From: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> To: joro@8bytes.org Cc: aliguori@us.ibm.com, avi@redhat.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Subject: [RFC PATCH 7/7] acpi: fix bug in acpi_checksum() caused by garbage in checksum field Date: Tue, 30 Mar 2010 11:20:08 +0300 [thread overview] Message-ID: <7498607873ad7c9ff59d0a24d35391c0e4ba0a11.1269936879.git.eduard.munteanu@linux360.ro> (raw) In-Reply-To: <cover.1269936879.git.eduard.munteanu@linux360.ro> The whole table must sum to zero. We need to ignore garbage in the checksum field (i.e. consider it zero) when checksumming. It is legitimate to have garbage there, as the checksum makes sense only when the table has been filled. Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> --- hw/acpi.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/hw/acpi.c b/hw/acpi.c index f067f85..bb015f3 100644 --- a/hw/acpi.c +++ b/hw/acpi.c @@ -832,11 +832,16 @@ size_t acpi_tables_len, acpi_tables_prev_len; static int acpi_checksum(const uint8_t *data, int len) { int sum, i; + struct acpi_table_header *acpi_hdr; sum = 0; for(i = 0; i < len; i++) sum += data[i]; + /* Ignore preexisting garbage in checksum. */ + acpi_hdr = (struct acpi_table_header *) data; + sum -= acpi_hdr->checksum; + return (-sum) & 0xff; } -- 1.6.4.4
WARNING: multiple messages have this Message-ID (diff)
From: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> To: joro@8bytes.org Cc: aliguori@us.ibm.com, Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>, avi@redhat.com, kvm@vger.kernel.org, qemu-devel@nongnu.org Subject: [Qemu-devel] [RFC PATCH 7/7] acpi: fix bug in acpi_checksum() caused by garbage in checksum field Date: Tue, 30 Mar 2010 11:20:08 +0300 [thread overview] Message-ID: <7498607873ad7c9ff59d0a24d35391c0e4ba0a11.1269936879.git.eduard.munteanu@linux360.ro> (raw) In-Reply-To: <cover.1269936879.git.eduard.munteanu@linux360.ro> The whole table must sum to zero. We need to ignore garbage in the checksum field (i.e. consider it zero) when checksumming. It is legitimate to have garbage there, as the checksum makes sense only when the table has been filled. Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> --- hw/acpi.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/hw/acpi.c b/hw/acpi.c index f067f85..bb015f3 100644 --- a/hw/acpi.c +++ b/hw/acpi.c @@ -832,11 +832,16 @@ size_t acpi_tables_len, acpi_tables_prev_len; static int acpi_checksum(const uint8_t *data, int len) { int sum, i; + struct acpi_table_header *acpi_hdr; sum = 0; for(i = 0; i < len; i++) sum += data[i]; + /* Ignore preexisting garbage in checksum. */ + acpi_hdr = (struct acpi_table_header *) data; + sum -= acpi_hdr->checksum; + return (-sum) & 0xff; } -- 1.6.4.4
next prev parent reply other threads:[~2010-03-30 8:20 UTC|newest] Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-03-30 8:20 [RFC PATCH 0/7] Beginning implementing the AMD IOMMU emulation Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [RFC PATCH 1/7] acpi: qemu_realloc() might return a different pointer Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [RFC PATCH 2/7] acpi: split and rename acpi_table_add() Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [RFC PATCH 3/7] acpi: move table header definition into pc.h Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [RFC PATCH 4/7] sparc: rename hw/iommu.c Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-03-30 17:06 ` Blue Swirl 2010-03-30 17:06 ` Blue Swirl 2010-03-30 19:28 ` Joerg Roedel 2010-03-30 19:28 ` Joerg Roedel 2010-03-30 20:00 ` Blue Swirl 2010-03-30 20:00 ` Blue Swirl 2010-03-30 20:15 ` Eduard - Gabriel Munteanu 2010-03-30 20:15 ` Eduard - Gabriel Munteanu 2010-03-31 7:27 ` Gerd Hoffmann 2010-03-31 7:27 ` Gerd Hoffmann 2010-03-30 8:20 ` [RFC PATCH 5/7] x86-64: AMD IOMMU stub Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-03-30 20:37 ` Blue Swirl 2010-03-30 20:37 ` [Qemu-devel] " Blue Swirl 2010-03-30 8:20 ` [RFC PATCH 6/7] acpi: cleanup acpi_checksum() Eduard - Gabriel Munteanu 2010-03-30 8:20 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-03-30 8:20 ` Eduard - Gabriel Munteanu [this message] 2010-03-30 8:20 ` [Qemu-devel] [RFC PATCH 7/7] acpi: fix bug in acpi_checksum() caused by garbage in checksum field Eduard - Gabriel Munteanu 2010-03-30 15:10 ` Richard Henderson 2010-03-30 15:10 ` Richard Henderson 2010-03-30 19:40 ` [RFC PATCH 0/7] Beginning implementing the AMD IOMMU emulation Joerg Roedel 2010-03-30 19:40 ` [Qemu-devel] " Joerg Roedel 2010-03-31 5:38 ` Avi Kivity 2010-03-31 5:38 ` [Qemu-devel] " Avi Kivity
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