summaryrefslogtreecommitdiffstats
path: root/arch/arm/include/asm/uaccess-asm.h
diff options
context:
space:
mode:
authorDavid S. Miller <davem@davemloft.net>2020-05-31 17:48:46 -0700
committerDavid S. Miller <davem@davemloft.net>2020-05-31 17:48:46 -0700
commit1806c13dc2532090d742ce03847b22367fb20ad6 (patch)
tree7507ddebec3046173a4308e1e0dd8701cd498d0f /arch/arm/include/asm/uaccess-asm.h
parent1079a34c56c535c3e27df8def0d3c5069d2de129 (diff)
parentbdc48fa11e46f867ea4d75fa59ee87a7f48be144 (diff)
downloadlinux-1806c13dc2532090d742ce03847b22367fb20ad6.tar.gz
linux-1806c13dc2532090d742ce03847b22367fb20ad6.tar.bz2
linux-1806c13dc2532090d742ce03847b22367fb20ad6.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
xdp_umem.c had overlapping changes between the 64-bit math fix for the calculation of npgs and the removal of the zerocopy memory type which got rid of the chunk_size_nohdr member. The mlx5 Kconfig conflict is a case where we just take the net-next copy of the Kconfig entry dependency as it takes on the ESWITCH dependency by one level of indirection which is what the 'net' conflicting change is trying to ensure. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/arm/include/asm/uaccess-asm.h')
-rw-r--r--arch/arm/include/asm/uaccess-asm.h117
1 files changed, 117 insertions, 0 deletions
diff --git a/arch/arm/include/asm/uaccess-asm.h b/arch/arm/include/asm/uaccess-asm.h
new file mode 100644
index 000000000000..907571fd05c6
--- /dev/null
+++ b/arch/arm/include/asm/uaccess-asm.h
@@ -0,0 +1,117 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_UACCESS_ASM_H__
+#define __ASM_UACCESS_ASM_H__
+
+#include <asm/asm-offsets.h>
+#include <asm/domain.h>
+#include <asm/memory.h>
+#include <asm/thread_info.h>
+
+ .macro csdb
+#ifdef CONFIG_THUMB2_KERNEL
+ .inst.w 0xf3af8014
+#else
+ .inst 0xe320f014
+#endif
+ .endm
+
+ .macro check_uaccess, addr:req, size:req, limit:req, tmp:req, bad:req
+#ifndef CONFIG_CPU_USE_DOMAINS
+ adds \tmp, \addr, #\size - 1
+ sbcscc \tmp, \tmp, \limit
+ bcs \bad
+#ifdef CONFIG_CPU_SPECTRE
+ movcs \addr, #0
+ csdb
+#endif
+#endif
+ .endm
+
+ .macro uaccess_mask_range_ptr, addr:req, size:req, limit:req, tmp:req
+#ifdef CONFIG_CPU_SPECTRE
+ sub \tmp, \limit, #1
+ subs \tmp, \tmp, \addr @ tmp = limit - 1 - addr
+ addhs \tmp, \tmp, #1 @ if (tmp >= 0) {
+ subshs \tmp, \tmp, \size @ tmp = limit - (addr + size) }
+ movlo \addr, #0 @ if (tmp < 0) addr = NULL
+ csdb
+#endif
+ .endm
+
+ .macro uaccess_disable, tmp, isb=1
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+ /*
+ * Whenever we re-enter userspace, the domains should always be
+ * set appropriately.
+ */
+ mov \tmp, #DACR_UACCESS_DISABLE
+ mcr p15, 0, \tmp, c3, c0, 0 @ Set domain register
+ .if \isb
+ instr_sync
+ .endif
+#endif
+ .endm
+
+ .macro uaccess_enable, tmp, isb=1
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+ /*
+ * Whenever we re-enter userspace, the domains should always be
+ * set appropriately.
+ */
+ mov \tmp, #DACR_UACCESS_ENABLE
+ mcr p15, 0, \tmp, c3, c0, 0
+ .if \isb
+ instr_sync
+ .endif
+#endif
+ .endm
+
+#if defined(CONFIG_CPU_SW_DOMAIN_PAN) || defined(CONFIG_CPU_USE_DOMAINS)
+#define DACR(x...) x
+#else
+#define DACR(x...)
+#endif
+
+ /*
+ * Save the address limit on entry to a privileged exception.
+ *
+ * If we are using the DACR for kernel access by the user accessors
+ * (CONFIG_CPU_USE_DOMAINS=y), always reset the DACR kernel domain
+ * back to client mode, whether or not \disable is set.
+ *
+ * If we are using SW PAN, set the DACR user domain to no access
+ * if \disable is set.
+ */
+ .macro uaccess_entry, tsk, tmp0, tmp1, tmp2, disable
+ ldr \tmp1, [\tsk, #TI_ADDR_LIMIT]
+ mov \tmp2, #TASK_SIZE
+ str \tmp2, [\tsk, #TI_ADDR_LIMIT]
+ DACR( mrc p15, 0, \tmp0, c3, c0, 0)
+ DACR( str \tmp0, [sp, #SVC_DACR])
+ str \tmp1, [sp, #SVC_ADDR_LIMIT]
+ .if \disable && IS_ENABLED(CONFIG_CPU_SW_DOMAIN_PAN)
+ /* kernel=client, user=no access */
+ mov \tmp2, #DACR_UACCESS_DISABLE
+ mcr p15, 0, \tmp2, c3, c0, 0
+ instr_sync
+ .elseif IS_ENABLED(CONFIG_CPU_USE_DOMAINS)
+ /* kernel=client */
+ bic \tmp2, \tmp0, #domain_mask(DOMAIN_KERNEL)
+ orr \tmp2, \tmp2, #domain_val(DOMAIN_KERNEL, DOMAIN_CLIENT)
+ mcr p15, 0, \tmp2, c3, c0, 0
+ instr_sync
+ .endif
+ .endm
+
+ /* Restore the user access state previously saved by uaccess_entry */
+ .macro uaccess_exit, tsk, tmp0, tmp1
+ ldr \tmp1, [sp, #SVC_ADDR_LIMIT]
+ DACR( ldr \tmp0, [sp, #SVC_DACR])
+ str \tmp1, [\tsk, #TI_ADDR_LIMIT]
+ DACR( mcr p15, 0, \tmp0, c3, c0, 0)
+ .endm
+
+#undef DACR
+
+#endif /* __ASM_UACCESS_ASM_H__ */