From: Masahiro Yamada masahiroy@kernel.org
[ Upstream commit dbac14a5a05ff8e1ce7c0da0e1f520ce39ec62ea ]
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 none of the in-tree call-sites (arch/arm/xen/enlighten.c, arch/x86/xen/grant-table.c) is compiled as modular.
Fixes: 243848fc018c ("xen/grant-table: Move xlated_setup_gnttab_pages to common place") Reported-by: Stephen Rothwell sfr@canb.auug.org.au Signed-off-by: Masahiro Yamada masahiroy@kernel.org Reviewed-by: Oleksandr Tyshchenko oleksandr_tyshchenko@epam.com Acked-by: Stefano Stabellini sstabellini@kernel.org Link: https://lore.kernel.org/r/20220606045920.4161881-1-masahiroy@kernel.org Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/xen/xlate_mmu.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c index 34742c6e189e..f17c4c03db30 100644 --- a/drivers/xen/xlate_mmu.c +++ b/drivers/xen/xlate_mmu.c @@ -261,7 +261,6 @@ int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt,
return 0; } -EXPORT_SYMBOL_GPL(xen_xlate_map_ballooned_pages);
struct remap_pfn { struct mm_struct *mm;