[PATCH v2 03/12] um: Add generic stub_syscall6 function

benjamin
2024-04-29T13:48:29Z

From: Benjamin Berg <benjamin@sipsolutions.net>

This function will be used by the new syscall handling code.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
---
arch/x86/um/shared/sysdep/stub_32.h | 22 ++++++++++++++++++++++
arch/x86/um/shared/sysdep/stub_64.h | 16 ++++++++++++++++
2 files changed, 38 insertions(+)

diff --git a/arch/x86/um/shared/sysdep/stub_32.h b/arch/x86/um/shared/sysdep/stub_32.h
index 2748b7ee031a..ab08a69fb57f 100644
--- a/arch/x86/um/shared/sysdep/stub_32.h
+++ b/arch/x86/um/shared/sysdep/stub_32.h
@@ -80,6 +80,28 @@ static __always_inline long stub_syscall5(long syscall, long arg1, long arg2,
return ret;
}

+static __always_inline long stub_syscall6(long syscall, long arg1, long arg2,
+ long arg3, long arg4, long arg5,
+ long arg6)
+{
+ struct syscall_args {
+ int ebx, ebp;
+ } args = { arg1, arg6 };
+ long ret;
+
+ __asm__ volatile ("pushl %%ebp;"
+ "movl 0x4(%%ebx),%%ebp;"
+ "movl (%%ebx),%%ebx;"
+ "int $0x80;"
+ "popl %%ebp"
+ : "=a" (ret)
+ : "0" (syscall), "b" (&args),
+ "c" (arg2), "d" (arg3), "S" (arg4), "D" (arg5)
+ : "memory");
+
+ return ret;
+}
+
static __always_inline void trap_myself(void)
{
__asm("int3");
diff --git a/arch/x86/um/shared/sysdep/stub_64.h b/arch/x86/um/shared/sysdep/stub_64.h
index 50c5e0529dfb..d27b34d75d70 100644
--- a/arch/x86/um/shared/sysdep/stub_64.h
+++ b/arch/x86/um/shared/sysdep/stub_64.h
@@ -80,6 +80,22 @@ static __always_inline long stub_syscall5(long syscall, long arg1, long arg2,
return ret;
}

+static __always_inline long stub_syscall6(long syscall, long arg1, long arg2,
+ long arg3, long arg4, long arg5,
+ long arg6)
+{
+ long ret;
+
+ __asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; movq %7,%%r9 ; "
+ __syscall
+ : "=a" (ret)
+ : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
+ "g" (arg4), "g" (arg5), "g" (arg6)
+ : __syscall_clobber, "r10", "r8", "r9");
+
+ return ret;
+}
+
static __always_inline void trap_myself(void)
{
__asm("int3");
--
2.44.0