From 518bca17bd39d87a35b9f7c7f186f08dc9e4be15 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Tue, 28 May 2019 15:42:37 -0400
Subject: [PATCH 16/63] Always log to a memfd regardless of loglevel.
This writes all debug logs to a memfd, so that they'll always show up in
strace.
Signed-off-by: Peter Jones <pjones@redhat.com>
---
src/error.c | 88 ++++++++++++++++++++++++++++++++++---
src/include/efivar/efivar.h | 7 +++
src/libefivar.map.in | 1 +
src/util.h | 26 +++++------
4 files changed, 102 insertions(+), 20 deletions(-)
diff --git a/src/error.c b/src/error.c
index df03d7f45e0..5dc43197c50 100644
--- a/src/error.c
+++ b/src/error.c
@@ -26,6 +26,7 @@
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
+#include <sys/mman.h>
#include <unistd.h>
#include "efiboot.h"
@@ -162,7 +163,58 @@ efi_error_pop(void)
clear_error_entry(&error_table[current]);
}
-void PUBLIC DESTRUCTOR
+static int efi_verbose;
+static FILE *efi_errlog, *efi_dbglog;
+static int efi_dbglog_fd = -1;
+static int stashed_log_level;
+static char efi_dbglog_buf[4096];
+
+void PUBLIC
+efi_stash_loglevel_(int level)
+{
+ stashed_log_level = level;
+}
+
+static ssize_t
+dbglog_write(void *cookie UNUSED, const char *buf, size_t size)
+{
+ FILE *log = efi_errlog ? efi_errlog : stderr;
+ ssize_t ret = size;
+
+ if (efi_get_verbose() >= stashed_log_level) {
+ ret = fwrite(buf, 1, size, log);
+ } else if (efi_dbglog_fd >= 0) {
+ lseek(efi_dbglog_fd, 0, SEEK_SET);
+ write(efi_dbglog_fd, buf, size);
+ }
+ return ret;
+}
+
+static int
+dbglog_seek(void *cookie UNUSED, off64_t *offset, int whence)
+{
+ FILE *log = efi_errlog ? efi_errlog : stderr;
+ return fseek(log, *offset, whence);
+}
+
+static int
+dbglog_close(void *cookie UNUSED)
+{
+ if (efi_dbglog_fd >= 0) {
+ close(efi_dbglog_fd);
+ efi_dbglog_fd = -1;
+ }
+ if (efi_errlog) {
+ int ret = fclose(efi_errlog);
+ efi_errlog = NULL;
+ return ret;
+ }
+
+ errno = EBADF;
+ return -1;
+}
+
+void PUBLIC
efi_error_clear(void)
{
if (error_table) {
@@ -177,15 +229,39 @@ efi_error_clear(void)
current = 0;
}
-static int efi_verbose;
-static FILE *efi_errlog;
+void DESTRUCTOR
+efi_error_fini(void)
+{
+ efi_error_clear();
+ if (efi_dbglog) {
+ fclose(efi_dbglog);
+ efi_dbglog = NULL;
+ }
+}
+
+static void CONSTRUCTOR
+efi_error_init(void)
+{
+ cookie_io_functions_t io_funcs = {
+ .write = dbglog_write,
+ .seek = dbglog_seek,
+ .close = dbglog_close,
+ };
+
+ efi_dbglog_fd = memfd_create("efivar-debug.log", MFD_CLOEXEC);
+ if (efi_dbglog_fd == -1)
+ return;
+
+ efi_dbglog = fopencookie(NULL, "a", io_funcs);
+ if (efi_dbglog)
+ setvbuf(efi_dbglog, efi_dbglog_buf, _IOLBF,
+ sizeof(efi_dbglog_buf));
+}
FILE PUBLIC *
efi_get_logfile(void)
{
- if (efi_errlog)
- return efi_errlog;
- return stderr;
+ return efi_dbglog;
}
void PUBLIC
diff --git a/src/include/efivar/efivar.h b/src/include/efivar/efivar.h
index dabf41789e5..343d1c557da 100644
--- a/src/include/efivar/efivar.h
+++ b/src/include/efivar/efivar.h
@@ -188,6 +188,7 @@ extern int efi_error_set(const char *filename,
__attribute__((__format__ (printf, 5, 6)));
extern void efi_error_clear(void);
extern void efi_error_pop(void);
+extern void efi_stash_loglevel_(int level);
#else
static inline int
__attribute__((__nonnull__ (2, 3, 4, 5, 6)))
@@ -225,6 +226,12 @@ efi_error_pop(void)
{
return;
}
+
+static inline void
+efi_stash_loglevel_(int level __attribute__((__unused__)))
+{
+ return;
+}
#endif
#define efi_error_real__(errval, file, function, line, fmt, args...) \
diff --git a/src/libefivar.map.in b/src/libefivar.map.in
index 8e50d574f10..8965b729917 100644
--- a/src/libefivar.map.in
+++ b/src/libefivar.map.in
@@ -133,4 +133,5 @@ LIBEFIVAR_1.37 {
LIBEFIVAR_1.38 {
global: efi_error_pop;
+ efi_stash_loglevel_;
} LIBEFIVAR_1.37;
diff --git a/src/util.h b/src/util.h
index a6a80e754ec..337762c9902 100644
--- a/src/util.h
+++ b/src/util.h
@@ -382,15 +382,14 @@ swizzle_guid_to_uuid(efi_guid_t *guid)
#define log_(file, line, func, level, fmt, args...) \
({ \
- if (efi_get_verbose() >= level) { \
- FILE *logfile_ = efi_get_logfile(); \
- int len_ = strlen(fmt); \
- fprintf(logfile_, "%s:%d %s(): ", \
- file, line, func); \
- fprintf(logfile_, fmt, ## args); \
- if (!len_ || fmt[len_ - 1] != '\n') \
- fprintf(logfile_, "\n"); \
- } \
+ efi_stash_loglevel_(level); \
+ FILE *logfile_ = efi_get_logfile(); \
+ int len_ = strlen(fmt); \
+ fprintf(logfile_, "%s:%d %s(): ", \
+ file, line, func); \
+ fprintf(logfile_, fmt, ## args); \
+ if (!len_ || fmt[len_ - 1] != '\n') \
+ fprintf(logfile_, "\n"); \
})
#define LOG_VERBOSE 0
@@ -402,11 +401,10 @@ swizzle_guid_to_uuid(efi_guid_t *guid)
#define debug(fmt, args...) log(LOG_DEBUG, fmt, ## args)
#define log_hex_(file, line, func, level, buf, size) \
({ \
- if (efi_get_verbose() >= level) { \
- fhexdumpf(efi_get_logfile(), "%s:%d %s(): ", \
- (uint8_t *)buf, size, \
- file, line, func); \
- } \
+ efi_stash_loglevel_(level); \
+ fhexdumpf(efi_get_logfile(), "%s:%d %s(): ", \
+ (uint8_t *)buf, size, \
+ file, line, func); \
})
#define log_hex(level, buf, size) log_hex_(__FILE__, __LINE__, __func__, level, buf, size)
#define debug_hex(buf, size) log_hex(LOG_DEBUG, buf, size)
--
2.26.2