernel.org, Nick Desaulniers , linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Bjorn Helgaas , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Nathan Chancellor writes: > On Mon, Jun 03, 2019 at 03:11:58PM -0700, Nathan Chancellor wrote: >> When building with -Wsometimes-uninitialized, clang warns: >> >> drivers/pci/hotplug/rpaphp_core.c:243:14: warning: variable 'fndit' is >> used uninitialized whenever 'for' loop exits because its condition is >> false [-Wsometimes-uninitialized] >> for (j = 0; j < entries; j++) { >> ^~~~~~~~~~~ >> drivers/pci/hotplug/rpaphp_core.c:256:6: note: uninitialized use occurs >> here >> if (fndit) >> ^~~~~ >> drivers/pci/hotplug/rpaphp_core.c:243:14: note: remove the condition if >> it is always true >> for (j = 0; j < entries; j++) { >> ^~~~~~~~~~~ >> drivers/pci/hotplug/rpaphp_core.c:233:14: note: initialize the variable >> 'fndit' to silence this warning >> int j, fndit; >> ^ >> = 0 >> >> fndit is only used to gate a sprintf call, which can be moved into the >> loop to simplify the code and eliminate the local variable, which will >> fix this warning. >> >> Link: https://github.com/ClangBuiltLinux/linux/issues/504 >> Fixes: 2fcf3ae508c2 ("hotplug/drc-info: Add code to search ibm,drc-info property") >> Suggested-by: Nick Desaulniers >> Signed-off-by: Nathan Chancellor >> --- >> >> v1 -> v2: >> >> * Eliminate fndit altogether by shuffling the sprintf call into the for >> loop and changing the if conditional, as suggested by Nick. >> >> drivers/pci/hotplug/rpaphp_core.c | 18 +++++++----------- >> 1 file changed, 7 insertions(+), 11 deletions(-) >> >> diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c >> index bcd5d357ca23..c3899ee1db99 100644 >> --- a/drivers/pci/hotplug/rpaphp_core.c >> +++ b/drivers/pci/hotplug/rpaphp_core.c >> @@ -230,7 +230,7 @@ static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name, >> struct of_drc_info drc; >> const __be32 *value; >> char cell_drc_name[MAX_DRC_NAME_LEN]; >> - int j, fndit; >> + int j; >> >> info = of_find_property(dn->parent, "ibm,drc-info", NULL); >> if (info == NULL) >> @@ -245,17 +245,13 @@ static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name, >> >> /* Should now know end of current entry */ >> >> - if (my_index > drc.last_drc_index) >> - continue; >> - >> - fndit = 1; >> - break; >> + /* Found it */ >> + if (my_index <= drc.last_drc_index) { >> + sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix, >> + my_index); >> + break; >> + } >> } >> - /* Found it */ >> - >> - if (fndit) >> - sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix, >> - my_index); >> >> if (((drc_name == NULL) || >> (drc_name && !strcmp(drc_name, cell_drc_name))) && >> -- >> 2.22.0.rc3 >> > > Hi all, > > Could someone please pick this up? I'll take it. I was expecting Bjorn to take it as a PCI patch, but I realise now that I merged that code in the first place so may as well take this too. I'll put it in my next branch once that opens next week. cheers