[CRIU] [PATCH 09/10] compel: Initial commit

[Pavel Emelyanov]

On 03/22/2016 10:15 PM, Cyrill Gorcunov wrote:
> The compel component is a replacement for several aspects of CRIU
> functionality: binary blobs generation for PIE parasite/restore code,
> and a library for parasite code injection and execution (to be implemented).

OK, so at this stage compel tool starts with

1) cflags
2) ldflags
3) piegen

right?


> --- a/criu/pie/piegen/main.c
> +++ b/compel/src/main.c
> @@ -14,19 +15,23 @@
>  #include <sys/mman.h>
>  
>  #include "compiler.h"
> -#include "config.h"
>  #include "piegen.h"
>  
> +FILE *fout;
> +
> +static const char compel_cflags_pie[] = "-fpie -Wa,--noexecstack -fno-stack-protector";
> +static const char compel_cflags_nopic[] = "-fno-pic -Wa,--noexecstack -fno-stack-protector";
> +static const char compel_ldflags[] = "-r";
> +
>  piegen_opt_t opts = {
>  	.input_filename		= NULL,
>  	.stream_name		= "stream",
>  	.prefix_name		= "__",
>  	.var_name		= "elf_relocs",
>  	.nrgotpcrel_name	= "nr_gotpcrel",
> +	.uapi_dir		= "compel/uapi",
>  };
>  
> -FILE *fout;
> -
>  static int handle_elf(void *mem, size_t size)
>  {
>  #if defined(CONFIG_X86_32) || defined(CONFIG_X86_64)
> @@ -65,43 +70,120 @@ static int handle_elf(void *mem, size_t size)
>  	return -1;
>  }
>  
> -/*
> - * That;s the tool to generate patches object files.
> - */
> -int main(int argc, char *argv[])
> +static int piegen(void)
>  {
>  	struct stat st;
> -	int opt, idx;
>  	void *mem;
>  	int fd;
>  
> -	static const char short_opts[] = "f:o:s:p:v:r:h";
> +	fd = open(opts.input_filename, O_RDONLY);
> +	if (fd < 0) {
> +		pr_perror("Can't open file %s", opts.input_filename);
> +		goto err;
> +	}
> +
> +	if (fstat(fd, &st)) {
> +		pr_perror("Can't stat file %s", opts.input_filename);
> +		goto err;
> +	}
> +
> +	fout = fopen(opts.output_filename, "w");
> +	if (fout == NULL) {
> +		pr_perror("Can't open %s", opts.output_filename);
> +		goto err;
> +	}
> +
> +	mem = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FILE, fd, 0);
> +	if (mem == MAP_FAILED) {
> +		pr_perror("Can't mmap file %s", opts.input_filename);
> +		goto err;
> +	}
> +
> +	if (handle_elf(mem, st.st_size)) {
> +		fclose(fout);
> +		unlink(opts.output_filename);
> +		goto err;
> +	}
> +
> +err:
> +	fclose(fout);
> +	printf("%s generated successfully.\n", opts.output_filename);
> +	return 0;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +	const char *current_cflags = NULL;
> +	int opt, idx, i;
> +	char *action;
> +
> +	typedef struct {
> +		const char	*arch;
> +		const char	*cflags;
> +	} compel_cflags_t;
> +
> +	static const compel_cflags_t compel_cflags[] = {
> +		{
> +			.arch	= "x86",
> +			.cflags	= compel_cflags_pie,
> +		}, {
> +			.arch	= "ia32",
> +			.cflags	= compel_cflags_nopic,
> +		}, {
> +			.arch	= "aarch64",
> +			.cflags	= compel_cflags_pie,
> +		}, {
> +			.arch	= "arm",
> +			.cflags	= compel_cflags_pie,
> +		}, {
> +			.arch	= "ppc64",
> +			.cflags	= compel_cflags_pie,
> +		},
> +	};
> +
> +	const char short_opts[] = "f:o:s:p:v:r:a:u:Vh";
>  	static struct option long_opts[] = {
> -		{ "file",	required_argument,	0, 'f' },
> -		{ "output",	required_argument,	0, 'o' },
> -		{ "stream",	required_argument,	0, 's' },
> -		{ "sym-prefix",	required_argument,	0, 'p' },
> -		{ "variable",	required_argument,	0, 'v' },
> -		{ "pcrelocs",	required_argument,	0, 'r' },
> -		{ "help",	required_argument,	0, 'h' },
> +		{ "arch",		required_argument,	0, 'a' },
> +		{ "file",		required_argument,	0, 'f' },
> +		{ "output",		required_argument,	0, 'o' },
> +		{ "stream",		required_argument,	0, 's' },
> +		{ "uapi-dir",		required_argument,	0, 'u' },
> +		{ "sym-prefix",		required_argument,	0, 'p' },
> +		{ "variable",		required_argument,	0, 'v' },
> +		{ "pcrelocs",		required_argument,	0, 'r' },
> +		{ "version",		no_argument,		0, 'V' },
> +		{ "help",		no_argument,		0, 'h' },

This seem to add much more than just moving the piegen code. What?