| Message ID | 20181010144322.14363-1-james.morse@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: mm: Use __pa_symbol() for set_swapper_pgd() | expand |
On Wed, Oct 10, 2018 at 03:43:22PM +0100, James Morse wrote: > commit 2330b7ca78350efcb ("arm64/mm: use fixmap to modify > swapper_pg_dir") modifies the swapper_pg_dir via the fixmap > as the kernel page tables have been moved to a read-only > part of the kernel mapping. > > Using __pa() to setup the fixmap causes CONFIG_DEBUG_VIRTUAL > to fire, as this function is used on the kernel-image swapper > address. The in_swapper_pgdir() test before each call of this > function means set_swapper_pgd() will only ever be called when > pgdp points somewhere in the kernel-image mapping of > swapper_pd_dir. Use __pa_symbol(). > > Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> > Signed-off-by: James Morse <james.morse@arm.com> > CC: Jun Yao <yaojun8558363@gmail.com> > Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > arch/arm64/mm/mmu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Since this only affects for-next/core, Catalin should pick this up for 4.20. Acked-by: Will Deacon <will.deacon@arm.com> Will
On Wed, Oct 10, 2018 at 03:43:22PM +0100, James Morse wrote: > commit 2330b7ca78350efcb ("arm64/mm: use fixmap to modify > swapper_pg_dir") modifies the swapper_pg_dir via the fixmap > as the kernel page tables have been moved to a read-only > part of the kernel mapping. > > Using __pa() to setup the fixmap causes CONFIG_DEBUG_VIRTUAL > to fire, as this function is used on the kernel-image swapper > address. The in_swapper_pgdir() test before each call of this > function means set_swapper_pgd() will only ever be called when > pgdp points somewhere in the kernel-image mapping of > swapper_pd_dir. Use __pa_symbol(). > > Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> > Signed-off-by: James Morse <james.morse@arm.com> > CC: Jun Yao <yaojun8558363@gmail.com> > Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Applied. Thanks.
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 6f0e2edcc114..6deb836a102a 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -74,7 +74,7 @@ void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd) pgd_t *fixmap_pgdp; spin_lock(&swapper_pgdir_lock); - fixmap_pgdp = pgd_set_fixmap(__pa(pgdp)); + fixmap_pgdp = pgd_set_fixmap(__pa_symbol(pgdp)); WRITE_ONCE(*fixmap_pgdp, pgd); /* * We need dsb(ishst) here to ensure the page-table-walker sees
commit 2330b7ca78350efcb ("arm64/mm: use fixmap to modify swapper_pg_dir") modifies the swapper_pg_dir via the fixmap as the kernel page tables have been moved to a read-only part of the kernel mapping. Using __pa() to setup the fixmap causes CONFIG_DEBUG_VIRTUAL to fire, as this function is used on the kernel-image swapper address. The in_swapper_pgdir() test before each call of this function means set_swapper_pgd() will only ever be called when pgdp points somewhere in the kernel-image mapping of swapper_pd_dir. Use __pa_symbol(). Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: James Morse <james.morse@arm.com> CC: Jun Yao <yaojun8558363@gmail.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> --- arch/arm64/mm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)