[PATCH v4 20/28] x86, irq: More strict checking about registering ioapic

From: Yinghai Lu
Date: Sat Aug 10 2013 - 22:52:25 EST


1. check overlaping gsi range
for hot-add ioapic case, BIOS may have some entries in MADT
and also have setting in pci root bus with _GSB of DSDT.

2. check if entries is in right range.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <sebastian@xxxxxxxxxxxxx>
---
arch/x86/kernel/apic/io_apic.c | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index b026cc7..60c6706 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3818,12 +3818,9 @@ void __init ioapic_insert_resources(void)
}
}

-int mp_find_ioapic(u32 gsi)
+static int __mp_find_ioapic(u32 gsi)
{
- int i = 0;
-
- if (nr_ioapics == 0)
- return -1;
+ int i;

/* Find the IOAPIC that manages this GSI. */
for_each_ioapic(i) {
@@ -3833,10 +3830,19 @@ int mp_find_ioapic(u32 gsi)
return i;
}

- printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
return -1;
}

+int mp_find_ioapic(u32 gsi)
+{
+ int ret = __mp_find_ioapic(gsi);
+
+ if (ret == -1)
+ pr_err("ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
+
+ return ret;
+}
+
int mp_find_ioapic_pin(int ioapic, u32 gsi)
{
struct mp_ioapic_gsi *gsi_cfg;
@@ -3888,6 +3894,11 @@ void __init mp_register_ioapic(int id, u32 address, u32 gsi_base)
if (bad_ioapic(address))
return;

+ /* already registered ? */
+ idx = __mp_find_ioapic(gsi_base);
+ if (idx >= 0)
+ return;
+
idx = find_first_zero_bit(ioapics_mask, MAX_IO_APICS);
if (idx >= MAX_IO_APICS) {
pr_warn("WARNING: Max # of I/O APICs (%d) exceeded, skipping\n",
@@ -3914,6 +3925,13 @@ void __init mp_register_ioapic(int id, u32 address, u32 gsi_base)
* and to prevent reprogramming of IOAPIC pins (PCI GSIs).
*/
entries = io_apic_get_redir_entries(idx);
+
+ if (!entries || entries > MP_MAX_IOAPIC_PIN) {
+ clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
+ memset(&ioapics[idx], 0, sizeof(struct ioapic));
+ return;
+ }
+
gsi_cfg = mp_ioapic_gsi_routing(idx);
gsi_cfg->gsi_base = gsi_base;
gsi_cfg->gsi_end = gsi_base + entries - 1;
--
1.8.1.4

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