From 2965faa5e03d1e71e9ff9aa143fff39e0a77543a Mon Sep 17 00:00:00 2001 From: Dave Young Date: Wed, 9 Sep 2015 15:38:55 -0700 Subject: kexec: split kexec_load syscall from kexec core code There are two kexec load syscalls, kexec_load another and kexec_file_load. kexec_file_load has been splited as kernel/kexec_file.c. In this patch I split kexec_load syscall code to kernel/kexec.c. And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and use kexec_file_load only, or vice verse. The original requirement is from Ted Ts'o, he want kexec kernel signature being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use kexec_load syscall can bypass the checking. Vivek Goyal proposed to create a common kconfig option so user can compile in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects KEXEC_CORE so that old config files still work. Because there's general code need CONFIG_KEXEC_CORE, so I updated all the architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects KEXEC_CORE in arch Kconfig. Also updated general kernel code with to kexec_load syscall. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Dave Young Cc: Eric W. Biederman Cc: Vivek Goyal Cc: Petr Tesarik Cc: Theodore Ts'o Cc: Josh Boyer Cc: David Howells Cc: Geert Uytterhoeven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 19b62b522158..715cc57cc66a 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -621,7 +621,7 @@ static struct ctl_table kern_table[] = { .proc_handler = proc_dointvec, }, #endif -#ifdef CONFIG_KEXEC +#ifdef CONFIG_KEXEC_CORE { .procname = "kexec_load_disabled", .data = &kexec_load_disabled, -- cgit v1.2.3 From 9a5bc726d559221a3394bb8ef97d0abc1ee94d00 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Wed, 9 Sep 2015 15:39:06 -0700 Subject: sysctl: fix int -> unsigned long assignments in INT_MIN case The following if (val < 0) *lvalp = (unsigned long)-val; is incorrect because the compiler is free to assume -val to be positive and use a sign-extend instruction for extending the bit pattern. This is a problem if val == INT_MIN: # echo -2147483648 >/proc/sys/dev/scsi/logging_level # cat /proc/sys/dev/scsi/logging_level -18446744071562067968 Cast to unsigned long before negation - that way we first sign-extend and then negate an unsigned, which is well defined. With this: # cat /proc/sys/dev/scsi/logging_level -2147483648 Signed-off-by: Ilya Dryomov Cc: Mikulas Patocka Cc: Robert Xiao Cc: "Eric W. Biederman" Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 715cc57cc66a..e69201d8094e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1995,7 +1995,7 @@ static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp, int val = *valp; if (val < 0) { *negp = true; - *lvalp = (unsigned long)-val; + *lvalp = -(unsigned long)val; } else { *negp = false; *lvalp = (unsigned long)val; @@ -2201,7 +2201,7 @@ static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp, int val = *valp; if (val < 0) { *negp = true; - *lvalp = (unsigned long)-val; + *lvalp = -(unsigned long)val; } else { *negp = false; *lvalp = (unsigned long)val; @@ -2436,7 +2436,7 @@ static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp, unsigned long lval; if (val < 0) { *negp = true; - lval = (unsigned long)-val; + lval = -(unsigned long)val; } else { *negp = false; lval = (unsigned long)val; @@ -2459,7 +2459,7 @@ static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp unsigned long lval; if (val < 0) { *negp = true; - lval = (unsigned long)-val; + lval = -(unsigned long)val; } else { *negp = false; lval = (unsigned long)val; @@ -2484,7 +2484,7 @@ static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp, unsigned long lval; if (val < 0) { *negp = true; - lval = (unsigned long)-val; + lval = -(unsigned long)val; } else { *negp = false; lval = (unsigned long)val; -- cgit v1.2.3