Re: [PATCH RESEND]kexec:i386/kexec-[bzImage|elf-x86]:x86_64/kexec-bzImage64: Use "\0" as command line instead of empty command line

[Zhang Yanfei <zhangyanfei.yes@gmail.com>]

于 2013年04月08日 17:29, Zhang Yanfei 写道:
> 于 2013年04月08日 17:23, Wang YanQing 写道:
>> This patch prevents the problems to happen below:
>> In setup_linux_bootloader_parameters_high
>> 120         cmdline_ptr = ((char *)real_mode) + cmdline_offset;
>> 121         memcpy(cmdline_ptr, cmdline, cmdline_len);
>> 122         cmdline_ptr[cmdline_len - 1] = '\0';
>>
>> if cmdline_len == 0, Line 122 will corrupt kernel16 buf just before the commandline.
>> And in do_bzImage_load, for example,
>> 369         cmdline_end = setup_base + kern16_size_needed + command_line_len - 1;
>> 370         elf_rel_set_symbol(&info->rhdr, "cmdline_end", &cmdline_end,
>> 371                            sizeof(unsigned long));
>> Line 369 will go wrong, too.
>>
>> Signed-off-by: Wang YanQing <udknight@gmail.com>
>> ---
>>  Hi Zhang Yanfei, could you give your signed-off-by to
>>  this patch?
> 
> Yeah.
> 
> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
> 
> Hi Simon, could you please take a look at this to see if the change is reasonable?
> After all, if no commadline, we make the commandline_len to 1. I don't know if
> this behaviour could be accepted by you.
> 

Hi Simon

What is your opinion about this patch?


>>
>>  kexec/arch/i386/kexec-bzImage.c     | 3 +++
>>  kexec/arch/i386/kexec-elf-x86.c     | 3 +++
>>  kexec/arch/x86_64/kexec-bzImage64.c | 6 +++++-
>>  3 files changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/kexec/arch/i386/kexec-bzImage.c b/kexec/arch/i386/kexec-bzImage.c
>> index 99fd790..29f280d 100644
>> --- a/kexec/arch/i386/kexec-bzImage.c
>> +++ b/kexec/arch/i386/kexec-bzImage.c
>> @@ -435,6 +435,9 @@ int bzImage_load(int argc, char **argv, const char *buf, off_t len,
>>  	command_line_len = 0;
>>  	if (command_line) {
>>  		command_line_len = strlen(command_line) +1;
>> +	} else {
>> +	    command_line = strdup("\0");
>> +	    command_line_len = 1;
>>  	}
>>  	ramdisk_buf = 0;
>>  	if (ramdisk) {
>> diff --git a/kexec/arch/i386/kexec-elf-x86.c b/kexec/arch/i386/kexec-elf-x86.c
>> index e62ebcb..788a209 100644
>> --- a/kexec/arch/i386/kexec-elf-x86.c
>> +++ b/kexec/arch/i386/kexec-elf-x86.c
>> @@ -161,6 +161,9 @@ int elf_x86_load(int argc, char **argv, const char *buf, off_t len,
>>  	command_line_len = 0;
>>  	if (command_line) {
>>  		command_line_len = strlen(command_line) +1;
>> +	} else {
>> +	    command_line = strdup("\0");
>> +	    command_line_len = 1;
>>  	}
>>  
>>  	/* Need to append some command line parameters internally in case of
>> diff --git a/kexec/arch/x86_64/kexec-bzImage64.c b/kexec/arch/x86_64/kexec-bzImage64.c
>> index 86e6d13..ec614a4 100644
>> --- a/kexec/arch/x86_64/kexec-bzImage64.c
>> +++ b/kexec/arch/x86_64/kexec-bzImage64.c
>> @@ -284,8 +284,12 @@ int bzImage64_load(int argc, char **argv, const char *buf, off_t len,
>>  	}
>>  	command_line = concat_cmdline(command_line, append);
>>  	command_line_len = 0;
>> -	if (command_line)
>> +	if (command_line) {
>>  		command_line_len = strlen(command_line) + 1;
>> +	} else {
>> +		command_line = strdup("\0");
>> +		command_line_len = 1;
>> +	}
>>  	ramdisk_buf = 0;
>>  	if (ramdisk)
>>  		ramdisk_buf = slurp_file(ramdisk, &ramdisk_length);
> 


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