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-rw-r--r--arch/powerpc/include/asm/book3s/32/kup.h150
-rw-r--r--arch/powerpc/include/asm/processor.h10
-rw-r--r--arch/powerpc/kernel/process.c3
-rw-r--r--arch/powerpc/mm/book3s32/kuap.c14
4 files changed, 104 insertions, 73 deletions
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index 68fbe28c6d7e..bac7edae64bf 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -42,36 +42,69 @@ static inline void kuep_unlock(void)
#include <linux/sched.h>
-static inline void kuap_update_sr(u32 sr, u32 addr, u32 end)
-{
- addr &= 0xf0000000; /* align addr to start of segment */
- barrier(); /* make sure thread.kuap is updated before playing with SRs */
- for (;;) {
- mtsr(sr, addr);
- addr += 0x10000000; /* address of next segment */
- if (addr >= end)
- break;
- sr += 0x111; /* next VSID */
- sr &= 0xf0ffffff; /* clear VSID overflow */
- }
+#define KUAP_NONE (~0UL)
+#define KUAP_ALL (~1UL)
+
+static inline void kuap_lock_one(unsigned long addr)
+{
+ mtsr(mfsr(addr) | SR_KS, addr);
+ isync(); /* Context sync required after mtsr() */
+}
+
+static inline void kuap_unlock_one(unsigned long addr)
+{
+ mtsr(mfsr(addr) & ~SR_KS, addr);
+ isync(); /* Context sync required after mtsr() */
+}
+
+static inline void kuap_lock_all(void)
+{
+ update_user_segments(mfsr(0) | SR_KS);
isync(); /* Context sync required after mtsr() */
}
+static inline void kuap_unlock_all(void)
+{
+ update_user_segments(mfsr(0) & ~SR_KS);
+ isync(); /* Context sync required after mtsr() */
+}
+
+void kuap_lock_all_ool(void);
+void kuap_unlock_all_ool(void);
+
+static inline void kuap_lock(unsigned long addr, bool ool)
+{
+ if (likely(addr != KUAP_ALL))
+ kuap_lock_one(addr);
+ else if (!ool)
+ kuap_lock_all();
+ else
+ kuap_lock_all_ool();
+}
+
+static inline void kuap_unlock(unsigned long addr, bool ool)
+{
+ if (likely(addr != KUAP_ALL))
+ kuap_unlock_one(addr);
+ else if (!ool)
+ kuap_unlock_all();
+ else
+ kuap_unlock_all_ool();
+}
+
static inline void kuap_save_and_lock(struct pt_regs *regs)
{
unsigned long kuap = current->thread.kuap;
- u32 addr = kuap & 0xf0000000;
- u32 end = kuap << 28;
if (kuap_is_disabled())
return;
regs->kuap = kuap;
- if (unlikely(!kuap))
+ if (unlikely(kuap == KUAP_NONE))
return;
- current->thread.kuap = 0;
- kuap_update_sr(mfsr(addr) | SR_KS, addr, end); /* Set Ks */
+ current->thread.kuap = KUAP_NONE;
+ kuap_lock(kuap, false);
}
static inline void kuap_user_restore(struct pt_regs *regs)
@@ -80,18 +113,12 @@ static inline void kuap_user_restore(struct pt_regs *regs)
static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
{
- u32 addr = regs->kuap & 0xf0000000;
- u32 end = regs->kuap << 28;
-
if (kuap_is_disabled())
return;
current->thread.kuap = regs->kuap;
- if (unlikely(regs->kuap == kuap))
- return;
-
- kuap_update_sr(mfsr(addr) & ~SR_KS, addr, end); /* Clear Ks */
+ kuap_unlock(regs->kuap, false);
}
static inline unsigned long kuap_get_and_assert_locked(void)
@@ -99,9 +126,9 @@ static inline unsigned long kuap_get_and_assert_locked(void)
unsigned long kuap = current->thread.kuap;
if (kuap_is_disabled())
- return 0;
+ return KUAP_NONE;
- WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != 0);
+ WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != KUAP_NONE);
return kuap;
}
@@ -114,8 +141,6 @@ static inline void kuap_assert_locked(void)
static __always_inline void allow_user_access(void __user *to, const void __user *from,
u32 size, unsigned long dir)
{
- u32 addr, end;
-
if (kuap_is_disabled())
return;
@@ -125,88 +150,71 @@ static __always_inline void allow_user_access(void __user *to, const void __user
if (!(dir & KUAP_WRITE))
return;
- addr = (__force u32)to;
-
- if (unlikely(addr >= TASK_SIZE || !size))
- return;
-
- end = min(addr + size, TASK_SIZE);
-
- current->thread.kuap = (addr & 0xf0000000) | ((((end - 1) >> 28) + 1) & 0xf);
- kuap_update_sr(mfsr(addr) & ~SR_KS, addr, end); /* Clear Ks */
+ current->thread.kuap = (__force u32)to;
+ kuap_unlock_one((__force u32)to);
}
static __always_inline void prevent_user_access(void __user *to, const void __user *from,
u32 size, unsigned long dir)
{
- u32 addr, end;
+ u32 kuap = current->thread.kuap;
if (kuap_is_disabled())
return;
BUILD_BUG_ON(!__builtin_constant_p(dir));
- if (dir & KUAP_CURRENT_WRITE) {
- u32 kuap = current->thread.kuap;
-
- if (unlikely(!kuap))
- return;
-
- addr = kuap & 0xf0000000;
- end = kuap << 28;
- } else if (dir & KUAP_WRITE) {
- addr = (__force u32)to;
- end = min(addr + size, TASK_SIZE);
-
- if (unlikely(addr >= TASK_SIZE || !size))
- return;
- } else {
+ if (!(dir & KUAP_WRITE))
return;
- }
- current->thread.kuap = 0;
- kuap_update_sr(mfsr(addr) | SR_KS, addr, end); /* set Ks */
+ current->thread.kuap = KUAP_NONE;
+ kuap_lock(kuap, true);
}
static inline unsigned long prevent_user_access_return(void)
{
unsigned long flags = current->thread.kuap;
- unsigned long addr = flags & 0xf0000000;
- unsigned long end = flags << 28;
- void __user *to = (__force void __user *)addr;
if (kuap_is_disabled())
- return 0;
+ return KUAP_NONE;
- if (flags)
- prevent_user_access(to, to, end - addr, KUAP_READ_WRITE);
+ if (flags != KUAP_NONE) {
+ current->thread.kuap = KUAP_NONE;
+ kuap_lock(flags, true);
+ }
return flags;
}
static inline void restore_user_access(unsigned long flags)
{
- unsigned long addr = flags & 0xf0000000;
- unsigned long end = flags << 28;
- void __user *to = (__force void __user *)addr;
-
if (kuap_is_disabled())
return;
- if (flags)
- allow_user_access(to, to, end - addr, KUAP_READ_WRITE);
+ if (flags != KUAP_NONE) {
+ current->thread.kuap = flags;
+ kuap_unlock(flags, true);
+ }
}
static inline bool
bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
{
- unsigned long begin = regs->kuap & 0xf0000000;
- unsigned long end = regs->kuap << 28;
+ unsigned long kuap = regs->kuap;
if (kuap_is_disabled())
return false;
- return is_write && (address < begin || address >= end);
+ if (!is_write || kuap == KUAP_ALL)
+ return false;
+ if (kuap == KUAP_NONE)
+ return true;
+
+ /* If faulting address doesn't match unlocked segment, unlock all */
+ if ((kuap ^ address) & 0xf0000000)
+ regs->kuap = KUAP_ALL;
+
+ return false;
}
#endif /* CONFIG_PPC_KUAP */
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 7bf8a15af224..aeb1a35163d1 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -276,7 +276,15 @@ struct thread_struct {
#define SPEFSCR_INIT
#endif
-#ifdef CONFIG_PPC32
+#if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
+#define INIT_THREAD { \
+ .ksp = INIT_SP, \
+ .pgdir = swapper_pg_dir, \
+ .kuap = ~0UL, /* KUAP_NONE */ \
+ .fpexc_mode = MSR_FE0 | MSR_FE1, \
+ SPEFSCR_INIT \
+}
+#elif defined(CONFIG_PPC32)
#define INIT_THREAD { \
.ksp = INIT_SP, \
.pgdir = swapper_pg_dir, \
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 2bd30acc843c..3626074acec9 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1745,6 +1745,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
#ifdef CONFIG_ALTIVEC
p->thread.vr_save_area = NULL;
#endif
+#if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
+ p->thread.kuap = KUAP_NONE;
+#endif
setup_ksp_vsid(p, sp);
diff --git a/arch/powerpc/mm/book3s32/kuap.c b/arch/powerpc/mm/book3s32/kuap.c
index 0e59c8b32c4f..9df6911b8fde 100644
--- a/arch/powerpc/mm/book3s32/kuap.c
+++ b/arch/powerpc/mm/book3s32/kuap.c
@@ -6,10 +6,22 @@
struct static_key_false disable_kuap_key;
EXPORT_SYMBOL(disable_kuap_key);
+void kuap_lock_all_ool(void)
+{
+ kuap_lock_all();
+}
+EXPORT_SYMBOL(kuap_lock_all_ool);
+
+void kuap_unlock_all_ool(void)
+{
+ kuap_unlock_all();
+}
+EXPORT_SYMBOL(kuap_unlock_all_ool);
+
void __init setup_kuap(bool disabled)
{
if (!disabled)
- kuap_update_sr(mfsr(0) | SR_KS, 0, TASK_SIZE);
+ kuap_lock_all_ool();
if (smp_processor_id() != boot_cpuid)
return;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 21:29:03 +0000