diff options
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 6 | ||||
| -rw-r--r-- | include/linux/init.h | 13 | ||||
| -rw-r--r-- | scripts/mod/modpost.c | 11 |
3 files changed, 28 insertions, 2 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 52e2d69ee53..8307b1bb337 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -11,7 +11,8 @@ /* .data section */ #define DATA_DATA \ - *(.data) + *(.data) \ + *(.data.init.refok) #define RODATA \ . = ALIGN(4096); \ @@ -147,7 +148,8 @@ * during second ld run in second ld pass when generating System.map */ #define TEXT_TEXT \ ALIGN_FUNCTION(); \ - *(.text) + *(.text) \ + *(.text.init.refok) /* sched.text is aling to function alignment to secure we have same * address even at second ld pass when generating System.map */ diff --git a/include/linux/init.h b/include/linux/init.h index e007ae4dc41..56ec4c62eee 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -45,6 +45,19 @@ #define __exitdata __attribute__ ((__section__(".exit.data"))) #define __exit_call __attribute_used__ __attribute__ ((__section__ (".exitcall.exit"))) +/* modpost check for section mismatches during the kernel build. + * A section mismatch happens when there are references from a + * code or data section to an init section (both code or data). + * The init sections are (for most archs) discarded by the kernel + * when early init has completed so all such references are potential bugs. + * For exit sections the same issue exists. + * The following markers are used for the cases where the reference to + * the init/exit section (code or data) is valid and will teach modpost + * not to issue a warning. + * The markers follow same syntax rules as __init / __initdata. */ +#define __init_refok noinline __attribute__ ((__section__ (".text.init.refok"))) +#define __initdata_refok __attribute__ ((__section__ (".data.init.refok"))) + #ifdef MODULE #define __exit __attribute__ ((__section__(".exit.text"))) #else diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 2909391a803..7c87267b6ff 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -583,6 +583,12 @@ static int strrcmp(const char *s, const char *sub) /** * Whitelist to allow certain references to pass with no warning. + * + * Pattern 0: + * Do not warn if funtion/data are marked with __init_refok/__initdata_refok. + * The pattern is identified by: + * fromsec = .text.init.refok | .data.init.refok + * * Pattern 1: * If a module parameter is declared __initdata and permissions=0 * then this is legal despite the warning generated. @@ -686,6 +692,11 @@ static int secref_whitelist(const char *modname, const char *tosec, NULL }; + /* Check for pattern 0 */ + if ((strcmp(fromsec, ".text.init.refok") == 0) || + (strcmp(fromsec, ".data.init.refok") == 0)) + return 1; + /* Check for pattern 1 */ if (strcmp(tosec, ".init.data") != 0) f1 = 0; |