diff options
Diffstat (limited to 'arch/sparc/kernel/etrap_64.S')
| -rw-r--r-- | arch/sparc/kernel/etrap_64.S | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/arch/sparc/kernel/etrap_64.S b/arch/sparc/kernel/etrap_64.S index 5c77a2e0e991..08cc41f64725 100644 --- a/arch/sparc/kernel/etrap_64.S +++ b/arch/sparc/kernel/etrap_64.S @@ -151,7 +151,32 @@ etrap_save: save %g2, -STACK_BIAS, %sp stx %g6, [%sp + PTREGS_OFF + PT_V9_G6] stx %g7, [%sp + PTREGS_OFF + PT_V9_G7] or %l7, %l0, %l7 - sethi %hi(TSTATE_TSO | TSTATE_PEF), %l0 +661: sethi %hi(TSTATE_TSO | TSTATE_PEF), %l0 + /* If userspace is using ADI, it could potentially pass + * a pointer with version tag embedded in it. To maintain + * the ADI security, we must enable PSTATE.mcde. Userspace + * would have already set TTE.mcd in an earlier call to + * kernel and set the version tag for the address being + * dereferenced. Setting PSTATE.mcde would ensure any + * access to userspace data through a system call honors + * ADI and does not allow a rogue app to bypass ADI by + * using system calls. Setting PSTATE.mcde only affects + * accesses to virtual addresses that have TTE.mcd set. + * Set PMCDPER to ensure any exceptions caused by ADI + * version tag mismatch are exposed before system call + * returns to userspace. Setting PMCDPER affects only + * writes to virtual addresses that have TTE.mcd set and + * have a version tag set as well. + */ + .section .sun_m7_1insn_patch, "ax" + .word 661b + sethi %hi(TSTATE_TSO | TSTATE_PEF | TSTATE_MCDE), %l0 + .previous +661: nop + .section .sun_m7_1insn_patch, "ax" + .word 661b + .word 0xaf902001 /* wrpr %g0, 1, %pmcdper */ + .previous or %l7, %l0, %l7 wrpr %l2, %tnpc wrpr %l7, (TSTATE_PRIV | TSTATE_IE), %tstate |