um: Setup physical memory in setup_arch() (b6323697) · Commits · 戴 / test

Currently UML sets up physical memory very early, long before setup_arch() was called by the kernel main function. This can cause problems when code paths in UML's memory setup code assume that the kernel is already running. i.e. when kmemleak is enabled it will evaluate current() in free_bootmem(). That early current() is undefined and UML explodes. Solve the problem by setting up physical memory in setup_arch(), at this stage the kernel has materialized and basic infrastructure such as current() works. Signed-off-by:

Richard Weinberger <richard@nod.at>

arch/um/kernel/um_arch.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -319,9 +319,6 @@ int __init linux_main(int argc, char **argv)

		start_vm = VMALLOC_START;

		setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
		mem_total_pages(physmem_size, iomem_size, highmem);

		virtmem_size = physmem_size;
		stack = (unsigned long) argv;
		stack &= ~(1024 * 1024 - 1);
		@@ -334,7 +331,6 @@ int __init linux_main(int argc, char **argv)
		printf("Kernel virtual memory size shrunk to %lu bytes\n",
		virtmem_size);

		stack_protections((unsigned long) &init_thread_info);
		os_flush_stdout();

		return start_uml();
		@@ -342,6 +338,10 @@ int __init linux_main(int argc, char **argv)

		void __init setup_arch(char **cmdline_p)
		{
		stack_protections((unsigned long) &init_thread_info);
		setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
		mem_total_pages(physmem_size, iomem_size, highmem);

		paging_init();
		strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
		*cmdline_p = command_line;

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