Subject: [RFC PATCH] Avoid all Linux /dev/mem accesses when -c is specified

From: Roy Franz <roy.franz@linaro.org>

Date: 05/15/2015 12:50 PM

To: linaro-uefi@lists.linaro.org, linaro-acpi@lists.linaro.org, graeme.gregory@linaro.org, al.stone@linaro.org

CC: Roy Franz <roy.franz@linaro.org>

Don't try to read the RSDP structure or RSDT/XSDT tables

from memory with the -c option.  These are now provided

as files in /sysfs, and this allows acpidump to function

when /dev/mem is not available, which will be the case

for Aarch64 servers.

Signed-off-by: Roy Franz <roy.franz@linaro.org>

---

 source/os_specific/service_layers/oslinuxtbl.c | 87 +++++++++++++-------------

 1 file changed, 43 insertions(+), 44 deletions(-)

Index: acpica-unix/source/os_specific/service_layers/oslinuxtbl.c

===================================================================

--- acpica-unix.orig/source/os_specific/service_layers/oslinuxtbl.c

+++ acpica-unix/source/os_specific/service_layers/oslinuxtbl.c

@@ -686,70 +686,69 @@ OslTableInitialize (

         return (AE_OK);

     }

+    if (!Gbl_DumpCustomizedTables)

+    {

     /* Get RSDP from memory */

-    Status = OslLoadRsdp ();

-    if (ACPI_FAILURE (Status))

-    {

-        return (Status);

-    }

+        Status = OslLoadRsdp ();

+        if (ACPI_FAILURE (Status))

+        {

+            return (Status);

+        }

-    /* Get XSDT from memory */

+        /* Get XSDT from memory */

-    if (Gbl_Rsdp.Revision && !Gbl_DoNotDumpXsdt)

-    {

-        if (Gbl_Xsdt)

+        if (Gbl_Rsdp.Revision && !Gbl_DoNotDumpXsdt)

         {

-            free (Gbl_Xsdt);

-            Gbl_Xsdt = NULL;

+            if (Gbl_Xsdt)

+            {

+                free (Gbl_Xsdt);

+                Gbl_Xsdt = NULL;

+            }

+

+            Gbl_Revision = 2;

+            Status = OslGetBiosTable (ACPI_SIG_XSDT, 0,

+                ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Xsdt), &Address);

+            if (ACPI_FAILURE (Status))

+            {

+                return (Status);

+            }

         }

-        Gbl_Revision = 2;

-        Status = OslGetBiosTable (ACPI_SIG_XSDT, 0,

-            ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Xsdt), &Address);

-        if (ACPI_FAILURE (Status))

+        /* Get RSDT from memory */

+

+        if (Gbl_Rsdp.RsdtPhysicalAddress)

         {

-            return (Status);

+            if (Gbl_Rsdt)

+            {

+                free (Gbl_Rsdt);

+                Gbl_Rsdt = NULL;

+            }

+

+            Status = OslGetBiosTable (ACPI_SIG_RSDT, 0,

+                ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Rsdt), &Address);

+            if (ACPI_FAILURE (Status))

+            {

+                return (Status);

+            }

         }

-    }

-    /* Get RSDT from memory */

+        /* Get FADT from memory */

-    if (Gbl_Rsdp.RsdtPhysicalAddress)

-    {

-        if (Gbl_Rsdt)

+        if (Gbl_Fadt)

         {

-            free (Gbl_Rsdt);

-            Gbl_Rsdt = NULL;

+            free (Gbl_Fadt);

+            Gbl_Fadt = NULL;

         }

-        Status = OslGetBiosTable (ACPI_SIG_RSDT, 0,

-            ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Rsdt), &Address);

+        Status = OslGetBiosTable (ACPI_SIG_FADT, 0,

+            ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Fadt), &Gbl_FadtAddress);

         if (ACPI_FAILURE (Status))

         {

             return (Status);

         }

-    }

-

-    /* Get FADT from memory */

-

-    if (Gbl_Fadt)

-    {

-        free (Gbl_Fadt);

-        Gbl_Fadt = NULL;

-    }

-    Status = OslGetBiosTable (ACPI_SIG_FADT, 0,

-        ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Fadt), &Gbl_FadtAddress);

-    if (ACPI_FAILURE (Status))

-    {

-        return (Status);

-    }

-

-    if (!Gbl_DumpCustomizedTables)

-    {

         /* Add mandatory tables to global table list first */

-

         Status = OslAddTableToList (ACPI_RSDP_NAME, 0);

         if (ACPI_FAILURE (Status))

         {