From: Simon Glass <simon.glass@canonical.com> Add malloc_dump_to_file() and malloc_log_to_file() functions to write heap dumps and malloc traffic logs to host files. This is useful for debugging memory leaks in sandbox by allowing comparison of before/after heap states with external tools like diff. These functions are only available in sandbox builds since they use host-filesystem access. Co-developed-by: Claude <noreply@anthropic.com> Signed-off-by: Simon Glass <simon.glass@canonical.com> --- common/dlmalloc.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++ include/malloc.h | 22 +++++++++++++++ 2 files changed, 90 insertions(+) diff --git a/common/dlmalloc.c b/common/dlmalloc.c index 7f00dea6eb1..e47f3c153a2 100644 --- a/common/dlmalloc.c +++ b/common/dlmalloc.c @@ -6144,6 +6144,38 @@ void malloc_log_dump(void) malloc_log_impl(log_to_console, NULL); } +#if IS_ENABLED(CONFIG_SANDBOX) +/* File output function for log */ +static void log_to_file(void *ctx, const char *fmt, ...) +{ + int fd = *(int *)ctx; + char buf[256]; + va_list args; + int len; + + va_start(args, fmt); + len = vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + + if (len > 0) + os_write(fd, buf, len); +} + +int malloc_log_to_file(const char *fname) +{ + int fd; + + fd = os_open(fname, OS_O_WRONLY | OS_O_CREAT | OS_O_TRUNC); + if (fd < 0) + return fd; + + malloc_log_impl(log_to_file, &fd); + os_close(fd); + + return 0; +} +#endif + int malloc_log_info(struct mlog_info *info) { if (!mlog.buf) @@ -7481,6 +7513,26 @@ static void dump_to_console(void *ctx, const char *fmt, ...) va_end(args); } +#if IS_ENABLED(CONFIG_SANDBOX) +#include <os.h> + +/* File output function for heap dump */ +static void dump_to_file(void *ctx, const char *fmt, ...) +{ + int fd = *(int *)ctx; + char buf[256]; + va_list args; + int len; + + va_start(args, fmt); + len = vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + + if (len > 0) + os_write(fd, buf, len); +} +#endif + static void malloc_dump_impl(dump_out_fn out, void *ctx) { mchunkptr q; @@ -7568,6 +7620,22 @@ void malloc_dump(void) malloc_dump_impl(dump_to_console, NULL); } +#if IS_ENABLED(CONFIG_SANDBOX) +int malloc_dump_to_file(const char *fname) +{ + int fd; + + fd = os_open(fname, OS_O_WRONLY | OS_O_CREAT | OS_O_TRUNC); + if (fd < 0) + return fd; + + malloc_dump_impl(dump_to_file, &fd); + os_close(fd); + + return 0; +} +#endif + int initf_malloc(void) { #if CONFIG_IS_ENABLED(SYS_MALLOC_F) diff --git a/include/malloc.h b/include/malloc.h index 4bd6458b70d..3deb90b2a0b 100644 --- a/include/malloc.h +++ b/include/malloc.h @@ -712,6 +712,17 @@ void malloc_disable_testing(void); */ void malloc_dump(void); +/** + * malloc_dump_to_file() - Write heap dump to a host file + * + * @fname: Path to the output file on the host filesystem + * Return: 0 on success, negative error code on failure + * + * This is only available in sandbox builds. It writes the same information + * as malloc_dump() but to a file instead of the console. + */ +int malloc_dump_to_file(const char *fname); + /** * malloc_log_start() - Start logging malloc traffic * @@ -733,6 +744,17 @@ void malloc_log_stop(void); */ void malloc_log_dump(void); +/** + * malloc_log_to_file() - Write malloc()-traffic log to a host file + * + * @fname: Path to the output file on the host filesystem + * Return: 0 on success, negative error code on failure + * + * This is only available in sandbox builds. It writes the same information + * as malloc_log_dump() but to a file instead of the console. + */ +int malloc_log_to_file(const char *fname); + /** * enum mlog_type - Type of malloc log entry */ -- 2.43.0