September 2024 - devel

TLS memory-leak with dlopen
by Lumingxiang 31 Oct '24

31 Oct '24

If a shared library (so) is loaded using dlopen and utilizes thread-local storage (TLS), the memory will not be freed upon thread exit, resulting in a memory leak. This issue has been resolved in glibc-2.14. However, it remains unresolved in uClibc. The following patch is based on the patch made in glibc and has been validated as effective on the x86-64 architecture. diff --git a/libpthread/nptl/allocatestack.c b/libpthread/nptl/allocatestack.c index 7ef884543..941ef22f0 100644 --- a/libpthread/nptl/allocatestack.c +++ b/libpthread/nptl/allocatestack.c @@ -24,6 +24,7 @@ #include <unistd.h> #include <sys/mman.h> #include <sys/param.h> +#include <dl-tls.h> #include <tls.h> #include <lowlevellock.h> #include <link.h> @@ -241,6 +242,10 @@ get_cached_stack (size_t *sizep, void **memp) /* Clear the DTV. */ dtv_t *dtv = GET_DTV (TLS_TPADJ (result)); + for (size_t cnt = 0; cnt < dtv[-1].counter; ++cnt) + if (! dtv[1 + cnt].pointer.is_static + && dtv[1 + cnt].pointer.val != TLS_DTV_UNALLOCATED) + free (dtv[1 + cnt].pointer.val); memset (dtv, '\0', (dtv[-1].counter + 1) * sizeof (dtv_t)); /* Re-initialize the TLS. */ diff --git a/libpthread/nptl/sysdeps/generic/dl-tls.c b/libpthread/nptl/sysdeps/generic/dl-tls.c index 7d25e4706..7b7991be8 100644 --- a/libpthread/nptl/sysdeps/generic/dl-tls.c +++ b/libpthread/nptl/sysdeps/generic/dl-tls.c @@ -45,8 +45,6 @@ to allow dynamic loading of modules defining IE-model TLS data. */ # define TLS_STATIC_SURPLUS 64 + DL_NNS * 100 -/* Value used for dtv entries for which the allocation is delayed. */ -# define TLS_DTV_UNALLOCATED ((void *) -1l) #ifndef SHARED extern dtv_t static_dtv; diff --git a/libpthread/nptl/sysdeps/x86_64/dl-tls.h b/libpthread/nptl/sysdeps/x86_64/dl-tls.h index d6c338cda..5cac55f33 100644 --- a/libpthread/nptl/sysdeps/x86_64/dl-tls.h +++ b/libpthread/nptl/sysdeps/x86_64/dl-tls.h @@ -26,3 +26,6 @@ typedef struct extern void *__tls_get_addr (tls_index *ti); + +/* Value used for dtv entries for which the allocation is delayed. */ +#define TLS_DTV_UNALLOCATED ((void *) -1l) Ref: https://sourceware.org/bugzilla/show_bug.cgi?id=12650 How to reproduce: ------------------------------------------------------------------------------------------------------------------------------------- 本邮件及其附件含有新华三集团的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from New H3C, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!

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[PATCH v2 1/2] mips64n32, time64: Select correct _dl_fstat impl
by Dmitry Chestnykh 10 Sep '24

10 Sep '24

With time64 enabled we have to use statx() instead of stat() or fstat() If the _dl_fstat implementation isn't selected correctly we can have multiple errors inside dynamic linker during startup of the system and of the almost every process Add sparc exclusion like in other places inside this header Signed-off-by: Dmitry Chestnykh <dm.chestnykh(a)gmail.com> --- ldso/include/dl-syscall.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ldso/include/dl-syscall.h b/ldso/include/dl-syscall.h index 180d03012..c143b8d45 100644 --- a/ldso/include/dl-syscall.h +++ b/ldso/include/dl-syscall.h @@ -168,7 +168,7 @@ static __always_inline int _dl_stat(const char *file_name, #if defined __NR_fstat64 && !defined __NR_fstat && (!defined(__UCLIBC_USE_TIME64__) || defined(__sparc__)) # define __NR__dl_fstat __NR_fstat64 static __always_inline _syscall2(int, _dl_fstat, int, fd, struct stat *, buf) -#elif defined __NR_fstat +#elif defined __NR_fstat && !defined __UCLIBC_USE_TIME64__ || defined(__sparc__) # define __NR__dl_fstat __NR_fstat static __always_inline _syscall2(int, _dl_fstat, int, fd, struct stat *, buf) #elif defined __NR_statx && defined __UCLIBC_HAVE_STATX__ -- 2.46.0

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[PATCH] NFC: Don't put function def inside function def
by Dmitry Chestnykh 09 Sep '24

09 Sep '24

clang rejects the code where function body is placed inside body of another function Signed-off-by: Dmitry Chestnykh <dm.chestnykh(a)gmail.com> --- libc/sysdeps/linux/common/rename.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/libc/sysdeps/linux/common/rename.c b/libc/sysdeps/linux/common/rename.c index 613ae4e44..821467e3c 100644 --- a/libc/sysdeps/linux/common/rename.c +++ b/libc/sysdeps/linux/common/rename.c @@ -18,10 +18,12 @@ int rename(const char *oldpath, const char *newpath) } #elif defined __NR_renameat2 # include <fcntl.h> + +_syscall5(int, renameat2, int, olddfd, const char *, oldpath, + int, newdfd, const char *, newpath, int, flags) + int rename(const char *oldpath, const char *newpath) { - _syscall5(int, renameat2, int, olddfd, const char *, oldpath, - int, newdfd, const char *, newpath, int, flags) return renameat2(AT_FDCWD, oldpath, AT_FDCWD, newpath, 0); } #else -- 2.46.0

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[PATCH 1/2] mips64n32, time64: Select correct _dl_fstat impl
by Dmitry Chestnykh 03 Sep '24

03 Sep '24

With time64 enabled we have to use statx() instead of stat() or fstat() If the _dl_fstat implementation isn't selected correctly we can have multiple errors inside dynamic linker during startup of the system and of the almost every process Signed-off-by: Dmitry Chestnykh <dm.chestnykh(a)gmail.com> --- ldso/include/dl-syscall.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ldso/include/dl-syscall.h b/ldso/include/dl-syscall.h index 180d03012..4b0d0f395 100644 --- a/ldso/include/dl-syscall.h +++ b/ldso/include/dl-syscall.h @@ -168,7 +168,7 @@ static __always_inline int _dl_stat(const char *file_name, #if defined __NR_fstat64 && !defined __NR_fstat && (!defined(__UCLIBC_USE_TIME64__) || defined(__sparc__)) # define __NR__dl_fstat __NR_fstat64 static __always_inline _syscall2(int, _dl_fstat, int, fd, struct stat *, buf) -#elif defined __NR_fstat +#elif defined __NR_fstat && !defined __UCLIBC_USE_TIME64__ # define __NR__dl_fstat __NR_fstat static __always_inline _syscall2(int, _dl_fstat, int, fd, struct stat *, buf) #elif defined __NR_statx && defined __UCLIBC_HAVE_STATX__ -- 2.46.0

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