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author | Masahiro Yamada <masahiroy@kernel.org> | 2022-06-06 07:59:20 +0300 |
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committer | Juergen Gross <jgross@suse.com> | 2022-06-07 09:11:35 +0300 |
commit | dbac14a5a05ff8e1ce7c0da0e1f520ce39ec62ea (patch) | |
tree | 6201cb85c327e6ae14d5e11f054f543dab24947a /drivers/xen | |
parent | fea981610c25173e6e5d63ccd4fce49739663ab0 (diff) | |
download | linux-dbac14a5a05ff8e1ce7c0da0e1f520ce39ec62ea.tar.xz |
xen: unexport __init-annotated xen_xlate_map_ballooned_pages()
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>
Diffstat (limited to 'drivers/xen')
-rw-r--r-- | drivers/xen/xlate_mmu.c | 1 |
1 files changed, 0 insertions, 1 deletions
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; |