| Message ID | 1465343547-19974-1-git-send-email-mcgrof@kernel.org |
|---|---|
| State | Accepted |
| Headers | show |
On Tue, Jun 07, 2016 at 04:52:27PM -0700, Luis R. Rodriguez wrote: > As of next-20160607 with allyesconfig we get this linker failure: > > MODPOST vmlinux.o > WARNING: vmlinux.o(.text+0x21bc0d): Section mismatch in reference from > the function intel_scu_devices_create() to the function > .init.text:i2c_register_board_info() > > This is caused by the fact that intel_scu_devices_create() calls > i2c_register_board_info() and intel_scu_devices_create() is not > annotated with __init. This typically involves manual code > inspection and if one is certain this is correct we would > just peg intel_scu_devices_create() with a __ref annotation. > > In this case this would be wrong though as the > intel_scu_devices_create() call is exported, and used in > the ipc_probe() on drivers/platform/x86/intel_scu_ipc.c. > The issue is that even though builtin_pci_driver(ipc_driver) > is used this just exposes the probe routine, which can occur > at any point in time if this bus supports hotplug. A race > can happen between kernel_init_freeable() that calls the init > calls (in this case registeres the intel_scu_ipc.c driver, and > later free_initmem(), which would free the i2c_register_board_info(). > If a probe happens later in boot i2c_register_board_info() would > not be present and we should get a page fault. > > Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> I don't see this merged yet on linux-next and this is still an issue. *Poke* Luis -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jun 07, 2016 at 04:52:27PM -0700, Luis R. Rodriguez wrote: > As of next-20160607 with allyesconfig we get this linker failure: > > MODPOST vmlinux.o > WARNING: vmlinux.o(.text+0x21bc0d): Section mismatch in reference from > the function intel_scu_devices_create() to the function > .init.text:i2c_register_board_info() > > This is caused by the fact that intel_scu_devices_create() calls > i2c_register_board_info() and intel_scu_devices_create() is not > annotated with __init. This typically involves manual code > inspection and if one is certain this is correct we would > just peg intel_scu_devices_create() with a __ref annotation. > > In this case this would be wrong though as the > intel_scu_devices_create() call is exported, and used in > the ipc_probe() on drivers/platform/x86/intel_scu_ipc.c. > The issue is that even though builtin_pci_driver(ipc_driver) > is used this just exposes the probe routine, which can occur > at any point in time if this bus supports hotplug. A race > can happen between kernel_init_freeable() that calls the init > calls (in this case registeres the intel_scu_ipc.c driver, and > later free_initmem(), which would free the i2c_register_board_info(). > If a probe happens later in boot i2c_register_board_info() would > not be present and we should get a page fault. > > Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Applied to for-current, thanks! Do you think this should go to stable?
On Sun, Jun 19, 2016 at 02:15:38PM +0200, Wolfram Sang wrote: > On Tue, Jun 07, 2016 at 04:52:27PM -0700, Luis R. Rodriguez wrote: > > As of next-20160607 with allyesconfig we get this linker failure: > > > > MODPOST vmlinux.o > > WARNING: vmlinux.o(.text+0x21bc0d): Section mismatch in reference from > > the function intel_scu_devices_create() to the function > > .init.text:i2c_register_board_info() > > > > This is caused by the fact that intel_scu_devices_create() calls > > i2c_register_board_info() and intel_scu_devices_create() is not > > annotated with __init. This typically involves manual code > > inspection and if one is certain this is correct we would > > just peg intel_scu_devices_create() with a __ref annotation. > > > > In this case this would be wrong though as the > > intel_scu_devices_create() call is exported, and used in > > the ipc_probe() on drivers/platform/x86/intel_scu_ipc.c. > > The issue is that even though builtin_pci_driver(ipc_driver) > > is used this just exposes the probe routine, which can occur > > at any point in time if this bus supports hotplug. A race > > can happen between kernel_init_freeable() that calls the init > > calls (in this case registeres the intel_scu_ipc.c driver, and > > later free_initmem(), which would free the i2c_register_board_info(). > > If a probe happens later in boot i2c_register_board_info() would > > not be present and we should get a page fault. > > > > Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> > > Applied to for-current, thanks! Do you think this should go to stable? Its a theoretical race, but a real one, but does fix allyesconfig builds. Up to you. Luis -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/i2c/i2c-boardinfo.c b/drivers/i2c/i2c-boardinfo.c index e33022e..77b1589 100644 --- a/drivers/i2c/i2c-boardinfo.c +++ b/drivers/i2c/i2c-boardinfo.c @@ -56,7 +56,7 @@ EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num); * The board info passed can safely be __initdata, but be careful of embedded * pointers (for platform_data, functions, etc) since that won't be copied. */ -int __init +int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned len) {
As of next-20160607 with allyesconfig we get this linker failure: MODPOST vmlinux.o WARNING: vmlinux.o(.text+0x21bc0d): Section mismatch in reference from the function intel_scu_devices_create() to the function .init.text:i2c_register_board_info() This is caused by the fact that intel_scu_devices_create() calls i2c_register_board_info() and intel_scu_devices_create() is not annotated with __init. This typically involves manual code inspection and if one is certain this is correct we would just peg intel_scu_devices_create() with a __ref annotation. In this case this would be wrong though as the intel_scu_devices_create() call is exported, and used in the ipc_probe() on drivers/platform/x86/intel_scu_ipc.c. The issue is that even though builtin_pci_driver(ipc_driver) is used this just exposes the probe routine, which can occur at any point in time if this bus supports hotplug. A race can happen between kernel_init_freeable() that calls the init calls (in this case registeres the intel_scu_ipc.c driver, and later free_initmem(), which would free the i2c_register_board_info(). If a probe happens later in boot i2c_register_board_info() would not be present and we should get a page fault. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> --- drivers/i2c/i2c-boardinfo.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)