2019-05-11 12:41:07

by Steven Rostedt

Subject: [PATCH] x86: Hide the int3_emulate_call/jmp functions from UML

From: "Steven Rostedt (VMware)" <[email protected]>

User Mode Linux does not have access to the ip or sp fields of the
pt_regs, and accessing them causes UML to fail to build. Hide the
int3_emulate_jmp() and int3_emulate_call() instructions from UML, as it
doesn't need them anyway.

Reported-by: kbuild test robot <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
---

[ I added this to my queue to test too ]

arch/x86/include/asm/text-patching.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/text-patching.h
b/arch/x86/include/asm/text-patching.h index 05861cc08787..0bbb07eaed6b
100644 --- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -39,6 +39,7 @@ extern int poke_int3_handler(struct pt_regs *regs);
extern void *text_poke_bp(void *addr, const void *opcode, size_t len,
void *handler); extern int after_bootmem;

+#ifndef CONFIG_UML_X86
static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned
long ip) {
regs->ip = ip;
@@ -65,6 +66,7 @@ static inline void int3_emulate_call(struct pt_regs
*regs, unsigned long func) int3_emulate_push(regs, regs->ip -
INT3_INSN_SIZE + CALL_INSN_SIZE); int3_emulate_jmp(regs, func);
}
-#endif
+#endif /* CONFIG_X86_64 */
+#endif /* !CONFIG_UML_X86 */

#endif /* _ASM_X86_TEXT_PATCHING_H */
--
2.20.1

2019-05-20 09:39:47

by Anton Ivanov

Subject: Re: [PATCH] x86: Hide the int3_emulate_call/jmp functions from UML

On 11/05/2019 13:39, Steven Rostedt wrote:
>
> From: "Steven Rostedt (VMware)" <[email protected]>
>
> User Mode Linux does not have access to the ip or sp fields of the
> pt_regs, and accessing them causes UML to fail to build. Hide the
> int3_emulate_jmp() and int3_emulate_call() instructions from UML, as it
> doesn't need them anyway.
>
> Reported-by: kbuild test robot <[email protected]>
> Signed-off-by: Steven Rostedt (VMware) <[email protected]>
> ---
>
> [ I added this to my queue to test too ]
>
> arch/x86/include/asm/text-patching.h | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/text-patching.h
> b/arch/x86/include/asm/text-patching.h index 05861cc08787..0bbb07eaed6b
> 100644 --- a/arch/x86/include/asm/text-patching.h
> +++ b/arch/x86/include/asm/text-patching.h
> @@ -39,6 +39,7 @@ extern int poke_int3_handler(struct pt_regs *regs);
> extern void *text_poke_bp(void *addr, const void *opcode, size_t len,
> void *handler); extern int after_bootmem;
>
> +#ifndef CONFIG_UML_X86
> static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned
> long ip) {
> regs->ip = ip;
> @@ -65,6 +66,7 @@ static inline void int3_emulate_call(struct pt_regs
> *regs, unsigned long func) int3_emulate_push(regs, regs->ip -
> INT3_INSN_SIZE + CALL_INSN_SIZE); int3_emulate_jmp(regs, func);
> }
> -#endif
> +#endif /* CONFIG_X86_64 */
> +#endif /* !CONFIG_UML_X86 */
>
> #endif /* _ASM_X86_TEXT_PATCHING_H */
>
The patch has been garbled by an auto-wrap. Can you resend it please.

--
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/

2019-05-20 18:19:06

by Steven Rostedt

Subject: Re: [PATCH] x86: Hide the int3_emulate_call/jmp functions from UML

On Mon, 20 May 2019 09:08:01 +0100
Anton Ivanov <[email protected]> wrote:

> On 11/05/2019 13:39, Steven Rostedt wrote:
> >
> > From: "Steven Rostedt (VMware)" <[email protected]>
> >
> > User Mode Linux does not have access to the ip or sp fields of the
> > pt_regs, and accessing them causes UML to fail to build. Hide the
> > int3_emulate_jmp() and int3_emulate_call() instructions from UML, as it
> > doesn't need them anyway.
> >
> > Reported-by: kbuild test robot <[email protected]>
> > Signed-off-by: Steven Rostedt (VMware) <[email protected]>
> > ---
> >
> > [ I added this to my queue to test too ]

Looks like when I added this text, claws-mail, decided to line wrap the
patch :-p


> >
> > arch/x86/include/asm/text-patching.h | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/include/asm/text-patching.h
> > b/arch/x86/include/asm/text-patching.h index 05861cc08787..0bbb07eaed6b
> > 100644 --- a/arch/x86/include/asm/text-patching.h
> > +++ b/arch/x86/include/asm/text-patching.h
> > @@ -39,6 +39,7 @@ extern int poke_int3_handler(struct pt_regs *regs);
> > extern void *text_poke_bp(void *addr, const void *opcode, size_t len,
> > void *handler); extern int after_bootmem;
> >
> > +#ifndef CONFIG_UML_X86
> > static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned
> > long ip) {
> > regs->ip = ip;
> > @@ -65,6 +66,7 @@ static inline void int3_emulate_call(struct pt_regs
> > *regs, unsigned long func) int3_emulate_push(regs, regs->ip -
> > INT3_INSN_SIZE + CALL_INSN_SIZE); int3_emulate_jmp(regs, func);
> > }
> > -#endif
> > +#endif /* CONFIG_X86_64 */
> > +#endif /* !CONFIG_UML_X86 */
> >
> > #endif /* _ASM_X86_TEXT_PATCHING_H */
> >
> The patch has been garbled by an auto-wrap. Can you resend it please.
>

Anyway, it's already in Linus's tree. It was required to keep UML
compiling with other changes that needed to get into the merge window.

-- Steve