The patch titled
Subject: arm: don't call addr_limit_user_check for nommu
has been added to the -mm tree. Its filename is
syscalls-use-uaccess_kernel-in-addr_limit_user_check-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/syscalls-use-uaccess_kernel-in-addr_limit_user_check-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/syscalls-use-uaccess_kernel-in-addr_limit_user_check-fix.patch
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------------------------------------------------------
From: Christoph Hellwig <hch@xxxxxx>
Subject: arm: don't call addr_limit_user_check for nommu
On arm nommu kernel use the same constant for USER_DS and KERNEL_DS, and
seqment_eq always returns false. With the current check in
addr_limit_user_check that works by accident, but when replacing
seqment_eq with uaccess_kerne it will fail. Just remove the not needed
check entirely.
Link: http://lkml.kernel.org/r/20200721045834.GA9613@xxxxxx
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm/kernel/signal.c | 2 ++
1 file changed, 2 insertions(+)
--- a/arch/arm/kernel/signal.c~syscalls-use-uaccess_kernel-in-addr_limit_user_check-fix
+++ a/arch/arm/kernel/signal.c
@@ -713,7 +713,9 @@ struct page *get_signal_page(void)
/* Defer to generic check */
asmlinkage void addr_limit_check_failed(void)
{
+#ifdef CONFIG_MMU
addr_limit_user_check();
+#endif
}
#ifdef CONFIG_DEBUG_RSEQ
_
Patches currently in -mm which might be from hch@xxxxxx are
syscalls-use-uaccess_kernel-in-addr_limit_user_check.patch
syscalls-use-uaccess_kernel-in-addr_limit_user_check-fix.patch
nds32-use-uaccess_kernel-in-show_regs.patch
riscv-include-asm-pgtableh-in-asm-uaccessh.patch
uaccess-remove-segment_eq.patch
uaccess-add-force_uaccess_beginend-helpers.patch
uaccess-add-force_uaccess_beginend-helpers-v2.patch
exec-use-force_uaccess_begin-during-exec-and-exit.patch
kernel-add-a-kernel_wait-helper.patch
