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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-09-11 19:18:28 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-09-11 19:18:28 +0100
commitc2172ce2303051764829d4958bd50a11ada0590f (patch)
treec465594496072249d2ad8ee4642f7c5dcd57e139 /arch/arm/kernel
parenta4a5a7379e4ca03c192b732d61e446994eb67bbc (diff)
parent0b61f2c0f37983c98ed4207f3f5e265938371b68 (diff)
downloadlinux-linaro-stable-c2172ce2303051764829d4958bd50a11ada0590f.tar.gz
Merge branch 'uaccess' into fixes
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/armksyms.c6
-rw-r--r--arch/arm/kernel/entry-armv.S32
-rw-r--r--arch/arm/kernel/entry-common.S2
-rw-r--r--arch/arm/kernel/entry-header.S112
-rw-r--r--arch/arm/kernel/head.S5
-rw-r--r--arch/arm/kernel/process.c51
-rw-r--r--arch/arm/kernel/swp_emulate.c3
-rw-r--r--arch/arm/kernel/traps.c1
8 files changed, 122 insertions, 90 deletions
diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index 5e5a51a99e68..f89811fb9a55 100644
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -97,9 +97,9 @@ EXPORT_SYMBOL(mmiocpy);
#ifdef CONFIG_MMU
EXPORT_SYMBOL(copy_page);
-EXPORT_SYMBOL(__copy_from_user);
-EXPORT_SYMBOL(__copy_to_user);
-EXPORT_SYMBOL(__clear_user);
+EXPORT_SYMBOL(arm_copy_from_user);
+EXPORT_SYMBOL(arm_copy_to_user);
+EXPORT_SYMBOL(arm_clear_user);
EXPORT_SYMBOL(__get_user_1);
EXPORT_SYMBOL(__get_user_2);
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index cb4fb1e69778..3e1c26eb32b4 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -149,10 +149,10 @@ ENDPROC(__und_invalid)
#define SPFIX(code...)
#endif
- .macro svc_entry, stack_hole=0, trace=1
+ .macro svc_entry, stack_hole=0, trace=1, uaccess=1
UNWIND(.fnstart )
UNWIND(.save {r0 - pc} )
- sub sp, sp, #(S_FRAME_SIZE + \stack_hole - 4)
+ sub sp, sp, #(S_FRAME_SIZE + 8 + \stack_hole - 4)
#ifdef CONFIG_THUMB2_KERNEL
SPFIX( str r0, [sp] ) @ temporarily saved
SPFIX( mov r0, sp )
@@ -167,7 +167,7 @@ ENDPROC(__und_invalid)
ldmia r0, {r3 - r5}
add r7, sp, #S_SP - 4 @ here for interlock avoidance
mov r6, #-1 @ "" "" "" ""
- add r2, sp, #(S_FRAME_SIZE + \stack_hole - 4)
+ add r2, sp, #(S_FRAME_SIZE + 8 + \stack_hole - 4)
SPFIX( addeq r2, r2, #4 )
str r3, [sp, #-4]! @ save the "real" r0 copied
@ from the exception stack
@@ -185,6 +185,11 @@ ENDPROC(__und_invalid)
@
stmia r7, {r2 - r6}
+ uaccess_save r0
+ .if \uaccess
+ uaccess_disable r0
+ .endif
+
.if \trace
#ifdef CONFIG_TRACE_IRQFLAGS
bl trace_hardirqs_off
@@ -194,7 +199,7 @@ ENDPROC(__und_invalid)
.align 5
__dabt_svc:
- svc_entry
+ svc_entry uaccess=0
mov r2, sp
dabt_helper
THUMB( ldr r5, [sp, #S_PSR] ) @ potentially updated CPSR
@@ -368,7 +373,7 @@ ENDPROC(__fiq_abt)
#error "sizeof(struct pt_regs) must be a multiple of 8"
#endif
- .macro usr_entry, trace=1
+ .macro usr_entry, trace=1, uaccess=1
UNWIND(.fnstart )
UNWIND(.cantunwind ) @ don't unwind the user space
sub sp, sp, #S_FRAME_SIZE
@@ -400,6 +405,10 @@ ENDPROC(__fiq_abt)
ARM( stmdb r0, {sp, lr}^ )
THUMB( store_user_sp_lr r0, r1, S_SP - S_PC )
+ .if \uaccess
+ uaccess_disable ip
+ .endif
+
@ Enable the alignment trap while in kernel mode
ATRAP( teq r8, r7)
ATRAP( mcrne p15, 0, r8, c1, c0, 0)
@@ -435,7 +444,7 @@ ENDPROC(__fiq_abt)
.align 5
__dabt_usr:
- usr_entry
+ usr_entry uaccess=0
kuser_cmpxchg_check
mov r2, sp
dabt_helper
@@ -458,7 +467,7 @@ ENDPROC(__irq_usr)
.align 5
__und_usr:
- usr_entry
+ usr_entry uaccess=0
mov r2, r4
mov r3, r5
@@ -484,6 +493,8 @@ __und_usr:
1: ldrt r0, [r4]
ARM_BE8(rev r0, r0) @ little endian instruction
+ uaccess_disable ip
+
@ r0 = 32-bit ARM instruction which caused the exception
@ r2 = PC value for the following instruction (:= regs->ARM_pc)
@ r4 = PC value for the faulting instruction
@@ -518,9 +529,10 @@ __und_usr_thumb:
2: ldrht r5, [r4]
ARM_BE8(rev16 r5, r5) @ little endian instruction
cmp r5, #0xe800 @ 32bit instruction if xx != 0
- blo __und_usr_fault_16 @ 16bit undefined instruction
+ blo __und_usr_fault_16_pan @ 16bit undefined instruction
3: ldrht r0, [r2]
ARM_BE8(rev16 r0, r0) @ little endian instruction
+ uaccess_disable ip
add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
str r2, [sp, #S_PC] @ it's a 2x16bit instr, update
orr r0, r0, r5, lsl #16
@@ -715,6 +727,8 @@ ENDPROC(no_fp)
__und_usr_fault_32:
mov r1, #4
b 1f
+__und_usr_fault_16_pan:
+ uaccess_disable ip
__und_usr_fault_16:
mov r1, #2
1: mov r0, sp
@@ -770,6 +784,8 @@ ENTRY(__switch_to)
ldr r4, [r2, #TI_TP_VALUE]
ldr r5, [r2, #TI_TP_VALUE + 4]
#ifdef CONFIG_CPU_USE_DOMAINS
+ mrc p15, 0, r6, c3, c0, 0 @ Get domain register
+ str r6, [r1, #TI_CPU_DOMAIN] @ Save old domain register
ldr r6, [r2, #TI_CPU_DOMAIN]
#endif
switch_tls r1, r4, r5, r3, r7
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index b48dd4f37f80..61974dfba132 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -174,6 +174,8 @@ ENTRY(vector_swi)
USER( ldr scno, [lr, #-4] ) @ get SWI instruction
#endif
+ uaccess_disable tbl
+
adr tbl, sys_call_table @ load syscall table pointer
#if defined(CONFIG_OABI_COMPAT)
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 1a0045abead7..0d22ad206d52 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -196,7 +196,7 @@
msr cpsr_c, \rtemp @ switch back to the SVC mode
.endm
-#ifndef CONFIG_THUMB2_KERNEL
+
.macro svc_exit, rpsr, irq = 0
.if \irq != 0
@ IRQs already off
@@ -215,6 +215,10 @@
blne trace_hardirqs_off
#endif
.endif
+ uaccess_restore
+
+#ifndef CONFIG_THUMB2_KERNEL
+ @ ARM mode SVC restore
msr spsr_cxsf, \rpsr
#if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_32v6K)
@ We must avoid clrex due to Cortex-A15 erratum #830321
@@ -222,6 +226,20 @@
strex r1, r2, [r0] @ clear the exclusive monitor
#endif
ldmia sp, {r0 - pc}^ @ load r0 - pc, cpsr
+#else
+ @ Thumb mode SVC restore
+ ldr lr, [sp, #S_SP] @ top of the stack
+ ldrd r0, r1, [sp, #S_LR] @ calling lr and pc
+
+ @ We must avoid clrex due to Cortex-A15 erratum #830321
+ strex r2, r1, [sp, #S_LR] @ clear the exclusive monitor
+
+ stmdb lr!, {r0, r1, \rpsr} @ calling lr and rfe context
+ ldmia sp, {r0 - r12}
+ mov sp, lr
+ ldr lr, [sp], #4
+ rfeia sp!
+#endif
.endm
@
@@ -241,6 +259,9 @@
@ on the stack remains correct).
@
.macro svc_exit_via_fiq
+ uaccess_restore
+#ifndef CONFIG_THUMB2_KERNEL
+ @ ARM mode restore
mov r0, sp
ldmib r0, {r1 - r14} @ abort is deadly from here onward (it will
@ clobber state restored below)
@@ -250,9 +271,27 @@
msr spsr_cxsf, r9
ldr r0, [r0, #S_R0]
ldmia r8, {pc}^
+#else
+ @ Thumb mode restore
+ add r0, sp, #S_R2
+ ldr lr, [sp, #S_LR]
+ ldr sp, [sp, #S_SP] @ abort is deadly from here onward (it will
+ @ clobber state restored below)
+ ldmia r0, {r2 - r12}
+ mov r1, #FIQ_MODE | PSR_I_BIT | PSR_F_BIT
+ msr cpsr_c, r1
+ sub r0, #S_R2
+ add r8, r0, #S_PC
+ ldmia r0, {r0 - r1}
+ rfeia r8
+#endif
.endm
+
.macro restore_user_regs, fast = 0, offset = 0
+ uaccess_enable r1, isb=0
+#ifndef CONFIG_THUMB2_KERNEL
+ @ ARM mode restore
mov r2, sp
ldr r1, [r2, #\offset + S_PSR] @ get calling cpsr
ldr lr, [r2, #\offset + S_PC]! @ get pc
@@ -270,72 +309,16 @@
@ after ldm {}^
add sp, sp, #\offset + S_FRAME_SIZE
movs pc, lr @ return & move spsr_svc into cpsr
- .endm
-
-#else /* CONFIG_THUMB2_KERNEL */
- .macro svc_exit, rpsr, irq = 0
- .if \irq != 0
- @ IRQs already off
-#ifdef CONFIG_TRACE_IRQFLAGS
- @ The parent context IRQs must have been enabled to get here in
- @ the first place, so there's no point checking the PSR I bit.
- bl trace_hardirqs_on
-#endif
- .else
- @ IRQs off again before pulling preserved data off the stack
- disable_irq_notrace
-#ifdef CONFIG_TRACE_IRQFLAGS
- tst \rpsr, #PSR_I_BIT
- bleq trace_hardirqs_on
- tst \rpsr, #PSR_I_BIT
- blne trace_hardirqs_off
-#endif
- .endif
- ldr lr, [sp, #S_SP] @ top of the stack
- ldrd r0, r1, [sp, #S_LR] @ calling lr and pc
-
- @ We must avoid clrex due to Cortex-A15 erratum #830321
- strex r2, r1, [sp, #S_LR] @ clear the exclusive monitor
-
- stmdb lr!, {r0, r1, \rpsr} @ calling lr and rfe context
- ldmia sp, {r0 - r12}
- mov sp, lr
- ldr lr, [sp], #4
- rfeia sp!
- .endm
-
- @
- @ svc_exit_via_fiq - like svc_exit but switches to FIQ mode before exit
- @
- @ For full details see non-Thumb implementation above.
- @
- .macro svc_exit_via_fiq
- add r0, sp, #S_R2
- ldr lr, [sp, #S_LR]
- ldr sp, [sp, #S_SP] @ abort is deadly from here onward (it will
- @ clobber state restored below)
- ldmia r0, {r2 - r12}
- mov r1, #FIQ_MODE | PSR_I_BIT | PSR_F_BIT
- msr cpsr_c, r1
- sub r0, #S_R2
- add r8, r0, #S_PC
- ldmia r0, {r0 - r1}
- rfeia r8
- .endm
-
-#ifdef CONFIG_CPU_V7M
- /*
- * Note we don't need to do clrex here as clearing the local monitor is
- * part of each exception entry and exit sequence.
- */
- .macro restore_user_regs, fast = 0, offset = 0
+#elif defined(CONFIG_CPU_V7M)
+ @ V7M restore.
+ @ Note that we don't need to do clrex here as clearing the local
+ @ monitor is part of the exception entry and exit sequence.
.if \offset
add sp, #\offset
.endif
v7m_exception_slow_exit ret_r0 = \fast
- .endm
-#else /* ifdef CONFIG_CPU_V7M */
- .macro restore_user_regs, fast = 0, offset = 0
+#else
+ @ Thumb mode restore
mov r2, sp
load_user_sp_lr r2, r3, \offset + S_SP @ calling sp, lr
ldr r1, [sp, #\offset + S_PSR] @ get calling cpsr
@@ -353,9 +336,8 @@
.endif
add sp, sp, #S_FRAME_SIZE - S_SP
movs pc, lr @ return & move spsr_svc into cpsr
- .endm
-#endif /* ifdef CONFIG_CPU_V7M / else */
#endif /* !CONFIG_THUMB2_KERNEL */
+ .endm
/*
* Context tracking subsystem. Used to instrument transitions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 29e2991465cb..04286fd9e09c 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -464,10 +464,7 @@ __enable_mmu:
#ifdef CONFIG_ARM_LPAE
mcrr p15, 0, r4, r5, c2 @ load TTBR0
#else
- mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
- domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
- domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \
- domain_val(DOMAIN_IO, DOMAIN_CLIENT))
+ mov r5, #DACR_INIT
mcr p15, 0, r5, c3, c0, 0 @ load domain access register
mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
#endif
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index f192a2a41719..e550a4541f48 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -129,12 +129,36 @@ void __show_regs(struct pt_regs *regs)
buf[4] = '\0';
#ifndef CONFIG_CPU_V7M
- printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
- buf, interrupts_enabled(regs) ? "n" : "ff",
- fast_interrupts_enabled(regs) ? "n" : "ff",
- processor_modes[processor_mode(regs)],
- isa_modes[isa_mode(regs)],
- get_fs() == get_ds() ? "kernel" : "user");
+ {
+ unsigned int domain = get_domain();
+ const char *segment;
+
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+ /*
+ * Get the domain register for the parent context. In user
+ * mode, we don't save the DACR, so lets use what it should
+ * be. For other modes, we place it after the pt_regs struct.
+ */
+ if (user_mode(regs))
+ domain = DACR_UACCESS_ENABLE;
+ else
+ domain = *(unsigned int *)(regs + 1);
+#endif
+
+ if ((domain & domain_mask(DOMAIN_USER)) ==
+ domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
+ segment = "none";
+ else if (get_fs() == get_ds())
+ segment = "kernel";
+ else
+ segment = "user";
+
+ printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
+ buf, interrupts_enabled(regs) ? "n" : "ff",
+ fast_interrupts_enabled(regs) ? "n" : "ff",
+ processor_modes[processor_mode(regs)],
+ isa_modes[isa_mode(regs)], segment);
+ }
#else
printk("xPSR: %08lx\n", regs->ARM_cpsr);
#endif
@@ -146,10 +170,9 @@ void __show_regs(struct pt_regs *regs)
buf[0] = '\0';
#ifdef CONFIG_CPU_CP15_MMU
{
- unsigned int transbase, dac;
+ unsigned int transbase, dac = get_domain();
asm("mrc p15, 0, %0, c2, c0\n\t"
- "mrc p15, 0, %1, c3, c0\n"
- : "=r" (transbase), "=r" (dac));
+ : "=r" (transbase));
snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
transbase, dac);
}
@@ -210,6 +233,16 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
+#ifdef CONFIG_CPU_USE_DOMAINS
+ /*
+ * Copy the initial value of the domain access control register
+ * from the current thread: thread->addr_limit will have been
+ * copied from the current thread via setup_thread_stack() in
+ * kernel/fork.c
+ */
+ thread->cpu_domain = get_domain();
+#endif
+
if (likely(!(p->flags & PF_KTHREAD))) {
*childregs = *current_pt_regs();
childregs->ARM_r0 = 0;
diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
index 1361756782c7..5b26e7efa9ea 100644
--- a/arch/arm/kernel/swp_emulate.c
+++ b/arch/arm/kernel/swp_emulate.c
@@ -141,11 +141,14 @@ static int emulate_swpX(unsigned int address, unsigned int *data,
while (1) {
unsigned long temp;
+ unsigned int __ua_flags;
+ __ua_flags = uaccess_save_and_enable();
if (type == TYPE_SWPB)
__user_swpb_asm(*data, address, res, temp);
else
__user_swp_asm(*data, address, res, temp);
+ uaccess_restore(__ua_flags);
if (likely(res != -EAGAIN) || signal_pending(current))
break;
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index d358226236f2..969f9d9e665f 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -870,7 +870,6 @@ void __init early_trap_init(void *vectors_base)
kuser_init(vectors_base);
flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
- modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
#else /* ifndef CONFIG_CPU_V7M */
/*
* on V7-M there is no need to copy the vector table to a dedicated