since there is a need for profiling babel and other subsystems (in my case, cake) on tiny systems, the attached patch has been sitting in my tree for a while, and supplied here in the hope it will be useful while its problems are sorted out...
... openwrt: Add support for musl in the linux kernel perf utility The linux kernel's "perf" profiling utility has a hard dependency on glibc's strerror_r which has a notorious incompatibility with other posix standards. This patch wraps the musl posix std strerr_r with something that behaves like glibc strerror_r - and currently breaks glibc support as I was unable to figure out a combination of defines that would work mutually across both C libraries. My current take on it is that linux mainline perf should switch to using strerror_l which is std and known to be thread safe, and would result in less code.... The patch only supports linux-4.4 but is easily extended backwards. H/T to stephen walker for the initial attempt, nbd for a refinement. untested on anything but arm at present.
From 866299c8c0902c8e21eee7b0f54c3abd74feb494 Mon Sep 17 00:00:00 2001 From: CeroWrt Admin <[email protected]> Date: Thu, 17 Dec 2015 12:49:36 +0100 Subject: [PATCH] openwrt: Add support for musl in the linux kernel perf utility The linux kernel's "perf" profiling utility has a hard dependency on glibc's strerror_r which is a notorious incompatability with other posix standards. This patch wraps the musl std strerr_r with something that behaves like glibc strerror_r - and currently breaks glibc support as I was unable to figure out a combination of defines that would work mutually across both C libraries. My current take on it is that linux mainline perf should switch to using strerror_l which is std and known to be thread safe. The patch only supports linux-4.4x but is easily extended backwards. H/T to stephen walker for the initial attempt. --- package/devel/perf/Makefile | 2 +- .../patches-4.4/280-perf-fixes-for-musl.patch | 143 +++++++++++++++++++++ 2 files changed, 144 insertions(+), 1 deletion(-) create mode 100644 target/linux/generic/patches-4.4/280-perf-fixes-for-musl.patch diff --git a/package/devel/perf/Makefile b/package/devel/perf/Makefile index 5e3d63f..27ef7b8 100644 --- a/package/devel/perf/Makefile +++ b/package/devel/perf/Makefile @@ -19,7 +19,7 @@ include $(INCLUDE_DIR)/package.mk define Package/perf SECTION:=devel CATEGORY:=Development - DEPENDS:= @USE_GLIBC +libelf1 +libdw +libpthread +librt +binutils + DEPENDS:=+libelf1 +libdw +libpthread +librt +binutils TITLE:=Linux performance monitoring tool VERSION:=$(LINUX_VERSION)-$(PKG_RELEASE) URL:=http://www.kernel.org diff --git a/target/linux/generic/patches-4.4/280-perf-fixes-for-musl.patch b/target/linux/generic/patches-4.4/280-perf-fixes-for-musl.patch new file mode 100644 index 0000000..029ac7d --- /dev/null +++ b/target/linux/generic/patches-4.4/280-perf-fixes-for-musl.patch @@ -0,0 +1,143 @@ +From 9673ba5369408008deef840e21edab3fa7a575fd Mon Sep 17 00:00:00 2001 +From: Dave Taht <[email protected]> +Date: Tue, 15 Dec 2015 17:19:14 +0100 +Subject: [PATCH] perf fixes for musl + +--- + tools/lib/api/fs/tracing_path.c | 3 +++ + tools/lib/traceevent/event-parse.c | 4 ++++ + tools/perf/perf.c | 17 ++++++++++++++++- + tools/perf/util/cache.h | 2 +- + tools/perf/util/cloexec.c | 4 ---- + tools/perf/util/cloexec.h | 4 ---- + tools/perf/util/util.h | 4 ++++ + 7 files changed, 28 insertions(+), 10 deletions(-) + +diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c +index a26bb5e..a04df38 100644 +--- a/tools/lib/api/fs/tracing_path.c ++++ b/tools/lib/api/fs/tracing_path.c +@@ -10,6 +10,9 @@ + #include "fs.h" + + #include "tracing_path.h" ++/* musl has a xpg compliant strerror_r by default */ ++#define strerror_r(err, buf, buflen) \ ++ (strerror_r(err, buf, buflen) ? NULL : buf) + + + char tracing_mnt[PATH_MAX] = "/sys/kernel/debug"; +diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c +index 2a912df..0644b42 100644 +--- a/tools/lib/traceevent/event-parse.c ++++ b/tools/lib/traceevent/event-parse.c +@@ -36,6 +36,10 @@ + #include "event-parse.h" + #include "event-utils.h" + ++/* musl has a xpg compliant strerror_r by default */ ++#define strerror_r(err, buf, buflen) \ ++ (strerror_r(err, buf, buflen) ? NULL : buf) ++ + static const char *input_buf; + static unsigned long long input_buf_ptr; + static unsigned long long input_buf_siz; +diff --git a/tools/perf/perf.c b/tools/perf/perf.c +index 3d4c7c0..91f57b0 100644 +--- a/tools/perf/perf.c ++++ b/tools/perf/perf.c +@@ -523,6 +523,21 @@ void pthread__unblock_sigwinch(void) + pthread_sigmask(SIG_UNBLOCK, &set, NULL); + } + ++unsigned cache_line_size(void); ++ ++unsigned cache_line_size(void) { ++ FILE * p = 0; ++ unsigned int i = 0; ++ p = fopen("/sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size", "r"); ++ if (p) { ++ if(fscanf(p, "%d", &i) != 1) { ++ perror("cannot determine cache line size"); ++ } ++ fclose(p); ++ } ++ return i; ++} ++ + int main(int argc, const char **argv) + { + const char *cmd; +@@ -530,7 +545,7 @@ int main(int argc, const char **argv) + + /* The page_size is placed in util object. */ + page_size = sysconf(_SC_PAGE_SIZE); +- cacheline_size = sysconf(_SC_LEVEL1_DCACHE_LINESIZE); ++ cacheline_size = cache_line_size(); + + cmd = perf_extract_argv0_path(argv[0]); + if (!cmd) +diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h +index c861373..599aa97 100644 +--- a/tools/perf/util/cache.h ++++ b/tools/perf/util/cache.h +@@ -71,7 +71,7 @@ extern char *perf_path(const char *fmt, ...) __attribute__((format (printf, 1, 2 + extern char *perf_pathdup(const char *fmt, ...) + __attribute__((format (printf, 1, 2))); + +-#ifndef __UCLIBC__ ++#if !defined(__UCLIBC__) && defined(__GLIBC__) + /* Matches the libc/libbsd function attribute so we declare this unconditionally: */ + extern size_t strlcpy(char *dest, const char *src, size_t size); + #endif +diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c +index 2babdda..85b5238 100644 +--- a/tools/perf/util/cloexec.c ++++ b/tools/perf/util/cloexec.c +@@ -7,15 +7,11 @@ + + static unsigned long flag = PERF_FLAG_FD_CLOEXEC; + +-#ifdef __GLIBC_PREREQ +-#if !__GLIBC_PREREQ(2, 6) + int __weak sched_getcpu(void) + { + errno = ENOSYS; + return -1; + } +-#endif +-#endif + + static int perf_flag_probe(void) + { +diff --git a/tools/perf/util/cloexec.h b/tools/perf/util/cloexec.h +index 3bee677..06904bc 100644 +--- a/tools/perf/util/cloexec.h ++++ b/tools/perf/util/cloexec.h +@@ -3,10 +3,6 @@ + + unsigned long perf_event_open_cloexec_flag(void); + +-#ifdef __GLIBC_PREREQ +-#if !__GLIBC_PREREQ(2, 6) && !defined(__UCLIBC__) + extern int sched_getcpu(void) __THROW; +-#endif +-#endif + + #endif /* __PERF_CLOEXEC_H */ +diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h +index dcc6590..16d398b 100644 +--- a/tools/perf/util/util.h ++++ b/tools/perf/util/util.h +@@ -358,4 +358,8 @@ int fetch_kernel_version(unsigned int *puint, + #define KVER_FMT "%d.%d.%d" + #define KVER_PARAM(x) KVER_VERSION(x), KVER_PATCHLEVEL(x), KVER_SUBLEVEL(x) + ++/* musl has a xpg compliant strerror_r by default */ ++#define strerror_r(err, buf, buflen) \ ++ (strerror_r(err, buf, buflen) ? NULL : buf) ++ + #endif /* GIT_COMPAT_UTIL_H */ +-- +2.5.0 + -- 2.5.0
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