diff options
Diffstat (limited to 'arch/loongarch/mm/extable.c')
-rw-r--r-- | arch/loongarch/mm/extable.c | 59 |
1 files changed, 50 insertions, 9 deletions
diff --git a/arch/loongarch/mm/extable.c b/arch/loongarch/mm/extable.c index bc20988f2b87..9ab69872dcff 100644 --- a/arch/loongarch/mm/extable.c +++ b/arch/loongarch/mm/extable.c @@ -2,21 +2,62 @@ /* * Copyright (C) 2020-2022 Loongson Technology Corporation Limited */ +#include <linux/bitfield.h> #include <linux/extable.h> -#include <linux/spinlock.h> -#include <asm/branch.h> #include <linux/uaccess.h> +#include <asm/asm-extable.h> +#include <asm/branch.h> + +static inline unsigned long +get_ex_fixup(const struct exception_table_entry *ex) +{ + return ((unsigned long)&ex->fixup + ex->fixup); +} + +static inline void regs_set_gpr(struct pt_regs *regs, + unsigned int offset, unsigned long val) +{ + if (offset && offset <= MAX_REG_OFFSET) + *(unsigned long *)((unsigned long)regs + offset) = val; +} + +static bool ex_handler_fixup(const struct exception_table_entry *ex, + struct pt_regs *regs) +{ + regs->csr_era = get_ex_fixup(ex); + + return true; +} + +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 * sizeof(unsigned long), -EFAULT); + regs_set_gpr(regs, reg_zero * sizeof(unsigned long), 0); + regs->csr_era = get_ex_fixup(ex); + + return true; +} -int fixup_exception(struct pt_regs *regs) +bool fixup_exception(struct pt_regs *regs) { - const struct exception_table_entry *fixup; + const struct exception_table_entry *ex; - fixup = search_exception_tables(exception_era(regs)); - if (fixup) { - regs->csr_era = fixup->fixup; + ex = search_exception_tables(exception_era(regs)); + if (!ex) + return false; - return 1; + switch (ex->type) { + case EX_TYPE_FIXUP: + return ex_handler_fixup(ex, regs); + case EX_TYPE_UACCESS_ERR_ZERO: + return ex_handler_uaccess_err_zero(ex, regs); + case EX_TYPE_BPF: + return ex_handler_bpf(ex, regs); } - return 0; + BUG(); } |