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syscalls: Remove start and number from syscall_get_arguments() args 

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/20161107213233.754809394@goodmis.org

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Dave Martin <dave.martin@arm.com>
Cc: "Dmitry V. Levin" <ldv@altlinux.org>
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-arch@vger.kernel.org
Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts
Acked-by: Max Filippov <jcmvbkbc@gmail.com> # For xtensa changes
Acked-by: Will Deacon <will.deacon@arm.com> # For the arm64 bits
Reviewed-by: Thomas Gleixner <tglx@linutronix.de> # for x86
Reviewed-by: Dmitry V. Levin <ldv@altlinux.org>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Red Hat) 2016-11-07 16:26:37 -05:00 committed by Steven Rostedt (VMware)
parent ed3bb00702
commit b35f549df1
29 changed files with 113 additions and 378 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/arc/include/asm/syscall.h
View File

@ -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);

23
arch/arm/include/asm/syscall.h
View File

@ -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;
args[0] = regs->ARM_ORIG_r0;
args++;
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;
args++;
i++;
n--;
}
memcpy(args, &regs->ARM_r0 + i, n * sizeof(args[0]));
memcpy(args, &regs->ARM_r0 + 1, 5 * sizeof(args[0]));
}
static inline void syscall_set_arguments(struct task_struct *task,

22
arch/arm64/include/asm/syscall.h
View File

@ -65,28 +65,12 @@ 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;
args[0] = regs->orig_x0;
args++;
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]));
}
if (i == 0) {
args[0] = regs->orig_x0;
args++;
i++;
n--;
}
memcpy(args, &regs->regs[i], n * sizeof(args[0]));
memcpy(args, &regs->regs[1], 5 * sizeof(args[0]));
}
static inline void syscall_set_arguments(struct task_struct *task,

41
arch/c6x/include/asm/syscall.h
View File

@ -46,40 +46,15 @@ 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)
struct pt_regs *regs,
unsigned long *args)
{
switch (i) {
case 0:
if (!n--)
break;
*args++ = regs->a4;
case 1:
if (!n--)
break;
*args++ = regs->b4;
case 2:
if (!n--)
break;
*args++ = regs->a6;
case 3:
if (!n--)
break;
*args++ = regs->b6;
case 4:
if (!n--)
break;
*args++ = regs->a8;
case 5:
if (!n--)
break;
*args++ = regs->b8;
case 6:
if (!n--)
break;
default:
BUG();
}
*args++ = regs->a4;
*args++ = regs->b4;
*args++ = regs->a6;
*args++ = regs->b6;
*args++ = regs->a8;
*args = regs->b8;
}
static inline void syscall_set_arguments(struct task_struct *task,

14
arch/csky/include/asm/syscall.h
View File

@ -43,17 +43,11 @@ 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)
{
BUG_ON(i + n > 6);
if (i == 0) {
args[0] = regs->orig_a0;
args++;
n--;
} else {
i--;
}
memcpy(args, &regs->a1 + i, n * sizeof(args[0]));
args[0] = regs->orig_a0;
args++;
memcpy(args, &regs->a1, 5 * sizeof(args[0]));
}
static inline void

34
arch/h8300/include/asm/syscall.h
View File

@ -17,34 +17,14 @@ syscall_get_nr(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)
{
BUG_ON(i + n > 6);
while (n > 0) {
switch (i) {
case 0:
*args++ = regs->er1;
break;
case 1:
*args++ = regs->er2;
break;
case 2:
*args++ = regs->er3;
break;
case 3:
*args++ = regs->er4;
break;
case 4:
*args++ = regs->er5;
break;
case 5:
*args++ = regs->er6;
break;
}
i++;
n--;
}
*args++ = regs->er1;
*args++ = regs->er2;
*args++ = regs->er3;
*args++ = regs->er4;
*args++ = regs->er5;
*args = regs->er6;
}

4
arch/hexagon/include/asm/syscall.h
View File

@ -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, &(&regs->r00)[i], n * sizeof(args[0]));
memcpy(args, &(&regs->r00)[0], 6 * sizeof(args[0]));
}
#endif

5
arch/ia64/include/asm/syscall.h
View File

@ -63,12 +63,9 @@ extern void ia64_syscall_get_set_arguments(struct task_struct *task,
unsigned long *args, int rw);
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);
ia64_syscall_get_set_arguments(task, regs, i, n, args, 0);
ia64_syscall_get_set_arguments(task, regs, 0, 6, args, 0);
}
static inline void syscall_set_arguments(struct task_struct *task,

4
arch/microblaze/include/asm/syscall.h
View File

@ -82,9 +82,11 @@ static inline void microblaze_set_syscall_arg(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 int i = 0;
unsigned int n = 6;
while (n--)
*args++ = microblaze_get_syscall_arg(regs, i++);
}

3
arch/mips/include/asm/syscall.h
View File

@ -116,9 +116,10 @@ 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 int i = 0;
unsigned int n = 6;
int ret;
/* O32 ABI syscall() */

2
arch/mips/kernel/ptrace.c
View File

@ -1419,7 +1419,7 @@ asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
sd.nr = syscall;
sd.arch = syscall_get_arch();
syscall_get_arguments(current, regs, 0, 6, args);
syscall_get_arguments(current, regs, args);
for (i = 0; i < 6; i++)
sd.args[i] = args[i];
sd.instruction_pointer = KSTK_EIP(current);

33
arch/nds32/include/asm/syscall.h
View File

@ -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, &regs->uregs[0] + i, n * sizeof(args[0]));
args[0] = regs->orig_r0;
args++;
memcpy(args, &regs->uregs[0] + 1, 5 * sizeof(args[0]));
}
/**

42
arch/nios2/include/asm/syscall.h
View File

@ -58,42 +58,14 @@ 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)
struct pt_regs *regs, unsigned long *args)
{
BUG_ON(i + n > 6);
switch (i) {
case 0:
if (!n--)
break;
*args++ = regs->r4;
case 1:
if (!n--)
break;
*args++ = regs->r5;
case 2:
if (!n--)
break;
*args++ = regs->r6;
case 3:
if (!n--)
break;
*args++ = regs->r7;
case 4:
if (!n--)
break;
*args++ = regs->r8;
case 5:
if (!n--)
break;
*args++ = regs->r9;
case 6:
if (!n--)
break;
default:
BUG();
}
*args++ = regs->r4;
*args++ = regs->r5;
*args++ = regs->r6;
*args++ = regs->r7;
*args++ = regs->r8;
*args = regs->r9;
}
static inline void syscall_set_arguments(struct task_struct *task,

6
arch/openrisc/include/asm/syscall.h
View File

@ -56,11 +56,9 @@ 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)
{
BUG_ON(i + n > 6);
memcpy(args, &regs->gpr[3 + i], n * sizeof(args[0]));
memcpy(args, &regs->gpr[3], 6 * sizeof(args[0]));
}
static inline void

30
arch/parisc/include/asm/syscall.h
View File

@ -18,29 +18,15 @@ static inline long syscall_get_nr(struct task_struct *tsk,
}
static inline void syscall_get_arguments(struct task_struct *tsk,
struct pt_regs *regs, unsigned int i,
unsigned int n, unsigned long *args)
struct pt_regs *regs,
unsigned long *args)
{
BUG_ON(i);
switch (n) {
case 6:
args[5] = regs->gr[21];
case 5:
args[4] = regs->gr[22];
case 4:
args[3] = regs->gr[23];
case 3:
args[2] = regs->gr[24];
case 2:
args[1] = regs->gr[25];
case 1:
args[0] = regs->gr[26];
case 0:
break;
default:
BUG();
}
args[5] = regs->gr[21];
args[4] = regs->gr[22];
args[3] = regs->gr[23];
args[2] = regs->gr[24];
args[1] = regs->gr[25];
args[0] = regs->gr[26];
}
static inline long syscall_get_return_value(struct task_struct *task,

8
arch/powerpc/include/asm/syscall.h
View File

@ -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;
#ifdef CONFIG_COMPAT
if (test_tsk_thread_flag(task, TIF_32BIT))
mask = 0xffffffff;
#endif
while (n--) {
if (n == 0 && i == 0)
if (n == 0)
val = regs->orig_gpr3;
else
val = regs->gpr[3 + i + n];
val = regs->gpr[3 + n];
args[n] = val & mask;
}

13
arch/riscv/include/asm/syscall.h
View File

@ -72,18 +72,11 @@ 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)
{
BUG_ON(i + n > 6);
if (i == 0) {
args[0] = regs->orig_a0;
args++;
n--;
} else {
i--;
}
memcpy(args, &regs->a1 + i, n * sizeof(args[0]));
args[0] = regs->orig_a0;
args++;
memcpy(args, &regs->a1, 5 * sizeof(args[0]));
}
static inline void syscall_set_arguments(struct task_struct *task,

17
arch/s390/include/asm/syscall.h
View File

@ -56,27 +56,20 @@ 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 mask = -1UL;
unsigned int n = 6;
/*
* No arguments for this syscall, there's nothing to do.
*/
if (!n)
return;
BUG_ON(i + n > 6);
#ifdef CONFIG_COMPAT
if (test_tsk_thread_flag(task, TIF_31BIT))
mask = 0xffffffff;
#endif
while (n-- > 0)
if (i + n > 0)
args[n] = regs->gprs[2 + i + n] & mask;
if (i == 0)
args[0] = regs->orig_gpr2 & mask;
if (n > 0)
args[n] = regs->gprs[2 + n] & mask;
args[0] = regs->orig_gpr2 & mask;
}
static inline void syscall_set_arguments(struct task_struct *task,

26
arch/sh/include/asm/syscall_32.h
View File

@ -48,30 +48,16 @@ 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)
{
/*
* Do this simply for now. If we need to start supporting
* fetching arguments from arbitrary indices, this will need some
* extra logic. Presently there are no in-tree users that depend
* on this behaviour.
*/
BUG_ON(i);
/* Argument pattern is: R4, R5, R6, R7, R0, R1 */
switch (n) {
case 6: args[5] = regs->regs[1];
case 5: args[4] = regs->regs[0];
case 4: args[3] = regs->regs[7];
case 3: args[2] = regs->regs[6];
case 2: args[1] = regs->regs[5];
case 1: args[0] = regs->regs[4];
case 0:
break;
default:
BUG();
}
args[5] = regs->regs[1];
args[4] = regs->regs[0];
args[3] = regs->regs[7];
args[2] = regs->regs[6];
args[1] = regs->regs[5];
args[0] = regs->regs[4];
}
static inline void syscall_set_arguments(struct task_struct *task,

4
arch/sh/include/asm/syscall_64.h
View File

@ -47,11 +47,9 @@ 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)
{
BUG_ON(i + n > 6);
memcpy(args, &regs->regs[2 + i], n * sizeof(args[0]));
memcpy(args, &regs->regs[2], 6 * sizeof(args[0]));
}
static inline void syscall_set_arguments(struct task_struct *task,

4
arch/sparc/include/asm/syscall.h
View File

@ -96,11 +96,11 @@ 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)
{
int zero_extend = 0;
unsigned int j;
unsigned int n = 6;
#ifdef CONFIG_SPARC64
if (test_tsk_thread_flag(task, TIF_32BIT))
@ -108,7 +108,7 @@ static inline void syscall_get_arguments(struct task_struct *task,
#endif
for (j = 0; j < n; j++) {
unsigned long val = regs->u_regs[UREG_I0 + i + j];
unsigned long val = regs->u_regs[UREG_I0 + j];
if (zero_extend)
args[j] = (u32) val;

39
arch/um/include/asm/syscall-generic.h
View File

@ -53,43 +53,16 @@ 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)
{
const struct uml_pt_regs *r = &regs->regs;
switch (i) {
case 0:
if (!n--)
break;
*args++ = UPT_SYSCALL_ARG1(r);
case 1:
if (!n--)
break;
*args++ = UPT_SYSCALL_ARG2(r);
case 2:
if (!n--)
break;
*args++ = UPT_SYSCALL_ARG3(r);
case 3:
if (!n--)
break;
*args++ = UPT_SYSCALL_ARG4(r);
case 4:
if (!n--)
break;
*args++ = UPT_SYSCALL_ARG5(r);
case 5:
if (!n--)
break;
*args++ = UPT_SYSCALL_ARG6(r);
case 6:
if (!n--)
break;
default:
BUG();
break;
}
*args++ = UPT_SYSCALL_ARG1(r);
*args++ = UPT_SYSCALL_ARG2(r);
*args++ = UPT_SYSCALL_ARG3(r);
*args++ = UPT_SYSCALL_ARG4(r);
*args++ = UPT_SYSCALL_ARG5(r);
*args = UPT_SYSCALL_ARG6(r);
}
static inline void syscall_set_arguments(struct task_struct *task,

73
arch/x86/include/asm/syscall.h
View File

@ -91,11 +91,9 @@ 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)
{
BUG_ON(i + n > 6);
memcpy(args, &regs->bx + i, n * sizeof(args[0]));
memcpy(args, &regs->bx, 6 * sizeof(args[0]));
}
static inline void syscall_set_arguments(struct task_struct *task,
@ -116,63 +114,26 @@ static inline int syscall_get_arch(void)
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
unsigned long *args)
{
# ifdef CONFIG_IA32_EMULATION
if (task->thread_info.status & TS_COMPAT)
switch (i) {
case 0:
if (!n--) break;
*args++ = regs->bx;
case 1:
if (!n--) break;
*args++ = regs->cx;
case 2:
if (!n--) break;
*args++ = regs->dx;
case 3:
if (!n--) break;
*args++ = regs->si;
case 4:
if (!n--) break;
*args++ = regs->di;
case 5:
if (!n--) break;
*args++ = regs->bp;
case 6:
if (!n--) break;
default:
BUG();
break;
}
else
if (task->thread_info.status & TS_COMPAT) {
*args++ = regs->bx;
*args++ = regs->cx;
*args++ = regs->dx;
*args++ = regs->si;
*args++ = regs->di;
*args = regs->bp;
} else
# endif
switch (i) {
case 0:
if (!n--) break;
*args++ = regs->di;
case 1:
if (!n--) break;
*args++ = regs->si;
case 2:
if (!n--) break;
*args++ = regs->dx;
case 3:
if (!n--) break;
*args++ = regs->r10;
case 4:
if (!n--) break;
*args++ = regs->r8;
case 5:
if (!n--) break;
*args++ = regs->r9;
case 6:
if (!n--) break;
default:
BUG();
break;
}
{
*args++ = regs->di;
*args++ = regs->si;
*args++ = regs->dx;
*args++ = regs->r10;
*args++ = regs->r8;
*args = regs->r9;
}
}
static inline void syscall_set_arguments(struct task_struct *task,

16
arch/xtensa/include/asm/syscall.h
View File

@ -59,23 +59,13 @@ 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)
{
static const unsigned int reg[] = XTENSA_SYSCALL_ARGUMENT_REGS;
unsigned int j;
unsigned int i;
if (n == 0)
return;
WARN_ON_ONCE(i + n > SYSCALL_MAX_ARGS);
for (j = 0; j < n; ++j) {
if (i + j < SYSCALL_MAX_ARGS)
args[j] = regs->areg[reg[i + j]];
else
args[j] = 0;
}
for (i = 0; i < 6; ++i)
args[i] = regs->areg[reg[i]];
}
static inline void syscall_set_arguments(struct task_struct *task,

11
include/asm-generic/syscall.h
View File

@ -105,21 +105,16 @@ 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. 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.
*/
void syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
unsigned int i, unsigned int n, unsigned long *args);
unsigned long *args);
/**
* syscall_set_arguments - change system call parameter value

2
include/trace/events/syscalls.h
View File

@ -28,7 +28,7 @@ TRACE_EVENT_FN(sys_enter,
TP_fast_assign(
__entry->id = id;
syscall_get_arguments(current, regs, 0, 6, __entry->args);
syscall_get_arguments(current, regs, __entry->args);
),
TP_printk("NR %ld (%lx, %lx, %lx, %lx, %lx, %lx)",

2
kernel/seccomp.c
View File

@ -149,7 +149,7 @@ static void populate_seccomp_data(struct seccomp_data *sd)
sd->nr = syscall_get_nr(task, regs);
sd->arch = syscall_get_arch();
syscall_get_arguments(task, regs, 0, 6, args);
syscall_get_arguments(task, regs, args);
sd->args[0] = args[0];
sd->args[1] = args[1];
sd->args[2] = args[2];

4
kernel/trace/trace_syscalls.c
View File

@ -348,7 +348,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
entry = ring_buffer_event_data(event);
entry->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, 6, args);
syscall_get_arguments(current, regs, args);
memcpy(entry->args, args, sizeof(unsigned long) * sys_data->nb_args);
event_trigger_unlock_commit(trace_file, buffer, event, entry,
@ -616,7 +616,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
return;
rec->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, 6, args);
syscall_get_arguments(current, regs, args);
memcpy(&rec->args, args, sizeof(unsigned long) * sys_data->nb_args);
if ((valid_prog_array &&

2
lib/syscall.c
View File

@ -27,7 +27,7 @@ static int collect_syscall(struct task_struct *target, struct syscall_info *info
info->data.nr = syscall_get_nr(target, regs);
if (info->data.nr != -1L)
syscall_get_arguments(target, regs, 0, 6,
syscall_get_arguments(target, regs,
(unsigned long *)&info->data.args[0]);
put_task_stack(target);