diff options
Diffstat (limited to 'arch/um/sys-x86_64/ptrace.c')
| -rw-r--r-- | arch/um/sys-x86_64/ptrace.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/arch/um/sys-x86_64/ptrace.c b/arch/um/sys-x86_64/ptrace.c index 74eee5c7c6d..147bbf05cbc 100644 --- a/arch/um/sys-x86_64/ptrace.c +++ b/arch/um/sys-x86_64/ptrace.c @@ -8,6 +8,7 @@ #include <asm/ptrace.h> #include <linux/sched.h> #include <linux/errno.h> +#include <linux/mm.h> #include <asm/uaccess.h> #include <asm/elf.h> @@ -136,9 +137,28 @@ void arch_switch(void) */ } +/* XXX Mostly copied from sys-i386 */ int is_syscall(unsigned long addr) { - panic("is_syscall"); + unsigned short instr; + int n; + + n = copy_from_user(&instr, (void __user *) addr, sizeof(instr)); + if(n){ + /* access_process_vm() grants access to vsyscall and stub, + * while copy_from_user doesn't. Maybe access_process_vm is + * slow, but that doesn't matter, since it will be called only + * in case of singlestepping, if copy_from_user failed. + */ + n = access_process_vm(current, addr, &instr, sizeof(instr), 0); + if(n != sizeof(instr)) { + printk("is_syscall : failed to read instruction from " + "0x%lx\n", addr); + return(1); + } + } + /* sysenter */ + return(instr == 0x050f); } int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu ) |