> diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
> index 3777189..e398d03 100644
> --- a/arch/x86/entry/syscall_32.c
> +++ b/arch/x86/entry/syscall_32.c
> @@ -10,7 +10,7 @@
> #else
> #define SYM(sym, compat) sym
> #define ia32_sys_call_table sys_call_table
> -#define __NR_ia32_syscall_max __NR_syscall_max
> +#define __NR_entry_INT80_compat_max __NR_syscall_max
> #endif
This change doesn't look intended. __NR_ia32_syscall_max is used by
all compat entry points, not just INT80,
--
Brian Gerst
* Brian Gerst <[email protected]> wrote:
> > diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
> > index 3777189..e398d03 100644
> > --- a/arch/x86/entry/syscall_32.c
> > +++ b/arch/x86/entry/syscall_32.c
> > @@ -10,7 +10,7 @@
> > #else
> > #define SYM(sym, compat) sym
> > #define ia32_sys_call_table sys_call_table
> > -#define __NR_ia32_syscall_max __NR_syscall_max
> > +#define __NR_entry_INT80_compat_max __NR_syscall_max
> > #endif
>
> This change doesn't look intended. __NR_ia32_syscall_max is used by
> all compat entry points, not just INT80,
Indeed!
How about the patch below?
Thanks,
Ingo
================>
>From 42b9d9a463bfb7252ede4eac24e50a4f013c6717 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <[email protected]>
Date: Mon, 8 Jun 2015 21:20:26 +0200
Subject: [PATCH] x86/asm/entry: (Re-)rename __NR_entry_INT80_compat_max to __NR_syscall_compat_max
Brian Gerst noticed that I did a weird rename in the following commit:
b2502b418e63 ("x86/asm/entry: Untangle 'system_call' into two entry points: entry_SYSCALL_64 and entry_INT80_32")
which renamed __NR_ia32_syscall_max to __NR_entry_INT80_compat_max.
Now the original name was a misnomer, but the new one is a misnomer as well,
as all compat syscall ABIs (such as x32) share the system call table, not just
INT80 based ones.
Rename it to __NR_syscall_compat_max.
Reported-by: Brian Gerst <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/entry/syscall_32.c | 6 +++---
arch/x86/kernel/asm-offsets_64.c | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index e398d033673f..8ea34f94e973 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -10,7 +10,7 @@
#else
#define SYM(sym, compat) sym
#define ia32_sys_call_table sys_call_table
-#define __NR_entry_INT80_compat_max __NR_syscall_max
+#define __NR_syscall_compat_max __NR_syscall_max
#endif
#define __SYSCALL_I386(nr, sym, compat) extern asmlinkage void SYM(sym, compat)(void) ;
@@ -23,11 +23,11 @@ typedef asmlinkage void (*sys_call_ptr_t)(void);
extern asmlinkage void sys_ni_syscall(void);
-__visible const sys_call_ptr_t ia32_sys_call_table[__NR_entry_INT80_compat_max+1] = {
+__visible const sys_call_ptr_t ia32_sys_call_table[__NR_syscall_compat_max+1] = {
/*
* Smells like a compiler bug -- it doesn't work
* when the & below is removed.
*/
- [0 ... __NR_entry_INT80_compat_max] = &sys_ni_syscall,
+ [0 ... __NR_syscall_compat_max] = &sys_ni_syscall,
#include <asm/syscalls_32.h>
};
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index 599afcf0005f..d8f42f902a0f 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -66,7 +66,7 @@ int main(void)
DEFINE(__NR_syscall_max, sizeof(syscalls_64) - 1);
DEFINE(NR_syscalls, sizeof(syscalls_64));
- DEFINE(__NR_entry_INT80_compat_max, sizeof(syscalls_ia32) - 1);
+ DEFINE(__NR_syscall_compat_max, sizeof(syscalls_ia32) - 1);
DEFINE(IA32_NR_syscalls, sizeof(syscalls_ia32));
return 0;
On Mon, Jun 8, 2015 at 3:25 PM, Ingo Molnar <[email protected]> wrote:
>
> * Brian Gerst <[email protected]> wrote:
>
>> > diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
>> > index 3777189..e398d03 100644
>> > --- a/arch/x86/entry/syscall_32.c
>> > +++ b/arch/x86/entry/syscall_32.c
>> > @@ -10,7 +10,7 @@
>> > #else
>> > #define SYM(sym, compat) sym
>> > #define ia32_sys_call_table sys_call_table
>> > -#define __NR_ia32_syscall_max __NR_syscall_max
>> > +#define __NR_entry_INT80_compat_max __NR_syscall_max
>> > #endif
>>
>> This change doesn't look intended. __NR_ia32_syscall_max is used by
>> all compat entry points, not just INT80,
>
> Indeed!
>
> How about the patch below?
>
> Thanks,
>
> Ingo
>
> ================>
> From 42b9d9a463bfb7252ede4eac24e50a4f013c6717 Mon Sep 17 00:00:00 2001
> From: Ingo Molnar <[email protected]>
> Date: Mon, 8 Jun 2015 21:20:26 +0200
> Subject: [PATCH] x86/asm/entry: (Re-)rename __NR_entry_INT80_compat_max to __NR_syscall_compat_max
>
> Brian Gerst noticed that I did a weird rename in the following commit:
>
> b2502b418e63 ("x86/asm/entry: Untangle 'system_call' into two entry points: entry_SYSCALL_64 and entry_INT80_32")
>
> which renamed __NR_ia32_syscall_max to __NR_entry_INT80_compat_max.
>
> Now the original name was a misnomer, but the new one is a misnomer as well,
> as all compat syscall ABIs (such as x32) share the system call table, not just
> INT80 based ones.
Not quite true. X32 is really an extension of the 64-bit ABI to
support the ILP32 data model. It uses the 64-bit SYSCALL entry point
and table, but with different syscall numbers for the syscalls that
need 32-bit pointer handling in data structures.
So, __NR_syscall_compat_max is only for the 32-bit ABI compat syscall
entries (int80, sysenter, and syscall from 32-bit mode), and not X32.
--
Brian Gerst
* Brian Gerst <[email protected]> wrote:
> On Mon, Jun 8, 2015 at 3:25 PM, Ingo Molnar <[email protected]> wrote:
> >
> > * Brian Gerst <[email protected]> wrote:
> >
> >> > diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
> >> > index 3777189..e398d03 100644
> >> > --- a/arch/x86/entry/syscall_32.c
> >> > +++ b/arch/x86/entry/syscall_32.c
> >> > @@ -10,7 +10,7 @@
> >> > #else
> >> > #define SYM(sym, compat) sym
> >> > #define ia32_sys_call_table sys_call_table
> >> > -#define __NR_ia32_syscall_max __NR_syscall_max
> >> > +#define __NR_entry_INT80_compat_max __NR_syscall_max
> >> > #endif
> >>
> >> This change doesn't look intended. __NR_ia32_syscall_max is used by
> >> all compat entry points, not just INT80,
> >
> > Indeed!
> >
> > How about the patch below?
> >
> > Thanks,
> >
> > Ingo
> >
> > ================>
> > From 42b9d9a463bfb7252ede4eac24e50a4f013c6717 Mon Sep 17 00:00:00 2001
> > From: Ingo Molnar <[email protected]>
> > Date: Mon, 8 Jun 2015 21:20:26 +0200
> > Subject: [PATCH] x86/asm/entry: (Re-)rename __NR_entry_INT80_compat_max to __NR_syscall_compat_max
> >
> > Brian Gerst noticed that I did a weird rename in the following commit:
> >
> > b2502b418e63 ("x86/asm/entry: Untangle 'system_call' into two entry points: entry_SYSCALL_64 and entry_INT80_32")
> >
> > which renamed __NR_ia32_syscall_max to __NR_entry_INT80_compat_max.
> >
> > Now the original name was a misnomer, but the new one is a misnomer as well,
> > as all compat syscall ABIs (such as x32) share the system call table, not just
> > INT80 based ones.
>
> Not quite true. X32 is really an extension of the 64-bit ABI to support the
> ILP32 data model. It uses the 64-bit SYSCALL entry point and table, but with
> different syscall numbers for the syscalls that need 32-bit pointer handling in
> data structures.
>
> So, __NR_syscall_compat_max is only for the 32-bit ABI compat syscall entries
> (int80, sysenter, and syscall from 32-bit mode), and not X32.
Indeed, and I knew this...
Fixed the brainfart in the changelog.
Thanks,
Ingo