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From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH] powerpc: fix inverted SET_FULL_REGS bitop
Date: Mon,  8 Mar 2021 18:55:30 +1000	[thread overview]
Message-ID: <20210308085530.3191843-1-npiggin@gmail.com> (raw)

This bit operation was inverted and set the low bit rather than cleared
it, breaking the ability to ptrace non-volatile GPRs after exec. Fix.

Fixes: feb9df3462e68 ("powerpc/64s: Always has full regs, so remove remnant checks")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
Well this is embarrassing. Condition flags should be represented by the
bit set, rather than bit clear. That would have made the mistake obvious
even at a glance.

In this case, this stuff is going away soon so I won't bother to change
it around.

Thanks,
Nick

 arch/powerpc/include/asm/ptrace.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 975ba260006a..1499e928ea6a 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -195,7 +195,7 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
 #define TRAP_FLAGS_MASK		0x11
 #define TRAP(regs)		((regs)->trap & ~TRAP_FLAGS_MASK)
 #define FULL_REGS(regs)		(((regs)->trap & 1) == 0)
-#define SET_FULL_REGS(regs)	((regs)->trap |= 1)
+#define SET_FULL_REGS(regs)	((regs)->trap &= ~1)
 #endif
 #define CHECK_FULL_REGS(regs)	BUG_ON(!FULL_REGS(regs))
 #define NV_REG_POISON		0xdeadbeefdeadbeefUL
@@ -210,7 +210,7 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
 #define TRAP_FLAGS_MASK		0x1F
 #define TRAP(regs)		((regs)->trap & ~TRAP_FLAGS_MASK)
 #define FULL_REGS(regs)		(((regs)->trap & 1) == 0)
-#define SET_FULL_REGS(regs)	((regs)->trap |= 1)
+#define SET_FULL_REGS(regs)	((regs)->trap &= ~1)
 #define IS_CRITICAL_EXC(regs)	(((regs)->trap & 2) != 0)
 #define IS_MCHECK_EXC(regs)	(((regs)->trap & 4) != 0)
 #define IS_DEBUG_EXC(regs)	(((regs)->trap & 8) != 0)
-- 
2.23.0


             reply	other threads:[~2021-03-08  8:56 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-08  8:55 Nicholas Piggin [this message]
2021-03-14 10:01 ` [PATCH] powerpc: fix inverted SET_FULL_REGS bitop Michael Ellerman
2021-03-08  9:52 [RFC PATCH 0/7] Move 64e to new interrupt return code Nicholas Piggin
2021-03-08  9:52 ` [PATCH] powerpc: fix inverted SET_FULL_REGS bitop Nicholas Piggin

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