Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Sender: Guenter Roeck <groeck7@gmail.com>
Date:   Tue, 27 Jun 2023 10:07:07 -0700
From:   Guenter Roeck <linux@roeck-us.net>
To:     Mark Rutland <mark.rutland@arm.com>
Cc:     linux-kernel@vger.kernel.org, akiyks@gmail.com,
        boqun.feng@gmail.com, corbet@lwn.net, keescook@chromium.org,
        linux@armlinux.org.uk, linux-doc@vger.kernel.org,
        mchehab@kernel.org, paulmck@kernel.org, peterz@infradead.org,
        rdunlap@infradead.org, sstabellini@kernel.org, will@kernel.org
Subject: Re: [PATCH v2 04/27] locking/atomic: make atomic*_{cmp,}xchg optional
Message-ID: <32395f1f-19e4-41da-9f67-68c7d21cf9b2@roeck-us.net>
References: <20230605070124.3741859-1-mark.rutland@arm.com>
 <20230605070124.3741859-5-mark.rutland@arm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230605070124.3741859-5-mark.rutland@arm.com>
Precedence: bulk

Hi,

On Mon, Jun 05, 2023 at 08:01:01AM +0100, Mark Rutland wrote:
> Most architectures define the atomic/atomic64 xchg and cmpxchg
> operations in terms of arch_xchg and arch_cmpxchg respectfully.
> 
> Add fallbacks for these cases and remove the trivial cases from arch
> code. On some architectures the existing definitions are kept as these
> are used to build other arch_atomic*() operations.
> 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Cc: Boqun Feng <boqun.feng@gmail.com>
> Cc: Paul E. McKenney <paulmck@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Will Deacon <will@kernel.org>

This patch results in:

ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined!

when trying to build sparc64:allmodconfig.

Guenter

---
bisect log:

# bad: [60e7c4a25da68cd826719b685babbd23e73b85b0] Add linux-next specific files for 20230626
# good: [45a3e24f65e90a047bef86f927ebdc4c710edaa1] Linux 6.4-rc7
git bisect start 'HEAD' 'v6.4-rc7'
# good: [1fc7b1b3c9c3211898874f51919fcb1cf6f1cc79] Merge branch 'main' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
git bisect good 1fc7b1b3c9c3211898874f51919fcb1cf6f1cc79
# good: [4fce1fc9cf89412590fb681fa480cde0b23b3381] Merge branch 'for-next' of git://git.kernel.dk/linux-block.git
git bisect good 4fce1fc9cf89412590fb681fa480cde0b23b3381
# bad: [cf1a0283badf6d0bfb91876583c24ef535a3c04c] Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
git bisect bad cf1a0283badf6d0bfb91876583c24ef535a3c04c
# bad: [3c5388e722ea98022b4d557ab33acca2eb16c4f0] Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
git bisect bad 3c5388e722ea98022b4d557ab33acca2eb16c4f0
# good: [997730bdbf14f352ab03e42461f500aafdabc03e] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git
git bisect good 997730bdbf14f352ab03e42461f500aafdabc03e
# bad: [6fd8266556af196763b9f876ed682873e605469b] Merge branch into tip/master: 'ras/core'
git bisect bad 6fd8266556af196763b9f876ed682873e605469b
# good: [37380ea71463658934c2d3167d559d4034ea1c5b] Merge branch into tip/master: 'irq/core'
git bisect good 37380ea71463658934c2d3167d559d4034ea1c5b
# bad: [a967852939f864c35f155a2f431292ad6fc3fed9] Merge branch into tip/master: 'locking/core'
git bisect bad a967852939f864c35f155a2f431292ad6fc3fed9
# bad: [e50f06ce2d876c740993b5e3d01e203520391ccd] locking/atomic: m68k: add preprocessor symbols
git bisect bad e50f06ce2d876c740993b5e3d01e203520391ccd
# good: [b1fe7f2cda2a003afe316ce8dfe8d3645694a67e] x86,intel_iommu: Replace cmpxchg_double()
git bisect good b1fe7f2cda2a003afe316ce8dfe8d3645694a67e
# good: [14d72d4b6f0e88b5f683c1a5b7a876a55055852d] locking/atomic: remove fallback comments
git bisect good 14d72d4b6f0e88b5f683c1a5b7a876a55055852d
# bad: [f739287ef57bc01155e556033462e9a6ff020c97] locking/atomic: arc: add preprocessor symbols
git bisect bad f739287ef57bc01155e556033462e9a6ff020c97
# bad: [d12157efc8e083c77d054675fcdd594f54cc7e2b] locking/atomic: make atomic*_{cmp,}xchg optional
git bisect bad d12157efc8e083c77d054675fcdd594f54cc7e2b
# good: [a7bafa7969da1c0e9c342c792d8224078d1c491c] locking/atomic: hexagon: remove redundant arch_atomic_cmpxchg
git bisect good a7bafa7969da1c0e9c342c792d8224078d1c491c
# first bad commit: [d12157efc8e083c77d054675fcdd594f54cc7e2b] locking/atomic: make atomic*_{cmp,}xchg optional