diff options
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/kup.h | 42 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/mmu-hash.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/kup.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 9 | ||||
| -rw-r--r-- | arch/powerpc/kernel/head_32.S | 15 | ||||
| -rw-r--r-- | arch/powerpc/mm/ppc_mmu_32.c | 13 | ||||
| -rw-r--r-- | arch/powerpc/platforms/Kconfig.cputype | 1 |
7 files changed, 85 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h new file mode 100644 index 000000000000..5f97c742ca71 --- /dev/null +++ b/arch/powerpc/include/asm/book3s/32/kup.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_POWERPC_BOOK3S_32_KUP_H +#define _ASM_POWERPC_BOOK3S_32_KUP_H + +#include <asm/book3s/32/mmu-hash.h> + +#ifdef __ASSEMBLY__ + +.macro kuep_update_sr gpr1, gpr2 /* NEVER use r0 as gpr2 due to addis */ +101: mtsrin \gpr1, \gpr2 + addi \gpr1, \gpr1, 0x111 /* next VSID */ + rlwinm \gpr1, \gpr1, 0, 0xf0ffffff /* clear VSID overflow */ + addis \gpr2, \gpr2, 0x1000 /* address of next segment */ + bdnz 101b + isync +.endm + +.macro kuep_lock gpr1, gpr2 +#ifdef CONFIG_PPC_KUEP + li \gpr1, NUM_USER_SEGMENTS + li \gpr2, 0 + mtctr \gpr1 + mfsrin \gpr1, \gpr2 + oris \gpr1, \gpr1, SR_NX@h /* set Nx */ + kuep_update_sr \gpr1, \gpr2 +#endif +.endm + +.macro kuep_unlock gpr1, gpr2 +#ifdef CONFIG_PPC_KUEP + li \gpr1, NUM_USER_SEGMENTS + li \gpr2, 0 + mtctr \gpr1 + mfsrin \gpr1, \gpr2 + rlwinm \gpr1, \gpr1, 0, ~SR_NX /* Clear Nx */ + kuep_update_sr \gpr1, \gpr2 +#endif +.endm + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_POWERPC_BOOK3S_32_KUP_H */ diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h index 5cb588395fdc..8c5727a322b1 100644 --- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h +++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h @@ -63,6 +63,9 @@ typedef pte_t *pgtable_t; #define PP_RWRW 2 /* Supervisor read/write, User read/write */ #define PP_RXRX 3 /* Supervisor read, User read */ +/* Values for Segment Registers */ +#define SR_NX 0x10000000 /* No Execute */ + #ifndef __ASSEMBLY__ /* diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h index 043c800ec5fb..5b5e39643a27 100644 --- a/arch/powerpc/include/asm/kup.h +++ b/arch/powerpc/include/asm/kup.h @@ -8,6 +8,9 @@ #ifdef CONFIG_PPC_8xx #include <asm/nohash/32/kup-8xx.h> #endif +#ifdef CONFIG_PPC_BOOK3S_32 +#include <asm/book3s/32/kup.h> +#endif #ifdef __ASSEMBLY__ #ifndef CONFIG_PPC_KUAP diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 1182bf603d3c..2f3d159c11d7 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -162,6 +162,9 @@ transfer_to_handler: andis. r12,r12,DBCR0_IDM@h #endif ACCOUNT_CPU_USER_ENTRY(r2, r11, r12) +#ifdef CONFIG_PPC_BOOK3S_32 + kuep_lock r11, r12 +#endif #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) beq+ 3f /* From user and task is ptraced - load up global dbcr0 */ @@ -427,6 +430,9 @@ BEGIN_FTR_SECTION END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) stwcx. r0,0,r1 /* to clear the reservation */ ACCOUNT_CPU_USER_EXIT(r2, r5, r7) +#ifdef CONFIG_PPC_BOOK3S_32 + kuep_unlock r5, r7 +#endif kuap_check r2, r4 lwz r4,_LINK(r1) lwz r5,_CCR(r1) @@ -821,6 +827,9 @@ restore_user: bnel- load_dbcr0 #endif ACCOUNT_CPU_USER_EXIT(r2, r10, r11) +#ifdef CONFIG_PPC_BOOK3S_32 + kuep_unlock r10, r11 +#endif b restore diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index e25b615e9f9e..19b46cb9f623 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -896,14 +896,24 @@ load_up_mmu: tophys(r6,r6) lwz r6,_SDR1@l(r6) mtspr SPRN_SDR1,r6 - li r0,16 /* load up segment register values */ + li r0, NUM_USER_SEGMENTS /* load up segment register values */ mtctr r0 /* for context 0 */ lis r3,0x2000 /* Ku = 1, VSID = 0 */ +#ifdef CONFIG_PPC_KUEP + oris r3, r3, SR_NX@h /* Set Nx */ +#endif li r4,0 3: mtsrin r3,r4 addi r3,r3,0x111 /* increment VSID */ addis r4,r4,0x1000 /* address of next segment */ bdnz 3b + li r0, 16 - NUM_USER_SEGMENTS /* load up kernel segment registers */ + mtctr r0 /* for context 0 */ + rlwinm r3, r3, 0, ~SR_NX /* Nx = 0 */ +3: mtsrin r3, r4 + addi r3, r3, 0x111 /* increment VSID */ + addis r4, r4, 0x1000 /* address of next segment */ + bdnz 3b /* Load the BAT registers with the values set up by MMU_init. MMU_init takes care of whether we're on a 601 or not. */ @@ -1007,6 +1017,9 @@ _ENTRY(switch_mmu_context) mulli r3,r3,897 /* multiply context by skew factor */ rlwinm r3,r3,4,8,27 /* VSID = (context & 0xfffff) << 4 */ addis r3,r3,0x6000 /* Set Ks, Ku bits */ +#ifdef CONFIG_PPC_KUEP + oris r3, r3, SR_NX@h /* Set Nx */ +#endif li r0,NUM_USER_SEGMENTS mtctr r0 diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c index f29d2f118b44..baa75673b1f5 100644 --- a/arch/powerpc/mm/ppc_mmu_32.c +++ b/arch/powerpc/mm/ppc_mmu_32.c @@ -394,3 +394,16 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base, else /* Anything else has 256M mapped */ memblock_set_current_limit(min_t(u64, first_memblock_size, 0x10000000)); } + +#ifdef CONFIG_PPC_KUEP +void __init setup_kuep(bool disabled) +{ + pr_info("Activating Kernel Userspace Execution Prevention\n"); + + if (cpu_has_feature(CPU_FTR_601)) + pr_warn("KUEP is not working on powerpc 601 (No NX bit in Seg Regs)\n"); + + if (disabled) + pr_warn("KUEP cannot be disabled yet on 6xx when compiled in\n"); +} +#endif diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index ab586963893a..6bc0a4c08c1c 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -25,6 +25,7 @@ config PPC_BOOK3S_32 bool "512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx" select PPC_FPU select PPC_HAVE_PMU_SUPPORT + select PPC_HAVE_KUEP config PPC_85xx bool "Freescale 85xx" |