[PATCH] arm: Omit fixmap calls in text patching code if CONFIG_MMU=n

From: Geert Uytterhoeven
Date: Mon Oct 26 2015 - 03:54:56 EST


If CONFIG_JUMP_LABEL=y and CONFIG_MMU=n:

arch/arm/kernel/patch.c: In function 'patch_map':
arch/arm/kernel/patch.c:39:129: error: 'L_PTE_YOUNG' undeclared (first use in this function)
set_fixmap(fixmap, page_to_phys(page));
^
arch/arm/kernel/patch.c:39:129: note: each undeclared identifier is reported only once for each function it appears in
arch/arm/kernel/patch.c:39:143: error: 'L_PTE_PRESENT' undeclared (first use in this function)
set_fixmap(fixmap, page_to_phys(page));
^
arch/arm/kernel/patch.c:39:159: error: 'L_PTE_XN' undeclared (first use in this function)
set_fixmap(fixmap, page_to_phys(page));
^
arch/arm/kernel/patch.c:39:170: error: 'L_PTE_DIRTY' undeclared (first use in this function)
set_fixmap(fixmap, page_to_phys(page));
^
arch/arm/kernel/patch.c:39:185: error: 'L_PTE_MT_WRITEBACK' undeclared (first use in this function)
set_fixmap(fixmap, page_to_phys(page));
^

Protect the calls to set_fixmap() and clear_fixmap() by #ifdef
CONFIG_MMU to fix this.

Fixes: commit ab0615e2d6fb0747 ("arm: use fixmap for text patching when text is RO")
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
---
http://kisskb.ellerman.id.au/kisskb/buildresult/12531538/

arch/arm/kernel/patch.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/arm/kernel/patch.c b/arch/arm/kernel/patch.c
index 69bda1a5707ee826..447b53a68be5bd6f 100644
--- a/arch/arm/kernel/patch.c
+++ b/arch/arm/kernel/patch.c
@@ -36,7 +36,9 @@ static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
else
__acquire(&patch_lock);

+#ifdef CONFIG_MMU
set_fixmap(fixmap, page_to_phys(page));
+#endif

return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));
}
@@ -44,7 +46,9 @@ static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
static void __kprobes patch_unmap(int fixmap, unsigned long *flags)
__releases(&patch_lock)
{
+#ifdef CONFIG_MMU
clear_fixmap(fixmap);
+#endif

if (flags)
spin_unlock_irqrestore(&patch_lock, *flags);
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/