driver/intel/fsp2_0: Disable NULL deref code when calling FSP
FSP needs interrupts disable so also disable generating exceptions
around debug registers.
Change-Id: Ia49dde68d45b71e231aaf32a0e6fd847f0e06146
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64426
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Reviewed-by: Uwe Poeche <uwe.poeche@siemens.com>
Reviewed-by: Sean Rhodes <sean@starlabs.systems>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/arch/x86/include/arch/null_breakpoint.h b/src/arch/x86/include/arch/null_breakpoint.h
index bc86dc0..9d69d3c 100644
--- a/src/arch/x86/include/arch/null_breakpoint.h
+++ b/src/arch/x86/include/arch/null_breakpoint.h
@@ -7,10 +7,15 @@
/* Places data and instructions breakpoints at address zero. */
void null_breakpoint_init(void);
+void null_breakpoint_disable(void);
#else
static inline void null_breakpoint_init(void)
{
- /* Not implemented */
+ /* Not implemented */
+}
+static inline void null_breakpoint_disable(void)
+{
+ /* Not implemented */
}
#endif
#endif /* _NULL_BREAKPOINT_H_ */
diff --git a/src/arch/x86/null_breakpoint.c b/src/arch/x86/null_breakpoint.c
index 4da6d87..70b94b6 100644
--- a/src/arch/x86/null_breakpoint.c
+++ b/src/arch/x86/null_breakpoint.c
@@ -57,11 +57,16 @@
create_instruction_breakpoint();
}
-static void null_breakpoint_disable(void *unused)
+void null_breakpoint_disable(void)
{
breakpoint_remove(null_fetch_bp);
breakpoint_remove(null_deref_bp);
}
-BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY, null_breakpoint_disable, NULL);
-BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_BOOT, BS_ON_ENTRY, null_breakpoint_disable, NULL);
+static void null_breakpoint_disable_hook(void *unused)
+{
+ null_breakpoint_disable();
+}
+
+BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY, null_breakpoint_disable_hook, NULL);
+BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_BOOT, BS_ON_ENTRY, null_breakpoint_disable_hook, NULL);
diff --git a/src/drivers/intel/fsp2_0/memory_init.c b/src/drivers/intel/fsp2_0/memory_init.c
index 4f95462..d6778b0 100644
--- a/src/drivers/intel/fsp2_0/memory_init.c
+++ b/src/drivers/intel/fsp2_0/memory_init.c
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
-#include <security/vboot/antirollback.h>
+#include <arch/null_breakpoint.h>
#include <arch/symbols.h>
#include <assert.h>
#include <cbfs.h>
@@ -11,17 +11,18 @@
#include <fsp/api.h>
#include <fsp/util.h>
#include <memrange.h>
+#include <mode_switch.h>
#include <mrc_cache.h>
#include <program_loading.h>
#include <romstage_handoff.h>
+#include <security/tpm/tspi.h>
+#include <security/vboot/antirollback.h>
+#include <security/vboot/vboot_common.h>
#include <string.h>
#include <symbols.h>
#include <timestamp.h>
-#include <security/vboot/vboot_common.h>
-#include <security/tpm/tspi.h>
-#include <vb2_api.h>
#include <types.h>
-#include <mode_switch.h>
+#include <vb2_api.h>
static uint8_t temp_ram[CONFIG_FSP_TEMP_RAM_SIZE] __aligned(sizeof(uint64_t));
@@ -293,6 +294,8 @@
fsp_raminit = (void *)(uintptr_t)(hdr->image_base + hdr->fsp_memory_init_entry_offset);
fsp_debug_before_memory_init(fsp_raminit, upd, &fspm_upd);
+ /* FSP disables the interrupt handler so remove debug exceptions temporarily */
+ null_breakpoint_disable();
post_code(POST_FSP_MEMORY_INIT);
timestamp_add_now(TS_FSP_MEMORY_INIT_START);
if (ENV_X86_64 && CONFIG(PLATFORM_USES_FSP2_X86_32))
@@ -301,6 +304,7 @@
(uintptr_t)fsp_get_hob_list_ptr());
else
status = fsp_raminit(&fspm_upd, fsp_get_hob_list_ptr());
+ null_breakpoint_init();
post_code(POST_FSP_MEMORY_EXIT);
timestamp_add_now(TS_FSP_MEMORY_INIT_END);
diff --git a/src/drivers/intel/fsp2_0/notify.c b/src/drivers/intel/fsp2_0/notify.c
index 5cd63d8..44e8795 100644
--- a/src/drivers/intel/fsp2_0/notify.c
+++ b/src/drivers/intel/fsp2_0/notify.c
@@ -1,5 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
+#include <arch/null_breakpoint.h>
#include <bootstate.h>
#include <console/console.h>
#include <cpu/x86/mtrr.h>
@@ -75,10 +76,13 @@
timestamp_add_now(data->timestamp_before);
post_code(data->post_code_before);
+ /* FSP disables the interrupt handler so remove debug exceptions temporarily */
+ null_breakpoint_disable();
if (ENV_X86_64 && CONFIG(PLATFORM_USES_FSP2_X86_32))
ret = protected_mode_call_1arg(fspnotify, (uintptr_t)¬ify_params);
else
ret = fspnotify(¬ify_params);
+ null_breakpoint_init();
timestamp_add_now(data->timestamp_after);
post_code(data->post_code_after);
diff --git a/src/drivers/intel/fsp2_0/silicon_init.c b/src/drivers/intel/fsp2_0/silicon_init.c
index 263ea3b..ae5d620 100644
--- a/src/drivers/intel/fsp2_0/silicon_init.c
+++ b/src/drivers/intel/fsp2_0/silicon_init.c
@@ -1,5 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
+#include <arch/null_breakpoint.h>
#include <bootsplash.h>
#include <cbfs.h>
#include <cbmem.h>
@@ -133,10 +134,13 @@
timestamp_add_now(TS_FSP_SILICON_INIT_START);
post_code(POST_FSP_SILICON_INIT);
+ /* FSP disables the interrupt handler so remove debug exceptions temporarily */
+ null_breakpoint_disable();
if (ENV_X86_64 && CONFIG(PLATFORM_USES_FSP2_X86_32))
status = protected_mode_call_1arg(silicon_init, (uintptr_t)upd);
else
status = silicon_init(upd);
+ null_breakpoint_init();
printk(BIOS_INFO, "FSPS returned %x\n", status);