Commit 40c93d7f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 fixes from Thomas Gleixner:

 - Move the command line preparation and the early command line parsing
   earlier so that the command line parameters which affect
   early_reserve_memory(), e.g. efi=nosftreserve, are taken into
   account. This was broken when the invocation of
   early_reserve_memory() was moved recently.

 - Use an atomic type for the SGX page accounting, which is read and
   written locklessly, to plug various race conditions related to it.

* tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sgx: Fix free page accounting
  x86/boot: Pull up cmdline preparation and early param parsing
parents af16bdea ac5d272a

arch/x86/kernel/cpu/sgx/main.c

+6 −6
Original line number Diff line number Diff line
@@ -28,8 +28,7 @@ static DECLARE_WAIT_QUEUE_HEAD(ksgxd_waitq); 
static LIST_HEAD(sgx_active_page_list);

static DEFINE_SPINLOCK(sgx_reclaimer_lock);



/* The free page list lock protected variables prepend the lock. */

static unsigned long sgx_nr_free_pages;

static atomic_long_t sgx_nr_free_pages = ATOMIC_LONG_INIT(0);



/* Nodes with one or more EPC sections. */

static nodemask_t sgx_numa_mask;
@@ -403,14 +402,15 @@ static void sgx_reclaim_pages(void) 


		spin_lock(&node->lock);

		list_add_tail(&epc_page->list, &node->free_page_list);

		sgx_nr_free_pages++;

		spin_unlock(&node->lock);

		atomic_long_inc(&sgx_nr_free_pages);

	}

}



static bool sgx_should_reclaim(unsigned long watermark)

{

	return sgx_nr_free_pages < watermark && !list_empty(&sgx_active_page_list);

	return atomic_long_read(&sgx_nr_free_pages) < watermark &&

	       !list_empty(&sgx_active_page_list);

}



static int ksgxd(void *p)
@@ -471,9 +471,9 @@ static struct sgx_epc_page *__sgx_alloc_epc_page_from_node(int nid) 


	page = list_first_entry(&node->free_page_list, struct sgx_epc_page, list);

	list_del_init(&page->list);

	sgx_nr_free_pages--;



	spin_unlock(&node->lock);

	atomic_long_dec(&sgx_nr_free_pages);



	return page;

}
@@ -625,9 +625,9 @@ void sgx_free_epc_page(struct sgx_epc_page *page) 
	spin_lock(&node->lock);



	list_add_tail(&page->list, &node->free_page_list);

	sgx_nr_free_pages++;



	spin_unlock(&node->lock);

	atomic_long_inc(&sgx_nr_free_pages);

}



static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size,

arch/x86/kernel/setup.c

+39 −27
Original line number Diff line number Diff line
@@ -742,6 +742,28 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p) 
	return 0;

}



static char *prepare_command_line(void)

{

#ifdef CONFIG_CMDLINE_BOOL

#ifdef CONFIG_CMDLINE_OVERRIDE

	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);

#else

	if (builtin_cmdline[0]) {

		/* append boot loader cmdline to builtin */

		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);

		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);

		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);

	}

#endif

#endif



	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);



	parse_early_param();



	return command_line;

}



/*

 * Determine if we were loaded by an EFI loader.  If so, then we have also been

 * passed the efi memmap, systab, etc., so we should use these data structures
@@ -830,6 +852,23 @@ void __init setup_arch(char **cmdline_p) 


	x86_init.oem.arch_setup();



	/*

	 * x86_configure_nx() is called before parse_early_param() (called by

	 * prepare_command_line()) to detect whether hardware doesn't support

	 * NX (so that the early EHCI debug console setup can safely call

	 * set_fixmap()). It may then be called again from within noexec_setup()

	 * during parsing early parameters to honor the respective command line

	 * option.

	 */

	x86_configure_nx();



	/*

	 * This parses early params and it needs to run before

	 * early_reserve_memory() because latter relies on such settings

	 * supplied as early params.

	 */

	*cmdline_p = prepare_command_line();



	/*

	 * Do some memory reservations *before* memory is added to memblock, so

	 * memblock allocations won't overwrite it.
@@ -863,33 +902,6 @@ void __init setup_arch(char **cmdline_p) 
	bss_resource.start = __pa_symbol(__bss_start);

	bss_resource.end = __pa_symbol(__bss_stop)-1;



#ifdef CONFIG_CMDLINE_BOOL

#ifdef CONFIG_CMDLINE_OVERRIDE

	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);

#else

	if (builtin_cmdline[0]) {

		/* append boot loader cmdline to builtin */

		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);

		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);

		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);

	}

#endif

#endif



	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);

	*cmdline_p = command_line;



	/*

	 * x86_configure_nx() is called before parse_early_param() to detect

	 * whether hardware doesn't support NX (so that the early EHCI debug

	 * console setup can safely call set_fixmap()). It may then be called

	 * again from within noexec_setup() during parsing early parameters

	 * to honor the respective command line option.

	 */

	x86_configure_nx();



	parse_early_param();



#ifdef CONFIG_MEMORY_HOTPLUG

	/*

	 * Memory used by the kernel cannot be hot-removed because Linux