Syscalls without arguments now has no ABI subs, instead of that macro
SYSCALL_DEFINE0() defines __abi_sys_name as aliase to __do_sys_name.
As a result in find_syscall_meta() kallsyms_lookup() returns
"__do_sys_name" which does not match with declared trace event.
Also see commit 1c758a2202a6 ("tracing/x86: Update syscall trace events
to handle new prefixed syscall func names")
Fixes: d2b5de495ee9 ("x86/entry: Refactor SYSCALL_DEFINE0 macros")
Signed-off-by: Konstantin Khlebnikov <[email protected]>
---
arch/x86/include/asm/ftrace.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 85be2f506272..70b96cae5b42 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -61,11 +61,12 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name
{
/*
* Compare the symbol name with the system call name. Skip the
- * "__x64_sys", "__ia32_sys" or simple "sys" prefix.
+ * "__x64_sys", "__ia32_sys", "__do_sys" or simple "sys" prefix.
*/
return !strcmp(sym + 3, name + 3) ||
(!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
- (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3));
+ (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3)) ||
+ (!strncmp(sym, "__do_sys", 8) && !strcmp(sym + 8, name + 3));
}
#ifndef COMPILE_OFFSETS
Bump, bug still present in 5.7.0-rc3
root@kernel0:~# uname -r
5.7.0-rc3-test
root@kernel0:~# ls -d /sys/kernel/tracing/events/syscalls/sys_enter_{sync,fsync}
ls: cannot access '/sys/kernel/tracing/events/syscalls/sys_enter_sync': No such file or directory
/sys/kernel/tracing/events/syscalls/sys_enter_fsync
On 08/04/2020 21.13, Konstantin Khlebnikov wrote:
> Syscalls without arguments now has no ABI subs, instead of that macro
> SYSCALL_DEFINE0() defines __abi_sys_name as aliase to __do_sys_name.
>
> As a result in find_syscall_meta() kallsyms_lookup() returns
> "__do_sys_name" which does not match with declared trace event.
>
> Also see commit 1c758a2202a6 ("tracing/x86: Update syscall trace events
> to handle new prefixed syscall func names")
>
> Fixes: d2b5de495ee9 ("x86/entry: Refactor SYSCALL_DEFINE0 macros")
> Signed-off-by: Konstantin Khlebnikov <[email protected]>
> ---
> arch/x86/include/asm/ftrace.h | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
> index 85be2f506272..70b96cae5b42 100644
> --- a/arch/x86/include/asm/ftrace.h
> +++ b/arch/x86/include/asm/ftrace.h
> @@ -61,11 +61,12 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name
> {
> /*
> * Compare the symbol name with the system call name. Skip the
> - * "__x64_sys", "__ia32_sys" or simple "sys" prefix.
> + * "__x64_sys", "__ia32_sys", "__do_sys" or simple "sys" prefix.
> */
> return !strcmp(sym + 3, name + 3) ||
> (!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
> - (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3));
> + (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3)) ||
> + (!strncmp(sym, "__do_sys", 8) && !strcmp(sym + 8, name + 3));
> }
>
> #ifndef COMPILE_OFFSETS
>
Konstantin Khlebnikov <[email protected]> writes:
> Syscalls without arguments now has no ABI subs, instead of that macro
What is 'ABI subs'?
> SYSCALL_DEFINE0() defines __abi_sys_name as aliase to __do_sys_name.
>
> As a result in find_syscall_meta() kallsyms_lookup() returns
> "__do_sys_name" which does not match with declared trace event.
>
> Also see commit 1c758a2202a6 ("tracing/x86: Update syscall trace events
> to handle new prefixed syscall func names")
>
> Fixes: d2b5de495ee9 ("x86/entry: Refactor SYSCALL_DEFINE0 macros")
> Signed-off-by: Konstantin Khlebnikov <[email protected]>
> ---
> arch/x86/include/asm/ftrace.h | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
> index 85be2f506272..70b96cae5b42 100644
> --- a/arch/x86/include/asm/ftrace.h
> +++ b/arch/x86/include/asm/ftrace.h
> @@ -61,11 +61,12 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name
> {
> /*
> * Compare the symbol name with the system call name. Skip the
> - * "__x64_sys", "__ia32_sys" or simple "sys" prefix.
> + * "__x64_sys", "__ia32_sys", "__do_sys" or simple "sys" prefix.
> */
> return !strcmp(sym + 3, name + 3) ||
> (!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
> - (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3));
> + (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3)) ||
> + (!strncmp(sym, "__do_sys", 8) && !strcmp(sym + 8, name + 3));
> }
>
> #ifndef COMPILE_OFFSETS
On 27/04/2020 17.44, Thomas Gleixner wrote:
> Konstantin Khlebnikov <[email protected]> writes:
>
>> Syscalls without arguments now has no ABI subs, instead of that macro
>
> What is 'ABI subs'?
typo. ABI stubs
That commmit d2b5de495ee9 ("x86/entry: Refactor SYSCALL_DEFINE0 macros")
replaced usual wrapper
long __x64_syscall()
{
return __do_sys_syscall();
}
with alias
long __x64_syscall() __alias__(__do_sys_syscall);
And now symbol lookup for entry point return "__do_sys_syscall"
rather than "__x64_syscall" and ftrace magic cannot determine
syscall number for entry point and vise versa.
>
>> SYSCALL_DEFINE0() defines __abi_sys_name as aliase to __do_sys_name.
>>
>> As a result in find_syscall_meta() kallsyms_lookup() returns
>> "__do_sys_name" which does not match with declared trace event.
>>
>> Also see commit 1c758a2202a6 ("tracing/x86: Update syscall trace events
>> to handle new prefixed syscall func names")
>>
>> Fixes: d2b5de495ee9 ("x86/entry: Refactor SYSCALL_DEFINE0 macros")
>> Signed-off-by: Konstantin Khlebnikov <[email protected]>
>> ---
>> arch/x86/include/asm/ftrace.h | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
>> index 85be2f506272..70b96cae5b42 100644
>> --- a/arch/x86/include/asm/ftrace.h
>> +++ b/arch/x86/include/asm/ftrace.h
>> @@ -61,11 +61,12 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name
>> {
>> /*
>> * Compare the symbol name with the system call name. Skip the
>> - * "__x64_sys", "__ia32_sys" or simple "sys" prefix.
>> + * "__x64_sys", "__ia32_sys", "__do_sys" or simple "sys" prefix.
>> */
>> return !strcmp(sym + 3, name + 3) ||
>> (!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
>> - (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3));
>> + (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3)) ||
>> + (!strncmp(sym, "__do_sys", 8) && !strcmp(sym + 8, name + 3));
>> }
>>
>> #ifndef COMPILE_OFFSETS
On Mon, 27 Apr 2020 16:16:20 +0300
Konstantin Khlebnikov <[email protected]> wrote:
> Bump, bug still present in 5.7.0-rc3
>
> root@kernel0:~# uname -r
> 5.7.0-rc3-test
>
> root@kernel0:~# ls -d /sys/kernel/tracing/events/syscalls/sys_enter_{sync,fsync}
> ls: cannot access '/sys/kernel/tracing/events/syscalls/sys_enter_sync': No such file or directory
> /sys/kernel/tracing/events/syscalls/sys_enter_fsync
>
> On 08/04/2020 21.13, Konstantin Khlebnikov wrote:
> > Syscalls without arguments now has no ABI subs, instead of that macro
> > SYSCALL_DEFINE0() defines __abi_sys_name as aliase to __do_sys_name.
> >
> > As a result in find_syscall_meta() kallsyms_lookup() returns
> > "__do_sys_name" which does not match with declared trace event.
> >
> > Also see commit 1c758a2202a6 ("tracing/x86: Update syscall trace events
> > to handle new prefixed syscall func names")
This is the first I've seen of this patch.
> >
> > Fixes: d2b5de495ee9 ("x86/entry: Refactor SYSCALL_DEFINE0 macros")
> > Signed-off-by: Konstantin Khlebnikov <[email protected]>
> > ---
> > arch/x86/include/asm/ftrace.h | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
> > index 85be2f506272..70b96cae5b42 100644
> > --- a/arch/x86/include/asm/ftrace.h
> > +++ b/arch/x86/include/asm/ftrace.h
> > @@ -61,11 +61,12 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name
> > {
> > /*
> > * Compare the symbol name with the system call name. Skip the
> > - * "__x64_sys", "__ia32_sys" or simple "sys" prefix.
> > + * "__x64_sys", "__ia32_sys", "__do_sys" or simple "sys" prefix.
> > */
> > return !strcmp(sym + 3, name + 3) ||
> > (!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
> > - (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3));
> > + (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3)) ||
> > + (!strncmp(sym, "__do_sys", 8) && !strcmp(sym + 8, name + 3));
> > }
Acked-by: Steven Rostedt (VMware) <[email protected]>
-- Steve
> >
> > #ifndef COMPILE_OFFSETS
> >
The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: fdc63ff0e49c588884992b4b2656345a5e878b32
Gitweb: https://git.kernel.org/tip/fdc63ff0e49c588884992b4b2656345a5e878b32
Author: Konstantin Khlebnikov <[email protected]>
AuthorDate: Wed, 08 Apr 2020 21:13:10 +03:00
Committer: Thomas Gleixner <[email protected]>
CommitterDate: Fri, 01 May 2020 19:15:40 +02:00
ftrace/x86: Fix trace event registration for syscalls without arguments
The refactoring of SYSCALL_DEFINE0() macros removed the ABI stubs and
simply defines __abi_sys_$NAME as alias of __do_sys_$NAME.
As a result kallsyms_lookup() returns "__do_sys_$NAME" which does not match
with the declared trace event name.
See also commit 1c758a2202a6 ("tracing/x86: Update syscall trace events to
handle new prefixed syscall func names").
Add __do_sys_ to the valid prefixes which are checked in
arch_syscall_match_sym_name().
Fixes: d2b5de495ee9 ("x86/entry: Refactor SYSCALL_DEFINE0 macros")
Signed-off-by: Konstantin Khlebnikov <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Link: https://lkml.kernel.org/r/158636958997.7900.16485049455470033557.stgit@buzz
---
arch/x86/include/asm/ftrace.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 85be2f5..70b96ca 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -61,11 +61,12 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name
{
/*
* Compare the symbol name with the system call name. Skip the
- * "__x64_sys", "__ia32_sys" or simple "sys" prefix.
+ * "__x64_sys", "__ia32_sys", "__do_sys" or simple "sys" prefix.
*/
return !strcmp(sym + 3, name + 3) ||
(!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
- (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3));
+ (!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3)) ||
+ (!strncmp(sym, "__do_sys", 8) && !strcmp(sym + 8, name + 3));
}
#ifndef COMPILE_OFFSETS