From 94ed30e505f8a6d9dca8a2006f6dfced1bff9dec Mon Sep 17 00:00:00 2001 From: Daniel Black Date: Fri, 10 Feb 2023 12:58:57 +1100 Subject: [PATCH] MDEV-30613 output_core_info crashes in my_read() and my_getwd(). The cause is my_errno define which depends on my_thread_var being a not null pointer otherwise it will be de-referenced and cause a SEGV already in the signal handler. Replace uses of these functions in the output_core_info using posix read/getcwd functions instead. The getwd fallback in my_getcwd isn't needed as its been obsolute for a very long time. Thanks Vladislav Vaintroub for diagnosis and posix recommendation. --- sql/signal_handler.cc | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/sql/signal_handler.cc b/sql/signal_handler.cc index 2ddda3cec9d..96c067b717e 100644 --- a/sql/signal_handler.cc +++ b/sql/signal_handler.cc @@ -27,6 +27,7 @@ #ifdef __WIN__ #include +#include #define SIGNAL_FMT "exception 0x%x" #else #define SIGNAL_FMT "signal %d" @@ -67,27 +68,27 @@ static inline void output_core_info() my_safe_printf_stderr("Writing a core file...\nWorking directory at %.*s\n", (int) len, buff); } - if ((fd= my_open("/proc/self/limits", O_RDONLY, MYF(0))) >= 0) + if ((fd= open("/proc/self/limits", O_RDONLY, MYF(0))) >= 0) { my_safe_printf_stderr("Resource Limits:\n"); - while ((len= my_read(fd, (uchar*)buff, sizeof(buff), MYF(0))) > 0) + while ((len= read(fd, (uchar*)buff, sizeof(buff))) > 0) { my_write_stderr(buff, len); } - my_close(fd, MYF(0)); + close(fd); } #ifdef __linux__ - if ((fd= my_open("/proc/sys/kernel/core_pattern", O_RDONLY, MYF(0))) >= 0) + if ((fd= open("/proc/sys/kernel/core_pattern", O_RDONLY, MYF(0))) >= 0) { - len= my_read(fd, (uchar*)buff, sizeof(buff), MYF(0)); + len= read(fd, (uchar*)buff, sizeof(buff)); my_safe_printf_stderr("Core pattern: %.*s\n", (int) len, buff); - my_close(fd, MYF(0)); + close(fd); } - if ((fd= my_open("/proc/version", O_RDONLY, MYF(0))) >= 0) + if ((fd= open("/proc/version", O_RDONLY)) >= 0) { - len= my_read(fd, (uchar*)buff, sizeof(buff), MYF(0)); + len= read(fd, (uchar*)buff, sizeof(buff)); my_safe_printf_stderr("Kernel version: %.*s\n", (int) len, buff); - my_close(fd, MYF(0)); + close(fd); } #endif #elif defined(__APPLE__) || defined(__FreeBSD__) @@ -101,11 +102,14 @@ static inline void output_core_info() { my_safe_printf_stderr("Kernel version: %.*s\n", (int) len, buff); } -#else +#elif defined(HAVE_GETCWD) char buff[80]; - my_getwd(buff, sizeof(buff), 0); - my_safe_printf_stderr("Writing a core file at %s\n", buff); - fflush(stderr); + + if (getcwd(buff, sizeof(buff))) + { + my_safe_printf_stderr("Writing a core file at %.*s\n", (int) sizeof(buff), buff); + fflush(stderr); + } #endif }