x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments
For the 32-bit syscall interface, 64-bit arguments (loff_t) are passed via
a pair of 32-bit registers. These register pairs end up in consecutive stack
slots, which matches the C ABI for 64-bit arguments. But when accessing the
registers directly from pt_regs, the wrapper needs to manually reassemble the
64-bit value. These wrappers already exist for 32-bit compat, so make them
available to 32-bit native in preparation for enabling pt_regs-based syscalls.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Link: https://lkml.kernel.org/r/20200313195144.164260-16-brgerst@gmail.com
diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile
index 33c51c0..77f70b9 100644
--- a/arch/x86/um/Makefile
+++ b/arch/x86/um/Makefile
@@ -21,6 +21,7 @@
obj-$(CONFIG_ELF_CORE) += elfcore.o
subarch-y = ../lib/string_32.o ../lib/atomic64_32.o ../lib/atomic64_cx8_32.o
+subarch-y += ../kernel/sys_ia32.o
else