From: Arnd Bergmann <arnd@arndb.de>
To: Marc Zyngier <maz@kernel.org>, Mike Rapoport <rppt@linux.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Brian Cain <bcain@codeaurora.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Christophe Leroy <christophe.leroy@c-s.fr>,
Fenghua Yu <fenghua.yu@intel.com>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Guan Xuetao <gxt@pku.edu.cn>, James Morse <james.morse@arm.com>,
Jonas Bonn <jonas@southpole.se>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Ley Foon Tan <ley.foon.tan@intel.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Paul Mackerras <paulus@samba.org>, Rich Felker <dalias@libc.org>,
Russell King <linux@armlinux.org.uk>,
Stafford Horne <shorne@gmail.com>,
Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Tony Luck <tony.luck@intel.com>, Will Deacon <will@kernel.org>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Paolo Bonzini <pbonzini@redhat.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: [PATCH] arm64: kvm: fix gcc-10 shift warning
Date: Wed, 29 Apr 2020 20:56:20 +0200 [thread overview]
Message-ID: <20200429185657.4085975-1-arnd@arndb.de> (raw)
gcc-10 warns that the 32-bit zero cannot be shifted more than
32 bits to the right:
arch/arm64/kvm/../../../virt/kvm/arm/mmu.c: In function 'clear_hyp_p4d_entry':
arch/arm64/include/asm/pgtable.h:630:35: error: right shift count >= width of type [-Werror=shift-count-overflow]
630 | #define pud_index(addr) (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
| ^~
arch/arm64/include/asm/memory.h:271:45: note: in definition of macro '__phys_to_virt'
271 | #define __phys_to_virt(x) ((unsigned long)((x) - physvirt_offset))
| ^
arch/arm64/include/asm/pgtable.h:633:42: note: in expansion of macro '__va'
633 | #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr))))
| ^~~~
arch/arm64/include/asm/pgtable.h:632:73: note: in expansion of macro 'pud_index'
632 | #define pud_offset_phys(dir, addr) (p4d_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t))
| ^~~~~~~~~
arch/arm64/include/asm/pgtable.h:633:47: note: in expansion of macro 'pud_offset_phys'
633 | #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr))))
| ^~~~~~~~~~~~~~~
arch/arm64/kvm/../../../virt/kvm/arm/mmu.c:510:36: note: in expansion of macro 'pud_offset'
510 | pud_t *pud_table __maybe_unused = pud_offset(p4d, 0);
| ^~~~~~~~~~
This is harmless, and the warning is a little bit silly for
a zero constant, but it's trivial to fix by making it an
unsigned long, so do that.
Fixes: 22998131ab33 ("arm64: add support for folded p4d page tables")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
virt/kvm/arm/mmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 48d4288c5f1b..534d9798c3cb 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -507,7 +507,7 @@ static void clear_hyp_pgd_entry(pgd_t *pgd)
static void clear_hyp_p4d_entry(p4d_t *p4d)
{
- pud_t *pud_table __maybe_unused = pud_offset(p4d, 0);
+ pud_t *pud_table __maybe_unused = pud_offset(p4d, 0UL);
VM_BUG_ON(p4d_huge(*p4d));
p4d_clear(p4d);
pud_free(NULL, pud_table);
--
2.26.0
next reply other threads:[~2020-04-29 18:58 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-29 18:56 Arnd Bergmann [this message]
2020-04-29 21:09 ` [PATCH] arm64: kvm: fix gcc-10 shift warning Will Deacon
2020-04-29 22:42 ` Stephen Rothwell
2020-04-30 8:02 ` Marc Zyngier
2020-04-30 8:29 ` Will Deacon
2020-04-30 9:39 ` Stephen Rothwell
2020-04-30 9:50 ` Will Deacon
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