#define EX_TYPE_NONE 0
#define EX_TYPE_FIXUP 1
#define EX_TYPE_BPF 2
+#define EX_TYPE_UACCESS_ERR_ZERO 3
#ifdef __ASSEMBLY__
#else /* __ASSEMBLY__ */
+#include <linux/bits.h>
#include <linux/stringify.h>
+#include <asm/gpr-num.h>
#define __ASM_EXTABLE_RAW(insn, fixup, type, data) \
".pushsection __ex_table, \"a\"\n" \
#define _ASM_EXTABLE(insn, fixup) \
__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")
+#define EX_DATA_REG_ERR_SHIFT 0
+#define EX_DATA_REG_ERR GENMASK(4, 0)
+#define EX_DATA_REG_ZERO_SHIFT 5
+#define EX_DATA_REG_ZERO GENMASK(9, 5)
+
+#define EX_DATA_REG(reg, gpr) \
+ "((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
+
+#define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero) \
+ __DEFINE_ASM_GPR_NUMS \
+ __ASM_EXTABLE_RAW(#insn, #fixup, \
+ __stringify(EX_TYPE_UACCESS_ERR_ZERO), \
+ "(" \
+ EX_DATA_REG(ERR, err) " | " \
+ EX_DATA_REG(ZERO, zero) \
+ ")")
+
+#define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err) \
+ _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero)
+
#endif /* __ASSEMBLY__ */
#endif /* __ASM_ASM_EXTABLE_H */
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
{ \
- uintptr_t tmp; \
__enable_user_access(); \
__asm__ __volatile__ ( \
"1: " insn " \n" \
"2: \n" \
- " .section .fixup,\"ax\" \n" \
- " .balign 4 \n" \
- "3: li %[r],%[e] \n" \
- " jump 2b,%[t] \n" \
- " .previous \n" \
- _ASM_EXTABLE(1b, 3b) \
+ _ASM_EXTABLE_UACCESS_ERR(1b, 2b, %[r]) \
: [r] "+r" (ret), [ov] "=&r" (oldval), \
- [u] "+m" (*uaddr), [t] "=&r" (tmp) \
- : [op] "Jr" (oparg), [e] "i" (-EFAULT) \
+ [u] "+m" (*uaddr) \
+ : [op] "Jr" (oparg) \
: "memory"); \
__disable_user_access(); \
}
"2: sc.w.aqrl %[t],%z[nv],%[u] \n"
" bnez %[t],1b \n"
"3: \n"
- " .section .fixup,\"ax\" \n"
- " .balign 4 \n"
- "4: li %[r],%[e] \n"
- " jump 3b,%[t] \n"
- " .previous \n"
- _ASM_EXTABLE(1b, 4b) \
- _ASM_EXTABLE(2b, 4b) \
+ _ASM_EXTABLE_UACCESS_ERR(1b, 3b, %[r]) \
+ _ASM_EXTABLE_UACCESS_ERR(2b, 3b, %[r]) \
: [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr), [t] "=&r" (tmp)
- : [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "i" (-EFAULT)
+ : [ov] "Jr" (oldval), [nv] "Jr" (newval)
: "memory");
__disable_user_access();
#define __get_user_asm(insn, x, ptr, err) \
do { \
- uintptr_t __tmp; \
__typeof__(x) __x; \
__asm__ __volatile__ ( \
"1:\n" \
- " " insn " %1, %3\n" \
+ " " insn " %1, %2\n" \
"2:\n" \
- " .section .fixup,\"ax\"\n" \
- " .balign 4\n" \
- "3:\n" \
- " li %0, %4\n" \
- " li %1, 0\n" \
- " jump 2b, %2\n" \
- " .previous\n" \
- _ASM_EXTABLE(1b, 3b) \
- : "+r" (err), "=&r" (__x), "=r" (__tmp) \
- : "m" (*(ptr)), "i" (-EFAULT)); \
+ _ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 2b, %0, %1) \
+ : "+r" (err), "=&r" (__x) \
+ : "m" (*(ptr))); \
(x) = __x; \
} while (0)
do { \
u32 __user *__ptr = (u32 __user *)(ptr); \
u32 __lo, __hi; \
- uintptr_t __tmp; \
__asm__ __volatile__ ( \
"1:\n" \
- " lw %1, %4\n" \
+ " lw %1, %3\n" \
"2:\n" \
- " lw %2, %5\n" \
+ " lw %2, %4\n" \
"3:\n" \
- " .section .fixup,\"ax\"\n" \
- " .balign 4\n" \
- "4:\n" \
- " li %0, %6\n" \
- " li %1, 0\n" \
- " li %2, 0\n" \
- " jump 3b, %3\n" \
- " .previous\n" \
- _ASM_EXTABLE(1b, 4b) \
- _ASM_EXTABLE(2b, 4b) \
- : "+r" (err), "=&r" (__lo), "=r" (__hi), \
- "=r" (__tmp) \
- : "m" (__ptr[__LSW]), "m" (__ptr[__MSW]), \
- "i" (-EFAULT)); \
+ _ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 3b, %0, %1) \
+ _ASM_EXTABLE_UACCESS_ERR_ZERO(2b, 3b, %0, %1) \
+ : "+r" (err), "=&r" (__lo), "=r" (__hi) \
+ : "m" (__ptr[__LSW]), "m" (__ptr[__MSW])); \
+ if (err) \
+ __hi = 0; \
(x) = (__typeof__(x))((__typeof__((x)-(x)))( \
(((u64)__hi << 32) | __lo))); \
} while (0)
#define __put_user_asm(insn, x, ptr, err) \
do { \
- uintptr_t __tmp; \
__typeof__(*(ptr)) __x = x; \
__asm__ __volatile__ ( \
"1:\n" \
- " " insn " %z3, %2\n" \
+ " " insn " %z2, %1\n" \
"2:\n" \
- " .section .fixup,\"ax\"\n" \
- " .balign 4\n" \
- "3:\n" \
- " li %0, %4\n" \
- " jump 2b, %1\n" \
- " .previous\n" \
- _ASM_EXTABLE(1b, 3b) \
- : "+r" (err), "=r" (__tmp), "=m" (*(ptr)) \
- : "rJ" (__x), "i" (-EFAULT)); \
+ _ASM_EXTABLE_UACCESS_ERR(1b, 2b, %0) \
+ : "+r" (err), "=m" (*(ptr)) \
+ : "rJ" (__x)); \
} while (0)
#ifdef CONFIG_64BIT
do { \
u32 __user *__ptr = (u32 __user *)(ptr); \
u64 __x = (__typeof__((x)-(x)))(x); \
- uintptr_t __tmp; \
__asm__ __volatile__ ( \
"1:\n" \
- " sw %z4, %2\n" \
+ " sw %z3, %1\n" \
"2:\n" \
- " sw %z5, %3\n" \
+ " sw %z4, %2\n" \
"3:\n" \
- " .section .fixup,\"ax\"\n" \
- " .balign 4\n" \
- "4:\n" \
- " li %0, %6\n" \
- " jump 3b, %1\n" \
- " .previous\n" \
- _ASM_EXTABLE(1b, 4b) \
- _ASM_EXTABLE(2b, 4b) \
- : "+r" (err), "=r" (__tmp), \
+ _ASM_EXTABLE_UACCESS_ERR(1b, 3b, %0) \
+ _ASM_EXTABLE_UACCESS_ERR(2b, 3b, %0) \
+ : "+r" (err), \
"=m" (__ptr[__LSW]), \
"=m" (__ptr[__MSW]) \
- : "rJ" (__x), "rJ" (__x >> 32), "i" (-EFAULT)); \
+ : "rJ" (__x), "rJ" (__x >> 32)); \
} while (0)
#endif /* CONFIG_64BIT */
*/
+#include <linux/bitfield.h>
#include <linux/extable.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <asm/asm-extable.h>
+#include <asm/ptrace.h>
static inline unsigned long
get_ex_fixup(const struct exception_table_entry *ex)
return true;
}
+static inline void regs_set_gpr(struct pt_regs *regs, unsigned int offset,
+ unsigned long val)
+{
+ if (unlikely(offset > MAX_REG_OFFSET))
+ return;
+
+ if (!offset)
+ *(unsigned long *)((unsigned long)regs + offset) = val;
+}
+
+static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex,
+ struct pt_regs *regs)
+{
+ int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
+ int reg_zero = FIELD_GET(EX_DATA_REG_ZERO, ex->data);
+
+ regs_set_gpr(regs, reg_err, -EFAULT);
+ regs_set_gpr(regs, reg_zero, 0);
+
+ regs->epc = get_ex_fixup(ex);
+ return true;
+}
+
bool fixup_exception(struct pt_regs *regs)
{
const struct exception_table_entry *ex;
return ex_handler_fixup(ex, regs);
case EX_TYPE_BPF:
return ex_handler_bpf(ex, regs);
+ case EX_TYPE_UACCESS_ERR_ZERO:
+ return ex_handler_uaccess_err_zero(ex, regs);
}
BUG();