Le 28/01/2025 à 10:16, Dmitry V. Levin a écrit :
Similar to syscall_set_arguments() that complements
syscall_get_arguments(), introduce syscall_set_nr()
that complements syscall_get_nr().
syscall_set_nr() is going to be needed along with
syscall_set_arguments() on all HAVE_ARCH_TRACEHOOK
architectures to implement PTRACE_SET_SYSCALL_INFO API.
Signed-off-by: Dmitry V. Levin <ldv@xxxxxxxxx>
Tested-by: Charlie Jenkins <charlie@xxxxxxxxxxxx>
Reviewed-by: Charlie Jenkins <charlie@xxxxxxxxxxxx>
---
arch/arc/include/asm/syscall.h | 11 +++++++++++
arch/arm/include/asm/syscall.h | 24 ++++++++++++++++++++++++
arch/arm64/include/asm/syscall.h | 16 ++++++++++++++++
arch/hexagon/include/asm/syscall.h | 7 +++++++
arch/loongarch/include/asm/syscall.h | 7 +++++++
arch/m68k/include/asm/syscall.h | 7 +++++++
arch/microblaze/include/asm/syscall.h | 7 +++++++
arch/mips/include/asm/syscall.h | 14 ++++++++++++++
arch/nios2/include/asm/syscall.h | 5 +++++
arch/openrisc/include/asm/syscall.h | 6 ++++++
arch/parisc/include/asm/syscall.h | 7 +++++++
arch/powerpc/include/asm/syscall.h | 10 ++++++++++
arch/riscv/include/asm/syscall.h | 7 +++++++
arch/s390/include/asm/syscall.h | 12 ++++++++++++
arch/sh/include/asm/syscall_32.h | 12 ++++++++++++
arch/sparc/include/asm/syscall.h | 12 ++++++++++++
arch/um/include/asm/syscall-generic.h | 5 +++++
arch/x86/include/asm/syscall.h | 7 +++++++
arch/xtensa/include/asm/syscall.h | 7 +++++++
include/asm-generic/syscall.h | 14 ++++++++++++++
20 files changed, 197 insertions(+)
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index 76020b66286b..712daa90e643 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -61,6 +61,22 @@ static inline void syscall_set_return_value(struct task_struct *task,
regs->regs[0] = val;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->syscallno = nr;
+ if (nr == -1) {
+ /*
+ * When the syscall number is set to -1, the syscall will be
+ * skipped. In this case the syscall return value has to be
+ * set explicitly, otherwise the first syscall argument is
+ * returned as the syscall return value.
+ */
+ syscall_set_return_value(task, regs, -ENOSYS, 0);
+ }
+}
+
#define SYSCALL_MAX_ARGS 6
static inline void syscall_get_arguments(struct task_struct *task,
diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h
index 521f279e6b33..7505dcfed247 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -39,6 +39,16 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
return -1;
}
+static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr)
+{
+ /*
+ * Unlike syscall_get_nr(), syscall_set_nr() can be called only when
+ * the target task is stopped for tracing on entering syscall, so
+ * there is no need to have the same check syscall_get_nr() has.
+ */
+ regs->gpr[0] = nr;
Doesn't the same as for ARM64 apply here as well ?
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
