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From:   Shuah Khan <skhan@linuxfoundation.org>
To:     robert.moore@intel.com, rafael.j.wysocki@intel.com, lenb@kernel.org
Cc:     Shuah Khan <skhan@linuxfoundation.org>, linux-acpi@vger.kernel.org,
        devel@acpica.org, linux-kernel@vger.kernel.org
Subject: [PATCH] ACPICA: Fix sprintf() INT_MAX -Wformat-truncation= warn
Date:   Wed, 16 Nov 2022 08:22:58 -0700
Message-Id: <20221116152258.28772-1-skhan@linuxfoundation.org>
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utprint module is included in tools/acpidump and when acpidump is built,
the following warning occurs.

 CC       tools/acpidump/utprint.o
/usr/include/x86_64-linux-gnu/bits/stdio2.h: In function ‘sprintf’:
../../../../../drivers/acpi/acpica/utprint.c:602:18: warning: specified bound 4294901760 exceeds ‘INT_MAX’ [-Wformat-truncation=]
  602 |         length = vsnprintf(string, ACPI_UINT32_MAX-ACPI_UINT16_MAX,
      |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  603 |                         format, args);
      |                         ~~~~~~~~~~~~~

Fix sprintf() to use ACPI_UINT32_MAX/2 to get rid of the truncate problem.
This change is inline other sprintf() implementations.

If using ACPI_UINT32_MAX is necessary in the kernel, acpidump might require
special case to get rid of this truncate problem.

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 drivers/acpi/acpica/utprint.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/acpica/utprint.c b/drivers/acpi/acpica/utprint.c
index d5aa2109847f..02cff16c8f77 100644
--- a/drivers/acpi/acpica/utprint.c
+++ b/drivers/acpi/acpica/utprint.c
@@ -599,7 +599,7 @@ int sprintf(char *string, const char *format, ...)
 	int length;
 
 	va_start(args, format);
-	length = vsnprintf(string, ACPI_UINT32_MAX, format, args);
+	length = vsnprintf(string, ACPI_UINT32_MAX/2, format, args);
 	va_end(args);
 
 	return (length);
-- 
2.34.1