* [PATCH 0/2] PCI: rcar: Fix of_find_matching_node() reference leak
@ 2022-06-22 2:57 Bjorn Helgaas
2022-06-22 2:57 ` [PATCH 1/2] PCI: rcar: Add dev struct for of_device_get_match_data() Bjorn Helgaas
2022-06-22 2:57 ` [PATCH 2/2] PCI: rcar: Resolve of_find_matching_node() reference leak Bjorn Helgaas
0 siblings, 2 replies; 5+ messages in thread
From: Bjorn Helgaas @ 2022-06-22 2:57 UTC (permalink / raw)
To: Marek Vasut, Yoshihiro Shimoda
Cc: Liang He, Geert Uytterhoeven, Lorenzo Pieralisi, Rob Herring,
Krzysztof Wilczyński, linux-pci, linux-renesas-soc,
linux-kernel, Bjorn Helgaas
From: Bjorn Helgaas <bhelgaas@google.com>
Alternate proposal for Liang's patch [1].
This is a bulkier fix, but removes the redundant
rcar_pcie_abort_handler_of_match[] table.
It also simplifies the unusual device_initcall()/builtin_platform_driver()
construct, which seems unnecessary as far as I can tell.
Compile-tested only.
[1] https://lore.kernel.org/r/20220621070145.4080147-1-windhl@126.com
Bjorn Helgaas (2):
PCI: rcar: Add dev struct for of_device_get_match_data()
PCI: rcar: Resolve of_find_matching_node() reference leak
drivers/pci/controller/pcie-rcar-host.c | 113 +++++++++++++-----------
1 file changed, 60 insertions(+), 53 deletions(-)
--
2.25.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 1/2] PCI: rcar: Add dev struct for of_device_get_match_data()
2022-06-22 2:57 [PATCH 0/2] PCI: rcar: Fix of_find_matching_node() reference leak Bjorn Helgaas
@ 2022-06-22 2:57 ` Bjorn Helgaas
2022-06-22 2:57 ` [PATCH 2/2] PCI: rcar: Resolve of_find_matching_node() reference leak Bjorn Helgaas
1 sibling, 0 replies; 5+ messages in thread
From: Bjorn Helgaas @ 2022-06-22 2:57 UTC (permalink / raw)
To: Marek Vasut, Yoshihiro Shimoda
Cc: Liang He, Geert Uytterhoeven, Lorenzo Pieralisi, Rob Herring,
Krzysztof Wilczyński, linux-pci, linux-renesas-soc,
linux-kernel, Bjorn Helgaas, Geert Uytterhoeven
From: Bjorn Helgaas <bhelgaas@google.com>
Add a struct rcar_variant to hold details about differences between the
different R-Car variants we support. No functional change intended.
The benefit is that we can find all this information with the existing
single of_device_get_match_data() call. A subsequent commit will remove
an of_find_matching_node() call by extending this structure.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Liang He <windhl@126.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
---
drivers/pci/controller/pcie-rcar-host.c | 53 +++++++++++++++----------
1 file changed, 33 insertions(+), 20 deletions(-)
diff --git a/drivers/pci/controller/pcie-rcar-host.c b/drivers/pci/controller/pcie-rcar-host.c
index 997c4df6a1e7..ccf13aafa1e5 100644
--- a/drivers/pci/controller/pcie-rcar-host.c
+++ b/drivers/pci/controller/pcie-rcar-host.c
@@ -56,13 +56,19 @@ static void __iomem *pcie_base;
static struct device *pcie_dev;
#endif
+struct rcar_pcie_host;
+
+struct rcar_variant {
+ int (*phy_init_fn)(struct rcar_pcie_host *host);
+};
+
/* Structure representing the PCIe interface */
struct rcar_pcie_host {
- struct rcar_pcie pcie;
- struct phy *phy;
- struct clk *bus_clk;
- struct rcar_msi msi;
- int (*phy_init_fn)(struct rcar_pcie_host *host);
+ struct rcar_pcie pcie;
+ struct phy *phy;
+ struct clk *bus_clk;
+ struct rcar_msi msi;
+ const struct rcar_variant *variant;
};
static DEFINE_SPINLOCK(pmsr_lock);
@@ -958,19 +964,26 @@ static int rcar_pcie_parse_map_dma_ranges(struct rcar_pcie_host *host)
return err;
}
+static const struct rcar_variant rcar_h1_data = {
+ .phy_init_fn = rcar_pcie_phy_init_h1,
+};
+
+static const struct rcar_variant rcar_gen2_data = {
+ .phy_init_fn = rcar_pcie_phy_init_gen2,
+};
+
+static const struct rcar_variant rcar_gen3_data = {
+ .phy_init_fn = rcar_pcie_phy_init_gen3,
+};
+
static const struct of_device_id rcar_pcie_of_match[] = {
- { .compatible = "renesas,pcie-r8a7779",
- .data = rcar_pcie_phy_init_h1 },
- { .compatible = "renesas,pcie-r8a7790",
- .data = rcar_pcie_phy_init_gen2 },
- { .compatible = "renesas,pcie-r8a7791",
- .data = rcar_pcie_phy_init_gen2 },
- { .compatible = "renesas,pcie-rcar-gen2",
- .data = rcar_pcie_phy_init_gen2 },
- { .compatible = "renesas,pcie-r8a7795",
- .data = rcar_pcie_phy_init_gen3 },
- { .compatible = "renesas,pcie-rcar-gen3",
- .data = rcar_pcie_phy_init_gen3 },
+ { .compatible = "renesas,pcie-r8a7779", .data = &rcar_h1_data },
+ { .compatible = "renesas,pcie-r8a7790", .data = &rcar_gen2_data },
+ { .compatible = "renesas,pcie-r8a7791", .data = &rcar_gen2_data },
+ { .compatible = "renesas,pcie-rcar-gen2", .data = &rcar_gen2_data },
+
+ { .compatible = "renesas,pcie-r8a7795", .data = &rcar_gen3_data },
+ { .compatible = "renesas,pcie-rcar-gen3", .data = &rcar_gen3_data },
{},
};
@@ -1015,8 +1028,8 @@ static int rcar_pcie_probe(struct platform_device *pdev)
if (err)
goto err_clk_disable;
- host->phy_init_fn = of_device_get_match_data(dev);
- err = host->phy_init_fn(host);
+ host->variant = of_device_get_match_data(dev);
+ err = host->variant->phy_init_fn(host);
if (err) {
dev_err(dev, "failed to init PCIe PHY\n");
goto err_clk_disable;
@@ -1084,7 +1097,7 @@ static int __maybe_unused rcar_pcie_resume(struct device *dev)
return 0;
/* Failure to get a link might just be that no cards are inserted */
- err = host->phy_init_fn(host);
+ err = host->variant->phy_init_fn(host);
if (err) {
dev_info(dev, "PCIe link down\n");
return 0;
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] PCI: rcar: Resolve of_find_matching_node() reference leak
2022-06-22 2:57 [PATCH 0/2] PCI: rcar: Fix of_find_matching_node() reference leak Bjorn Helgaas
2022-06-22 2:57 ` [PATCH 1/2] PCI: rcar: Add dev struct for of_device_get_match_data() Bjorn Helgaas
@ 2022-06-22 2:57 ` Bjorn Helgaas
2022-06-22 7:45 ` Geert Uytterhoeven
1 sibling, 1 reply; 5+ messages in thread
From: Bjorn Helgaas @ 2022-06-22 2:57 UTC (permalink / raw)
To: Marek Vasut, Yoshihiro Shimoda
Cc: Liang He, Geert Uytterhoeven, Lorenzo Pieralisi, Rob Herring,
Krzysztof Wilczyński, linux-pci, linux-renesas-soc,
linux-kernel, Bjorn Helgaas, Geert Uytterhoeven
From: Bjorn Helgaas <bhelgaas@google.com>
Previously, rcar_pcie_init() used of_find_matching_node() to search the
entire device tree for compatible strings for which we need to install an
abort handler. If we found one, we got a device_node with refcount
incremented, but we discarded the pointer and never released that
reference.
Extend the struct rcar_variant to indicate whether each variant requires an
abort handler. Install the handler in rcar_pcie_probe() when needed.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Liang He <windhl@126.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
---
drivers/pci/controller/pcie-rcar-host.c | 60 +++++++++++--------------
1 file changed, 27 insertions(+), 33 deletions(-)
diff --git a/drivers/pci/controller/pcie-rcar-host.c b/drivers/pci/controller/pcie-rcar-host.c
index ccf13aafa1e5..139a0274b9e0 100644
--- a/drivers/pci/controller/pcie-rcar-host.c
+++ b/drivers/pci/controller/pcie-rcar-host.c
@@ -60,6 +60,7 @@ struct rcar_pcie_host;
struct rcar_variant {
int (*phy_init_fn)(struct rcar_pcie_host *host);
+ bool hook_aborts;
};
/* Structure representing the PCIe interface */
@@ -964,12 +965,35 @@ static int rcar_pcie_parse_map_dma_ranges(struct rcar_pcie_host *host)
return err;
}
+#ifdef CONFIG_ARM
+static int rcar_pcie_aarch32_abort_handler(unsigned long addr,
+ unsigned int fsr, struct pt_regs *regs)
+{
+ return !fixup_exception(regs);
+}
+#endif
+
+static void rcar_pcie_hook_aborts(void)
+{
+#ifdef CONFIG_ARM
+#ifdef CONFIG_ARM_LPAE
+ hook_fault_code(17, rcar_pcie_aarch32_abort_handler, SIGBUS, 0,
+ "asynchronous external abort");
+#else
+ hook_fault_code(22, rcar_pcie_aarch32_abort_handler, SIGBUS, 0,
+ "imprecise external abort");
+#endif
+#endif
+}
+
static const struct rcar_variant rcar_h1_data = {
.phy_init_fn = rcar_pcie_phy_init_h1,
+ .hook_aborts = true,
};
static const struct rcar_variant rcar_gen2_data = {
.phy_init_fn = rcar_pcie_phy_init_gen2,
+ .hook_aborts = true,
};
static const struct rcar_variant rcar_gen3_data = {
@@ -1035,6 +1059,9 @@ static int rcar_pcie_probe(struct platform_device *pdev)
goto err_clk_disable;
}
+ if (host->variant->hook_aborts)
+ rcar_pcie_hook_aborts();
+
/* Failure to get a link might just be that no cards are inserted */
if (rcar_pcie_hw_init(pcie)) {
dev_info(dev, "PCIe link down\n");
@@ -1153,37 +1180,4 @@ static struct platform_driver rcar_pcie_driver = {
},
.probe = rcar_pcie_probe,
};
-
-#ifdef CONFIG_ARM
-static int rcar_pcie_aarch32_abort_handler(unsigned long addr,
- unsigned int fsr, struct pt_regs *regs)
-{
- return !fixup_exception(regs);
-}
-
-static const struct of_device_id rcar_pcie_abort_handler_of_match[] __initconst = {
- { .compatible = "renesas,pcie-r8a7779" },
- { .compatible = "renesas,pcie-r8a7790" },
- { .compatible = "renesas,pcie-r8a7791" },
- { .compatible = "renesas,pcie-rcar-gen2" },
- {},
-};
-
-static int __init rcar_pcie_init(void)
-{
- if (of_find_matching_node(NULL, rcar_pcie_abort_handler_of_match)) {
-#ifdef CONFIG_ARM_LPAE
- hook_fault_code(17, rcar_pcie_aarch32_abort_handler, SIGBUS, 0,
- "asynchronous external abort");
-#else
- hook_fault_code(22, rcar_pcie_aarch32_abort_handler, SIGBUS, 0,
- "imprecise external abort");
-#endif
- }
-
- return platform_driver_register(&rcar_pcie_driver);
-}
-device_initcall(rcar_pcie_init);
-#else
builtin_platform_driver(rcar_pcie_driver);
-#endif
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] PCI: rcar: Resolve of_find_matching_node() reference leak
2022-06-22 2:57 ` [PATCH 2/2] PCI: rcar: Resolve of_find_matching_node() reference leak Bjorn Helgaas
@ 2022-06-22 7:45 ` Geert Uytterhoeven
2022-06-22 11:05 ` Bjorn Helgaas
0 siblings, 1 reply; 5+ messages in thread
From: Geert Uytterhoeven @ 2022-06-22 7:45 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: Marek Vasut, Yoshihiro Shimoda, Liang He, Lorenzo Pieralisi,
Rob Herring, Krzysztof Wilczyński, linux-pci, Linux-Renesas,
Linux Kernel Mailing List, Bjorn Helgaas
Hi Bjorn,
On Wed, Jun 22, 2022 at 4:57 AM Bjorn Helgaas <helgaas@kernel.org> wrote:
> From: Bjorn Helgaas <bhelgaas@google.com>
>
> Previously, rcar_pcie_init() used of_find_matching_node() to search the
> entire device tree for compatible strings for which we need to install an
> abort handler. If we found one, we got a device_node with refcount
> incremented, but we discarded the pointer and never released that
> reference.
>
> Extend the struct rcar_variant to indicate whether each variant requires an
> abort handler. Install the handler in rcar_pcie_probe() when needed.
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Liang He <windhl@126.com>
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Thanks for your patch!
> --- a/drivers/pci/controller/pcie-rcar-host.c
> +++ b/drivers/pci/controller/pcie-rcar-host.c
> @@ -964,12 +965,35 @@ static int rcar_pcie_parse_map_dma_ranges(struct rcar_pcie_host *host)
> return err;
> }
>
> +#ifdef CONFIG_ARM
> +static int rcar_pcie_aarch32_abort_handler(unsigned long addr,
> + unsigned int fsr, struct pt_regs *regs)
> +{
> + return !fixup_exception(regs);
> +}
> +#endif
> +
> +static void rcar_pcie_hook_aborts(void)
> +{
> +#ifdef CONFIG_ARM
> +#ifdef CONFIG_ARM_LPAE
> + hook_fault_code(17, rcar_pcie_aarch32_abort_handler, SIGBUS, 0,
> + "asynchronous external abort");
> +#else
> + hook_fault_code(22, rcar_pcie_aarch32_abort_handler, SIGBUS, 0,
> + "imprecise external abort");
> +#endif
> +#endif
> +}
> +
> static const struct rcar_variant rcar_h1_data = {
> .phy_init_fn = rcar_pcie_phy_init_h1,
> + .hook_aborts = true,
> };
>
> static const struct rcar_variant rcar_gen2_data = {
> .phy_init_fn = rcar_pcie_phy_init_gen2,
> + .hook_aborts = true,
> };
>
> static const struct rcar_variant rcar_gen3_data = {
> @@ -1035,6 +1059,9 @@ static int rcar_pcie_probe(struct platform_device *pdev)
> goto err_clk_disable;
> }
>
> + if (host->variant->hook_aborts)
> + rcar_pcie_hook_aborts();
I was quite sure there was a good reason why this was not done in
.probe() before...
And indeed, the original submission[1] did have a comment explaining
that:
+ /*
+ * Since probe() can be deferred we need to make sure that
+ * hook_fault_code is not called after __init memory is freed
+ * by kernel and since rcar_pcie_abort_handler() is a no-op,
+ * we can install the handler here without risking it
+ * accessing some uninitialized driver state.
+ */
No idea why it was removed in v2 and later, but the point is:
hook_fault_code() is __init, so you cannot call it from a deferred
probe.
And you should have got a section mismatch warning ;-)
[1] https://lore.kernel.org/all/20200912211853.15321-1-marek.vasut@gmail.com/
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] PCI: rcar: Resolve of_find_matching_node() reference leak
2022-06-22 7:45 ` Geert Uytterhoeven
@ 2022-06-22 11:05 ` Bjorn Helgaas
0 siblings, 0 replies; 5+ messages in thread
From: Bjorn Helgaas @ 2022-06-22 11:05 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Marek Vasut, Yoshihiro Shimoda, Liang He, Lorenzo Pieralisi,
Rob Herring, Krzysztof Wilczyński, linux-pci, Linux-Renesas,
Linux Kernel Mailing List, Bjorn Helgaas
On Wed, Jun 22, 2022 at 09:45:49AM +0200, Geert Uytterhoeven wrote:
> Hi Bjorn,
>
> On Wed, Jun 22, 2022 at 4:57 AM Bjorn Helgaas <helgaas@kernel.org> wrote:
> > From: Bjorn Helgaas <bhelgaas@google.com>
> >
> > Previously, rcar_pcie_init() used of_find_matching_node() to search the
> > entire device tree for compatible strings for which we need to install an
> > abort handler. If we found one, we got a device_node with refcount
> > incremented, but we discarded the pointer and never released that
> > reference.
> >
> > Extend the struct rcar_variant to indicate whether each variant requires an
> > abort handler. Install the handler in rcar_pcie_probe() when needed.
> >
> > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: Liang He <windhl@126.com>
> > Cc: Geert Uytterhoeven <geert@linux-m68k.org>
>
> Thanks for your patch!
>
> > --- a/drivers/pci/controller/pcie-rcar-host.c
> > +++ b/drivers/pci/controller/pcie-rcar-host.c
>
> > @@ -964,12 +965,35 @@ static int rcar_pcie_parse_map_dma_ranges(struct rcar_pcie_host *host)
> > return err;
> > }
> >
> > +#ifdef CONFIG_ARM
> > +static int rcar_pcie_aarch32_abort_handler(unsigned long addr,
> > + unsigned int fsr, struct pt_regs *regs)
> > +{
> > + return !fixup_exception(regs);
> > +}
> > +#endif
> > +
> > +static void rcar_pcie_hook_aborts(void)
> > +{
> > +#ifdef CONFIG_ARM
> > +#ifdef CONFIG_ARM_LPAE
> > + hook_fault_code(17, rcar_pcie_aarch32_abort_handler, SIGBUS, 0,
> > + "asynchronous external abort");
> > +#else
> > + hook_fault_code(22, rcar_pcie_aarch32_abort_handler, SIGBUS, 0,
> > + "imprecise external abort");
> > +#endif
> > +#endif
> > +}
> > +
> > static const struct rcar_variant rcar_h1_data = {
> > .phy_init_fn = rcar_pcie_phy_init_h1,
> > + .hook_aborts = true,
> > };
> >
> > static const struct rcar_variant rcar_gen2_data = {
> > .phy_init_fn = rcar_pcie_phy_init_gen2,
> > + .hook_aborts = true,
> > };
> >
> > static const struct rcar_variant rcar_gen3_data = {
> > @@ -1035,6 +1059,9 @@ static int rcar_pcie_probe(struct platform_device *pdev)
> > goto err_clk_disable;
> > }
> >
> > + if (host->variant->hook_aborts)
> > + rcar_pcie_hook_aborts();
>
> I was quite sure there was a good reason why this was not done in
> .probe() before...
>
> And indeed, the original submission[1] did have a comment explaining
> that:
>
> + /*
> + * Since probe() can be deferred we need to make sure that
> + * hook_fault_code is not called after __init memory is freed
> + * by kernel and since rcar_pcie_abort_handler() is a no-op,
> + * we can install the handler here without risking it
> + * accessing some uninitialized driver state.
> + */
>
> No idea why it was removed in v2 and later, but the point is:
> hook_fault_code() is __init, so you cannot call it from a deferred
> probe.
> And you should have got a section mismatch warning ;-)
Oooh, thanks for that! I missed the builtin_platform_driver_probe()
vs builtin_platform_driver() difference that explains why doing this
at probe-time works for pci-ixp4xx.c but not here.
Bjorn
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-06-22 11:05 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-22 2:57 [PATCH 0/2] PCI: rcar: Fix of_find_matching_node() reference leak Bjorn Helgaas
2022-06-22 2:57 ` [PATCH 1/2] PCI: rcar: Add dev struct for of_device_get_match_data() Bjorn Helgaas
2022-06-22 2:57 ` [PATCH 2/2] PCI: rcar: Resolve of_find_matching_node() reference leak Bjorn Helgaas
2022-06-22 7:45 ` Geert Uytterhoeven
2022-06-22 11:05 ` Bjorn Helgaas
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