[kvm-unit-tests PATCH 8/8] efi: parse KUT_ENV= from load options into environ

[Giacomo Mazzola <gmazz@amazon.de>]

Allow EFI applications to receive environment variables via the UEFI
load options string.  If any argv element contains 'KUT_ENV=', the
value after the '=' is parsed as a comma-separated list of KEY=VAL
pairs and fed to setup_env().  The KUT_ENV= argument is then removed
from argv so tests do not see it as a spurious positional argument.

This lets a UEFI boot manager pass runtime configuration (e.g.
KUT_ENV=PARAM_1=VALUE_1,PARAM_2=VALUE_2) without needing an initrd
environ file — useful in EFI environments where no filesystem is
available to the test.

Signed-off-by: Giacomo Mazzola <gmazz@amazon.de>
---
 lib/efi.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/lib/efi.c b/lib/efi.c
index d1be2bfc..650671e9 100644
--- a/lib/efi.c
+++ b/lib/efi.c
@@ -13,6 +13,8 @@
 #include <asm/setup.h>
 #include "efi.h"
 
+#define COMMAND_LINE_SIZE  2048
+
 /* From each arch */
 extern char *initrd;
 extern u32 initrd_size;
@@ -139,7 +141,6 @@ static char *efi_convert_cmdline(struct efi_loaded_image_64 *image, int *cmd_lin
 	int options_bytes = 0, safe_options_bytes = 0;  /* UTF-8 bytes */
 	bool in_quote = false;
 	efi_status_t status;
-	const int COMMAND_LINE_SIZE = 2048;
 
 	if (options) {
 		s2 = options;
@@ -397,6 +398,39 @@ static void efi_load_initrd(void)
 	}
 }
 
+#define ENV_STR "KUT_ENV"
+
+static void efi_setup_env(void)
+{
+	char *env = NULL, *p;
+	int i, size = 0;
+
+	for (i = 0; i < __argc && !env; i++)
+		env = strstr(__argv[i], ENV_STR "=");
+
+	if (!env)
+		return;
+
+	/* Remove the KUT_ENV= argument from argv. */
+	__argv[i - 1] = __argv[__argc - 1];
+	__argv[__argc - 1] = NULL;
+	__argc -= 1;
+
+	env += strlen(ENV_STR) + 1; /* skip past 'KUT_ENV=' */
+	p = env;
+	while (*p && !isspace(*p) && size < COMMAND_LINE_SIZE) {
+		if (*p == ',')
+			*p = '\n';
+		size++;
+		p++;
+	}
+
+	if (size >= COMMAND_LINE_SIZE)
+		report_abort("Cmdline arguments too long, or bad format");
+
+	setup_env(env, size);
+}
+
 efi_status_t efi_main(efi_handle_t handle, efi_system_table_t *sys_tab)
 {
 	int ret;
@@ -434,6 +468,7 @@ efi_status_t efi_main(efi_handle_t handle, efi_system_table_t *sys_tab)
 		goto efi_main_error;
 	}
 	setup_args(cmdline_ptr);
+	efi_setup_env();
 
 	efi_load_initrd();
 
-- 
2.47.3




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