[PATCH v6 29/76] x86/idt: Split idt_data setup out of set_intr_gate()

Joerg Roedel
2020-08-24T08:56:30Z

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 separatly.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200724160336.5435-29-joro@8bytes.org
---
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 34fcc58b81b5..c19773174221 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);