[tip: x86/seves] x86/idt: Split idt_data setup out of set_intr_gate()

[tip-bot2 for Joerg Roedel]

The following commit has been merged into the x86/seves branch of tip:

Commit-ID:     4bed2266cc6f9c3f6cd91378ea4fc76edde674cf
Gitweb:        https://git.kernel.org/tip/4bed2266cc6f9c3f6cd91378ea4fc76edde674cf
Author:        Joerg Roedel <jroedel@xxxxxxx>
AuthorDate:    Mon, 07 Sep 2020 15:15:29 +02:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Mon, 07 Sep 2020 21:30:38 +02:00

x86/idt: Split idt_data setup out of set_intr_gate()

The code to setup idt_data is needed for early exception handling, but
set_intr_gate() can't be used that early because it has pv-ops in its
code path which don't work that early.

Split out the idt_data initialization part from set_intr_gate() so
that it can be used separately.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200907131613.12703-29-joro@xxxxxxxxxx
---
 arch/x86/kernel/idt.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 7ecf9ba..53946c1 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -205,18 +205,24 @@ idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size, bool sy
 	}
 }
 
+static void init_idt_data(struct idt_data *data, unsigned int n,
+			  const void *addr)
+{
+	BUG_ON(n > 0xFF);
+
+	memset(data, 0, sizeof(*data));
+	data->vector	= n;
+	data->addr	= addr;
+	data->segment	= __KERNEL_CS;
+	data->bits.type	= GATE_INTERRUPT;
+	data->bits.p	= 1;
+}
+
 static __init void set_intr_gate(unsigned int n, const void *addr)
 {
 	struct idt_data data;
 
-	BUG_ON(n > 0xFF);
-
-	memset(&data, 0, sizeof(data));
-	data.vector	= n;
-	data.addr	= addr;
-	data.segment	= __KERNEL_CS;
-	data.bits.type	= GATE_INTERRUPT;
-	data.bits.p	= 1;
+	init_idt_data(&data, n, addr);
 
 	idt_setup_from_table(idt_table, &data, 1, false);
 }