From f71dd7dc2dc989dc712b246a74d243e4b2c5f8a7 Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Mon, 22 Jan 2018 14:37:25 -0600
Subject: 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>
---
 arch/arm/kernel/ptrace.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

(limited to 'arch/arm')

diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 58e3771e4c5b..7724b0f661b3 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -390,7 +390,6 @@ static void ptrace_hbptriggered(struct perf_event *bp,
 	struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 	long num;
 	int i;
-	siginfo_t info;
 
 	for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
 		if (current->thread.debug.hbp[i] == bp)
@@ -398,12 +397,7 @@ static void ptrace_hbptriggered(struct perf_event *bp,
 
 	num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
 
-	info.si_signo	= SIGTRAP;
-	info.si_errno	= (int)num;
-	info.si_code	= TRAP_HWBKPT;
-	info.si_addr	= (void __user *)(bkpt->trigger);
-
-	force_sig_info(SIGTRAP, &info, current);
+	force_sig_ptrace_errno_trap((int)num, (void __user *)(bkpt->trigger));
 }
 
 /*
-- 
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