signal/ptrace: Add force_sig_ptrace_errno_trap and use it where needed

There are so many places that build struct siginfo by hand that at
least one of them is bound to get it wrong.  A handful of cases in the
kernel arguably did just that when using the errno field of siginfo to
pass no errno values to userspace.  The usage is limited to a single
si_code so at least does not mess up anything else.

Encapsulate this questionable pattern in a helper function so
that the userspace ABI is preserved.

Update all of the places that use this pattern to use the new helper
function.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This commit is contained in:
Eric W. Biederman 2018-01-22 14:37:25 -06:00
parent 47355040d2
commit f71dd7dc2d
6 changed files with 25 additions and 23 deletions

View file

@ -1599,6 +1599,21 @@ int force_sig_pkuerr(void __user *addr, u32 pkey)
}
#endif
/* For the crazy architectures that include trap information in
* the errno field, instead of an actual errno value.
*/
int force_sig_ptrace_errno_trap(int errno, void __user *addr)
{
struct siginfo info;
clear_siginfo(&info);
info.si_signo = SIGTRAP;
info.si_errno = errno;
info.si_code = TRAP_HWBKPT;
info.si_addr = addr;
return force_sig_info(info.si_signo, &info, current);
}
int kill_pgrp(struct pid *pid, int sig, int priv)
{
int ret;