6 files changed, 42 insertions, 6 deletions

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 12b8c8f8ec07..17685e19aed8 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -1776,9 +1776,9 @@ config DEBUG_UART_8250_FLOW_CONTROL
         default y if ARCH_EBSA110 || DEBUG_FOOTBRIDGE_COM1 || DEBUG_GEMINI || ARCH_RPC
 
 config DEBUG_UNCOMPRESS
-        bool
+        bool "Enable decompressor debugging via DEBUG_LL output"
         depends on ARCH_MULTIPLATFORM || PLAT_SAMSUNG || ARM_SINGLE_ARMV7M
-        default y if DEBUG_LL && !DEBUG_OMAP2PLUS_UART && \
+        depends on DEBUG_LL && !DEBUG_OMAP2PLUS_UART && \
                      (!DEBUG_TEGRA_UART || !ZBOOT_ROM) && \
                      !DEBUG_BRCMSTB_UART
         help
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index ad301f107dd2..bc8d4bbd82e2 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -518,4 +518,22 @@ THUMB(	orr	\reg , \reg , #PSR_T_BIT	)
 #endif
         .endm
 
+        .macro  bug, msg, line
+#ifdef CONFIG_THUMB2_KERNEL
+1:      .inst   0xde02
+#else
+1:      .inst   0xe7f001f2
+#endif
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+        .pushsection .rodata.str, "aMS", %progbits, 1
+2:      .asciz  "\msg"
+        .popsection
+        .pushsection __bug_table, "aw"
+        .align  2
+        .word   1b, 2b
+        .hword  \line
+        .popsection
+#endif
+        .endm
+
 #endif /* __ASM_ASSEMBLER_H__ */
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 1c462381c225..150ece66ddf3 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -232,6 +232,18 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd)
 #define pte_valid_user(pte)     \
         (pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte))
 
+static inline bool pte_access_permitted(pte_t pte, bool write)
+{
+        pteval_t mask = L_PTE_PRESENT | L_PTE_USER;
+        pteval_t needed = mask;
+
+        if (write)
+                mask |= L_PTE_RDONLY;
+
+        return (pte_val(pte) & mask) == needed;
+}
+#define pte_access_permitted pte_access_permitted
+
 #if __LINUX_ARM_ARCH__ < 6
 static inline void __sync_icache_dcache(pte_t pteval)
 {
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index d523cd8439a3..7f4d80c2db6b 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -300,6 +300,8 @@
         mov     r2, sp
         ldr     r1, [r2, #\offset + S_PSR]      @ get calling cpsr
         ldr     lr, [r2, #\offset + S_PC]!      @ get pc
+        tst     r1, #0xcf
+        bne     1f
         msr     spsr_cxsf, r1                   @ save in spsr_svc
 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_32v6K)
         @ We must avoid clrex due to Cortex-A15 erratum #830321
@@ -314,6 +316,7 @@
                                                 @ after ldm {}^
         add     sp, sp, #\offset + PT_REGS_SIZE
         movs    pc, lr                          @ return & move spsr_svc into cpsr
+1:      bug     "Returning to usermode but unexpected PSR bits set?", \@
 #elif defined(CONFIG_CPU_V7M)
         @ V7M restore.
         @ Note that we don't need to do clrex here as clearing the local
@@ -329,6 +332,8 @@
         ldr     r1, [sp, #\offset + S_PSR]      @ get calling cpsr
         ldr     lr, [sp, #\offset + S_PC]       @ get pc
         add     sp, sp, #\offset + S_SP
+        tst     r1, #0xcf
+        bne     1f
         msr     spsr_cxsf, r1                   @ save in spsr_svc
 
         @ We must avoid clrex due to Cortex-A15 erratum #830321
@@ -341,6 +346,7 @@
         .endif
         add     sp, sp, #PT_REGS_SIZE - S_SP
         movs    pc, lr                          @ return & move spsr_svc into cpsr
+1:      bug     "Returning to usermode but unexpected PSR bits set?", \@
 #endif  /* !CONFIG_THUMB2_KERNEL */
         .endm
 
diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c
index 35ff45470dbf..fc3b44028cfb 100644
--- a/arch/arm/mm/dump.c
+++ b/arch/arm/mm/dump.c
@@ -129,8 +129,8 @@ static const struct prot_bits section_bits[] = {
                 .val    = PMD_SECT_USER,
                 .set    = "USR",
         }, {
-                .mask   = L_PMD_SECT_RDONLY,
-                .val    = L_PMD_SECT_RDONLY,
+                .mask   = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
+                .val    = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
                 .set    = "ro",
                 .clear  = "RW",
 #elif __LINUX_ARM_ARCH__ >= 6
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 81d4482b6861..a1f11a7ee81b 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -629,8 +629,8 @@ static struct section_perm ro_perms[] = {
                 .start  = (unsigned long)_stext,
                 .end    = (unsigned long)__init_begin,
 #ifdef CONFIG_ARM_LPAE
-                .mask   = ~L_PMD_SECT_RDONLY,
-                .prot   = L_PMD_SECT_RDONLY,
+                .mask   = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2),
+                .prot   = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
 #else
                 .mask   = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
                 .prot   = PMD_SECT_APX | PMD_SECT_AP_WRITE,