diff mbox series

sparc: fix compat siginfo ABI regression

Message ID 20180413141901.GA15253@altlinux.org
State Accepted
Delegated to: David Miller
Headers show
Series sparc: fix compat siginfo ABI regression | expand

Commit Message

Dmitry V. Levin April 13, 2018, 2:19 p.m. UTC
Starting with commit v4.14-rc1~60^2^2~1, a SIGFPE signal sent via kill
results to wrong values in si_pid and si_uid fields of compat siginfo_t.

This happens due to FPE_FIXME being defined to 0 for sparc, and at the
same time siginfo_layout() introduced by the same commit returns
SIL_FAULT for SIGFPE if si_code == SI_USER and FPE_FIXME is defined to 0.

Fix this regression by removing FPE_FIXME macro and changing all its users
to assign FPE_FLTUNK to si_code instead of FPE_FIXME.

Note that FPE_FLTUNK is a new macro introduced by commit
266da65e9156d93e1126e185259a4aae68188d0e.

Tested with commit v4.16-11958-g16e205cf42da.

This bug was found by strace test suite.

Link: https://github.com/strace/strace/issues/21
Fixes: cc731525f26a ("signal: Remove kernel interal si_code magic")
Thanks-to: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
---
 arch/sparc/include/uapi/asm/siginfo.h | 7 -------
 arch/sparc/kernel/traps_32.c          | 2 +-
 arch/sparc/kernel/traps_64.c          | 2 +-
 3 files changed, 2 insertions(+), 9 deletions(-)

Comments

David Miller June 5, 2018, 6:30 p.m. UTC | #1
From: "Dmitry V. Levin" <ldv@altlinux.org>
Date: Fri, 13 Apr 2018 17:19:02 +0300

> Starting with commit v4.14-rc1~60^2^2~1, a SIGFPE signal sent via kill
> results to wrong values in si_pid and si_uid fields of compat siginfo_t.
> 
> This happens due to FPE_FIXME being defined to 0 for sparc, and at the
> same time siginfo_layout() introduced by the same commit returns
> SIL_FAULT for SIGFPE if si_code == SI_USER and FPE_FIXME is defined to 0.
> 
> Fix this regression by removing FPE_FIXME macro and changing all its users
> to assign FPE_FLTUNK to si_code instead of FPE_FIXME.
> 
> Note that FPE_FLTUNK is a new macro introduced by commit
> 266da65e9156d93e1126e185259a4aae68188d0e.
> 
> Tested with commit v4.16-11958-g16e205cf42da.
> 
> This bug was found by strace test suite.
> 
> Link: https://github.com/strace/strace/issues/21
> Fixes: cc731525f26a ("signal: Remove kernel interal si_code magic")
> Thanks-to: Anatoly Pugachev <matorola@gmail.com>
> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>

Applied and queued up for -stable, thank you.
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diff mbox series

Patch

diff --git a/arch/sparc/include/uapi/asm/siginfo.h b/arch/sparc/include/uapi/asm/siginfo.h
index 896ce44..e704955 100644
--- a/arch/sparc/include/uapi/asm/siginfo.h
+++ b/arch/sparc/include/uapi/asm/siginfo.h
@@ -18,13 +18,6 @@ 
 #define SI_NOINFO	32767		/* no information in siginfo_t */
 
 /*
- * SIGFPE si_codes
- */
-#ifdef __KERNEL__
-#define FPE_FIXME	0	/* Broken dup of SI_USER */
-#endif /* __KERNEL__ */
-
-/*
  * SIGEMT si_codes
  */
 #define EMT_TAGOVF	1	/* tag overflow */
diff --git a/arch/sparc/kernel/traps_32.c b/arch/sparc/kernel/traps_32.c
index b1ed763..33cd35b 100644
--- a/arch/sparc/kernel/traps_32.c
+++ b/arch/sparc/kernel/traps_32.c
@@ -307,7 +307,7 @@  void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 	info.si_errno = 0;
 	info.si_addr = (void __user *)pc;
 	info.si_trapno = 0;
-	info.si_code = FPE_FIXME;
+	info.si_code = FPE_FLTUNK;
 	if ((fsr & 0x1c000) == (1 << 14)) {
 		if (fsr & 0x10)
 			info.si_code = FPE_FLTINV;
diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 462a21a..e81072a 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -2372,7 +2372,7 @@  static void do_fpe_common(struct pt_regs *regs)
 		info.si_errno = 0;
 		info.si_addr = (void __user *)regs->tpc;
 		info.si_trapno = 0;
-		info.si_code = FPE_FIXME;
+		info.si_code = FPE_FLTUNK;
 		if ((fsr & 0x1c000) == (1 << 14)) {
 			if (fsr & 0x10)
 				info.si_code = FPE_FLTINV;