[PATCH 3.16 259/306] x86/apic/uv: Silence a shift wrapping warning

From: Ben Hutchings
Date: Wed Feb 15 2017 - 19:24:58 EST


3.16.40-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit c4597fd756836a5fb7900f2091797ab564390ad0 upstream.

'm_io' is stored in 6 bits so it's a number in the 0-63 range. Static
analysis tools complain that 1 << 63 will wrap so I have changed it to
1ULL << m_io.

This code is over three years old so presumably the bug doesn't happen
very frequently in real life or someone would have complained by now.

Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Alex Thorlton <athorlton@xxxxxxx>
Cc: Dimitri Sivanich <sivanich@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Travis <travis@xxxxxxx>
Cc: Nathan Zimmer <nzimmer@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: kernel-janitors@xxxxxxxxxxxxxxx
Fixes: b15cc4a12bed ("x86, uv, uv3: Update x2apic Support for SGI UV3")
Link: http://lkml.kernel.org/r/20161123221908.GA23997@mwanda
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/apic/x2apic_uv_x.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -633,9 +633,9 @@ static __init void map_mmioh_high_uv3(in
l = li;
}
addr1 = (base << shift) +
- f * (unsigned long)(1 << m_io);
+ f * (1ULL << m_io);
addr2 = (base << shift) +
- (l + 1) * (unsigned long)(1 << m_io);
+ (l + 1) * (1ULL << m_io);
pr_info("UV: %s[%03d..%03d] NASID 0x%04x ADDR 0x%016lx - 0x%016lx\n",
id, fi, li, lnasid, addr1, addr2);
if (max_io < l)