usermode: move sysenter save/restore registers

Have the sysenter callee-saved registers saved and restored by the callee instead of by the caller, like syscall does. Signed-off-by: Johannes Wikner <[email protected]>
KernelTestFramework · Aug 28, 2023 · ca6b946 · ca6b946
1 parent 65ee0d1
commit ca6b946
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Showing 2 changed files with 3 additions and 2 deletions.
diff --git a/arch/x86/entry.S b/arch/x86/entry.S
@@ -225,6 +225,7 @@ END_FUNC(syscall_handler_entry)
 ENTRY(sysenter_handler_entry)
     push %_ASM_CX
     push %_ASM_DX
+    SAVE_CALLEE_SAVED_REGS
     syscall_from_usermode
 
     cmp $SYSCALL_EXIT, %_ASM_AX
@@ -236,6 +237,7 @@ ENTRY(sysenter_handler_entry)
     call syscall_handler
 
     syscall_to_usermode
+    RESTORE_CALLEE_SAVED_REGS
     pop %_ASM_DX
     pop %_ASM_CX
 

diff --git a/common/usermode.c b/common/usermode.c
@@ -163,11 +163,10 @@ static inline long __user_text _sysenter(long syscall_nr, long arg1, long arg2,
 
     /* clang-format off */
     asm volatile (
-        SAVE_CALLEE_SAVED_REGS()
         "mov %%" STR(_ASM_SP) ", %%" STR(_ASM_CX) "\n"
         "lea 1f(%%"STR(_ASM_IP)"), %%" STR(_ASM_DX) "\n"
         "sysenter\n"
-        "1: " RESTORE_CALLEE_SAVED_REGS()
+        "1: "
         : "=a"(return_code)
         : "0"(syscall_nr), "S"(arg1), "D" (arg2), "r" (_arg3), "r"(_arg4), "r"(_arg5)
         : STR(_ASM_CX), STR(_ASM_DX)