[Qemu-devel] [PULL for-2.7 0/4] Error reporting patches for 2016-08-08

[Qemu-devel] [PULL for-2.7 0/4] Error reporting patches for 2016-08-08

[Markus Armbruster]

The following changes since commit 51009170d8fc263cfdcd5a60fe3ba213daa3d15b:

  tests: Rename qtests which have names ending "error" (2016-08-05 15:27:15 +0100)

are available in the git repository at:

  git://repo.or.cz/qemu/armbru.git tags/pull-error-2016-08-08

for you to fetch changes up to 7ea7d36e3493d4dac7f20e46d0ca499bbb3251a6:

  error: Fix error_printf() calls lacking newlines (2016-08-08 09:01:27 +0200)

----------------------------------------------------------------
Error reporting patches for 2016-08-08

----------------------------------------------------------------
Markus Armbruster (4):
      error: Strip trailing '\n' from error string arguments (again)
      checkpatch: Fix newline detection in error_setg() & friends
      vfio: Use error_report() instead of error_printf() for errors
      error: Fix error_printf() calls lacking newlines

 hw/i386/pc.c                             |  2 +-
 hw/mips/cps.c                            |  2 +-
 hw/nvram/fw_cfg.c                        |  2 +-
 hw/ppc/spapr_cpu_core.c                  |  2 +-
 hw/vfio/platform.c                       |  2 +-
 kvm-all.c                                |  2 +-
 qemu-img.c                               |  4 ++--
 scripts/checkpatch.pl                    |  5 ++++-
 scripts/coccinelle/err-bad-newline.cocci | 29 +++++++++++++++++++++++++++++
 slirp/slirp.c                            |  8 ++++----
 target-i386/kvm.c                        |  2 +-
 ui/vnc.c                                 |  2 +-
 12 files changed, 47 insertions(+), 15 deletions(-)
 create mode 100644 scripts/coccinelle/err-bad-newline.cocci

-- 
2.5.5

[Qemu-devel] [PULL for-2.7 1/4] error: Strip trailing '\n' from error string arguments (again)

[Markus Armbruster]

Commit 9af9e0f, 6daf194d, be62a2eb and 312fd5f got rid of a bunch, but
they keep coming back.  checkpatch.pl tries to flag them since commit
5d596c2, but it's not very good at it.  Offenders tracked down with
Coccinelle script scripts/coccinelle/err-bad-newline.cocci, an updated
version of the script from commit 312fd5f.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1470224274-31522-2-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 hw/mips/cps.c                            |  2 +-
 hw/nvram/fw_cfg.c                        |  2 +-
 hw/ppc/spapr_cpu_core.c                  |  2 +-
 qemu-img.c                               |  4 ++--
 scripts/coccinelle/err-bad-newline.cocci | 29 +++++++++++++++++++++++++++++
 slirp/slirp.c                            |  8 ++++----
 target-i386/kvm.c                        |  2 +-
 7 files changed, 39 insertions(+), 10 deletions(-)
 create mode 100644 scripts/coccinelle/err-bad-newline.cocci

diff --git a/hw/mips/cps.c b/hw/mips/cps.c
index 77c6217..4ef337d 100644
--- a/hw/mips/cps.c
+++ b/hw/mips/cps.c
@@ -73,7 +73,7 @@ static void mips_cps_realize(DeviceState *dev, Error **errp)
     for (i = 0; i < s->num_vp; i++) {
         cpu = cpu_mips_init(s->cpu_model);
         if (cpu == NULL) {
-            error_setg(errp, "%s: CPU initialization failed\n",  __func__);
+            error_setg(errp, "%s: CPU initialization failed",  __func__);
             return;
         }
 
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index f10d5ec..6a68e59 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -744,7 +744,7 @@ static int get_fw_cfg_order(FWCfgState *s, const char *name)
     }
 
     /* Stick unknown stuff at the end. */
-    error_report("warning: Unknown firmware file in legacy mode: %s\n", name);
+    error_report("warning: Unknown firmware file in legacy mode: %s", name);
     return FW_CFG_ORDER_OVERRIDE_LAST;
 }
 
diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
index 170ed15..3ec47b7 100644
--- a/hw/ppc/spapr_cpu_core.c
+++ b/hw/ppc/spapr_cpu_core.c
@@ -234,7 +234,7 @@ void spapr_core_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
     }
 
     if (cc->core_id % smp_threads) {
-        error_setg(&local_err, "invalid core id %d\n", cc->core_id);
+        error_setg(&local_err, "invalid core id %d", cc->core_id);
         goto out;
     }
 
diff --git a/qemu-img.c b/qemu-img.c
index 2e40e1f..d2865a5 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -3490,7 +3490,7 @@ typedef struct BenchData {
 static void bench_undrained_flush_cb(void *opaque, int ret)
 {
     if (ret < 0) {
-        error_report("Failed flush request: %s\n", strerror(-ret));
+        error_report("Failed flush request: %s", strerror(-ret));
         exit(EXIT_FAILURE);
     }
 }
@@ -3501,7 +3501,7 @@ static void bench_cb(void *opaque, int ret)
     BlockAIOCB *acb;
 
     if (ret < 0) {
-        error_report("Failed request: %s\n", strerror(-ret));
+        error_report("Failed request: %s", strerror(-ret));
         exit(EXIT_FAILURE);
     }
 
diff --git a/scripts/coccinelle/err-bad-newline.cocci b/scripts/coccinelle/err-bad-newline.cocci
new file mode 100644
index 0000000..1316cc8
--- /dev/null
+++ b/scripts/coccinelle/err-bad-newline.cocci
@@ -0,0 +1,29 @@
+// Error messages should not contain newlines.  This script finds
+// messages that do.  Fixing them is manual.
+@r@
+expression errp, eno, cls, fmt;
+position p;
+@@
+(
+error_report(fmt, ...)@p
+|
+error_setg(errp, fmt, ...)@p
+|
+error_setg_errno(errp, eno, fmt, ...)@p
+|
+error_setg_win32(errp, eno, cls, fmt, ...)@p
+|
+error_prepend(errp, fmt, ...)@p
+|
+error_setg_file_open(errp, eno, cls, fmt, ...)@p
+|
+error_reportf_err(errp, fmt, ...)@p
+|
+error_set(errp, cls, fmt, ...)@p
+)
+@script:python@
+fmt << r.fmt;
+p << r.p;
+@@
+if "\\n" in str(fmt):
+    print "%s:%s:%s:%s" % (p[0].file, p[0].line, p[0].column, fmt)
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 7eb183d..47a1652 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -1197,8 +1197,8 @@ static void slirp_socket_save(QEMUFile *f, struct socket *so)
         qemu_put_be16(f, so->so_fport);
         break;
     default:
-        error_report(
-                "so_ffamily unknown, unable to save so_faddr and so_fport\n");
+        error_report("so_ffamily unknown, unable to save so_faddr and"
+                     " so_fport");
     }
     qemu_put_be16(f, so->so_lfamily);
     switch (so->so_lfamily) {
@@ -1207,8 +1207,8 @@ static void slirp_socket_save(QEMUFile *f, struct socket *so)
         qemu_put_be16(f, so->so_lport);
         break;
     default:
-        error_report(
-                "so_ffamily unknown, unable to save so_laddr and so_lport\n");
+        error_report("so_ffamily unknown, unable to save so_laddr and"
+                     " so_lport");
     }
     qemu_put_byte(f, so->so_iptos);
     qemu_put_byte(f, so->so_emu);
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 9697e16..0b2016a 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -3250,7 +3250,7 @@ int kvm_arch_irqchip_create(MachineState *ms, KVMState *s)
     if (machine_kernel_irqchip_split(ms)) {
         ret = kvm_vm_enable_cap(s, KVM_CAP_SPLIT_IRQCHIP, 0, 24);
         if (ret) {
-            error_report("Could not enable split irqchip mode: %s\n",
+            error_report("Could not enable split irqchip mode: %s",
                          strerror(-ret));
             exit(1);
         } else {
-- 
2.5.5

[Qemu-devel] [PULL for-2.7 2/4] checkpatch: Fix newline detection in error_setg() & friends

[Markus Armbruster]

Commit 5d596c2's regexp assumes the error message string is the first
argument.  Correct for error_report(), wrong for all the others.
Relax the regexp to match newline in anywhere.  This might cause
additional false positives.

While there, update the list of error_reporting functions.

Cc: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1470224274-31522-3-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 scripts/checkpatch.pl | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index b7cb4ab..9297087 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2514,11 +2514,14 @@ sub process {
 	my $qemu_error_funcs = qr{error_setg|
 				error_setg_errno|
 				error_setg_win32|
+				error_setg_file_open|
 				error_set|
+				error_prepend|
+				error_reportf_err|
 				error_vreport|
 				error_report}x;
 
-	if ($rawline =~ /\b(?:$qemu_error_funcs)\s*\(\s*\".*\\n/) {
+	if ($rawline =~ /\b(?:$qemu_error_funcs)\s*\(.*\".*\\n/) {
 		WARN("Error messages should not contain newlines\n" . $herecurr);
 	}
 
-- 
2.5.5

[Qemu-devel] [PULL for-2.7 3/4] vfio: Use error_report() instead of error_printf() for errors

[Markus Armbruster]

Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1470224274-31522-4-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 hw/vfio/platform.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index 1798a00..a559e7b 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -496,7 +496,7 @@ static int vfio_populate_device(VFIODevice *vbasedev)
         irq.index = i;
         ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_IRQ_INFO, &irq);
         if (ret) {
-            error_printf("vfio: error getting device %s irq info",
+            error_report("vfio: error getting device %s irq info",
                          vbasedev->name);
             goto irq_err;
         } else {
-- 
2.5.5

[Qemu-devel] [PULL for-2.7 4/4] error: Fix error_printf() calls lacking newlines

[Markus Armbruster]

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1470224274-31522-5-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 hw/i386/pc.c | 2 +-
 kvm-all.c    | 2 +-
 ui/vnc.c     | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 47593b7..022dd1b 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -381,7 +381,7 @@ ISADevice *pc_find_fdc0(void)
         error_report("warning: multiple floppy disk controllers with "
                      "iobase=0x3f0 have been found");
         error_printf("the one being picked for CMOS setup might not reflect "
-                     "your intent");
+                     "your intent\n");
     }
 
     return state.floppy;
diff --git a/kvm-all.c b/kvm-all.c
index 65608de..ebf35b0 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -2143,7 +2143,7 @@ void kvm_device_access(int fd, int group, uint64_t attr,
     if (err < 0) {
         error_report("KVM_%s_DEVICE_ATTR failed: %s",
                      write ? "SET" : "GET", strerror(-err));
-        error_printf("Group %d attr 0x%016" PRIx64, group, attr);
+        error_printf("Group %d attr 0x%016" PRIx64 "\n", group, attr);
         abort();
     }
 }
diff --git a/ui/vnc.c b/ui/vnc.c
index 4ce9034..853b57e 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -3201,7 +3201,7 @@ int vnc_display_password(const char *id, const char *password)
     }
     if (vs->auth == VNC_AUTH_NONE) {
         error_printf_unless_qmp("If you want use passwords please enable "
-                                "password auth using '-vnc ${dpy},password'.");
+                                "password auth using '-vnc ${dpy},password'.\n");
         return -EINVAL;
     }
 
-- 
2.5.5

Re: [Qemu-devel] [PULL for-2.7 0/4] Error reporting patches for 2016-08-08

[no-reply]

Hi,

Your series seems to have some coding style problems. See output below for
more information:

Message-id: 1470640761-17579-1-git-send-email-armbru@redhat.com
Type: series
Subject: [Qemu-devel] [PULL for-2.7 0/4] Error reporting patches for 2016-08-08

=== TEST SCRIPT BEGIN ===
#!/bin/bash

BASE=base
n=1
total=$(git log --oneline $BASE.. | wc -l)
failed=0

commits="$(git log --format=%H --reverse $BASE..)"
for c in $commits; do
    echo "Checking PATCH $n/$total: $(git show --no-patch --format=%s $c)..."
    if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then
        failed=1
        echo
    fi
    n=$((n+1))
done

exit $failed
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
From https://github.com/patchew-project/qemu
 * [new tag]         patchew/1470640761-17579-1-git-send-email-armbru@redhat.com -> patchew/1470640761-17579-1-git-send-email-armbru@redhat.com
Switched to a new branch 'test'
ab5847c error: Fix error_printf() calls lacking newlines
51b0c39 vfio: Use error_report() instead of error_printf() for errors
5c88cff checkpatch: Fix newline detection in error_setg() & friends
b194612 error: Strip trailing '\n' from error string arguments (again)

=== OUTPUT BEGIN ===
Checking PATCH 1/4: error: Strip trailing '\n' from error string arguments (again)...
Checking PATCH 2/4: checkpatch: Fix newline detection in error_setg() & friends...
ERROR: code indent should never use tabs
#27: FILE: scripts/checkpatch.pl:2517:
+^I^I^I^Ierror_setg_file_open|$

ERROR: code indent should never use tabs
#29: FILE: scripts/checkpatch.pl:2519:
+^I^I^I^Ierror_prepend|$

ERROR: code indent should never use tabs
#30: FILE: scripts/checkpatch.pl:2520:
+^I^I^I^Ierror_reportf_err|$

ERROR: code indent should never use tabs
#35: FILE: scripts/checkpatch.pl:2524:
+^Iif ($rawline =~ /\b(?:$qemu_error_funcs)\s*\(.*\".*\\n/) {$

total: 4 errors, 0 warnings, 15 lines checked

Your patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

Checking PATCH 3/4: vfio: Use error_report() instead of error_printf() for errors...
Checking PATCH 4/4: error: Fix error_printf() calls lacking newlines...
=== OUTPUT END ===

Test command exited with code: 1

Re: [Qemu-devel] [PULL for-2.7 0/4] Error reporting patches for 2016-08-08

[Peter Maydell]

On 8 August 2016 at 08:19, Markus Armbruster <armbru@redhat.com> wrote:
> The following changes since commit 51009170d8fc263cfdcd5a60fe3ba213daa3d15b:
>
>   tests: Rename qtests which have names ending "error" (2016-08-05 15:27:15 +0100)
>
> are available in the git repository at:
>
>   git://repo.or.cz/qemu/armbru.git tags/pull-error-2016-08-08
>
> for you to fetch changes up to 7ea7d36e3493d4dac7f20e46d0ca499bbb3251a6:
>
>   error: Fix error_printf() calls lacking newlines (2016-08-08 09:01:27 +0200)
>
> ----------------------------------------------------------------
> Error reporting patches for 2016-08-08
>
> ----------------------------------------------------------------
> Markus Armbruster (4):
>       error: Strip trailing '\n' from error string arguments (again)
>       checkpatch: Fix newline detection in error_setg() & friends
>       vfio: Use error_report() instead of error_printf() for errors
>       error: Fix error_printf() calls lacking newlines

Applied, thanks.

-- PMM

Re: [Qemu-devel] [PULL for-2.7 0/4] Error reporting patches for 2016-08-08

[Markus Armbruster]

Automated trivial patch checking at work, woot!

I dropped no-reply@ec2-52-6-146-230.compute-1.amazonaws.com manually.
Fam, you might want to add a Reply-to: header.

no-reply@ec2-52-6-146-230.compute-1.amazonaws.com writes:

> Hi,
>
> Your series seems to have some coding style problems. See output below for
> more information:
>
> Message-id: 1470640761-17579-1-git-send-email-armbru@redhat.com
> Type: series
> Subject: [Qemu-devel] [PULL for-2.7 0/4] Error reporting patches for 2016-08-08
>
> === TEST SCRIPT BEGIN ===
> #!/bin/bash
>
> BASE=base
> n=1
> total=$(git log --oneline $BASE.. | wc -l)
> failed=0
>
> commits="$(git log --format=%H --reverse $BASE..)"
> for c in $commits; do
>     echo "Checking PATCH $n/$total: $(git show --no-patch --format=%s $c)..."
>     if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then
>         failed=1
>         echo
>     fi
>     n=$((n+1))
> done
>
> exit $failed
> === TEST SCRIPT END ===
>
> Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
> From https://github.com/patchew-project/qemu
>  * [new tag]         patchew/1470640761-17579-1-git-send-email-armbru@redhat.com -> patchew/1470640761-17579-1-git-send-email-armbru@redhat.com
> Switched to a new branch 'test'
> ab5847c error: Fix error_printf() calls lacking newlines
> 51b0c39 vfio: Use error_report() instead of error_printf() for errors
> 5c88cff checkpatch: Fix newline detection in error_setg() & friends
> b194612 error: Strip trailing '\n' from error string arguments (again)
>
> === OUTPUT BEGIN ===
> Checking PATCH 1/4: error: Strip trailing '\n' from error string arguments (again)...
> Checking PATCH 2/4: checkpatch: Fix newline detection in error_setg() & friends...
> ERROR: code indent should never use tabs
> #27: FILE: scripts/checkpatch.pl:2517:
> +^I^I^I^Ierror_setg_file_open|$
>
> ERROR: code indent should never use tabs
> #29: FILE: scripts/checkpatch.pl:2519:
> +^I^I^I^Ierror_prepend|$
>
> ERROR: code indent should never use tabs
> #30: FILE: scripts/checkpatch.pl:2520:
> +^I^I^I^Ierror_reportf_err|$
>
> ERROR: code indent should never use tabs
> #35: FILE: scripts/checkpatch.pl:2524:
> +^Iif ($rawline =~ /\b(?:$qemu_error_funcs)\s*\(.*\".*\\n/) {$
>
> total: 4 errors, 0 warnings, 15 lines checked
>
> Your patch has style problems, please review.  If any of these errors
> are false positives report them to the maintainer, see
> CHECKPATCH in MAINTAINERS.
>
> Checking PATCH 3/4: vfio: Use error_report() instead of error_printf() for errors...
> Checking PATCH 4/4: error: Fix error_printf() calls lacking newlines...
> === OUTPUT END ===
>
> Test command exited with code: 1

I refrained from expanding tabs in the lines I touched.  26 out of 35
patches touching checkpatch.pl add tabs.  1911 out of 2615
checkpatch.pl's lines contain tabs.

Perhaps we should suppress this error for checkpatch.pl itself.  Or we
should make up our minds once and for all to expand tabs there.

Re: [Qemu-devel] [PULL for-2.7 0/4] Error reporting patches for 2016-08-08

[Fam Zheng]

On Mon, 08/08 16:58, Markus Armbruster wrote:
> Automated trivial patch checking at work, woot!
> 
> I dropped no-reply@ec2-52-6-146-230.compute-1.amazonaws.com manually.
> Fam, you might want to add a Reply-to: header.
> 
> no-reply@ec2-52-6-146-230.compute-1.amazonaws.com writes:
> 
> > Hi,
> >
> > Your series seems to have some coding style problems. See output below for
> > more information:
> >
> > Message-id: 1470640761-17579-1-git-send-email-armbru@redhat.com
> > Type: series
> > Subject: [Qemu-devel] [PULL for-2.7 0/4] Error reporting patches for 2016-08-08
> >
> > === TEST SCRIPT BEGIN ===
> > #!/bin/bash
> >
> > BASE=base
> > n=1
> > total=$(git log --oneline $BASE.. | wc -l)
> > failed=0
> >
> > commits="$(git log --format=%H --reverse $BASE..)"
> > for c in $commits; do
> >     echo "Checking PATCH $n/$total: $(git show --no-patch --format=%s $c)..."
> >     if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then
> >         failed=1
> >         echo
> >     fi
> >     n=$((n+1))
> > done
> >
> > exit $failed
> > === TEST SCRIPT END ===
> >
> > Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
> > From https://github.com/patchew-project/qemu
> >  * [new tag]         patchew/1470640761-17579-1-git-send-email-armbru@redhat.com -> patchew/1470640761-17579-1-git-send-email-armbru@redhat.com
> > Switched to a new branch 'test'
> > ab5847c error: Fix error_printf() calls lacking newlines
> > 51b0c39 vfio: Use error_report() instead of error_printf() for errors
> > 5c88cff checkpatch: Fix newline detection in error_setg() & friends
> > b194612 error: Strip trailing '\n' from error string arguments (again)
> >
> > === OUTPUT BEGIN ===
> > Checking PATCH 1/4: error: Strip trailing '\n' from error string arguments (again)...
> > Checking PATCH 2/4: checkpatch: Fix newline detection in error_setg() & friends...
> > ERROR: code indent should never use tabs
> > #27: FILE: scripts/checkpatch.pl:2517:
> > +^I^I^I^Ierror_setg_file_open|$
> >
> > ERROR: code indent should never use tabs
> > #29: FILE: scripts/checkpatch.pl:2519:
> > +^I^I^I^Ierror_prepend|$
> >
> > ERROR: code indent should never use tabs
> > #30: FILE: scripts/checkpatch.pl:2520:
> > +^I^I^I^Ierror_reportf_err|$
> >
> > ERROR: code indent should never use tabs
> > #35: FILE: scripts/checkpatch.pl:2524:
> > +^Iif ($rawline =~ /\b(?:$qemu_error_funcs)\s*\(.*\".*\\n/) {$
> >
> > total: 4 errors, 0 warnings, 15 lines checked
> >
> > Your patch has style problems, please review.  If any of these errors
> > are false positives report them to the maintainer, see
> > CHECKPATCH in MAINTAINERS.
> >
> > Checking PATCH 3/4: vfio: Use error_report() instead of error_printf() for errors...
> > Checking PATCH 4/4: error: Fix error_printf() calls lacking newlines...
> > === OUTPUT END ===
> >
> > Test command exited with code: 1
> 
> I refrained from expanding tabs in the lines I touched.  26 out of 35
> patches touching checkpatch.pl add tabs.  1911 out of 2615
> checkpatch.pl's lines contain tabs.
> 
> Perhaps we should suppress this error for checkpatch.pl itself.  Or we
> should make up our minds once and for all to expand tabs there.

Not worth enough to pollute the git blame output IMO.

Perhaps tabs can be ignored by checkpatch.pl when the surrounding untouched
code uses tabs already? That's not an ultimate solution to the tab vs space
dilemma when writing patches to such files, but this seems a relatively
common pattern of ignored warning.

Fam