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[efi] Inhibit our driver Start() method during disconnection attempts

Some HP BIOSes (observed with a Z840) seem to attempt to connect our
drivers in the middle of our call to DisconnectController().  The
precise chain of events is unclear, but the symptom is that we see
several calls to our Supported() and Start() methods, followed by a
system lock-up.

Work around this dubious BIOS behaviour by explicitly failing calls to
our Start() method while we are in the middle of attempting to
disconnect drivers.

Reported-by: Jordan Wright <jordan.m.wright@disney.com>
Debugged-by: Adrian Lucrèce Céleste <adrianlucrececeleste@airmail.cc>
Debugged-by: Christian Nilsson <nikize@gmail.com>
Tested-by: Jordan Wright <jordan.m.wright@disney.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
tags/v1.20.1
Michael Brown 7 years ago
parent
commit
74d90b33f8
1 changed files with 16 additions and 0 deletions
  1. 16
    0
      src/interface/efi/efi_driver.c

+ 16
- 0
src/interface/efi/efi_driver.c View File

@@ -44,6 +44,9 @@ static EFI_DRIVER_BINDING_PROTOCOL efi_driver_binding;
44 44
 /** List of controlled EFI devices */
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 static LIST_HEAD ( efi_devices );
46 46
 
47
+/** We are currently disconnecting drivers */
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+static int efi_driver_disconnecting;
49
+
47 50
 /**
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  * Find EFI device
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  *
@@ -159,6 +162,14 @@ efi_driver_start ( EFI_DRIVER_BINDING_PROTOCOL *driver __unused,
159 162
 		goto err_already_started;
160 163
 	}
161 164
 
165
+	/* Do nothing if we are currently disconnecting drivers */
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+	if ( efi_driver_disconnecting ) {
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+		DBGC ( device, "EFIDRV %s refusing to start during "
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+		       "disconnection\n", efi_handle_name ( device ) );
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+		efirc = EFI_NOT_READY;
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+		goto err_disconnecting;
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+	}
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+
162 173
 	/* Open device path */
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 	if ( ( efirc = bs->OpenProtocol ( device,
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 					  &efi_device_path_protocol_guid,
@@ -220,6 +231,7 @@ efi_driver_start ( EFI_DRIVER_BINDING_PROTOCOL *driver __unused,
220 231
 				    efi_image_handle, device );
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 	}
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  err_open_path:
234
+ err_disconnecting:
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  err_already_started:
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 	return efirc;
225 237
 }
@@ -411,6 +423,7 @@ static int efi_driver_connect ( EFI_HANDLE device ) {
411 423
 	DBGC2_EFI_PROTOCOLS ( device, device );
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 	DBGC ( device, "EFIDRV %s disconnecting existing drivers\n",
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 	       efi_handle_name ( device ) );
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+	efi_driver_disconnecting = 1;
414 427
 	if ( ( efirc = bs->DisconnectController ( device, NULL,
415 428
 						  NULL ) ) != 0 ) {
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 		rc = -EEFI ( efirc );
@@ -419,6 +432,7 @@ static int efi_driver_connect ( EFI_HANDLE device ) {
419 432
 		       strerror ( rc ) );
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 		/* Ignore the error and attempt to connect our drivers */
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 	}
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+	efi_driver_disconnecting = 0;
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 	DBGC2 ( device, "EFIDRV %s after disconnecting:\n",
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 		efi_handle_name ( device ) );
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 	DBGC2_EFI_PROTOCOLS ( device, device );
@@ -450,9 +464,11 @@ static int efi_driver_disconnect ( EFI_HANDLE device ) {
450 464
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
451 465
 
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 	/* Disconnect our driver */
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+	efi_driver_disconnecting = 1;
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 	bs->DisconnectController ( device,
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 				   efi_driver_binding.DriverBindingHandle,
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 				   NULL );
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+	efi_driver_disconnecting = 0;
456 472
 	return 0;
457 473
 }
458 474
 

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