* [PATCH] powerpc: fix inverted SET_FULL_REGS bitop
@ 2021-03-08 8:55 Nicholas Piggin
2021-03-14 10:01 ` Michael Ellerman
0 siblings, 1 reply; 3+ messages in thread
From: Nicholas Piggin @ 2021-03-08 8:55 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH] powerpc: fix inverted SET_FULL_REGS bitop
2021-03-08 9:52 [RFC PATCH 0/7] Move 64e to new interrupt return code Nicholas Piggin
@ 2021-03-08 9:52 ` Nicholas Piggin
0 siblings, 0 replies; 3+ messages in thread
From: Nicholas Piggin @ 2021-03-08 9:52 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] powerpc: fix inverted SET_FULL_REGS bitop
2021-03-08 8:55 [PATCH] powerpc: fix inverted SET_FULL_REGS bitop Nicholas Piggin
@ 2021-03-14 10:01 ` Michael Ellerman
0 siblings, 0 replies; 3+ messages in thread
From: Michael Ellerman @ 2021-03-14 10:01 UTC (permalink / raw)
To: linuxppc-dev, Nicholas Piggin
On Mon, 8 Mar 2021 18:55:30 +1000, Nicholas Piggin wrote:
> 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.
Applied to powerpc/fixes.
[1/1] powerpc: Fix inverted SET_FULL_REGS bitop
https://git.kernel.org/powerpc/c/73ac79881804eed2e9d76ecdd1018037f8510cb1
cheers
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-03-08 8:55 [PATCH] powerpc: fix inverted SET_FULL_REGS bitop Nicholas Piggin
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