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authorIngo Molnar <mingo@kernel.org>2017-12-01 12:32:48 +0300
committerIngo Molnar <mingo@kernel.org>2017-12-17 14:58:53 +0300
commit0fd2e9c53d82704a3ba87ea1980ec515188c5316 (patch)
treea828c396110053feba9e65307a4e802b00966519 /arch/x86/kernel/ldt.c
parent1784f9144b143a1e8b19fe94083b040aa559182b (diff)
parent1e4c4f610f774df6088d7c065b2dd4d22adba698 (diff)
downloadlinux-0fd2e9c53d82704a3ba87ea1980ec515188c5316.tar.xz
Merge commit 'upstream-x86-entry' into WIP.x86/mm
Pull in a minimal set of v4.15 entry code changes, for a base for the MM isolation patches. Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/ldt.c')
-rw-r--r--arch/x86/kernel/ldt.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 4d17bacf4030..ae5615b03def 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -13,6 +13,7 @@
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/smp.h>
+#include <linux/syscalls.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/uaccess.h>
@@ -295,8 +296,8 @@ out:
return error;
}
-asmlinkage int sys_modify_ldt(int func, void __user *ptr,
- unsigned long bytecount)
+SYSCALL_DEFINE3(modify_ldt, int , func , void __user * , ptr ,
+ unsigned long , bytecount)
{
int ret = -ENOSYS;
@@ -314,5 +315,14 @@ asmlinkage int sys_modify_ldt(int func, void __user *ptr,
ret = write_ldt(ptr, bytecount, 0);
break;
}
- return ret;
+ /*
+ * The SYSCALL_DEFINE() macros give us an 'unsigned long'
+ * return type, but tht ABI for sys_modify_ldt() expects
+ * 'int'. This cast gives us an int-sized value in %rax
+ * for the return code. The 'unsigned' is necessary so
+ * the compiler does not try to sign-extend the negative
+ * return codes into the high half of the register when
+ * taking the value from int->long.
+ */
+ return (unsigned int)ret;
}