user/sven/linux.git/scripts/basic, branch v4.9.146

fixdep: faster CONFIG_ search

2016-08-24T20:34:19Z

Do you think kernel build is 100% dominated by gcc? You are wrong! One small utility called "fixdep" consistently manages to sneak into profile's first page (unless you have small monitor of course). The choke point is this clever code: for (; m < end; m++) { if (*m == INT_CONF) { p = (char *) m ; goto conf; } if (*m == INT_ONFI) { p = (char *) m-1; goto conf; } if (*m == INT_NFIG) { p = (char *) m-2; goto conf; } if (*m == INT_FIG_) { p = (char *) m-3; goto conf; } 4 branches per 4 characters is not fast. Use strstr(3), so that SSE2 etc can be used. With this patch, fixdep is so deep at the bottom, it is hard to find it. Signed-off-by: Alexey Dobriyan Signed-off-by: Michal Marek

scripts: Fix size mismatch of kexec_purgatory_size

2016-07-22T12:05:40Z

bin2c is used to create a valid C file out of a binary file where two symbols will be globally defined: and _size. is passed as the first parameter of the host binary. Building using goto-cc reported that the purgatory binary code (the only current user of this utility) declares kexec_purgatory_size as 'size_t' where bin2c generate _size to be 'int' so in a 64-bit host where sizeof(size_t) > sizeof(int) this type mismatch will always yield the wrong value for big-endian architectures while for little-endian it will be wrong if the object laid in memory directly after kexec_purgatory_size contains non-zero value at the time of reading. This commit changes _size to be size_t instead. Note: Another way to fix the problem is to change the type of kexec_purgatory_size to be 'int' as there's this check in code: (kexec_purgatory_size <= 0) Signed-off-by: Michael Tautschnig Cc: Vivek Goyal Acked-by: Dave Young Signed-off-by: Michal Marek

kbuild: add fine grained build dependencies for exported symbols

2016-03-29T20:30:56Z

Like with kconfig options, we now have the ability to compile in and out individual EXPORT_SYMBOL() declarations based on the content of include/generated/autoksyms.h. However we don't want the entire world to be rebuilt whenever that file is touched. Let's apply the same build dependency trick used for CONFIG_* symbols where the time stamp of empty files whose paths matching those symbols is used to trigger fine grained rebuilds. In our case the key is the symbol name passed to EXPORT_SYMBOL(). However, unlike config options, we cannot just use fixdep to parse the source code for EXPORT_SYMBOL(ksym) because several variants exist and parsing them all in a separate tool, and keeping it in synch, is not trivially maintainable. Furthermore, there are variants such as EXPORT_SYMBOL_GPL(pci_user_read_config_##size); that are instanciated via a macro for which we can't easily determine the actual exported symbol name(s) short of actually running the preprocessor on them. Storing the symbol name string in a special ELF section doesn't work for targets that output assembly or preprocessed source. So the best way is really to leverage the preprocessor by having it output actual symbol names anchored by a special sequence that can be easily filtered out. Then the list of symbols is simply fed to fixdep to be merged with the other dependencies. That implies the preprocessor is executed twice for each source file. A previous attempt relied on a warning pragma for each EXPORT_SYMBOL() instance that was filtered apart from stderr by the build system with a sed script during the actual compilation pass. Unfortunately the preprocessor/compiler diagnostic output isn't stable between versions and this solution, although more efficient, was deemed too fragile. Because of the lowercasing performed by fixdep, there might be name collisions triggering spurious rebuilds for similar symbols. But this shouldn't be a big issue in practice. (This is the case for CONFIG_* symbols and I didn't want to be different here, whatever the original reason for doing so.) To avoid needless build overhead, the exported symbol name gathering is performed only when CONFIG_TRIM_UNUSED_KSYMS is selected. Signed-off-by: Nicolas Pitre Acked-by: Rusty Russell

fixdep: accept extra dependencies on stdin

2016-03-29T20:19:40Z

... and merge them in the list of parsed dependencies. Signed-off-by: Nicolas Pitre

kbuild: fixdep: Check fstat(2) return value

2016-02-17T21:52:04Z

Coverity has recently added a check that will find when we don't check the return code from fstat(2). Copy/paste the checking logic that print_deps() has with an appropriate re-wording of the perror() message. Signed-off-by: Tom Rini Signed-off-by: Michal Marek

fixdep: constify strrcmp arguments

2015-12-07T11:42:55Z

strrcmp only performs read access to the memory addressed by its arguments so make them const pointers. Signed-off-by: Nicolas Iooss Signed-off-by: Michal Marek

kbuild: fixdep: drop meaningless hash table initialization

2015-08-24T14:36:08Z

The clear_config() is called just once at the beginning of this program, but the global variable hashtab[] is already zero-filled at the start-up. Signed-off-by: Masahiro Yamada Signed-off-by: Michal Marek

kbuild: fixdep: optimize code slightly

2015-08-24T14:36:08Z

If the target string matches "CONFIG_", move the pointer p forward. This saves several 7-chars adjustments. Signed-off-by: Masahiro Yamada Signed-off-by: Michal Marek

kernel: build bin2c based on config option CONFIG_BUILD_BIN2C

2014-08-08T22:57:32Z

currently bin2c builds only if CONFIG_IKCONFIG=y. But bin2c will now be used by kexec too. So make it compilation dependent on CONFIG_BUILD_BIN2C and this config option can be selected by CONFIG_KEXEC and CONFIG_IKCONFIG. Signed-off-by: Vivek Goyal Cc: Borislav Petkov Cc: Michael Kerrisk Cc: Yinghai Lu Cc: Eric Biederman Cc: H. Peter Anvin Cc: Matthew Garrett Cc: Greg Kroah-Hartman Cc: Dave Young Cc: WANG Chao Cc: Baoquan He Cc: Andy Lutomirski Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

bin2c: move bin2c in scripts/basic

2014-08-08T22:57:32Z

This patch series does not do kernel signature verification yet. I plan to post another patch series for that. Now distributions are already signing PE/COFF bzImage with PKCS7 signature I plan to parse and verify those signatures. Primary goal of this patchset is to prepare groundwork so that kernel image can be signed and signatures be verified during kexec load. This should help with two things. - It should allow kexec/kdump on secureboot enabled machines. - In general it can help even without secureboot. By being able to verify kernel image signature in kexec, it should help with avoiding module signing restrictions. Matthew Garret showed how to boot into a custom kernel, modify first kernel's memory and then jump back to old kernel and bypass any policy one wants to. This patch (of 15): Kexec wants to use bin2c and it wants to use it really early in the build process. See arch/x86/purgatory/ code in later patches. So move bin2c in scripts/basic so that it can be built very early and be usable by arch/x86/purgatory/ Signed-off-by: Vivek Goyal Cc: Borislav Petkov Cc: Michael Kerrisk Cc: Yinghai Lu Cc: Eric Biederman Cc: H. Peter Anvin Cc: Matthew Garrett Cc: Greg Kroah-Hartman Cc: Dave Young Cc: WANG Chao Cc: Baoquan He Cc: Andy Lutomirski Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds