[PATCH] MdeModulePkg/MdeModulePkg.dec: Clarify usage of PcdHeapGuardPropertyMask

[PATCH] MdeModulePkg/MdeModulePkg.dec: Clarify usage of PcdHeapGuardPropertyMask

[Jian J Wang]

Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
---
 MdeModulePkg/MdeModulePkg.dec | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 8efad57766..d134ec798a 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -939,13 +939,17 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPoolType|0x0|UINT64|0x30001053
 
   ## This mask is to control Heap Guard behavior.
+  # Note that due to the limit in pool memory implementation and the alignment
+  # requirement of UEFI spec, BIT7 is a try-best setting which cannot guarantee
+  # that the returned pool is exactly adjacent to head guard page or tail guard
+  # page.
   #   BIT0 - Enable UEFI page guard.<BR>
   #   BIT1 - Enable UEFI pool guard.<BR>
   #   BIT2 - Enable SMM page guard.<BR>
   #   BIT3 - Enable SMM pool guard.<BR>
   #   BIT7 - The direction of Guard Page for Pool Guard.
-  #          0 - The returned pool is adjacent to the bottom guard page.<BR>
-  #          1 - The returned pool is adjacent to the top guard page.<BR>
+  #          0 - The returned pool is near the tail guard page.<BR>
+  #          1 - The returned pool is near the head guard page.<BR>
   # @Prompt The Heap Guard feature mask
   gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask|0x0|UINT8|0x30001054
 
-- 
2.15.1.windows.2

Re: [PATCH] MdeModulePkg/MdeModulePkg.dec: Clarify usage of PcdHeapGuardPropertyMask

[Zeng, Star]

Please also the *.uni file accordingly, with that, Reviewed-by: Star Zeng <star.zeng@intel.com>


Thanks,
Star
-----Original Message-----
From: Wang, Jian J 
Sent: Thursday, December 21, 2017 1:08 PM
To: edk2-devel@lists.01.org
Cc: Zeng, Star <star.zeng@intel.com>; Dong, Eric <eric.dong@intel.com>
Subject: [PATCH] MdeModulePkg/MdeModulePkg.dec: Clarify usage of PcdHeapGuardPropertyMask

Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
---
 MdeModulePkg/MdeModulePkg.dec | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 8efad57766..d134ec798a 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -939,13 +939,17 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPoolType|0x0|UINT64|0x30001053
 
   ## This mask is to control Heap Guard behavior.
+  # Note that due to the limit in pool memory implementation and the alignment
+  # requirement of UEFI spec, BIT7 is a try-best setting which cannot guarantee
+  # that the returned pool is exactly adjacent to head guard page or tail guard
+  # page.
   #   BIT0 - Enable UEFI page guard.<BR>
   #   BIT1 - Enable UEFI pool guard.<BR>
   #   BIT2 - Enable SMM page guard.<BR>
   #   BIT3 - Enable SMM pool guard.<BR>
   #   BIT7 - The direction of Guard Page for Pool Guard.
-  #          0 - The returned pool is adjacent to the bottom guard page.<BR>
-  #          1 - The returned pool is adjacent to the top guard page.<BR>
+  #          0 - The returned pool is near the tail guard page.<BR>
+  #          1 - The returned pool is near the head guard page.<BR>
   # @Prompt The Heap Guard feature mask
   gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask|0x0|UINT8|0x30001054
 
-- 
2.15.1.windows.2

Re: [PATCH] MdeModulePkg/MdeModulePkg.dec: Clarify usage of PcdHeapGuardPropertyMask

[Wang, Jian J]

Thanks. .uni file will be updated accordingly.

Regards,
Jian

> -----Original Message-----
> From: Zeng, Star
> Sent: Thursday, December 21, 2017 1:15 PM
> To: Wang, Jian J <jian.j.wang@intel.com>; edk2-devel@lists.01.org
> Cc: Dong, Eric <eric.dong@intel.com>; Zeng, Star <star.zeng@intel.com>
> Subject: RE: [PATCH] MdeModulePkg/MdeModulePkg.dec: Clarify usage of
> PcdHeapGuardPropertyMask
> 
> Please also the *.uni file accordingly, with that, Reviewed-by: Star Zeng
> <star.zeng@intel.com>
> 
> 
> Thanks,
> Star
> -----Original Message-----
> From: Wang, Jian J
> Sent: Thursday, December 21, 2017 1:08 PM
> To: edk2-devel@lists.01.org
> Cc: Zeng, Star <star.zeng@intel.com>; Dong, Eric <eric.dong@intel.com>
> Subject: [PATCH] MdeModulePkg/MdeModulePkg.dec: Clarify usage of
> PcdHeapGuardPropertyMask
> 
> Cc: Star Zeng <star.zeng@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
> ---
>  MdeModulePkg/MdeModulePkg.dec | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/MdeModulePkg/MdeModulePkg.dec
> b/MdeModulePkg/MdeModulePkg.dec
> index 8efad57766..d134ec798a 100644
> --- a/MdeModulePkg/MdeModulePkg.dec
> +++ b/MdeModulePkg/MdeModulePkg.dec
> @@ -939,13 +939,17 @@
> 
> gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPoolType|0x0|UINT64|0x30
> 001053
> 
>    ## This mask is to control Heap Guard behavior.
> +  # Note that due to the limit in pool memory implementation and the
> alignment
> +  # requirement of UEFI spec, BIT7 is a try-best setting which cannot guarantee
> +  # that the returned pool is exactly adjacent to head guard page or tail guard
> +  # page.
>    #   BIT0 - Enable UEFI page guard.<BR>
>    #   BIT1 - Enable UEFI pool guard.<BR>
>    #   BIT2 - Enable SMM page guard.<BR>
>    #   BIT3 - Enable SMM pool guard.<BR>
>    #   BIT7 - The direction of Guard Page for Pool Guard.
> -  #          0 - The returned pool is adjacent to the bottom guard page.<BR>
> -  #          1 - The returned pool is adjacent to the top guard page.<BR>
> +  #          0 - The returned pool is near the tail guard page.<BR>
> +  #          1 - The returned pool is near the head guard page.<BR>
>    # @Prompt The Heap Guard feature mask
> 
> gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask|0x0|UINT8|0
> x30001054
> 
> --
> 2.15.1.windows.2