| Message ID | 20200627070147.297535-1-aneesh.kumar@linux.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 19ab500edb5d6020010caba48ce3b4ce4182ab63 |
| Headers | show |
| Series | [1/2] powerpc/mm/book3s54/pkeys: make pkey access check work on execute_only_key | expand |
On Sat, 27 Jun 2020 12:31:46 +0530, Aneesh Kumar K.V wrote: > pkey_access_permitted() should not check for pkey is available in UAMOR or not. > The kernel needs to do that check only while allocating keys. This also makes > sure execute_only_key which is marked as non-manageable via UAMOR gives the > right access check return w.r.t pkey_access_permitted(). > > This fix the page fault loop when using PROT_EXEC as below > > [...] Patch 1 applied to powerpc/fixes. [1/2] powerpc/mm/pkeys: Make pkey access check work on execute_only_key https://git.kernel.org/powerpc/c/19ab500edb5d6020010caba48ce3b4ce4182ab63 cheers
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c index 1199fc2bfaec..ca5fcb4bff32 100644 --- a/arch/powerpc/mm/book3s64/pkeys.c +++ b/arch/powerpc/mm/book3s64/pkeys.c @@ -353,9 +353,6 @@ static bool pkey_access_permitted(int pkey, bool write, bool execute) int pkey_shift; u64 amr; - if (!is_pkey_enabled(pkey)) - return true; - pkey_shift = pkeyshift(pkey); if (execute && !(read_iamr() & (IAMR_EX_BIT << pkey_shift))) return true;
pkey_access_permitted() should not check for pkey is available in UAMOR or not. The kernel needs to do that check only while allocating keys. This also makes sure execute_only_key which is marked as non-manageable via UAMOR gives the right access check return w.r.t pkey_access_permitted(). This fix the page fault loop when using PROT_EXEC as below addr = mmap(0, page_sz, PROT_EXEC, MAP_FILE | MAP_PRIVATE, fildes, 0); x = *addr); Fixes: c46241a370a6 ("powerpc/pkeys: Check vma before returning key fault error to the user") Reported-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> --- arch/powerpc/mm/book3s64/pkeys.c | 3 --- 1 file changed, 3 deletions(-)