| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 357/411] net: mdio: unexport __init-annotated mdio_bus_init() | Date | Mon, 13 Jun 2022 12:10:30 +0200 |
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From: Masahiro Yamada <masahiroy@kernel.org>
[ 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> --- 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 b0a439248ff6..05c24db507a2 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -753,7 +753,6 @@ int __init mdio_bus_init(void) return ret; } -EXPORT_SYMBOL_GPL(mdio_bus_init); #if IS_ENABLED(CONFIG_PHYLIB) void mdio_bus_exit(void) -- 2.35.1
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