[coreboot-gerrit] Patch set updated for coreboot: 96226e2 amd/agesa/f*/Lib/amdlib.c: Integer overflow in loop construct

[Edward O'Callaghan (eocallaghan@alterapraxis.com)]

Edward O'Callaghan (eocallaghan at alterapraxis.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/7676

-gerrit

commit 96226e20b2ba3f4f3196b9fdada50d811bb2cd35
Author: Edward O'Callaghan <eocallaghan at alterapraxis.com>
Date:   Sun Dec 7 05:20:14 2014 +1100

    amd/agesa/f*/Lib/amdlib.c: Integer overflow in loop construct
    
    As is the case in commit:
    
     3312ed7 amd/agesa/f1?/Lib/amdlib.c: Integer overflow in loop construct
    
    The semantics of this loop relies on an integer overflow in Index >=0
    that implies a return value of (UINT8)-1 which around wraps to 0xFF, or
    VOLT_UNSUPPORTED.
    
    Also fix an infinite loop.
    
    Change-Id: Iced3eff3ae7b8935db3bdd6147372cf3b540883c
    Signed-off-by: Edward O'Callaghan <eocallaghan at alterapraxis.com>
---
 src/vendorcode/amd/agesa/f10/Lib/amdlib.c   | 18 +++++++++++++-----
 src/vendorcode/amd/agesa/f12/Lib/amdlib.c   | 18 +++++++++++++-----
 src/vendorcode/amd/agesa/f14/Lib/amdlib.c   | 18 +++++++++++++-----
 src/vendorcode/amd/agesa/f15/Lib/amdlib.c   | 17 ++++++++++++-----
 src/vendorcode/amd/agesa/f15tn/Lib/amdlib.c | 18 +++++++++++++-----
 src/vendorcode/amd/agesa/f16kb/Lib/amdlib.c | 18 +++++++++++++-----
 6 files changed, 77 insertions(+), 30 deletions(-)

diff --git a/src/vendorcode/amd/agesa/f10/Lib/amdlib.c b/src/vendorcode/amd/agesa/f10/Lib/amdlib.c
index 83e6a00..b26c599 100644
--- a/src/vendorcode/amd/agesa/f10/Lib/amdlib.c
+++ b/src/vendorcode/amd/agesa/f10/Lib/amdlib.c
@@ -339,17 +339,25 @@ LibAmdBitScanForward (
   }
   return (UINT8) Index;
 }
+
 UINT8
 LibAmdBitScanReverse (
   IN       UINT32 value
 )
 {
-  UINT8 Index;
-  for (Index = 31; Index >= 0; Index--){
-      if (value & (1 << Index)) return Index;
-  }
-  return 0xFF;
+  uint8_t bit = 31;
+  do {
+    if (value & (1 << 31))
+      return bit;
+
+    value <<= 1;
+    bit--;
+
+  } while (value != 0)
+
+  return 0xFF; /* Error code inficating no bit found */
 }
+
 VOID
 LibAmdMsrRead (
   IN       UINT32 MsrAddress,
diff --git a/src/vendorcode/amd/agesa/f12/Lib/amdlib.c b/src/vendorcode/amd/agesa/f12/Lib/amdlib.c
index 1ca9b55..7a0cee2 100644
--- a/src/vendorcode/amd/agesa/f12/Lib/amdlib.c
+++ b/src/vendorcode/amd/agesa/f12/Lib/amdlib.c
@@ -343,17 +343,25 @@ LibAmdBitScanForward (
   }
   return (UINT8) Index;
 }
+
 UINT8
 LibAmdBitScanReverse (
   IN       UINT32 value
 )
 {
-  UINT8 Index;
-  for (Index = 31; Index >= 0; Index--){
-      if (value & (1 << Index)) return Index;
-  }
-  return 0xFF;
+  uint8_t bit = 31;
+  do {
+    if (value & (1 << 31))
+      return bit;
+
+    value <<= 1;
+    bit--;
+
+  } while (value != 0)
+
+  return 0xFF; /* Error code inficating no bit found */
 }
+
 VOID
 LibAmdMsrRead (
   IN       UINT32 MsrAddress,
diff --git a/src/vendorcode/amd/agesa/f14/Lib/amdlib.c b/src/vendorcode/amd/agesa/f14/Lib/amdlib.c
index 963aa7e..e6afe9e 100644
--- a/src/vendorcode/amd/agesa/f14/Lib/amdlib.c
+++ b/src/vendorcode/amd/agesa/f14/Lib/amdlib.c
@@ -343,17 +343,25 @@ LibAmdBitScanForward (
   }
   return (UINT8) Index;
 }
+
 UINT8
 LibAmdBitScanReverse (
   IN       UINT32 value
 )
 {
-  UINT8 Index;
-  for (Index = 31; Index >= 0; Index--){
-      if (value & (1 << Index)) return Index;
-  }
-  return 0xFF;
+  uint8_t bit = 31;
+  do {
+    if (value & (1 << 31))
+      return bit;
+
+    value <<= 1;
+    bit--;
+
+  } while (value != 0)
+
+  return 0xFF; /* Error code inficating no bit found */
 }
+
 VOID
 LibAmdMsrRead (
   IN       UINT32 MsrAddress,
diff --git a/src/vendorcode/amd/agesa/f15/Lib/amdlib.c b/src/vendorcode/amd/agesa/f15/Lib/amdlib.c
index 1180ad2..7be95f0 100644
--- a/src/vendorcode/amd/agesa/f15/Lib/amdlib.c
+++ b/src/vendorcode/amd/agesa/f15/Lib/amdlib.c
@@ -343,16 +343,23 @@ LibAmdBitScanForward (
   }
   return (UINT8) Index;
 }
+
 UINT8
 LibAmdBitScanReverse (
   IN       UINT32 value
 )
 {
-  UINT8 Index;
-  for (Index = 31; Index >= 0; Index--){
-      if (value & (1 << Index)) return Index;
-  }
-  return 0xFF;
+  uint8_t bit = 31;
+  do {
+    if (value & (1 << 31))
+      return bit;
+
+    value <<= 1;
+    bit--;
+
+  } while (value != 0)
+
+  return 0xFF; /* Error code inficating no bit found */
 }
 
 UINT64
diff --git a/src/vendorcode/amd/agesa/f15tn/Lib/amdlib.c b/src/vendorcode/amd/agesa/f15tn/Lib/amdlib.c
index a2c424a..b9af90c 100644
--- a/src/vendorcode/amd/agesa/f15tn/Lib/amdlib.c
+++ b/src/vendorcode/amd/agesa/f15tn/Lib/amdlib.c
@@ -354,17 +354,25 @@ LibAmdBitScanForward (
   }
   return (UINT8) Index;
 }
+
 UINT8
 LibAmdBitScanReverse (
   IN       UINT32 value
 )
 {
-  UINT8 Index;
-  for (Index = 31; Index >= 0; Index--){
-      if (value & (1 << Index)) return Index;
-  }
-  return 0xFF;
+  uint8_t bit = 31;
+  do {
+    if (value & (1 << 31))
+      return bit;
+
+    value <<= 1;
+    bit--;
+
+  } while (value != 0)
+
+  return 0xFF; /* Error code inficating no bit found */
 }
+
 VOID
 LibAmdMsrRead (
   IN       UINT32 MsrAddress,
diff --git a/src/vendorcode/amd/agesa/f16kb/Lib/amdlib.c b/src/vendorcode/amd/agesa/f16kb/Lib/amdlib.c
index d0e66b9..7de5dc2 100644
--- a/src/vendorcode/amd/agesa/f16kb/Lib/amdlib.c
+++ b/src/vendorcode/amd/agesa/f16kb/Lib/amdlib.c
@@ -355,17 +355,25 @@ LibAmdBitScanForward (
   }
   return (UINT8) Index;
 }
+
 UINT8
 LibAmdBitScanReverse (
   IN       UINT32 value
 )
 {
-  UINTN Index;
-  for (Index = 31; Index >= 0; Index--){
-      if (value & (1 << Index)) break;
-  }
-  return (UINT8) Index;
+  uint8_t bit = 31;
+  do {
+    if (value & (1 << 31))
+      return bit;
+
+    value <<= 1;
+    bit--;
+
+  } while (value != 0)
+
+  return 0xFF; /* Error code inficating no bit found */
 }
+
 VOID
 LibAmdMsrRead (
   IN       UINT32 MsrAddress,