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From 93036f97d3b6da59fadc2aab57401e42e9fc148f Mon Sep 17 00:00:00 2001
Message-ID: <93036f97d3b6da59fadc2aab57401e42e9fc148f.1707394627.git.jdenemar@redhat.com>
From: Peter Krempa <pkrempa@redhat.com>
Date: Mon, 29 Jan 2024 23:33:07 +0100
Subject: [PATCH] virPCIVPDReadVPDBytes: Refactor error handling
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Each caller was checking that the function read as many bytes as it
expected. Move the check inside virPCIVPDReadVPDBytes and make it report
a proper error rather than just a combination of VIR_DEBUG inside the
function and a random VIR_INFO in the caller.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
(cherry picked from commit c15a495902bab43454341361174c8ba3dadfcdd5)
https://issues.redhat.com/browse/RHEL-22314 [9.4.0]
---
src/util/virpcivpd.c | 73 +++++++++++++++++++++++---------------------
1 file changed, 38 insertions(+), 35 deletions(-)
diff --git a/src/util/virpcivpd.c b/src/util/virpcivpd.c
index 0021a88f2d..10cabff0b9 100644
--- a/src/util/virpcivpd.c
+++ b/src/util/virpcivpd.c
@@ -361,34 +361,40 @@ virPCIVPDResourceUpdateKeyword(virPCIVPDResource *res,
* @offset: The offset at which bytes need to be read.
* @csum: A pointer to a byte containing the current checksum value. Mutated by this function.
*
- * Returns: the number of VPD bytes read from the specified file descriptor. The csum value is
+ * Returns 0 if exactly @count bytes were read from @vpdFileFd. The csum value is
* also modified as bytes are read. If an error occurs while reading data from the VPD file
- * descriptor, it is reported and -1 is returned to the caller. If EOF is occurred, 0 is returned
- * to the caller.
+ * descriptor, it is reported and -1 is returned to the caller.
*/
-static size_t
-virPCIVPDReadVPDBytes(int vpdFileFd, uint8_t *buf, size_t count, off_t offset, uint8_t *csum)
+static int
+virPCIVPDReadVPDBytes(int vpdFileFd,
+ uint8_t *buf,
+ size_t count,
+ off_t offset,
+ uint8_t *csum)
{
ssize_t numRead = pread(vpdFileFd, buf, count, offset);
- if (numRead == -1) {
- VIR_DEBUG("Unable to read %zu bytes at offset %zd from fd: %d",
- count, (ssize_t)offset, vpdFileFd);
- } else if (numRead) {
- /*
- * Update the checksum for every byte read. Per the PCI(e) specs
- * the checksum is correct if the sum of all bytes in VPD from
- * VPD address 0 up to and including the VPD-R RV field's first
- * data byte is zero.
- */
- while (count--) {
- *csum += *buf;
- buf++;
- }
+ if (numRead != count) {
+ virReportError(VIR_ERR_OPERATION_FAILED, "%s",
+ _("failed to read the PCI VPD data"));
+ return -1;
+ }
+
+ /*
+ * Update the checksum for every byte read. Per the PCI(e) specs
+ * the checksum is correct if the sum of all bytes in VPD from
+ * VPD address 0 up to and including the VPD-R RV field's first
+ * data byte is zero.
+ */
+ while (count--) {
+ *csum += *buf;
+ buf++;
}
- return numRead;
+
+ return 0;
}
+
/**
* virPCIVPDParseVPDLargeResourceFields:
* @vpdFileFd: A file descriptor associated with a file containing PCI device VPD.
@@ -423,12 +429,9 @@ virPCIVPDParseVPDLargeResourceFields(int vpdFileFd, uint16_t resPos, uint16_t re
g_autofree char *fieldValue = NULL;
/* Keyword resources consist of keywords (2 ASCII bytes per the spec) and 1-byte length. */
- if (virPCIVPDReadVPDBytes(vpdFileFd, buf, 3, fieldPos, csum) != 3) {
- /* Invalid field encountered which means the resource itself is invalid too. Report
- * That VPD has invalid format and bail. */
- VIR_INFO("Could not read a resource field header - VPD has invalid format");
+ if (virPCIVPDReadVPDBytes(vpdFileFd, buf, 3, fieldPos, csum) < 0)
return false;
- }
+
fieldDataLen = buf[2];
/* Change the position to the field's data portion skipping the keyword and length bytes. */
fieldPos += 3;
@@ -474,10 +477,10 @@ virPCIVPDParseVPDLargeResourceFields(int vpdFileFd, uint16_t resPos, uint16_t re
VIR_INFO("A field data length violates the resource length boundary.");
return false;
}
- if (virPCIVPDReadVPDBytes(vpdFileFd, buf, bytesToRead, fieldPos, csum) != bytesToRead) {
- VIR_INFO("Could not parse a resource field data - VPD has invalid format");
+
+ if (virPCIVPDReadVPDBytes(vpdFileFd, buf, bytesToRead, fieldPos, csum) < 0)
return false;
- }
+
/* Advance the position to the first byte of the next field. */
fieldPos += fieldDataLen;
@@ -566,10 +569,9 @@ virPCIVPDParseVPDLargeResourceString(int vpdFileFd, uint16_t resPos,
/* The resource value is not NULL-terminated so add one more byte. */
g_autofree char *buf = g_malloc0(resDataLen + 1);
- if (virPCIVPDReadVPDBytes(vpdFileFd, (uint8_t *)buf, resDataLen, resPos, csum) != resDataLen) {
- VIR_INFO("Could not read a part of a resource - VPD has invalid format");
+ if (virPCIVPDReadVPDBytes(vpdFileFd, (uint8_t *)buf, resDataLen, resPos, csum) < 0)
return false;
- }
+
resValue = g_strdup(g_strstrip(buf));
if (!virPCIVPDResourceIsValidTextValue(resValue)) {
VIR_INFO("The string resource has invalid characters in its value");
@@ -610,8 +612,8 @@ virPCIVPDParse(int vpdFileFd)
while (resPos <= PCI_VPD_ADDR_MASK) {
/* Read the resource data type tag. */
- if (virPCIVPDReadVPDBytes(vpdFileFd, &tag, 1, resPos, &csum) != 1)
- break;
+ if (virPCIVPDReadVPDBytes(vpdFileFd, &tag, 1, resPos, &csum) < 0)
+ return NULL;
/* 0x80 == 0b10000000 - the large resource data type flag. */
if (tag & PCI_VPD_LARGE_RESOURCE_FLAG) {
@@ -620,9 +622,10 @@ virPCIVPDParse(int vpdFileFd)
* where the end tag should be. */
break;
}
+
/* Read the two length bytes of the large resource record. */
- if (virPCIVPDReadVPDBytes(vpdFileFd, headerBuf, 2, resPos + 1, &csum) != 2)
- break;
+ if (virPCIVPDReadVPDBytes(vpdFileFd, headerBuf, 2, resPos + 1, &csum) < 0)
+ return NULL;
resDataLen = headerBuf[0] + (headerBuf[1] << 8);
/* Change the position to the byte following the tag and length bytes. */
--
2.43.0
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