Re: [PATCH 5/6 v3] syscalls: Remove start and number from syscall_get_arguments() args
On Thu, 4 Apr 2019 21:17:58 +0300 "Dmitry V. Levin" wrote: > There are several places listed below where I'd prefer to see more readable > equivalents, but feel free to leave it to respective arch maintainers. I was going to do similar changes, but figured I'd do just that (let the arch maintainers further optimize the code). I made this more about fixing the interface and less about the optimization and clean ups that it can allow. -- Steve ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH 5/6 v3] syscalls: Remove start and number from syscall_get_arguments() args
On Mon, Apr 1, 2019 at 6:45 AM Steven Rostedt wrote: > > From: "Steven Rostedt (Red Hat)" > > At Linux Plumbers, Andy Lutomirski approached me and pointed out that the > function call syscall_get_arguments() implemented in x86 was horribly > written and not optimized for the standard case of passing in 0 and 6 for > the starting index and the number of system calls to get. When looking at > all the users of this function, I discovered that all instances pass in only > 0 and 6 for these arguments. Instead of having this function handle > different cases that are never used, simply rewrite it to return the first 6 > arguments of a system call. > > This should help out the performance of tracing system calls by ptrace, > ftrace and perf. [...] > arch/xtensa/include/asm/syscall.h | 16 ++ For xtensa changes: Acked-by: Max Filippov -- Thanks. -- Max ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH 5/6 v3] syscalls: Remove start and number from syscall_get_arguments() args
On Mon, Apr 01, 2019 at 09:41:09AM -0400, Steven Rostedt wrote:
> From: "Steven Rostedt (Red Hat)"
>
> At Linux Plumbers, Andy Lutomirski approached me and pointed out that the
> function call syscall_get_arguments() implemented in x86 was horribly
> written and not optimized for the standard case of passing in 0 and 6 for
> the starting index and the number of system calls to get. When looking at
> all the users of this function, I discovered that all instances pass in only
> 0 and 6 for these arguments. Instead of having this function handle
> different cases that are never used, simply rewrite it to return the first 6
> arguments of a system call.
>
> This should help out the performance of tracing system calls by ptrace,
> ftrace and perf.
>
> Link: http://lkml.kernel.org/r/20161107213233.754809...@goodmis.org
FWIW, you can add
Reviewed-by: Dmitry V. Levin
There are several places listed below where I'd prefer to see more readable
equivalents, but feel free to leave it to respective arch maintainers.
> diff --git a/arch/hexagon/include/asm/syscall.h
> b/arch/hexagon/include/asm/syscall.h
> index 4af9c7b6f13a..ae3a1e24fabd 100644
> --- a/arch/hexagon/include/asm/syscall.h
> +++ b/arch/hexagon/include/asm/syscall.h
> @@ -37,10 +37,8 @@ static inline long syscall_get_nr(struct task_struct *task,
>
> static inline void syscall_get_arguments(struct task_struct *task,
>struct pt_regs *regs,
> - unsigned int i, unsigned int n,
>unsigned long *args)
> {
> - BUG_ON(i + n > 6);
> - memcpy(args, &(®s->r00)[i], n * sizeof(args[0]));
> + memcpy(args, &(®s->r00)[0], 6 * sizeof(args[0]));
A shorter and slightly more readable equivalent is
memcpy(args, ®s->r00, 6 * sizeof(args[0]));
> diff --git a/arch/nds32/include/asm/syscall.h
> b/arch/nds32/include/asm/syscall.h
> index f7e5e86765fe..89a6ec8731d8 100644
> --- a/arch/nds32/include/asm/syscall.h
> +++ b/arch/nds32/include/asm/syscall.h
> @@ -108,42 +108,21 @@ void syscall_set_return_value(struct task_struct *task,
> struct pt_regs *regs,
> * syscall_get_arguments - extract system call parameter values
> * @task:task of interest, must be blocked
> * @regs:task_pt_regs() of @task
> - * @i: argument index [0,5]
> - * @n: number of arguments; n+i must be [1,6].
> * @args:array filled with argument values
> *
> - * Fetches @n arguments to the system call starting with the @i'th argument
> - * (from 0 through 5). Argument @i is stored in @args[0], and so on.
> - * An arch inline version is probably optimal when @i and @n are constants.
> + * Fetches 6 arguments to the system call (from 0 through 5). The first
> + * argument is stored in @args[0], and so on.
> *
> * It's only valid to call this when @task is stopped for tracing on
> * entry to a system call, due to %TIF_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT.
> - * It's invalid to call this with @i + @n > 6; we only support system calls
> - * taking up to 6 arguments.
> */
> #define SYSCALL_MAX_ARGS 6
> void syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
> -unsigned int i, unsigned int n, unsigned long *args)
> +unsigned long *args)
> {
> - if (n == 0)
> - return;
> - if (i + n > SYSCALL_MAX_ARGS) {
> - unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i;
> - unsigned int n_bad = n + i - SYSCALL_MAX_ARGS;
> - pr_warning("%s called with max args %d, handling only %d\n",
> -__func__, i + n, SYSCALL_MAX_ARGS);
> - memset(args_bad, 0, n_bad * sizeof(args[0]));
> - memset(args_bad, 0, n_bad * sizeof(args[0]));
> - }
> -
> - if (i == 0) {
> - args[0] = regs->orig_r0;
> - args++;
> - i++;
> - n--;
> - }
> -
> - memcpy(args, ®s->uregs[0] + i, n * sizeof(args[0]));
> + args[0] = regs->orig_r0;
> + args++;
> + memcpy(args, ®s->uregs[0] + 1, 5 * sizeof(args[0]));
> }
A shorter and slightly more readable equivalent of the last memcpy is
memcpy(args, ®s->uregs[1], 5 * sizeof(args[0]));
> diff --git a/arch/powerpc/include/asm/syscall.h
> b/arch/powerpc/include/asm/syscall.h
> index 1a0e7a8b1c81..5c9b9dc82b7e 100644
> --- a/arch/powerpc/include/asm/syscall.h
> +++ b/arch/powerpc/include/asm/syscall.h
> @@ -65,22 +65,20 @@ static inline void syscall_set_return_value(struct
> task_struct *task,
>
> static inline void syscall_get_arguments(struct task_struct *task,
>struct pt_regs *regs,
> - unsigned int i, unsigned int n,
>unsigned long *args)
> {
> unsigned long val, mask = -1UL;
> -
> - BUG_ON(i + n > 6);
> + unsigned int n = 6;
>
Re: [PATCH 5/6 v3] syscalls: Remove start and number from syscall_get_arguments() args
On Mon, 1 Apr 2019, Steven Rostedt wrote: > From: "Steven Rostedt (Red Hat)" > > At Linux Plumbers, Andy Lutomirski approached me and pointed out that the > function call syscall_get_arguments() implemented in x86 was horribly > written and not optimized for the standard case of passing in 0 and 6 for > the starting index and the number of system calls to get. When looking at > all the users of this function, I discovered that all instances pass in only > 0 and 6 for these arguments. Instead of having this function handle > different cases that are never used, simply rewrite it to return the first 6 > arguments of a system call. > > This should help out the performance of tracing system calls by ptrace, > ftrace and perf. > > Link: http://lkml.kernel.org/r/20161107213233.754809...@goodmis.org For x86: Reviewed-by: Thomas Gleixner ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH 5/6 v3] syscalls: Remove start and number from syscall_get_arguments() args
Hi Steven, On Mon, Apr 01, 2019 at 09:41:09AM -0400, Steven Rostedt wrote: > From: "Steven Rostedt (Red Hat)" > > At Linux Plumbers, Andy Lutomirski approached me and pointed out that the > function call syscall_get_arguments() implemented in x86 was horribly > written and not optimized for the standard case of passing in 0 and 6 for > the starting index and the number of system calls to get. When looking at > all the users of this function, I discovered that all instances pass in only > 0 and 6 for these arguments. Instead of having this function handle > different cases that are never used, simply rewrite it to return the first 6 > arguments of a system call. > > This should help out the performance of tracing system calls by ptrace, > ftrace and perf. > > Link: http://lkml.kernel.org/r/20161107213233.754809...@goodmis.org > > Cc: Oleg Nesterov > Cc: Thomas Gleixner > Cc: Kees Cook > Cc: Andy Lutomirski > Cc: Dominik Brodowski > Cc: Dave Martin > Cc: "Dmitry V. Levin" > Cc: x...@kernel.org > Cc: linux-snps-arc@lists.infradead.org > Cc: linux-ker...@vger.kernel.org > Cc: linux-arm-ker...@lists.infradead.org > Cc: linux-c6x-...@linux-c6x.org > Cc: uclinux-h8-de...@lists.sourceforge.jp > Cc: linux-hexa...@vger.kernel.org > Cc: linux-i...@vger.kernel.org > Cc: linux-m...@vger.kernel.org > Cc: nios2-...@lists.rocketboards.org > Cc: openr...@lists.librecores.org > Cc: linux-par...@vger.kernel.org > Cc: linuxppc-...@lists.ozlabs.org > Cc: linux-ri...@lists.infradead.org > Cc: linux-s...@vger.kernel.org > Cc: linux...@vger.kernel.org > Cc: sparcli...@vger.kernel.org > Cc: linux...@lists.infradead.org > Cc: linux-xte...@linux-xtensa.org > Cc: linux-a...@vger.kernel.org > Reported-by: Andy Lutomirski > Signed-off-by: Steven Rostedt (VMware) Acked-by: Paul Burton # MIPS parts Thanks, Paul ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[PATCH 5/6 v3] syscalls: Remove start and number from syscall_get_arguments() args
From: "Steven Rostedt (Red Hat)"
At Linux Plumbers, Andy Lutomirski approached me and pointed out that the
function call syscall_get_arguments() implemented in x86 was horribly
written and not optimized for the standard case of passing in 0 and 6 for
the starting index and the number of system calls to get. When looking at
all the users of this function, I discovered that all instances pass in only
0 and 6 for these arguments. Instead of having this function handle
different cases that are never used, simply rewrite it to return the first 6
arguments of a system call.
This should help out the performance of tracing system calls by ptrace,
ftrace and perf.
Link: http://lkml.kernel.org/r/20161107213233.754809...@goodmis.org
Cc: Oleg Nesterov
Cc: Thomas Gleixner
Cc: Kees Cook
Cc: Andy Lutomirski
Cc: Dominik Brodowski
Cc: Dave Martin
Cc: "Dmitry V. Levin"
Cc: x...@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-ker...@vger.kernel.org
Cc: linux-arm-ker...@lists.infradead.org
Cc: linux-c6x-...@linux-c6x.org
Cc: uclinux-h8-de...@lists.sourceforge.jp
Cc: linux-hexa...@vger.kernel.org
Cc: linux-i...@vger.kernel.org
Cc: linux-m...@vger.kernel.org
Cc: nios2-...@lists.rocketboards.org
Cc: openr...@lists.librecores.org
Cc: linux-par...@vger.kernel.org
Cc: linuxppc-...@lists.ozlabs.org
Cc: linux-ri...@lists.infradead.org
Cc: linux-s...@vger.kernel.org
Cc: linux...@vger.kernel.org
Cc: sparcli...@vger.kernel.org
Cc: linux...@lists.infradead.org
Cc: linux-xte...@linux-xtensa.org
Cc: linux-a...@vger.kernel.org
Reported-by: Andy Lutomirski
Signed-off-by: Steven Rostedt (VMware)
---
arch/arc/include/asm/syscall.h| 7 ++-
arch/arm/include/asm/syscall.h| 23 ++---
arch/arm64/include/asm/syscall.h | 22 ++--
arch/c6x/include/asm/syscall.h| 41 +++
arch/csky/include/asm/syscall.h | 14 ++---
arch/h8300/include/asm/syscall.h | 34 +++--
arch/hexagon/include/asm/syscall.h| 4 +-
arch/ia64/include/asm/syscall.h | 5 +-
arch/microblaze/include/asm/syscall.h | 4 +-
arch/mips/include/asm/syscall.h | 3 +-
arch/mips/kernel/ptrace.c | 2 +-
arch/nds32/include/asm/syscall.h | 33 +++-
arch/nios2/include/asm/syscall.h | 42 +++
arch/openrisc/include/asm/syscall.h | 6 +--
arch/parisc/include/asm/syscall.h | 30 +++
arch/powerpc/include/asm/syscall.h| 8 ++-
arch/riscv/include/asm/syscall.h | 13 ++---
arch/s390/include/asm/syscall.h | 17 ++-
arch/sh/include/asm/syscall_32.h | 26 +++---
arch/sh/include/asm/syscall_64.h | 4 +-
arch/sparc/include/asm/syscall.h | 4 +-
arch/um/include/asm/syscall-generic.h | 39 +++---
arch/x86/include/asm/syscall.h| 73 +++
arch/xtensa/include/asm/syscall.h | 16 ++
include/asm-generic/syscall.h | 11 ++--
include/trace/events/syscalls.h | 2 +-
kernel/seccomp.c | 2 +-
kernel/trace/trace_syscalls.c | 4 +-
lib/syscall.c | 2 +-
29 files changed, 113 insertions(+), 378 deletions(-)
diff --git a/arch/arc/include/asm/syscall.h b/arch/arc/include/asm/syscall.h
index 29de09804306..c7a4201ed62b 100644
--- a/arch/arc/include/asm/syscall.h
+++ b/arch/arc/include/asm/syscall.h
@@ -55,12 +55,11 @@ syscall_set_return_value(struct task_struct *task, struct
pt_regs *regs,
*/
static inline void
syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
- unsigned int i, unsigned int n, unsigned long *args)
+ unsigned long *args)
{
unsigned long *inside_ptregs = &(regs->r0);
- inside_ptregs -= i;
-
- BUG_ON((i + n) > 6);
+ unsigned int n = 6;
+ unsigned int i = 0;
while (n--) {
args[i++] = (*inside_ptregs);
diff --git a/arch/arm/include/asm/syscall.h b/arch/arm/include/asm/syscall.h
index 06dea6bce293..db969a2972ae 100644
--- a/arch/arm/include/asm/syscall.h
+++ b/arch/arm/include/asm/syscall.h
@@ -55,29 +55,12 @@ static inline void syscall_set_return_value(struct
task_struct *task,
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
-unsigned int i, unsigned int n,
unsigned long *args)
{
- if (n == 0)
- return;
-
- if (i + n > SYSCALL_MAX_ARGS) {
- unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i;
- unsigned int n_bad = n + i - SYSCALL_MAX_ARGS;
- pr_warn("%s called with max args %d, handling only %d\n",
- __func__, i + n, SYSCALL_MAX_ARGS);
- memset(args_bad, 0, n_bad * sizeof(args[0]));
- n = SYSCALL_MAX_ARGS - i;
- }
-
- if (i == 0) {
- args[0] = regs->ARM_ORIG_r0;
-
