diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-11 15:41:07 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-11 15:41:07 -0800 |
| commit | dcc0b49040c70ad827a7f3d58a21b01fdb14e749 (patch) | |
| tree | 4f8024e086e9f7bfeb8eeab052481a51593b90ac /arch | |
| parent | c05263df6c1ab82277cc3b2778b183b469a71a60 (diff) | |
| parent | 8c511eff1827239f24ded212b1bcda7ca5b16203 (diff) | |
Merge tag 'powerpc-5.11-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fix from Michael Ellerman:
"One fix for a regression seen in io_uring, introduced by our support
for KUAP (Kernel User Access Prevention) with the Hash MMU.
Thanks to Aneesh Kumar K.V, and Zorro Lang"
* tag 'powerpc-5.11-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/kuap: Allow kernel thread to access userspace after kthread_use_mm
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/kup.h | 16 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pkeys.h | 4 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s64/pkeys.c | 1 |
3 files changed, 12 insertions, 9 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h index f50f72e535aa..7d1ef7b9754e 100644 --- a/arch/powerpc/include/asm/book3s/64/kup.h +++ b/arch/powerpc/include/asm/book3s/64/kup.h @@ -199,25 +199,31 @@ DECLARE_STATIC_KEY_FALSE(uaccess_flush_key); #ifdef CONFIG_PPC_PKEY +extern u64 __ro_after_init default_uamor; +extern u64 __ro_after_init default_amr; +extern u64 __ro_after_init default_iamr; + #include <asm/mmu.h> #include <asm/ptrace.h> -/* - * For kernel thread that doesn't have thread.regs return - * default AMR/IAMR values. +/* usage of kthread_use_mm() should inherit the + * AMR value of the operating address space. But, the AMR value is + * thread-specific and we inherit the address space and not thread + * access restrictions. Because of this ignore AMR value when accessing + * userspace via kernel thread. */ static inline u64 current_thread_amr(void) { if (current->thread.regs) return current->thread.regs->amr; - return AMR_KUAP_BLOCKED; + return default_amr; } static inline u64 current_thread_iamr(void) { if (current->thread.regs) return current->thread.regs->iamr; - return AMR_KUEP_BLOCKED; + return default_iamr; } #endif /* CONFIG_PPC_PKEY */ diff --git a/arch/powerpc/include/asm/book3s/64/pkeys.h b/arch/powerpc/include/asm/book3s/64/pkeys.h index 3b8640498f5b..5b178139f3c0 100644 --- a/arch/powerpc/include/asm/book3s/64/pkeys.h +++ b/arch/powerpc/include/asm/book3s/64/pkeys.h @@ -5,10 +5,6 @@ #include <asm/book3s/64/hash-pkey.h> -extern u64 __ro_after_init default_uamor; -extern u64 __ro_after_init default_amr; -extern u64 __ro_after_init default_iamr; - static inline u64 vmflag_to_pte_pkey_bits(u64 vm_flags) { if (!mmu_has_feature(MMU_FTR_PKEY)) diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c index f1c6f264ed91..15dcc5ad91c5 100644 --- a/arch/powerpc/mm/book3s64/pkeys.c +++ b/arch/powerpc/mm/book3s64/pkeys.c @@ -31,6 +31,7 @@ static u32 initial_allocation_mask __ro_after_init; u64 default_amr __ro_after_init = ~0x0UL; u64 default_iamr __ro_after_init = 0x5555555555555555UL; u64 default_uamor __ro_after_init; +EXPORT_SYMBOL(default_amr); /* * Key used to implement PROT_EXEC mmap. Denies READ/WRITE * We pick key 2 because 0 is special key and 1 is reserved as per ISA. |