[PATCHv4 0/4] OPAL patches

[PATCHv4 0/4] OPAL patches

[Jon Derrick]

Just a couple of fixes for sed-opal to prevent faulty firmware from
allowing us to go off in the weeds, and a helper to remove some
duplicate code.

v3->v4:
uses IS_ERR since tok is embedded in the response buffer and cannot be NULL

v2->v3:
corrected the bad calculation on the response parser check and changed
it to only check the subpacket length

v1->v2:
left tok->len as a size_t
got everyone important on the same email thread

Jon Derrick (4):
  block/sed: Use ssize_t on atom parsers to return errors
  block/sed: Add helper to qualify response tokens
  block/sed: Check received header lengths
  MAINTAINERS: Remove powerpc's opal match

 MAINTAINERS      |   1 -
 block/sed-opal.c | 124 +++++++++++++++++++++++++++----------------------------
 2 files changed, 60 insertions(+), 65 deletions(-)

-- 
1.8.3.1

[PATCHv4 1/4] block/sed: Use ssize_t on atom parsers to return errors

[Jon Derrick]

The short atom parser can return an errno from decoding but does not
currently return the error as a signed value. Convert all of the parsers
to ssize_t.

Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Scott Bauer <scott.bauer@intel.com>
---
 block/sed-opal.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/block/sed-opal.c b/block/sed-opal.c
index e95b8a5..77623ad 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -635,8 +635,8 @@ static enum opal_token response_get_token(const struct parsed_resp *resp,
 	return tok->pos[0];
 }
 
-static size_t response_parse_tiny(struct opal_resp_tok *tok,
-				  const u8 *pos)
+static ssize_t response_parse_tiny(struct opal_resp_tok *tok,
+				   const u8 *pos)
 {
 	tok->pos = pos;
 	tok->len = 1;
@@ -652,8 +652,8 @@ static size_t response_parse_tiny(struct opal_resp_tok *tok,
 	return tok->len;
 }
 
-static size_t response_parse_short(struct opal_resp_tok *tok,
-				   const u8 *pos)
+static ssize_t response_parse_short(struct opal_resp_tok *tok,
+				    const u8 *pos)
 {
 	tok->pos = pos;
 	tok->len = (pos[0] & SHORT_ATOM_LEN_MASK) + 1;
@@ -665,7 +665,7 @@ static size_t response_parse_short(struct opal_resp_tok *tok,
 		tok->type = OPAL_DTA_TOKENID_SINT;
 	} else {
 		u64 u_integer = 0;
-		int i, b = 0;
+		ssize_t i, b = 0;
 
 		tok->type = OPAL_DTA_TOKENID_UINT;
 		if (tok->len > 9) {
@@ -682,8 +682,8 @@ static size_t response_parse_short(struct opal_resp_tok *tok,
 	return tok->len;
 }
 
-static size_t response_parse_medium(struct opal_resp_tok *tok,
-				    const u8 *pos)
+static ssize_t response_parse_medium(struct opal_resp_tok *tok,
+				     const u8 *pos)
 {
 	tok->pos = pos;
 	tok->len = (((pos[0] & MEDIUM_ATOM_LEN_MASK) << 8) | pos[1]) + 2;
@@ -699,8 +699,8 @@ static size_t response_parse_medium(struct opal_resp_tok *tok,
 	return tok->len;
 }
 
-static size_t response_parse_long(struct opal_resp_tok *tok,
-				  const u8 *pos)
+static ssize_t response_parse_long(struct opal_resp_tok *tok,
+				   const u8 *pos)
 {
 	tok->pos = pos;
 	tok->len = ((pos[1] << 16) | (pos[2] << 8) | pos[3]) + 4;
@@ -716,8 +716,8 @@ static size_t response_parse_long(struct opal_resp_tok *tok,
 	return tok->len;
 }
 
-static size_t response_parse_token(struct opal_resp_tok *tok,
-				   const u8 *pos)
+static ssize_t response_parse_token(struct opal_resp_tok *tok,
+				    const u8 *pos)
 {
 	tok->pos = pos;
 	tok->len = 1;
@@ -734,7 +734,7 @@ static int response_parse(const u8 *buf, size_t length,
 	struct opal_resp_tok *iter;
 	int num_entries = 0;
 	int total;
-	size_t token_length;
+	ssize_t token_length;
 	const u8 *pos;
 
 	if (!buf)
@@ -780,8 +780,8 @@ static int response_parse(const u8 *buf, size_t length,
 		else /* TOKEN */
 			token_length = response_parse_token(iter, pos);
 
-		if (token_length == -EINVAL)
-			return -EINVAL;
+		if (token_length < 0)
+			return token_length;
 
 		pos += token_length;
 		total -= token_length;
-- 
1.8.3.1

Re: [PATCHv4 1/4] block/sed: Use ssize_t on atom parsers to return errors

[Christoph Hellwig]

On Wed, Feb 15, 2017 at 02:45:54PM -0700, Jon Derrick wrote:
> The short atom parser can return an errno from decoding but does not
> currently return the error as a signed value. Convert all of the parsers
> to ssize_t.
> 
> Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
> Reviewed-by: Scott Bauer <scott.bauer@intel.com>

Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>

[PATCHv4 2/4] block/sed: Add helper to qualify response tokens

[Jon Derrick]

Add helper which verifies the response token is valid and matches the
expected value. Merges token_type and response_get_token.

Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Scott Bauer <scott.bauer@intel.com>
---
 block/sed-opal.c | 61 +++++++++++++++++++++++---------------------------------
 1 file changed, 25 insertions(+), 36 deletions(-)

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 77623ad..00673cf 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -591,48 +591,25 @@ static int cmd_finalize(struct opal_dev *cmd, u32 hsn, u32 tsn)
 	return 0;
 }
 
-static enum opal_response_token token_type(const struct parsed_resp *resp,
-					   int n)
+static const struct opal_resp_tok *response_get_token(
+				const struct parsed_resp *resp,
+				int n)
 {
 	const struct opal_resp_tok *tok;
 
 	if (n >= resp->num) {
 		pr_err("Token number doesn't exist: %d, resp: %d\n",
 		       n, resp->num);
-		return OPAL_DTA_TOKENID_INVALID;
+		return ERR_PTR(-EINVAL);
 	}
 
 	tok = &resp->toks[n];
 	if (tok->len == 0) {
 		pr_err("Token length must be non-zero\n");
-		return OPAL_DTA_TOKENID_INVALID;
+		return ERR_PTR(-EINVAL);
 	}
 
-	return tok->type;
-}
-
-/*
- * This function returns 0 in case of invalid token. One should call
- * token_type() first to find out if the token is valid or not.
- */
-static enum opal_token response_get_token(const struct parsed_resp *resp,
-					  int n)
-{
-	const struct opal_resp_tok *tok;
-
-	if (n >= resp->num) {
-		pr_err("Token number doesn't exist: %d, resp: %d\n",
-		       n, resp->num);
-		return 0;
-	}
-
-	tok = &resp->toks[n];
-	if (tok->len == 0) {
-		pr_err("Token length must be non-zero\n");
-		return 0;
-	}
-
-	return tok->pos[0];
+	return tok;
 }
 
 static ssize_t response_parse_tiny(struct opal_resp_tok *tok,
@@ -851,20 +828,32 @@ static u64 response_get_u64(const struct parsed_resp *resp, int n)
 	return resp->toks[n].stored.u;
 }
 
+static bool response_token_matches(const struct opal_resp_tok *token, u8 match)
+{
+	if (IS_ERR(token) ||
+	    token->type != OPAL_DTA_TOKENID_TOKEN ||
+	    token->pos[0] != match)
+		return false;
+	return true;
+}
+
 static u8 response_status(const struct parsed_resp *resp)
 {
-	if (token_type(resp, 0) == OPAL_DTA_TOKENID_TOKEN &&
-	    response_get_token(resp, 0) == OPAL_ENDOFSESSION) {
+	const struct opal_resp_tok *tok;
+
+	tok = response_get_token(resp, 0);
+	if (response_token_matches(tok, OPAL_ENDOFSESSION))
 		return 0;
-	}
 
 	if (resp->num < 5)
 		return DTAERROR_NO_METHOD_STATUS;
 
-	if (token_type(resp, resp->num - 1) != OPAL_DTA_TOKENID_TOKEN ||
-	    token_type(resp, resp->num - 5) != OPAL_DTA_TOKENID_TOKEN ||
-	    response_get_token(resp, resp->num - 1) != OPAL_ENDLIST ||
-	    response_get_token(resp, resp->num - 5) != OPAL_STARTLIST)
+	tok = response_get_token(resp, resp->num - 5);
+	if (!response_token_matches(tok, OPAL_STARTLIST))
+		return DTAERROR_NO_METHOD_STATUS;
+
+	tok = response_get_token(resp, resp->num - 1);
+	if (!response_token_matches(tok, OPAL_ENDLIST))
 		return DTAERROR_NO_METHOD_STATUS;
 
 	return response_get_u64(resp, resp->num - 4);
-- 
1.8.3.1

Re: [PATCHv4 2/4] block/sed: Add helper to qualify response tokens

[Christoph Hellwig]

On Wed, Feb 15, 2017 at 02:45:55PM -0700, Jon Derrick wrote:
> Add helper which verifies the response token is valid and matches the
> expected value. Merges token_type and response_get_token.
> 
> Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
> Reviewed-by: Scott Bauer <scott.bauer@intel.com>

Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>

[PATCHv4 3/4] block/sed: Check received header lengths

[Jon Derrick]

Add a buffer size check against discovery and response header lengths
before we loop over their buffers.

Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Scott Bauer <scott.bauer@intel.com>
---
 block/sed-opal.c | 35 +++++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 00673cf..383d5d6 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -340,10 +340,17 @@ static int opal_discovery0_end(struct opal_dev *dev)
 	const struct d0_header *hdr = (struct d0_header *)dev->resp;
 	const u8 *epos = dev->resp, *cpos = dev->resp;
 	u16 comid = 0;
+	u32 hlen = be32_to_cpu(hdr->length);
 
-	print_buffer(dev->resp, be32_to_cpu(hdr->length));
+	print_buffer(dev->resp, hlen);
 
-	epos += be32_to_cpu(hdr->length); /* end of buffer */
+	if (hlen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
+		pr_warn("Discovery length overflows buffer (%zu+%u)/%u\n",
+			sizeof(*hdr), hlen, IO_BUFFER_LENGTH);
+		return -EFAULT;
+	}
+
+	epos += hlen; /* end of buffer */
 	cpos += sizeof(*hdr); /* current position on buffer */
 
 	while (cpos < epos && supported) {
@@ -713,6 +720,7 @@ static int response_parse(const u8 *buf, size_t length,
 	int total;
 	ssize_t token_length;
 	const u8 *pos;
+	u32 clen, plen, slen;
 
 	if (!buf)
 		return -EFAULT;
@@ -724,17 +732,16 @@ static int response_parse(const u8 *buf, size_t length,
 	pos = buf;
 	pos += sizeof(*hdr);
 
-	pr_debug("Response size: cp: %d, pkt: %d, subpkt: %d\n",
-		 be32_to_cpu(hdr->cp.length),
-		 be32_to_cpu(hdr->pkt.length),
-		 be32_to_cpu(hdr->subpkt.length));
-
-	if (hdr->cp.length == 0 || hdr->pkt.length == 0 ||
-	    hdr->subpkt.length == 0) {
-		pr_err("Bad header length. cp: %d, pkt: %d, subpkt: %d\n",
-		       be32_to_cpu(hdr->cp.length),
-		       be32_to_cpu(hdr->pkt.length),
-		       be32_to_cpu(hdr->subpkt.length));
+	clen = be32_to_cpu(hdr->cp.length);
+	plen = be32_to_cpu(hdr->pkt.length);
+	slen = be32_to_cpu(hdr->subpkt.length);
+	pr_debug("Response size: cp: %u, pkt: %u, subpkt: %u\n",
+		 clen, plen, slen);
+
+	if (clen == 0 || plen == 0 || slen == 0 ||
+	    slen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
+		pr_err("Bad header length. cp: %u, pkt: %u, subpkt: %u\n",
+		       clen, plen, slen);
 		print_buffer(pos, sizeof(*hdr));
 		return -EINVAL;
 	}
@@ -743,7 +750,7 @@ static int response_parse(const u8 *buf, size_t length,
 		return -EFAULT;
 
 	iter = resp->toks;
-	total = be32_to_cpu(hdr->subpkt.length);
+	total = slen;
 	print_buffer(pos, total);
 	while (total > 0) {
 		if (pos[0] <= TINY_ATOM_BYTE) /* tiny atom */
-- 
1.8.3.1

Re: [PATCHv4 3/4] block/sed: Check received header lengths

[Christoph Hellwig]

On Wed, Feb 15, 2017 at 02:45:56PM -0700, Jon Derrick wrote:
> Add a buffer size check against discovery and response header lengths
> before we loop over their buffers.
> 
> Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
> Reviewed-by: Scott Bauer <scott.bauer@intel.com>

Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>

[PATCHv4 4/4] MAINTAINERS: Remove powerpc's opal match

[Jon Derrick]

PPC's 'opal' match pattern also matches block/sed-opal.c, where it looks
like the 'arch/powerpc' file pattern should be enough to match powerpc
opal code by itself. Remove the opal regex pattern from powerpc.

Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
---
 MAINTAINERS | 1 -
 1 file changed, 1 deletion(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index b983b25..430dd02 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7404,7 +7404,6 @@ F:	drivers/pci/hotplug/pnv_php.c
 F:	drivers/pci/hotplug/rpa*
 F:	drivers/scsi/ibmvscsi/
 F:	tools/testing/selftests/powerpc
-N:	opal
 N:	/pmac
 N:	powermac
 N:	powernv
-- 
1.8.3.1

Re: [PATCHv4 4/4] MAINTAINERS: Remove powerpc's opal match

[Andrew Donnellan]

On 16/02/17 08:45, Jon Derrick wrote:
> PPC's 'opal' match pattern also matches block/sed-opal.c, where it looks
> like the 'arch/powerpc' file pattern should be enough to match powerpc
> opal code by itself. Remove the opal regex pattern from powerpc.
>
> Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>

It looks like this change will exclude the following PPC OPAL related files:

drivers/tty/hvc/hvc_opal.c - HYPERVISOR VIRTUAL CONSOLE DRIVER (which 
lists linuxppc-dev as the mailing list, doesn't name a maintainer though)

drivers/i2c/busses/i2c-opal.c - I2C SUBSYSTEM

drivers/rtc/rtc-opal.c - REAL TIME CLOCK (RTC) SUBSYSTEM

Documentation/devicetree/bindings/i2c/i2c-opal.txt - I2C SUBSYSTEM, OPEN 
FIRMWARE AND FLATTENED DEVICE TREE BINDINGS

Documentation/devicetree/bindings/powerpc/opal - OPEN FIRMWARE AND 
FLATTENED DEVICE TREE BINDINGS

Documentation/devicetree/bindings/powerpc/opal/oppanel-opal.txt - OPEN 
FIRMWARE AND FLATTENED DEVICE TREE BINDINGS

Documentation/devicetree/bindings/rtc/rtc-opal.txt - OPEN FIRMWARE AND 
FLATTENED DEVICE TREE BINDINGS, REAL TIME CLOCK (RTC) SUBSYSTEM

Documentation/ABI/stable/sysfs-firmware-opal-elog - no other subsystem

Documentation/ABI/stable/sysfs-firmware-opal-dump - no other subsystem


-- 
Andrew Donnellan              OzLabs, ADL Canberra
andrew.donnellan@au1.ibm.com  IBM Australia Limited