Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
+12
-9
+11
-5
arch/powerpc/include/asm/book3s/64/kup.h
+11
-5
arch/powerpc/include/asm/book3s/64/kup.h
···
199
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#ifdef CONFIG_PPC_PKEY
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+
extern u64 __ro_after_init default_uamor;
203
+
extern u64 __ro_after_init default_amr;
204
+
extern u64 __ro_after_init default_iamr;
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+
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#include <asm/mmu.h>
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#include <asm/ptrace.h>
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-
/*
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-
* For kernel thread that doesn't have thread.regs return
207
-
* default AMR/IAMR values.
209
+
/* usage of kthread_use_mm() should inherit the
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+
* AMR value of the operating address space. But, the AMR value is
211
+
* thread-specific and we inherit the address space and not thread
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+
* access restrictions. Because of this ignore AMR value when accessing
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+
* userspace via kernel thread.
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*/
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static inline u64 current_thread_amr(void)
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{
211
217
if (current->thread.regs)
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return current->thread.regs->amr;
213
-
return AMR_KUAP_BLOCKED;
219
+
return default_amr;
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}
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static inline u64 current_thread_iamr(void)
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{
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if (current->thread.regs)
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return current->thread.regs->iamr;
220
-
return AMR_KUEP_BLOCKED;
226
+
return default_iamr;
221
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}
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#endif /* CONFIG_PPC_PKEY */
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-4
arch/powerpc/include/asm/book3s/64/pkeys.h
-4
arch/powerpc/include/asm/book3s/64/pkeys.h
···
5
5
6
6
#include <asm/book3s/64/hash-pkey.h>
7
7
8
-
extern u64 __ro_after_init default_uamor;
9
-
extern u64 __ro_after_init default_amr;
10
-
extern u64 __ro_after_init default_iamr;
11
-
12
8
static inline u64 vmflag_to_pte_pkey_bits(u64 vm_flags)
13
9
{
14
10
if (!mmu_has_feature(MMU_FTR_PKEY))
+1
arch/powerpc/mm/book3s64/pkeys.c
+1
arch/powerpc/mm/book3s64/pkeys.c
···
31
31
u64 default_amr __ro_after_init = ~0x0UL;
32
32
u64 default_iamr __ro_after_init = 0x5555555555555555UL;
33
33
u64 default_uamor __ro_after_init;
34
+
EXPORT_SYMBOL(default_amr);
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/*
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* Key used to implement PROT_EXEC mmap. Denies READ/WRITE
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* We pick key 2 because 0 is special key and 1 is reserved as per ISA.