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authorMaarten Lankhorst <maarten.lankhorst@linux.intel.com>2024-05-28 22:21:34 +0200
committerMaarten Lankhorst <maarten.lankhorst@linux.intel.com>2024-05-28 22:21:34 +0200
commitf73a058be5d70dd81a43f16b2bbff4b1576a7af8 (patch)
treeb7959c01cf7a5d95c7c4d5b61929ff9123370322 /arch/arm/include/asm/uaccess-asm.h
parentdma-buf: handle testing kthreads creation failure (diff)
parentMerge tag 'drm-misc-fixes-2024-05-23' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes (diff)
downloadwireguard-linux-f73a058be5d70dd81a43f16b2bbff4b1576a7af8.tar.xz
wireguard-linux-f73a058be5d70dd81a43f16b2bbff4b1576a7af8.zip
Merge remote-tracking branch 'drm/drm-fixes' into drm-misc-fixes
v6.10-rc1 is released, forward from v6.9 Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Diffstat (limited to 'arch/arm/include/asm/uaccess-asm.h')
-rw-r--r--arch/arm/include/asm/uaccess-asm.h58
1 files changed, 54 insertions, 4 deletions
diff --git a/arch/arm/include/asm/uaccess-asm.h b/arch/arm/include/asm/uaccess-asm.h
index 65da32e1f1c1..4bccd895d954 100644
--- a/arch/arm/include/asm/uaccess-asm.h
+++ b/arch/arm/include/asm/uaccess-asm.h
@@ -39,8 +39,9 @@
#endif
.endm
+#if defined(CONFIG_CPU_SW_DOMAIN_PAN)
+
.macro uaccess_disable, tmp, isb=1
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
/*
* Whenever we re-enter userspace, the domains should always be
* set appropriately.
@@ -50,11 +51,9 @@
.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.
@@ -64,15 +63,61 @@
.if \isb
instr_sync
.endif
-#endif
.endm
+#elif defined(CONFIG_CPU_TTBR0_PAN)
+
+ .macro uaccess_disable, tmp, isb=1
+ /*
+ * Disable TTBR0 page table walks (EDP0 = 1), use the reserved ASID
+ * from TTBR1 (A1 = 1) and enable TTBR1 page table walks for kernel
+ * addresses by reducing TTBR0 range to 32MB (T0SZ = 7).
+ */
+ mrc p15, 0, \tmp, c2, c0, 2 @ read TTBCR
+ orr \tmp, \tmp, #TTBCR_EPD0 | TTBCR_T0SZ_MASK
+ orr \tmp, \tmp, #TTBCR_A1
+ mcr p15, 0, \tmp, c2, c0, 2 @ write TTBCR
+ .if \isb
+ instr_sync
+ .endif
+ .endm
+
+ .macro uaccess_enable, tmp, isb=1
+ /*
+ * Enable TTBR0 page table walks (T0SZ = 0, EDP0 = 0) and ASID from
+ * TTBR0 (A1 = 0).
+ */
+ mrc p15, 0, \tmp, c2, c0, 2 @ read TTBCR
+ bic \tmp, \tmp, #TTBCR_EPD0 | TTBCR_T0SZ_MASK
+ bic \tmp, \tmp, #TTBCR_A1
+ mcr p15, 0, \tmp, c2, c0, 2 @ write TTBCR
+ .if \isb
+ instr_sync
+ .endif
+ .endm
+
+#else
+
+ .macro uaccess_disable, tmp, isb=1
+ .endm
+
+ .macro uaccess_enable, tmp, isb=1
+ .endm
+
+#endif
+
#if defined(CONFIG_CPU_SW_DOMAIN_PAN) || defined(CONFIG_CPU_USE_DOMAINS)
#define DACR(x...) x
#else
#define DACR(x...)
#endif
+#ifdef CONFIG_CPU_TTBR0_PAN
+#define PAN(x...) x
+#else
+#define PAN(x...)
+#endif
+
/*
* Save the address limit on entry to a privileged exception.
*
@@ -86,6 +131,8 @@
.macro uaccess_entry, tsk, tmp0, tmp1, tmp2, disable
DACR( mrc p15, 0, \tmp0, c3, c0, 0)
DACR( str \tmp0, [sp, #SVC_DACR])
+ PAN( mrc p15, 0, \tmp0, c2, c0, 2)
+ PAN( str \tmp0, [sp, #SVC_TTBCR])
.if \disable && IS_ENABLED(CONFIG_CPU_SW_DOMAIN_PAN)
/* kernel=client, user=no access */
mov \tmp2, #DACR_UACCESS_DISABLE
@@ -104,8 +151,11 @@
.macro uaccess_exit, tsk, tmp0, tmp1
DACR( ldr \tmp0, [sp, #SVC_DACR])
DACR( mcr p15, 0, \tmp0, c3, c0, 0)
+ PAN( ldr \tmp0, [sp, #SVC_TTBCR])
+ PAN( mcr p15, 0, \tmp0, c2, c0, 2)
.endm
#undef DACR
+#undef PAN
#endif /* __ASM_UACCESS_ASM_H__ */