diff options
| author | Khalid Aziz <khalid.aziz@oracle.com> | 2018-02-23 15:46:41 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-03-18 07:38:48 -0700 |
| commit | 74a04967482faa7144b93dae3b2e913870dd421c (patch) | |
| tree | 387f2497cfd053d99504a00ff8ccce0dd5fbd647 /arch/sparc/kernel/rtrap_64.S | |
| parent | a4602b62d9fdea41412ba765bbf32ecfc2b6a94c (diff) | |
sparc64: Add support for ADI (Application Data Integrity)
ADI is a new feature supported on SPARC M7 and newer processors to allow
hardware to catch rogue accesses to memory. ADI is supported for data
fetches only and not instruction fetches. An app can enable ADI on its
data pages, set version tags on them and use versioned addresses to
access the data pages. Upper bits of the address contain the version
tag. On M7 processors, upper four bits (bits 63-60) contain the version
tag. If a rogue app attempts to access ADI enabled data pages, its
access is blocked and processor generates an exception. Please see
Documentation/sparc/adi.txt for further details.
This patch extends mprotect to enable ADI (TSTATE.mcde), enable/disable
MCD (Memory Corruption Detection) on selected memory ranges, enable
TTE.mcd in PTEs, return ADI parameters to userspace and save/restore ADI
version tags on page swap out/in or migration. ADI is not enabled by
default for any task. A task must explicitly enable ADI on a memory
range and set version tag for ADI to be effective for the task.
Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/kernel/rtrap_64.S')
| -rw-r--r-- | arch/sparc/kernel/rtrap_64.S | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/arch/sparc/kernel/rtrap_64.S b/arch/sparc/kernel/rtrap_64.S index 0b21042ab181..f6528884a2c8 100644 --- a/arch/sparc/kernel/rtrap_64.S +++ b/arch/sparc/kernel/rtrap_64.S @@ -25,13 +25,31 @@ .align 32 __handle_preemption: call SCHEDULE_USER - wrpr %g0, RTRAP_PSTATE, %pstate +661: wrpr %g0, RTRAP_PSTATE, %pstate + /* If userspace is using ADI, it could potentially pass + * a pointer with version tag embedded in it. To maintain + * the ADI security, we must re-enable PSTATE.mcde before + * we continue execution in the kernel for another thread. + */ + .section .sun_m7_1insn_patch, "ax" + .word 661b + wrpr %g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate + .previous ba,pt %xcc, __handle_preemption_continue wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate __handle_user_windows: call fault_in_user_windows - wrpr %g0, RTRAP_PSTATE, %pstate +661: wrpr %g0, RTRAP_PSTATE, %pstate + /* If userspace is using ADI, it could potentially pass + * a pointer with version tag embedded in it. To maintain + * the ADI security, we must re-enable PSTATE.mcde before + * we continue execution in the kernel for another thread. + */ + .section .sun_m7_1insn_patch, "ax" + .word 661b + wrpr %g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate + .previous ba,pt %xcc, __handle_preemption_continue wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate @@ -48,7 +66,16 @@ __handle_signal: add %sp, PTREGS_OFF, %o0 mov %l0, %o2 call do_notify_resume - wrpr %g0, RTRAP_PSTATE, %pstate +661: wrpr %g0, RTRAP_PSTATE, %pstate + /* If userspace is using ADI, it could potentially pass + * a pointer with version tag embedded in it. To maintain + * the ADI security, we must re-enable PSTATE.mcde before + * we continue execution in the kernel for another thread. + */ + .section .sun_m7_1insn_patch, "ax" + .word 661b + wrpr %g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate + .previous wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate /* Signal delivery can modify pt_regs tstate, so we must |