Re: [patch v2] x86, UV: integer wrap bug in uv_hub_ipi_value()
From: walter harms <hidden>
Date: 2012-12-02 15:34:05
Also in:
lkml
Am 02.12.2012 11:44, schrieb Dan Carpenter:
quoted hunk ↗ jump to hunk
This is a static checker fix. The problem is that we store the bits from "uv_apicid_hibits" into "apicid" (the high 16 bits) but then we shift it 16 bit to the left. "apicid" is an int so it wraps and we lose them. Signed-off-by: Dan Carpenter <redacted> --- v2: Style fix. Don't use ulong. I don't have this hardware so I can't test it. There may also be other bugs which this patch does not addressed. These files are only compiled on x86_64 and "unsigned long" is used throughout to mean 64 bits.diff --git a/arch/x86/include/asm/uv/uv_hub.h b/arch/x86/include/asm/uv/uv_hub.h index 21f7385..e7a83d5 100644 --- a/arch/x86/include/asm/uv/uv_hub.h +++ b/arch/x86/include/asm/uv/uv_hub.h@@ -577,7 +577,7 @@ static unsigned long uv_hub_ipi_value(int apicid, int vector, int mode) { apicid |= uv_apicid_hibits; return (1UL << UVH_IPI_INT_SEND_SHFT) | - ((apicid) << UVH_IPI_INT_APIC_ID_SHFT) | + ((unsigned long)apicid << UVH_IPI_INT_APIC_ID_SHFT) | (mode << UVH_IPI_INT_DELIVERY_MODE_SHFT) | (vector << UVH_IPI_INT_VECTOR_SHFT); }diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index 8cfade9..6d93b2f 100644 --- a/arch/x86/kernel/apic/x2apic_uv_x.c +++ b/arch/x86/kernel/apic/x2apic_uv_x.c@@ -194,13 +194,13 @@ static int __cpuinit uv_wakeup_secondary(int phys_apicid, unsigned long start_ri pnode = uv_apicid_to_pnode(phys_apicid); phys_apicid |= uv_apicid_hibits; val = (1UL << UVH_IPI_INT_SEND_SHFT) | - (phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | + ((unsigned long)phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | ((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) | APIC_DM_INIT; uv_write_global_mmr64(pnode, UVH_IPI_INT, val); val = (1UL << UVH_IPI_INT_SEND_SHFT) | - (phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | + ((unsigned long)phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | ((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) | APIC_DM_STARTUP; uv_write_global_mmr64(pnode, UVH_IPI_INT, val);
making this more readable is hard but what is about:
val=(1UL << UVH_IPI_INT_SEND_SHFT) |
((unsigned long)phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) |
((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12);
uv_write_global_mmr64(pnode, UVH_IPI_INT, val|APIC_DM_INIT);
uv_write_global_mmr64(pnode, UVH_IPI_INT, val|APIC_DM_STARTUP);
just my 2 cents,
re
wh
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