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| author |   Christophe Leroy <christophe.leroy@c-s.fr> | 2019-03-11 08:30:35 +0000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2019-04-21 23:11:46 +1000 |
| commit | 31ed2b13c48d779efc838ad54e30121e088a62af (patch) | |
| tree | 80890f996c246cd567e2822230b68340919adebf /arch/powerpc/kernel/entry_32.S | |
| parent | powerpc/8xx: Add Kernel Userspace Access Protection (diff) | |
| download | linux-dev-31ed2b13c48d779efc838ad54e30121e088a62af.tar.xz linux-dev-31ed2b13c48d779efc838ad54e30121e088a62af.zip | |
powerpc/32s: Implement Kernel Userspace Execution Prevention.
To implement Kernel Userspace Execution Prevention, this patch
sets NX bit on all user segments on kernel entry and clears NX bit
on all user segments on kernel exit.
Note that powerpc 601 doesn't have the NX bit, so KUEP will not
work on it. A warning is displayed at startup.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 9 |
1 files changed, 9 insertions, 0 deletions
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 |