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Use the unprivileged variant of the load and store instructions most

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places possible in the kernel. This forces these functions to fail if
userspace is unable to access a given memory location, even if it is in
the user memory range.

This will simplify adding Privileged Access Never support later.

MFC after:	1 week
Sponsored by:	DARPA, AFRL
This commit is contained in:
Andrew Turner 2017-04-12 12:34:27 +00:00
parent 02676f0961
commit c577e950d8
2 changed files with 12 additions and 11 deletions
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3
sys/arm64/arm64/copyinout.S
View File

@ -103,7 +103,8 @@ ENTRY(copyinstr)
ldr x7, =VM_MAXUSER_ADDRESS
1: cmp x0, x7
b.cs copyio_fault
ldrb w4, [x0], #1 /* Load from uaddr */
ldtrb w4, [x0] /* Load from uaddr */
add x0, x0, #1 /* Next char */
strb w4, [x1], #1 /* Store in kaddr */
add x5, x5, #1 /* count++ */
cbz w4, 2f /* Break when NUL-terminated */

20
sys/arm64/arm64/support.S
View File

@ -97,7 +97,7 @@ ENTRY(fubyte)
b.cs fsu_fault_nopcb
adr x6, fsu_fault /* Load the fault handler */
SET_FAULT_HANDLER(x6, x1) /* And set it */
ldrb w0, [x0] /* Try loading the data */
ldtrb w0, [x0] /* Try loading the data */
SET_FAULT_HANDLER(xzr, x1) /* Reset the fault handler */
ret /* Return */
END(fubyte)
@ -111,7 +111,7 @@ ENTRY(fuword16)
b.cs fsu_fault_nopcb
adr x6, fsu_fault /* Load the fault handler */
SET_FAULT_HANDLER(x6, x1) /* And set it */
ldrh w0, [x0] /* Try loading the data */
ldtrh w0, [x0] /* Try loading the data */
SET_FAULT_HANDLER(xzr, x1) /* Reset the fault handler */
ret /* Return */
END(fuword16)
@ -125,7 +125,7 @@ ENTRY(fueword32)
b.cs fsu_fault_nopcb
adr x6, fsu_fault /* Load the fault handler */
SET_FAULT_HANDLER(x6, x2) /* And set it */
ldr w0, [x0] /* Try loading the data */
ldtr w0, [x0] /* Try loading the data */
SET_FAULT_HANDLER(xzr, x2) /* Reset the fault handler */
str w0, [x1] /* Save the data in kernel space */
mov w0, #0 /* Success */
@ -143,7 +143,7 @@ EENTRY(fueword64)
b.cs fsu_fault_nopcb
adr x6, fsu_fault /* Load the fault handler */
SET_FAULT_HANDLER(x6, x2) /* And set it */
ldr x0, [x0] /* Try loading the data */
ldtr x0, [x0] /* Try loading the data */
SET_FAULT_HANDLER(xzr, x2) /* Reset the fault handler */
str x0, [x1] /* Save the data in kernel space */
mov x0, #0 /* Success */
@ -160,7 +160,7 @@ ENTRY(subyte)
b.cs fsu_fault_nopcb
adr x6, fsu_fault /* Load the fault handler */
SET_FAULT_HANDLER(x6, x2) /* And set it */
strb w1, [x0] /* Try storing the data */
sttrb w1, [x0] /* Try storing the data */
SET_FAULT_HANDLER(xzr, x2) /* Reset the fault handler */
mov x0, #0 /* Success */
ret /* Return */
@ -175,7 +175,7 @@ ENTRY(suword16)
b.cs fsu_fault_nopcb
adr x6, fsu_fault /* Load the fault handler */
SET_FAULT_HANDLER(x6, x2) /* And set it */
strh w1, [x0] /* Try storing the data */
sttrh w1, [x0] /* Try storing the data */
SET_FAULT_HANDLER(xzr, x2) /* Reset the fault handler */
mov x0, #0 /* Success */
ret /* Return */
@ -190,7 +190,7 @@ ENTRY(suword32)
b.cs fsu_fault_nopcb
adr x6, fsu_fault /* Load the fault handler */
SET_FAULT_HANDLER(x6, x2) /* And set it */
str w1, [x0] /* Try storing the data */
sttr w1, [x0] /* Try storing the data */
SET_FAULT_HANDLER(xzr, x2) /* Reset the fault handler */
mov x0, #0 /* Success */
ret /* Return */
@ -206,7 +206,7 @@ EENTRY(suword64)
b.cs fsu_fault_nopcb
adr x6, fsu_fault /* Load the fault handler */
SET_FAULT_HANDLER(x6, x2) /* And set it */
str x1, [x0] /* Try storing the data */
sttr x1, [x0] /* Try storing the data */
SET_FAULT_HANDLER(xzr, x2) /* Reset the fault handler */
mov x0, #0 /* Success */
ret /* Return */
@ -237,7 +237,7 @@ ENTRY(fuswintr)
b.cs fsu_fault_nopcb
adr x6, fsu_intr_fault /* Load the fault handler */
SET_FAULT_HANDLER(x6, x1) /* And set it */
ldr w0, [x0] /* Try loading the data */
ldtr w0, [x0] /* Try loading the data */
SET_FAULT_HANDLER(xzr, x1) /* Reset the fault handler */
ret /* Return */
END(fuswintr)
@ -251,7 +251,7 @@ ENTRY(suswintr)
b.cs fsu_fault_nopcb
adr x6, fsu_intr_fault /* Load the fault handler */
SET_FAULT_HANDLER(x6, x2) /* And set it */
str w1, [x0] /* Try storing the data */
sttr w1, [x0] /* Try storing the data */
SET_FAULT_HANDLER(xzr, x2) /* Reset the fault handler */
mov x0, #0 /* Success */
ret /* Return */