From: Masahiro Yamada masahiroy@kernel.org
stable inclusion from stable-v5.10.122 commit 7759c3222815b945a94b212bc0c6cdec475cfec2 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5W6OE
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 35b42dce619701f1300fb8498dae82c9bb1f0263 ]
EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic.
modpost used to detect it, but it has been broken for a decade.
Recently, I fixed modpost so it started to warn it again, then this showed up in linux-next builds.
There are two ways to fix it:
- Remove __init - Remove EXPORT_SYMBOL
I chose the latter for this case because the only in-tree call-site, drivers/net/phy/phy_device.c is never compiled as modular. (CONFIG_PHYLIB is boolean)
Fixes: 90eff9096c01 ("net: phy: Allow splitting MDIO bus/device support from PHYs") Reported-by: Stephen Rothwell sfr@canb.auug.org.au Signed-off-by: Masahiro Yamada masahiroy@kernel.org Reviewed-by: Florian Fainelli f.fainelli@gmail.com Reviewed-by: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com --- drivers/net/phy/mdio_bus.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index c416ab1d2b00..c1cbdac4b376 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -1008,7 +1008,6 @@ int __init mdio_bus_init(void)
return ret; } -EXPORT_SYMBOL_GPL(mdio_bus_init);
#if IS_ENABLED(CONFIG_PHYLIB) void mdio_bus_exit(void)