[patch] x86/apic/uv: silence a shift wrapping warning

[patch] x86/apic/uv: silence a shift wrapping warning

[Dan Carpenter]

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.

Fixes: b15cc4a12bed ("x86, uv, uv3: Update x2apic Support for SGI UV3")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
Please review this one, carefully because I'm not positive about it.

diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index aeef53c..35690a1 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -815,9 +815,9 @@ static __init void map_mmioh_high_uv3(int index, int min_pnode, int max_pnode)
 				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)

[tip:x86/urgent] x86/apic/uv: Silence a shift wrapping warning

[tip-bot for Dan Carpenter]

Commit-ID:  c4597fd756836a5fb7900f2091797ab564390ad0
Gitweb:     http://git.kernel.org/tip/c4597fd756836a5fb7900f2091797ab564390ad0
Author:     Dan Carpenter <dan.carpenter@oracle.com>
AuthorDate: Thu, 24 Nov 2016 01:19:08 +0300
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 24 Nov 2016 06:01:05 +0100

x86/apic/uv: Silence a shift wrapping warning

'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@oracle.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Travis <travis@sgi.com>
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
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@kernel.org>
---
 arch/x86/kernel/apic/x2apic_uv_x.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index aeef53c..35690a1 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -815,9 +815,9 @@ static __init void map_mmioh_high_uv3(int index, int min_pnode, int max_pnode)
 				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)

Re: [tip:x86/urgent] x86/apic/uv: Silence a shift wrapping warning

[Alex Thorlton]

On Wed, Nov 23, 2016 at 10:25:48PM -0800, tip-bot for Dan Carpenter wrote:
> Commit-ID:  c4597fd756836a5fb7900f2091797ab564390ad0
> Gitweb:     http://git.kernel.org/tip/c4597fd756836a5fb7900f2091797ab564390ad0
> Author:     Dan Carpenter <dan.carpenter@oracle.com>
> AuthorDate: Thu, 24 Nov 2016 01:19:08 +0300
> Committer:  Ingo Molnar <mingo@kernel.org>
> CommitDate: Thu, 24 Nov 2016 06:01:05 +0100
> 
> x86/apic/uv: Silence a shift wrapping warning
> 
> '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@oracle.com>
> Cc: Alex Thorlton <athorlton@sgi.com>

Acked-by: Alex Thorlton <athorlton@sgi.com>

- Alex