On Wed, May 20, 2020 at 06:38:53PM +0200, Ard Biesheuvel wrote:
> On Wed, 20 May 2020 at 18:38, Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote:
> >
> > On Tue, May 19, 2020 at 11:07:55AM -0400, Arvind Sankar wrote:
> > > On Tue, May 19, 2020 at 10:22:40AM +0200, Ard Biesheuvel wrote:
> > > > On Mon, 18 May 2020 at 21:07, Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote:
> > > > > @@ -100,7 +123,9 @@ efi_status_t efi_parse_options(char const *cmdline)
> > > > > if (!strcmp(param, "nokaslr")) {
> > > > > efi_nokaslr = true;
> > > > > } else if (!strcmp(param, "quiet")) {
> > > > > - efi_quiet = true;
> > > > > + efi_loglevel = CONSOLE_LOGLEVEL_QUIET;
> > > > > + } else if (!strcmp(param, "debug")) {
> > > > > + efi_loglevel = CONSOLE_LOGLEVEL_DEBUG;
> > > >
> > > > Should we wire this to 'efi=debug' instead?
> > > >
> > >
> > > Sure.
> >
> > Do you prefer it wired up to both or just efi=debug?
> >
>
> Let's stick with efi=debug, that is what all other EFI code uses.
Ok -- you can replace the patch with the attached version. Only change
is in efi_parse_options.
Author: Arvind Sankar <nivedita@xxxxxxxxxxxx>
Date: Thu May 14 19:33:39 2020 -0400
efi/libstub: Implement printk-style logging
Use the efi_printk function in efi_info/efi_err, and add efi_debug. This
allows formatted output at different log levels.
Add the notion of a loglevel instead of just quiet/not-quiet, and
parse the efi=debug kernel parameter in addition to quiet.
Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx>
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index 5ecafc57619a..1f5a00b4f201 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -11,6 +11,7 @@
#include <linux/efi.h>
#include <linux/kernel.h>
+#include <linux/printk.h> /* For CONSOLE_LOGLEVEL_* */
#include <asm/efi.h>
#include "efistub.h"
@@ -18,7 +19,7 @@
bool efi_nochunk;
bool efi_nokaslr;
bool efi_noinitrd;
-bool efi_quiet;
+int efi_loglevel = CONSOLE_LOGLEVEL_DEFAULT;
bool efi_novamap;
static bool efi_nosoftreserve;
@@ -58,6 +59,28 @@ int efi_printk(const char *fmt, ...)
char printf_buf[256];
va_list args;
int printed;
+ int loglevel = printk_get_level(fmt);
+
+ switch (loglevel) {
+ case '0' ... '9':
+ loglevel -= '0';
+ break;
+ default:
+ /*
+ * Use loglevel -1 for cases where we just want to print to
+ * the screen.
+ */
+ loglevel = -1;
+ break;
+ }
+
+ if (loglevel >= efi_loglevel)
+ return 0;
+
+ if (loglevel >= 0)
+ efi_puts("EFI stub: ");
+
+ fmt = printk_skip_level(fmt);
va_start(args, fmt);
printed = vsnprintf(printf_buf, sizeof(printf_buf), fmt, args);
@@ -100,7 +123,7 @@ efi_status_t efi_parse_options(char const *cmdline)
if (!strcmp(param, "nokaslr")) {
efi_nokaslr = true;
} else if (!strcmp(param, "quiet")) {
- efi_quiet = true;
+ efi_loglevel = CONSOLE_LOGLEVEL_QUIET;
} else if (!strcmp(param, "noinitrd")) {
efi_noinitrd = true;
} else if (!strcmp(param, "efi") && val) {
@@ -114,6 +137,8 @@ efi_status_t efi_parse_options(char const *cmdline)
efi_disable_pci_dma = true;
if (parse_option_str(val, "no_disable_early_pci_dma"))
efi_disable_pci_dma = false;
+ if (parse_option_str(val, "debug"))
+ efi_loglevel = CONSOLE_LOGLEVEL_DEBUG;
} else if (!strcmp(param, "video") &&
val && strstarts(val, "efifb:")) {
efi_parse_option_graphics(val + strlen("efifb:"));
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index caa7dcc71c69..3a323a009836 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -6,6 +6,7 @@
#include <linux/compiler.h>
#include <linux/efi.h>
#include <linux/kernel.h>
+#include <linux/kern_levels.h>
#include <linux/types.h>
#include <asm/efi.h>
@@ -34,7 +35,7 @@
extern bool efi_nochunk;
extern bool efi_nokaslr;
extern bool efi_noinitrd;
-extern bool efi_quiet;
+extern int efi_loglevel;
extern bool efi_novamap;
extern const efi_system_table_t *efi_system_table;
@@ -49,11 +50,12 @@ extern const efi_system_table_t *efi_system_table;
#endif
-#define efi_info(msg) do { \
- if (!efi_quiet) efi_puts("EFI stub: "msg); \
-} while (0)
-
-#define efi_err(msg) efi_puts("EFI stub: ERROR: "msg)
+#define efi_info(fmt, ...) \
+ efi_printk(KERN_INFO fmt, ##__VA_ARGS__)
+#define efi_err(fmt, ...) \
+ efi_printk(KERN_ERR "ERROR: " fmt, ##__VA_ARGS__)
+#define efi_debug(fmt, ...) \
+ efi_printk(KERN_DEBUG "DEBUG: " fmt, ##__VA_ARGS__)
/* Helper macros for the usual case of using simple C variables: */
#ifndef fdt_setprop_inplace_var
