[Devel] [PATCH] handle Linux systems without /dev/mem

[Al Stone <ahs3 at redhat.com>]

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On arm64 systems in particular, the use of /dev/mem is not recommended.  The
contents may or may not be valid depending on the memory map being used, since
they are not standardized.

The attached patch will cause arm64 (aka ARMv8 or AArch64) Linux systems to
use a new file called source/os_specific/service_layers/oslinuxtbl_nodevmem.c
(a subset of the oslinuxtbl.c code) that allows acpidump to read all ACPI
tables from /sys/firmware/acpi instead of from /dev/mem.  This will help ensure
that the tables retrieved are the ones actually being used and that their
content is correct.

This patch applies on top of the 20150515 version, and I have included it in
the 20150515-2 versions of the Fedora and Debian packages.  I've tried the
resulting acpidump on x86, x86_64 and arm64 systems and it seems to work well.

Signed-off-by: Al Stone <ahs3(a)redhat.com>

-- 
ciao,
al
-----------------------------------
Al Stone
Software Engineer
Red Hat, Inc.
ahs3(a)redhat.com
-----------------------------------

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diff -Naur acpica-unix2-20150515/generate/unix/acpidump/Makefile acpica-unix2-20150515.devmem/generate/unix/acpidump/Makefile
--- acpica-unix2-20150515/generate/unix/acpidump/Makefile	2015-05-15 17:49:17.000000000 -0600
+++ acpica-unix2-20150515.devmem/generate/unix/acpidump/Makefile	2015-06-02 15:00:31.813746336 -0600
@@ -67,10 +67,17 @@
 OBJECTS += \
 	$(OBJDIR)/osbsdtbl.o
 else
+
+ifeq ($(NO_DEV_MEM), true)
+OBJECTS += \
+	$(OBJDIR)/oslinuxtbl_nodevmem.o
+else
 OBJECTS += \
 	$(OBJDIR)/oslinuxtbl.o
 endif
 
+endif
+
 #
 # Flags specific to acpidump
 #
diff -Naur acpica-unix2-20150515/generate/unix/Makefile.config acpica-unix2-20150515.devmem/generate/unix/Makefile.config
--- acpica-unix2-20150515/generate/unix/Makefile.config	2015-06-03 14:57:30.328724317 -0600
+++ acpica-unix2-20150515.devmem/generate/unix/Makefile.config	2015-06-02 15:03:53.727560100 -0600
@@ -49,6 +49,7 @@
 LINKPROG =   $(CC) $(OBJECTS) -o $(PROG) $(LDFLAGS) $(OPT_LDFLAGS)
 PREFIX ?=    /usr
 INSTALLDIR = $(PREFIX)/bin
+UNAME_M := $(shell uname -m)
 UNAME_S := $(shell uname -s)
 
 #
@@ -70,6 +71,12 @@
 HOST =       _NetBSD
 endif
 
+ifeq ($(UNAME_S), Linux)
+ifeq ($(UNAME_M), aarch64)
+NO_DEV_MEM ?= true
+endif
+endif
+
 ifeq ($(HOST), _APPLE)
 INSTALL  =   cp
 INSTALLFLAGS ?= -f
diff -Naur acpica-unix2-20150515/source/os_specific/service_layers/oslinuxtbl_nodevmem.c acpica-unix2-20150515.devmem/source/os_specific/service_layers/oslinuxtbl_nodevmem.c
--- acpica-unix2-20150515/source/os_specific/service_layers/oslinuxtbl_nodevmem.c	1969-12-31 17:00:00.000000000 -0700
+++ acpica-unix2-20150515.devmem/source/os_specific/service_layers/oslinuxtbl_nodevmem.c	2015-06-02 16:14:38.088031027 -0600
@@ -0,0 +1,734 @@
+/******************************************************************************
+ *
+ * Module Name: oslinuxtbl_nodevmem - Linux OSL for obtaining ACPI tables
+ *                                    that assumes you cannot use /dev/mem
+ *
+ *****************************************************************************/
+
+#include "acpidump.h"
+
+
+#define _COMPONENT          ACPI_OS_SERVICES
+        ACPI_MODULE_NAME    ("oslinuxtbl_nodevmem")
+
+
+#ifndef PATH_MAX
+#define PATH_MAX 256
+#endif
+
+
+/* List of information about obtained ACPI tables */
+
+typedef struct osl_table_info
+{
+    struct osl_table_info   *Next;
+    UINT32                  Instance;
+    char                    Signature[ACPI_NAME_SIZE];
+
+} OSL_TABLE_INFO;
+
+/* Local prototypes */
+
+static ACPI_STATUS
+OslTableInitialize (
+    void);
+
+static ACPI_STATUS
+OslTableNameFromFile (
+    char                    *Filename,
+    char                    *Signature,
+    UINT32                  *Instance);
+
+static ACPI_STATUS
+OslAddTableToList (
+    char                    *Signature,
+    UINT32                  Instance);
+
+static ACPI_STATUS
+OslReadTableFromFile (
+    char                    *Filename,
+    ACPI_SIZE               FileOffset,
+    char                    *Signature,
+    ACPI_TABLE_HEADER       **Table);
+
+static ACPI_STATUS
+OslListAcpiTables (
+    char                    *Directory);
+
+static ACPI_STATUS
+OslGetAcpiTable (
+    char                    *Pathname,
+    char                    *Signature,
+    UINT32                  Instance,
+    ACPI_TABLE_HEADER       **Table,
+    ACPI_PHYSICAL_ADDRESS   *Address);
+
+static ACPI_STATUS
+OslGetLastStatus (
+    ACPI_STATUS             DefaultStatus);
+
+
+/* File locations */
+
+#define DYNAMIC_TABLE_DIR   "/sys/firmware/acpi/tables/dynamic"
+#define STATIC_TABLE_DIR    "/sys/firmware/acpi/tables"
+
+/* Should we get dynamically loaded SSDTs from DYNAMIC_TABLE_DIR? */
+
+UINT8                   Gbl_DumpDynamicTables = TRUE;
+
+/* Initialization flags */
+
+UINT8                   Gbl_TableListInitialized = FALSE;
+
+/* Revision of RSD PTR */
+
+UINT8                   Gbl_Revision = 0;
+
+OSL_TABLE_INFO          *Gbl_TableListHead = NULL;
+UINT32                  Gbl_TableCount = 0;
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    OslGetLastStatus
+ *
+ * PARAMETERS:  DefaultStatus   - Default error status to return
+ *
+ * RETURN:      Status; Converted from errno.
+ *
+ * DESCRIPTION: Get last errno and conver it to ACPI_STATUS.
+ *
+ *****************************************************************************/
+
+static ACPI_STATUS
+OslGetLastStatus (
+    ACPI_STATUS             DefaultStatus)
+{
+
+    switch (errno)
+    {
+    case EACCES:
+    case EPERM:
+
+        return (AE_ACCESS);
+
+    case ENOENT:
+
+        return (AE_NOT_FOUND);
+
+    case ENOMEM:
+
+        return (AE_NO_MEMORY);
+
+    default:
+
+        return (DefaultStatus);
+    }
+}
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    AcpiOsGetTableByAddress
+ *
+ * PARAMETERS:  Address         - Physical address of the ACPI table
+ *              Table           - Where a pointer to the table is returned
+ *
+ * RETURN:      Status; Table buffer is returned if AE_OK.
+ *              AE_NOT_FOUND: A valid table was not found at the address
+ *
+ * DESCRIPTION: Get an ACPI table via a physical memory address.
+ *
+ *****************************************************************************/
+
+ACPI_STATUS
+AcpiOsGetTableByAddress (
+    ACPI_PHYSICAL_ADDRESS   Address,
+    ACPI_TABLE_HEADER       **Table)
+{
+    /*
+     * If this source file is being used, there is no reliable access
+     * to /dev/mem on this system.  Hence, we cannot retrieve a table
+     * by address at all and will always return AE_NOT_FOUND.
+     */
+
+    return AE_NOT_FOUND;
+}
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    AcpiOsGetTableByName
+ *
+ * PARAMETERS:  Signature       - ACPI Signature for desired table. Must be
+ *                                a null terminated 4-character string.
+ *              Instance        - Multiple table support for SSDT/UEFI (0...n)
+ *                                Must be 0 for other tables.
+ *              Table           - Where a pointer to the table is returned
+ *              Address         - Where the table physical address is returned
+ *
+ * RETURN:      Status; Table buffer and physical address returned if AE_OK.
+ *              AE_LIMIT: Instance is beyond valid limit
+ *              AE_NOT_FOUND: A table with the signature was not found
+ *
+ * NOTE:        Assumes the input signature is uppercase.
+ *
+ *****************************************************************************/
+
+ACPI_STATUS
+AcpiOsGetTableByName (
+    char                    *Signature,
+    UINT32                  Instance,
+    ACPI_TABLE_HEADER       **Table,
+    ACPI_PHYSICAL_ADDRESS   *Address)
+{
+    ACPI_STATUS             Status;
+
+
+    /* Get main ACPI tables from memory on first invocation of this function */
+
+    Status = OslTableInitialize ();
+    if (ACPI_FAILURE (Status))
+    {
+        return (Status);
+    }
+
+    /* Attempt to get the table from the static directory */
+
+    Status = OslGetAcpiTable (STATIC_TABLE_DIR, Signature,
+        Instance, Table, Address);
+
+    if (ACPI_FAILURE (Status) && Status == AE_LIMIT)
+    {
+        if (Gbl_DumpDynamicTables)
+        {
+            /* Attempt to get a dynamic table */
+
+            Status = OslGetAcpiTable (DYNAMIC_TABLE_DIR, Signature,
+                Instance, Table, Address);
+        }
+    }
+
+    return (Status);
+}
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    OslAddTableToList
+ *
+ * PARAMETERS:  Signature       - Table signature
+ *              Instance        - Table instance
+ *
+ * RETURN:      Status; Successfully added if AE_OK.
+ *              AE_NO_MEMORY: Memory allocation error
+ *
+ * DESCRIPTION: Insert a table structure into OSL table list.
+ *
+ *****************************************************************************/
+
+static ACPI_STATUS
+OslAddTableToList (
+    char                    *Signature,
+    UINT32                  Instance)
+{
+    OSL_TABLE_INFO          *NewInfo;
+    OSL_TABLE_INFO          *Next;
+    UINT32                  NextInstance = 0;
+    BOOLEAN                 Found = FALSE;
+
+
+    NewInfo = calloc (1, sizeof (OSL_TABLE_INFO));
+    if (!NewInfo)
+    {
+        return (AE_NO_MEMORY);
+    }
+
+    ACPI_MOVE_NAME (NewInfo->Signature, Signature);
+
+    if (!Gbl_TableListHead)
+    {
+        Gbl_TableListHead = NewInfo;
+    }
+    else
+    {
+        Next = Gbl_TableListHead;
+        while (1)
+        {
+            if (ACPI_COMPARE_NAME (Next->Signature, Signature))
+            {
+                if (Next->Instance == Instance)
+                {
+                    Found = TRUE;
+                }
+                if (Next->Instance >= NextInstance)
+                {
+                    NextInstance = Next->Instance + 1;
+                }
+            }
+
+            if (!Next->Next)
+            {
+                break;
+            }
+            Next = Next->Next;
+        }
+        Next->Next = NewInfo;
+    }
+
+    if (Found)
+    {
+        if (Instance)
+        {
+            fprintf (stderr,
+                "%4.4s: Warning unmatched table instance %d, expected %d\n",
+                Signature, Instance, NextInstance);
+        }
+        Instance = NextInstance;
+    }
+
+    NewInfo->Instance = Instance;
+    Gbl_TableCount++;
+
+    return (AE_OK);
+}
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    AcpiOsGetTableByIndex
+ *
+ * PARAMETERS:  Index           - Which table to get
+ *              Table           - Where a pointer to the table is returned
+ *              Instance        - Where a pointer to the table instance no. is
+ *                                returned
+ *              Address         - Where the table physical address is returned
+ *
+ * RETURN:      Status; Table buffer and physical address returned if AE_OK.
+ *              AE_LIMIT: Index is beyond valid limit
+ *
+ * DESCRIPTION: Get an ACPI table via an index value (0 through n). Returns
+ *              AE_LIMIT when an invalid index is reached. Index is not
+ *              necessarily an index into the RSDT/XSDT.
+ *
+ *****************************************************************************/
+
+ACPI_STATUS
+AcpiOsGetTableByIndex (
+    UINT32                  Index,
+    ACPI_TABLE_HEADER       **Table,
+    UINT32                  *Instance,
+    ACPI_PHYSICAL_ADDRESS   *Address)
+{
+    OSL_TABLE_INFO          *Info;
+    ACPI_STATUS             Status;
+    UINT32                  i;
+
+
+    /* Get main ACPI tables from memory on first invocation of this function */
+
+    Status = OslTableInitialize ();
+    if (ACPI_FAILURE (Status))
+    {
+        return (Status);
+    }
+
+    /* Validate Index */
+
+    if (Index >= Gbl_TableCount)
+    {
+        return (AE_LIMIT);
+    }
+
+    /* Point to the table list entry specified by the Index argument */
+
+    Info = Gbl_TableListHead;
+    for (i = 0; i < Index; i++)
+    {
+        Info = Info->Next;
+    }
+
+    /* Now we can just get the table via the signature */
+
+    Status = AcpiOsGetTableByName (Info->Signature, Info->Instance,
+        Table, Address);
+
+    if (ACPI_SUCCESS (Status))
+    {
+        *Instance = Info->Instance;
+    }
+    return (Status);
+}
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    OslTableInitialize
+ *
+ * PARAMETERS:  None
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Initialize ACPI table data. Get and store main ACPI tables to
+ *              local variables. Main ACPI tables include RSDT, FADT, RSDT,
+ *              and/or XSDT.
+ *
+ *****************************************************************************/
+
+static ACPI_STATUS
+OslTableInitialize (
+    void)
+{
+    ACPI_STATUS             Status;
+
+    if (Gbl_TableListInitialized)
+    {
+        return (AE_OK);
+    }
+
+    /* Add all tables found in the static directory */
+
+    Status = OslListAcpiTables (STATIC_TABLE_DIR);
+    if (ACPI_FAILURE (Status))
+    {
+        return (Status);
+    }
+
+    if (Gbl_DumpDynamicTables)
+    {
+        /* Add all dynamically loaded tables in the dynamic directory */
+
+        Status = OslListAcpiTables (DYNAMIC_TABLE_DIR);
+        if (ACPI_FAILURE (Status))
+        {
+            return (Status);
+        }
+    }
+
+    Gbl_TableListInitialized = TRUE;
+    return (AE_OK);
+}
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    OslListAcpiTables
+ *
+ * PARAMETERS:  Directory           - Directory that contains the tables
+ *
+ * RETURN:      Status; Table list is initialized if AE_OK.
+ *
+ * DESCRIPTION: Add ACPI tables to the table list from a directory.
+ *
+ *****************************************************************************/
+
+static ACPI_STATUS
+OslListAcpiTables (
+    char                    *Directory)
+{
+    void                    *TableDir;
+    UINT32                  Instance;
+    char                    TempName[ACPI_NAME_SIZE];
+    char                    *Filename;
+    ACPI_STATUS             Status = AE_OK;
+
+
+    /* Open the requested directory */
+
+    TableDir = AcpiOsOpenDirectory (Directory, "*", REQUEST_FILE_ONLY);
+    if (!TableDir)
+    {
+        return (OslGetLastStatus (AE_NOT_FOUND));
+    }
+
+    /* Examine all entries in this directory */
+
+    while ((Filename = AcpiOsGetNextFilename (TableDir)))
+    {
+        /* Extract table name and instance number */
+
+        Status = OslTableNameFromFile (Filename, TempName, &Instance);
+
+        /* Ignore meaningless files */
+
+        if (ACPI_FAILURE (Status))
+        {
+            continue;
+        }
+
+        /* Add new info node to global table list */
+
+        Status = OslAddTableToList (TempName, Instance);
+        if (ACPI_FAILURE (Status))
+        {
+            break;
+        }
+    }
+
+    AcpiOsCloseDirectory (TableDir);
+    return (Status);
+}
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    OslTableNameFromFile
+ *
+ * PARAMETERS:  Filename            - File that contains the desired table
+ *              Signature           - Pointer to 4-character buffer to store
+ *                                    extracted table signature.
+ *              Instance            - Pointer to integer to store extracted
+ *                                    table instance number.
+ *
+ * RETURN:      Status; Table name is extracted if AE_OK.
+ *
+ * DESCRIPTION: Extract table signature and instance number from a table file
+ *              name.
+ *
+ *****************************************************************************/
+
+static ACPI_STATUS
+OslTableNameFromFile (
+    char                    *Filename,
+    char                    *Signature,
+    UINT32                  *Instance)
+{
+
+    /* Ignore meaningless files */
+
+    if (strlen (Filename) < ACPI_NAME_SIZE)
+    {
+        return (AE_BAD_SIGNATURE);
+    }
+
+    /* Extract instance number */
+
+    if (isdigit ((int) Filename[ACPI_NAME_SIZE]))
+    {
+        sscanf (&Filename[ACPI_NAME_SIZE], "%u", Instance);
+    }
+    else if (strlen (Filename) != ACPI_NAME_SIZE)
+    {
+        return (AE_BAD_SIGNATURE);
+    }
+    else
+    {
+        *Instance = 0;
+    }
+
+    /* Extract signature */
+
+    ACPI_MOVE_NAME (Signature, Filename);
+    return (AE_OK);
+}
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    OslReadTableFromFile
+ *
+ * PARAMETERS:  Filename            - File that contains the desired table
+ *              FileOffset          - Offset of the table in file
+ *              Signature           - Optional ACPI Signature for desired table.
+ *                                    A null terminated 4-character string.
+ *              Table               - Where a pointer to the table is returned
+ *
+ * RETURN:      Status; Table buffer is returned if AE_OK.
+ *
+ * DESCRIPTION: Read a ACPI table from a file.
+ *
+ *****************************************************************************/
+
+static ACPI_STATUS
+OslReadTableFromFile (
+    char                    *Filename,
+    ACPI_SIZE               FileOffset,
+    char                    *Signature,
+    ACPI_TABLE_HEADER       **Table)
+{
+    FILE                    *TableFile;
+    ACPI_TABLE_HEADER       Header;
+    ACPI_TABLE_HEADER       *LocalTable = NULL;
+    UINT32                  TableLength;
+    INT32                   Count;
+    ACPI_STATUS             Status = AE_OK;
+
+
+    /* Open the file */
+
+    TableFile = fopen (Filename, "rb");
+    if (TableFile == NULL)
+    {
+        fprintf (stderr, "Could not open table file: %s\n", Filename);
+        return (OslGetLastStatus (AE_NOT_FOUND));
+    }
+
+    fseek (TableFile, FileOffset, SEEK_SET);
+
+    /* Read the Table header to get the table length */
+
+    Count = fread (&Header, 1, sizeof (ACPI_TABLE_HEADER), TableFile);
+    if (Count != sizeof (ACPI_TABLE_HEADER))
+    {
+        fprintf (stderr, "Could not read table header: %s\n", Filename);
+        Status = AE_BAD_HEADER;
+        goto Exit;
+    }
+
+    /* If signature is specified, it must match the table */
+
+    if (Signature)
+    {
+        if (ACPI_VALIDATE_RSDP_SIG (Signature))
+        {
+            if (!ACPI_VALIDATE_RSDP_SIG (Header.Signature)) {
+                fprintf (stderr, "Incorrect RSDP signature: found %8.8s\n",
+                    Header.Signature);
+                Status = AE_BAD_SIGNATURE;
+                goto Exit;
+            }
+        }
+        else if (!ACPI_COMPARE_NAME (Signature, Header.Signature))
+        {
+            fprintf (stderr, "Incorrect signature: Expecting %4.4s, found %4.4s\n",
+                Signature, Header.Signature);
+            Status = AE_BAD_SIGNATURE;
+            goto Exit;
+        }
+    }
+
+    TableLength = ApGetTableLength (&Header);
+    if (TableLength == 0)
+    {
+        Status = AE_BAD_HEADER;
+        goto Exit;
+    }
+
+    /* Read the entire table into a local buffer */
+
+    LocalTable = calloc (1, TableLength);
+    if (!LocalTable)
+    {
+        fprintf (stderr,
+            "%4.4s: Could not allocate buffer for table of length %X\n",
+            Header.Signature, TableLength);
+        Status = AE_NO_MEMORY;
+        goto Exit;
+    }
+
+    fseek (TableFile, FileOffset, SEEK_SET);
+
+    Count = fread (LocalTable, 1, TableLength, TableFile);
+    if (Count != TableLength)
+    {
+        fprintf (stderr, "%4.4s: Could not read table content\n",
+            Header.Signature);
+        Status = AE_INVALID_TABLE_LENGTH;
+        goto Exit;
+    }
+
+    /* Validate checksum */
+
+    (void) ApIsValidChecksum (LocalTable);
+
+Exit:
+    fclose (TableFile);
+    *Table = LocalTable;
+    return (Status);
+}
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    OslGetAcpiTable
+ *
+ * PARAMETERS:  Pathname        - Directory to find Linux ACPI table
+ *              Signature       - ACPI Signature for desired table. Must be
+ *                                a null terminated 4-character string.
+ *              Instance        - Multiple table support for SSDT/UEFI (0...n)
+ *                                Must be 0 for other tables.
+ *              Table           - Where a pointer to the table is returned
+ *              Address         - Where the table physical address is returned
+ *
+ * RETURN:      Status; Table buffer is returned if AE_OK.
+ *              AE_LIMIT: Instance is beyond valid limit
+ *              AE_NOT_FOUND: A table with the signature was not found
+ *
+ * DESCRIPTION: Get an OS ACPI table.
+ *
+ *****************************************************************************/
+
+static ACPI_STATUS
+OslGetAcpiTable (
+    char                    *Pathname,
+    char                    *Signature,
+    UINT32                  Instance,
+    ACPI_TABLE_HEADER       **Table,
+    ACPI_PHYSICAL_ADDRESS   *Address)
+{
+    void                    *TableDir;
+    UINT32                  CurrentInstance = 0;
+    char                    TempName[ACPI_NAME_SIZE];
+    char                    TableFilename[PATH_MAX];
+    char                    *Filename;
+    ACPI_STATUS             Status;
+
+
+    /* Open the directory for ACPI tables */
+
+    TableDir = AcpiOsOpenDirectory (Pathname, "*", REQUEST_FILE_ONLY);
+    if (!TableDir)
+    {
+        return (OslGetLastStatus (AE_NOT_FOUND));
+    }
+
+    /* Attempt to find the table in the directory */
+
+    while ((Filename = AcpiOsGetNextFilename (TableDir)))
+    {
+        /* Ignore meaningless files */
+
+        if (!ACPI_COMPARE_NAME (Filename, Signature))
+        {
+            continue;
+        }
+
+        /* Extract table name and instance number */
+
+        Status = OslTableNameFromFile (Filename, TempName, &CurrentInstance);
+
+        /* Ignore meaningless files */
+
+        if (ACPI_FAILURE (Status) || CurrentInstance != Instance)
+        {
+            continue;
+        }
+
+        /* Create the table pathname */
+
+        if (Instance != 0)
+        {
+            sprintf (TableFilename, "%s/%4.4s%d", Pathname, TempName, Instance);
+        }
+        else
+        {
+            sprintf (TableFilename, "%s/%4.4s", Pathname, TempName);
+        }
+        break;
+    }
+
+    AcpiOsCloseDirectory (TableDir);
+
+    if (!Filename)
+    {
+        return (AE_LIMIT);
+    }
+
+    /* There is no physical address saved for ACPI tables, use zero */
+
+    *Address = 0;
+    Status = OslReadTableFromFile (TableFilename, 0, NULL, Table);
+
+    return (Status);
+}