> -----Original Message----- > From: owner-linux-security-module@xxxxxxxxxxxxxxx [mailto:owner-linux- > security-module@xxxxxxxxxxxxxxx] On Behalf Of Alison Schofield > Sent: Saturday, September 8, 2018 10:36 AM > To: dhowells@xxxxxxxxxx; tglx@xxxxxxxxxxxxx > Cc: Huang, Kai <kai.huang@xxxxxxxxx>; Nakajima, Jun > <jun.nakajima@xxxxxxxxx>; Shutemov, Kirill <kirill.shutemov@xxxxxxxxx>; > Hansen, Dave <dave.hansen@xxxxxxxxx>; Sakkinen, Jarkko > <jarkko.sakkinen@xxxxxxxxx>; jmorris@xxxxxxxxx; keyrings@xxxxxxxxxxxxxxx; > linux-security-module@xxxxxxxxxxxxxxx; mingo@xxxxxxxxxx; hpa@xxxxxxxxx; > x86@xxxxxxxxxx; linux-mm@xxxxxxxxx > Subject: [RFC 04/12] x86/mm: Add helper functions to manage memory > encryption keys > > Define a global mapping structure to track the mapping of userspace keys to > hardware keyids in MKTME (Multi-Key Total Memory Encryption). > This data will be used for the memory encryption system call and the kernel key > service API. > > Implement helper functions to access this mapping structure and make them > visible to the MKTME Kernel Key Service: security/keys/mktme_keys > > Signed-off-by: Alison Schofield <alison.schofield@xxxxxxxxx> > --- > arch/x86/include/asm/mktme.h | 11 ++++++ > arch/x86/mm/mktme.c | 85 > ++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 96 insertions(+) Maybe it's better to put those changes to include/keys/mktme-type.h, and security/keys/mktme_key.c? It seems you don't have to involve linux-mm and x86 guys by doing so? Thanks, -Kai > > diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h > index dbfbd955da98..f6acd551457f 100644 > --- a/arch/x86/include/asm/mktme.h > +++ b/arch/x86/include/asm/mktme.h > @@ -13,6 +13,17 @@ extern phys_addr_t mktme_keyid_mask; extern int > mktme_nr_keyids; extern int mktme_keyid_shift; > > +/* Manage mappings between hardware keyids and userspace keys */ extern > +int mktme_map_alloc(void); extern void mktme_map_free(void); extern > +void mktme_map_lock(void); extern void mktme_map_unlock(void); extern > +int mktme_map_get_free_keyid(void); extern void > +mktme_map_clear_keyid(int keyid); extern void mktme_map_set_keyid(int > +keyid, unsigned int serial); extern int > +mktme_map_keyid_from_serial(unsigned int serial); extern unsigned int > +mktme_map_serial_from_keyid(int keyid); > + > extern struct page_ext_operations page_mktme_ops; > > #define page_keyid page_keyid > diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c index > 660caf6a5ce1..5246d8323359 100644 > --- a/arch/x86/mm/mktme.c > +++ b/arch/x86/mm/mktme.c > @@ -63,6 +63,91 @@ int vma_keyid(struct vm_area_struct *vma) > return (prot & mktme_keyid_mask) >> mktme_keyid_shift; } > > +/* > + * struct mktme_mapping and the mktme_map_* functions manage the > +mapping > + * of userspace keys to hardware keyids in MKTME. They are used by the > + * the encrypt_mprotect system call and the MKTME Key Service API. > + */ > +struct mktme_mapping { > + struct mutex lock; /* protect this map & HW state */ > + unsigned int mapped_keyids; > + unsigned int serial[]; > +}; > + > +struct mktme_mapping *mktme_map; > + > +static inline long mktme_map_size(void) { > + long size = 0; > + > + size += sizeof(mktme_map); > + size += sizeof(mktme_map->serial[0]) * mktme_nr_keyids; > + return size; > +} > + > +int mktme_map_alloc(void) > +{ > + mktme_map = kzalloc(mktme_map_size(), GFP_KERNEL); > + if (!mktme_map) > + return 0; > + mutex_init(&mktme_map->lock); > + return 1; > +} > + > +void mktme_map_free(void) > +{ > + kfree(mktme_map); > +} > + > +void mktme_map_lock(void) > +{ > + mutex_lock(&mktme_map->lock); > +} > + > +void mktme_map_unlock(void) > +{ > + mutex_unlock(&mktme_map->lock); > +} > + > +void mktme_map_set_keyid(int keyid, unsigned int serial) { > + mktme_map->serial[keyid] = serial; > + mktme_map->mapped_keyids++; > +} > + > +void mktme_map_clear_keyid(int keyid) > +{ > + mktme_map->serial[keyid] = 0; > + mktme_map->mapped_keyids--; > +} > + > +unsigned int mktme_map_serial_from_keyid(int keyid) { > + return mktme_map->serial[keyid]; > +} > + > +int mktme_map_keyid_from_serial(unsigned int serial) { > + int i; > + > + for (i = 1; i < mktme_nr_keyids; i++) > + if (mktme_map->serial[i] == serial) > + return i; > + return 0; > +} > + > +int mktme_map_get_free_keyid(void) > +{ > + int i; > + > + if (mktme_map->mapped_keyids < mktme_nr_keyids) { > + for (i = 1; i < mktme_nr_keyids; i++) > + if (mktme_map->serial[i] == 0) > + return i; > + } > + return 0; > +} > + > void prep_encrypted_page(struct page *page, int order, int keyid, bool zero) { > int i; > -- > 2.14.1
