[PATCH v2 11/11] um: switch ptrace FP register access to nolibc

Benjamin Berg
2025-09-19T15:36:15Z

From: Benjamin Berg <benjamin.berg@intel.com>

The registers.c file only contains the routines for floating point
register access in ptrace mode and initial size detection. After the
addition of sys/uio.h and sys/ptrace.h to nolibc it can be moved to use
it by using the sys_ptrace() wrapper.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>

---
v2:
- Use new sys_ptrace from nolibc
---
arch/x86/um/os-Linux/Makefile | 5 ++++-
arch/x86/um/os-Linux/registers.c | 16 ++++------------
2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/arch/x86/um/os-Linux/Makefile b/arch/x86/um/os-Linux/Makefile
index 77a308aaa5ec..d37320430822 100644
--- a/arch/x86/um/os-Linux/Makefile
+++ b/arch/x86/um/os-Linux/Makefile
@@ -3,10 +3,13 @@
# Licensed under the GPL
#

-obj-y = registers.o mcontext.o
+obj-y = mcontext.o

obj-$(CONFIG_X86_32) += tls.o

USER_OBJS := $(obj-y)

+obj-y += registers.o
+NOLIBC_OBJS := registers.o
+
include $(srctree)/arch/um/scripts/Makefile.rules
diff --git a/arch/x86/um/os-Linux/registers.c b/arch/x86/um/os-Linux/registers.c
index eb1cdadc8a61..e570e29c3d73 100644
--- a/arch/x86/um/os-Linux/registers.c
+++ b/arch/x86/um/os-Linux/registers.c
@@ -28,9 +28,7 @@ int get_fp_registers(int pid, unsigned long *regs)
.iov_len = host_fp_size,
};

- if (ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov) < 0)
- return -errno;
- return 0;
+ return sys_ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);
}

int put_fp_registers(int pid, unsigned long *regs)
@@ -40,9 +38,7 @@ int put_fp_registers(int pid, unsigned long *regs)
.iov_len = host_fp_size,
};

- if (ptrace(PTRACE_SETREGSET, pid, ptrace_regset, &iov) < 0)
- return -errno;
- return 0;
+ return sys_ptrace(PTRACE_SETREGSET, pid, ptrace_regset, &iov);
}

int arch_init_registers(int pid)
@@ -60,9 +56,7 @@ int arch_init_registers(int pid)

/* GDB has x86_xsave_length, which uses x86_cpuid_count */
ptrace_regset = NT_X86_XSTATE;
- ret = ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);
- if (ret)
- ret = -errno;
+ ret = sys_ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);

if (ret == -ENODEV) {
#ifdef CONFIG_X86_32
@@ -71,9 +65,7 @@ int arch_init_registers(int pid)
ptrace_regset = NT_PRFPREG;
#endif
iov.iov_len = 2 * 1024 * 1024;
- ret = ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);
- if (ret)
- ret = -errno;
+ ret = sys_ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);
}

munmap(iov.iov_base, 2 * 1024 * 1024);
--
2.51.0