[Xen-changelog] [xen staging] xen/arm: gic: Make sure the number of interrupt lines is valid before using it

[patchbot@xxxxxxx]

commit 30f5047b2c4e577436b505ba7627f34c3be02014
Author:     Julien Grall <julien.grall@xxxxxxx>
AuthorDate: Fri Nov 30 17:15:33 2018 +0000
Commit:     Julien Grall <julien.grall@xxxxxxx>
CommitDate: Wed Jan 23 13:40:02 2019 +0000

    xen/arm: gic: Make sure the number of interrupt lines is valid before using 
it
    
    GICv2 and GICv3 supports up to 1020 interrupts. However, the value computed
    from GICD_TYPER.ITLinesNumber can be up to 1024. On GICv3, we will end up to
    write in reserved registers that are right after the IROUTERs one as the
    value is not capped early enough.
    
    Cap the number of interrupts as soon as we compute it so we know we can
    safely using it afterwards.
    
    Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
    Reported-by: Jan-Peter Larsson <Jan-Peter.Larsson@xxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
    Release-Acked-by: Juergen Gross <jgross@xxxxxxxx>
---
 xen/arch/arm/gic-v2.c | 7 ++++---
 xen/arch/arm/gic-v3.c | 7 ++++---
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
index 1a744c576f..e9fb8a01ab 100644
--- a/xen/arch/arm/gic-v2.c
+++ b/xen/arch/arm/gic-v2.c
@@ -353,6 +353,10 @@ static void __init gicv2_dist_init(void)
 
     type = readl_gicd(GICD_TYPER);
     nr_lines = 32 * ((type & GICD_TYPE_LINES) + 1);
+    /* Only 1020 interrupts are supported */
+    nr_lines = min(1020U, nr_lines);
+    gicv2_info.nr_lines = nr_lines;
+
     gic_cpus = 1 + ((type & GICD_TYPE_CPUS) >> 5);
     printk("GICv2: %d lines, %d cpu%s%s (IID %8.8x).\n",
            nr_lines, gic_cpus, (gic_cpus == 1) ? "" : "s",
@@ -377,9 +381,6 @@ static void __init gicv2_dist_init(void)
     for ( i = 32; i < nr_lines; i += 32 )
         writel_gicd(~0x0, GICD_ICENABLER + (i / 32) * 4);
 
-    /* Only 1020 interrupts are supported */
-    gicv2_info.nr_lines = min(1020U, nr_lines);
-
     /* Turn on the distributor */
     writel_gicd(GICD_CTL_ENABLE, GICD_CTLR);
 }
diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index 6fbc106757..c9200d24e1 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -607,6 +607,10 @@ static void __init gicv3_dist_init(void)
     if ( type & GICD_TYPE_LPIS )
         gicv3_lpi_init_host_lpis(GICD_TYPE_ID_BITS(type));
 
+    /* Only 1020 interrupts are supported */
+    nr_lines = min(1020U, nr_lines);
+    gicv3_info.nr_lines = nr_lines;
+
     printk("GICv3: %d lines, (IID %8.8x).\n",
            nr_lines, readl_relaxed(GICD + GICD_IIDR));
 
@@ -646,9 +650,6 @@ static void __init gicv3_dist_init(void)
 
     for ( i = NR_GIC_LOCAL_IRQS; i < nr_lines; i++ )
         writeq_relaxed(affinity, GICD + GICD_IROUTER + i * 8);
-
-    /* Only 1020 interrupts are supported */
-    gicv3_info.nr_lines = min(1020U, nr_lines);
 }
 
 static int gicv3_enable_redist(void)
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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