Commit 9abcabe3 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

signal: Implement SIL_FAULT_TRAPNO 

Now that si_trapno is part of the union in _si_fault and available on
all architectures, add SIL_FAULT_TRAPNO and update siginfo_layout to
return SIL_FAULT_TRAPNO when the code assumes si_trapno is valid.

There is room for future changes to reduce when si_trapno is valid but
this is all that is needed to make si_trapno and the other members of
the the union in _sigfault mutually exclusive.

Update the code that uses siginfo_layout to deal with SIL_FAULT_TRAPNO
and have the same code ignore si_trapno in in all other cases.

v1: https://lkml.kernel.org/r/m1o8dvs7s7.fsf_-_@fess.ebiederm.org
v2: https://lkml.kernel.org/r/20210505141101.11519-6-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20210517195748.8880-2-ebiederm@xmission.com


Reviewed-by: default avatarMarco Elver <elver@google.com>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent add0b32e

fs/signalfd.c

+3 −5
Original line number Diff line number Diff line
@@ -123,15 +123,13 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo, 
		 */

	case SIL_FAULT:

		new.ssi_addr = (long) kinfo->si_addr;

#ifdef __ARCH_SI_TRAPNO

		break;

	case SIL_FAULT_TRAPNO:

		new.ssi_addr = (long) kinfo->si_addr;

		new.ssi_trapno = kinfo->si_trapno;

#endif

		break;

	case SIL_FAULT_MCEERR:

		new.ssi_addr = (long) kinfo->si_addr;

#ifdef __ARCH_SI_TRAPNO

		new.ssi_trapno = kinfo->si_trapno;

#endif

		new.ssi_addr_lsb = (short) kinfo->si_addr_lsb;

		break;

	case SIL_PERF_EVENT:

include/linux/signal.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ enum siginfo_layout { 
	SIL_TIMER,

	SIL_POLL,

	SIL_FAULT,

	SIL_FAULT_TRAPNO,

	SIL_FAULT_MCEERR,

	SIL_FAULT_BNDERR,

	SIL_FAULT_PKUERR,

kernel/signal.c

+12 −22
Original line number Diff line number Diff line
@@ -1194,6 +1194,7 @@ static inline bool has_si_pid_and_uid(struct kernel_siginfo *info) 
	case SIL_TIMER:

	case SIL_POLL:

	case SIL_FAULT:

	case SIL_FAULT_TRAPNO:

	case SIL_FAULT_MCEERR:

	case SIL_FAULT_BNDERR:

	case SIL_FAULT_PKUERR:
@@ -2527,6 +2528,7 @@ static void hide_si_addr_tag_bits(struct ksignal *ksig) 
{

	switch (siginfo_layout(ksig->sig, ksig->info.si_code)) {

	case SIL_FAULT:

	case SIL_FAULT_TRAPNO:

	case SIL_FAULT_MCEERR:

	case SIL_FAULT_BNDERR:

	case SIL_FAULT_PKUERR:
@@ -3214,6 +3216,10 @@ enum siginfo_layout siginfo_layout(unsigned sig, int si_code) 
#endif

			else if ((sig == SIGTRAP) && (si_code == TRAP_PERF))

				layout = SIL_PERF_EVENT;

#ifdef __ARCH_SI_TRAPNO

			else if (layout == SIL_FAULT)

				layout = SIL_FAULT_TRAPNO;

#endif

		}

		else if (si_code <= NSIGPOLL)

			layout = SIL_POLL;
@@ -3317,30 +3323,22 @@ void copy_siginfo_to_external32(struct compat_siginfo *to, 
		break;

	case SIL_FAULT:

		to->si_addr = ptr_to_compat(from->si_addr);

#ifdef __ARCH_SI_TRAPNO

		break;

	case SIL_FAULT_TRAPNO:

		to->si_addr = ptr_to_compat(from->si_addr);

		to->si_trapno = from->si_trapno;

#endif

		break;

	case SIL_FAULT_MCEERR:

		to->si_addr = ptr_to_compat(from->si_addr);

#ifdef __ARCH_SI_TRAPNO

		to->si_trapno = from->si_trapno;

#endif

		to->si_addr_lsb = from->si_addr_lsb;

		break;

	case SIL_FAULT_BNDERR:

		to->si_addr = ptr_to_compat(from->si_addr);

#ifdef __ARCH_SI_TRAPNO

		to->si_trapno = from->si_trapno;

#endif

		to->si_lower = ptr_to_compat(from->si_lower);

		to->si_upper = ptr_to_compat(from->si_upper);

		break;

	case SIL_FAULT_PKUERR:

		to->si_addr = ptr_to_compat(from->si_addr);

#ifdef __ARCH_SI_TRAPNO

		to->si_trapno = from->si_trapno;

#endif

		to->si_pkey = from->si_pkey;

		break;

	case SIL_PERF_EVENT:
@@ -3401,30 +3399,22 @@ static int post_copy_siginfo_from_user32(kernel_siginfo_t *to, 
		break;

	case SIL_FAULT:

		to->si_addr = compat_ptr(from->si_addr);

#ifdef __ARCH_SI_TRAPNO

		break;

	case SIL_FAULT_TRAPNO:

		to->si_addr = compat_ptr(from->si_addr);

		to->si_trapno = from->si_trapno;

#endif

		break;

	case SIL_FAULT_MCEERR:

		to->si_addr = compat_ptr(from->si_addr);

#ifdef __ARCH_SI_TRAPNO

		to->si_trapno = from->si_trapno;

#endif

		to->si_addr_lsb = from->si_addr_lsb;

		break;

	case SIL_FAULT_BNDERR:

		to->si_addr = compat_ptr(from->si_addr);

#ifdef __ARCH_SI_TRAPNO

		to->si_trapno = from->si_trapno;

#endif

		to->si_lower = compat_ptr(from->si_lower);

		to->si_upper = compat_ptr(from->si_upper);

		break;

	case SIL_FAULT_PKUERR:

		to->si_addr = compat_ptr(from->si_addr);

#ifdef __ARCH_SI_TRAPNO

		to->si_trapno = from->si_trapno;

#endif

		to->si_pkey = from->si_pkey;

		break;

	case SIL_PERF_EVENT: