diff options
| -rw-r--r-- | arch/tile/include/uapi/asm/ptrace.h | 6 | ||||
| -rw-r--r-- | arch/tile/kernel/ptrace.c | 57 |
2 files changed, 46 insertions, 17 deletions
diff --git a/arch/tile/include/uapi/asm/ptrace.h b/arch/tile/include/uapi/asm/ptrace.h index c717d0fec72e..0d2208803b29 100644 --- a/arch/tile/include/uapi/asm/ptrace.h +++ b/arch/tile/include/uapi/asm/ptrace.h @@ -84,5 +84,11 @@ struct pt_regs { #define PTRACE_O_TRACEMIGRATE 0x00010000 #define PTRACE_EVENT_MIGRATE 16 +/* + * Flag bits in pt_regs.flags that are part of the ptrace API. + * We start our numbering higher up to avoid confusion with the + * non-ABI kernel-internal values that use the low 16 bits. + */ +#define PT_FLAGS_COMPAT 0x10000 /* process is an -m32 compat process */ #endif /* _UAPI_ASM_TILE_PTRACE_H */ diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c index e92e40527d6d..64ba102c5964 100644 --- a/arch/tile/kernel/ptrace.c +++ b/arch/tile/kernel/ptrace.c @@ -45,6 +45,41 @@ void ptrace_disable(struct task_struct *child) clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); } +/* + * Get registers from task and ready the result for userspace. + * Note that we localize the API issues to getregs() and putregs() at + * some cost in performance, e.g. we need a full pt_regs copy for + * PEEKUSR, and two copies for POKEUSR. But in general we expect + * GETREGS/PUTREGS to be the API of choice anyway. + */ +static char *getregs(struct task_struct *child, struct pt_regs *uregs) +{ + *uregs = *task_pt_regs(child); + + /* Set up flags ABI bits. */ + uregs->flags = 0; +#ifdef CONFIG_COMPAT + if (task_thread_info(child)->status & TS_COMPAT) + uregs->flags |= PT_FLAGS_COMPAT; +#endif + + return (char *)uregs; +} + +/* Put registers back to task. */ +static void putregs(struct task_struct *child, struct pt_regs *uregs) +{ + struct pt_regs *regs = task_pt_regs(child); + + /* Don't allow overwriting the kernel-internal flags word. */ + uregs->flags = regs->flags; + + /* Only allow setting the ICS bit in the ex1 word. */ + uregs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(uregs->ex1)); + + *regs = *uregs; +} + long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data) { @@ -53,14 +88,13 @@ long arch_ptrace(struct task_struct *child, long request, long ret = -EIO; char *childreg; struct pt_regs copyregs; - int ex1_offset; switch (request) { case PTRACE_PEEKUSR: /* Read register from pt_regs. */ if (addr >= PTREGS_SIZE) break; - childreg = (char *)task_pt_regs(child) + addr; + childreg = getregs(child, ©regs) + addr; #ifdef CONFIG_COMPAT if (is_compat_task()) { if (addr & (sizeof(compat_long_t)-1)) @@ -79,17 +113,7 @@ long arch_ptrace(struct task_struct *child, long request, case PTRACE_POKEUSR: /* Write register in pt_regs. */ if (addr >= PTREGS_SIZE) break; - childreg = (char *)task_pt_regs(child) + addr; - - /* Guard against overwrites of the privilege level. */ - ex1_offset = PTREGS_OFFSET_EX1; -#if defined(CONFIG_COMPAT) && defined(__BIG_ENDIAN) - if (is_compat_task()) /* point at low word */ - ex1_offset += sizeof(compat_long_t); -#endif - if (addr == ex1_offset) - data = PL_ICS_EX1(USER_PL, EX1_ICS(data)); - + childreg = getregs(child, ©regs) + addr; #ifdef CONFIG_COMPAT if (is_compat_task()) { if (addr & (sizeof(compat_long_t)-1)) @@ -102,11 +126,12 @@ long arch_ptrace(struct task_struct *child, long request, break; *(long *)childreg = data; } + putregs(child, ©regs); ret = 0; break; case PTRACE_GETREGS: /* Get all registers from the child. */ - if (copy_to_user(datap, task_pt_regs(child), + if (copy_to_user(datap, getregs(child, ©regs), sizeof(struct pt_regs)) == 0) { ret = 0; } @@ -115,9 +140,7 @@ long arch_ptrace(struct task_struct *child, long request, case PTRACE_SETREGS: /* Set all registers in the child. */ if (copy_from_user(©regs, datap, sizeof(struct pt_regs)) == 0) { - copyregs.ex1 = - PL_ICS_EX1(USER_PL, EX1_ICS(copyregs.ex1)); - *task_pt_regs(child) = copyregs; + putregs(child, ©regs); ret = 0; } break; |