Re: Linux 4.10-rc1

Al Viro
2016-12-26T09:18:59Z

On Mon, Dec 26, 2016 at 05:05:37PM +0800, Kefeng Wang wrote:
> It looks like we need revert the changes from assembly files.

Better yet, split the damn thing in two and include the asm-only part.

> diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
> diff --git a/arch/arm64/xen/hypercall.S b/arch/arm64/xen/hypercall.S

Missed those two... OK, how about this?

arm64: don't pull uaccess.h into *.S

Split asm-only parts of arm64 uaccess.h into a new header and use that
from *.S.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h
new file mode 100644
index 000000000000..df411f3e083c
--- /dev/null
+++ b/arch/arm64/include/asm/asm-uaccess.h
@@ -0,0 +1,65 @@
+#ifndef __ASM_ASM_UACCESS_H
+#define __ASM_ASM_UACCESS_H
+
+#include <asm/alternative.h>
+#include <asm/kernel-pgtable.h>
+#include <asm/sysreg.h>
+#include <asm/assembler.h>
+
+/*
+ * User access enabling/disabling macros.
+ */
+#ifdef CONFIG_ARM64_SW_TTBR0_PAN
+ .macro __uaccess_ttbr0_disable, tmp1
+ mrs \tmp1, ttbr1_el1 // swapper_pg_dir
+ add \tmp1, \tmp1, #SWAPPER_DIR_SIZE // reserved_ttbr0 at the end of swapper_pg_dir
+ msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1
+ isb
+ .endm
+
+ .macro __uaccess_ttbr0_enable, tmp1
+ get_thread_info \tmp1
+ ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1
+ msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1
+ isb
+ .endm
+
+ .macro uaccess_ttbr0_disable, tmp1
+alternative_if_not ARM64_HAS_PAN
+ __uaccess_ttbr0_disable \tmp1
+alternative_else_nop_endif
+ .endm
+
+ .macro uaccess_ttbr0_enable, tmp1, tmp2
+alternative_if_not ARM64_HAS_PAN
+ save_and_disable_irq \tmp2 // avoid preemption
+ __uaccess_ttbr0_enable \tmp1
+ restore_irq \tmp2
+alternative_else_nop_endif
+ .endm
+#else
+ .macro uaccess_ttbr0_disable, tmp1
+ .endm
+
+ .macro uaccess_ttbr0_enable, tmp1, tmp2
+ .endm
+#endif
+
+/*
+ * These macros are no-ops when UAO is present.
+ */
+ .macro uaccess_disable_not_uao, tmp1
+ uaccess_ttbr0_disable \tmp1
+alternative_if ARM64_ALT_PAN_NOT_UAO
+ SET_PSTATE_PAN(1)
+alternative_else_nop_endif
+ .endm
+
+ .macro uaccess_enable_not_uao, tmp1, tmp2
+ uaccess_ttbr0_enable \tmp1, \tmp2
+alternative_if ARM64_ALT_PAN_NOT_UAO
+ SET_PSTATE_PAN(0)
+alternative_else_nop_endif
+ .endm
+
+#endif
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index d26750ca6e06..46da3ea638bb 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -22,8 +22,6 @@
#include <asm/kernel-pgtable.h>
#include <asm/sysreg.h>

-#ifndef __ASSEMBLY__
-
/*
* User space memory access functions
*/
@@ -424,66 +422,4 @@ extern long strncpy_from_user(char *dest, const char __user *src, long count);
extern __must_check long strlen_user(const char __user *str);
extern __must_check long strnlen_user(const char __user *str, long n);

-#else /* __ASSEMBLY__ */
-
-#include <asm/assembler.h>
-
-/*
- * User access enabling/disabling macros.
- */
-#ifdef CONFIG_ARM64_SW_TTBR0_PAN
- .macro __uaccess_ttbr0_disable, tmp1
- mrs \tmp1, ttbr1_el1 // swapper_pg_dir
- add \tmp1, \tmp1, #SWAPPER_DIR_SIZE // reserved_ttbr0 at the end of swapper_pg_dir
- msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1
- isb
- .endm
-
- .macro __uaccess_ttbr0_enable, tmp1
- get_thread_info \tmp1
- ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1
- msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1
- isb
- .endm
-
- .macro uaccess_ttbr0_disable, tmp1
-alternative_if_not ARM64_HAS_PAN
- __uaccess_ttbr0_disable \tmp1
-alternative_else_nop_endif
- .endm
-
- .macro uaccess_ttbr0_enable, tmp1, tmp2
-alternative_if_not ARM64_HAS_PAN
- save_and_disable_irq \tmp2 // avoid preemption
- __uaccess_ttbr0_enable \tmp1
- restore_irq \tmp2
-alternative_else_nop_endif
- .endm
-#else
- .macro uaccess_ttbr0_disable, tmp1
- .endm
-
- .macro uaccess_ttbr0_enable, tmp1, tmp2
- .endm
-#endif
-
-/*
- * These macros are no-ops when UAO is present.
- */
- .macro uaccess_disable_not_uao, tmp1
- uaccess_ttbr0_disable \tmp1
-alternative_if ARM64_ALT_PAN_NOT_UAO
- SET_PSTATE_PAN(1)
-alternative_else_nop_endif
- .endm
-
- .macro uaccess_enable_not_uao, tmp1, tmp2
- uaccess_ttbr0_enable \tmp1, \tmp2
-alternative_if ARM64_ALT_PAN_NOT_UAO
- SET_PSTATE_PAN(0)
-alternative_else_nop_endif
- .endm
-
-#endif /* __ASSEMBLY__ */
-
#endif /* __ASM_UACCESS_H */
diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
index add4a1334085..e88fb99c1561 100644
--- a/arch/arm64/lib/clear_user.S
+++ b/arch/arm64/lib/clear_user.S
@@ -17,7 +17,7 @@
*/
#include <linux/linkage.h>

-#include <linux/uaccess.h>
+#include <asm/asm-uaccess.h>

.text

diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index fd6cd05593f9..4b5d826895ff 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -17,7 +17,7 @@
#include <linux/linkage.h>

#include <asm/cache.h>
-#include <linux/uaccess.h>
+#include <asm/asm-uaccess.h>

/*
* Copy from user space to a kernel buffer (alignment handled by the hardware)
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
index d828540ded6f..47184c3a97da 100644
--- a/arch/arm64/lib/copy_in_user.S
+++ b/arch/arm64/lib/copy_in_user.S
@@ -19,7 +19,7 @@
#include <linux/linkage.h>

#include <asm/cache.h>
-#include <linux/uaccess.h>
+#include <asm/asm-uaccess.h>

/*
* Copy from user space to user space (alignment handled by the hardware)
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 3e6ae2663b82..351f0766f7a6 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -17,7 +17,7 @@
#include <linux/linkage.h>

#include <asm/cache.h>
-#include <linux/uaccess.h>
+#include <asm/asm-uaccess.h>

/*
* Copy to user space from a kernel buffer (alignment handled by the hardware)
diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
index 17f422a4dc55..83c27b6e6dca 100644
--- a/arch/arm64/mm/cache.S
+++ b/arch/arm64/mm/cache.S
@@ -23,7 +23,7 @@
#include <asm/assembler.h>
#include <asm/cpufeature.h>
#include <asm/alternative.h>
-#include <linux/uaccess.h>
+#include <asm/asm-uaccess.h>

/*
* flush_icache_range(start,end)
diff --git a/arch/arm64/xen/hypercall.S b/arch/arm64/xen/hypercall.S
index 47cf3f9d89ff..947830a459d2 100644
--- a/arch/arm64/xen/hypercall.S
+++ b/arch/arm64/xen/hypercall.S
@@ -49,7 +49,7 @@

#include <linux/linkage.h>
#include <asm/assembler.h>
-#include <linux/uaccess.h>
+#include <asm/asm-uaccess.h>
#include <xen/interface/xen.h>