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esp32h2: enable memory protection scheme using PMA and PMP

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Closes IDF-6452
This commit is contained in:
Mahavir Jain
2023-03-10 09:36:32 +05:30
parent 745c06626d
commit fb1ef7c6d6
3 changed files with 163 additions and 54 deletions
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206
components/esp_hw_support/port/esp32h2/cpu_region_protect.c
View File

@@ -10,83 +10,181 @@
#include "esp_cpu.h"
#include "esp_fault.h"
// ESP32H2-TODO: IDF-6452
#ifdef BOOTLOADER_BUILD
// Without L bit set
#define CONDITIONAL_NONE 0x0
#define CONDITIONAL_RX PMP_R | PMP_X
#define CONDITIONAL_RW PMP_R | PMP_W
#define CONDITIONAL_RWX PMP_R | PMP_W | PMP_X
#else
// With L bit set
#define CONDITIONAL_NONE NONE
#define CONDITIONAL_RX RX
#define CONDITIONAL_RW RW
#define CONDITIONAL_RWX RWX
#endif
static void esp_cpu_configure_invalid_regions(void)
{
const unsigned PMA_NONE = PMA_L | PMA_EN;
__attribute__((unused)) const unsigned PMA_RW = PMA_L | PMA_EN | PMA_R | PMA_W;
__attribute__((unused)) const unsigned PMA_RX = PMA_L | PMA_EN | PMA_R | PMA_X;
__attribute__((unused)) const unsigned PMA_RWX = PMA_L | PMA_EN | PMA_R | PMA_W | PMA_X;
// 1. Gap at bottom of address space
PMA_ENTRY_SET_TOR(0, SOC_DEBUG_LOW, PMA_TOR | PMA_NONE);
// 2. Gap between debug region & IROM
PMA_ENTRY_SET_TOR(1, SOC_DEBUG_HIGH, PMA_NONE);
PMA_ENTRY_SET_TOR(2, SOC_IROM_MASK_LOW, PMA_TOR | PMA_NONE);
// 3. Gap between ROM & RAM
PMA_ENTRY_SET_TOR(3, SOC_DROM_MASK_HIGH, PMA_NONE);
PMA_ENTRY_SET_TOR(4, SOC_IRAM_LOW, PMA_TOR | PMA_NONE);
// 4. Gap between DRAM and I_Cache
PMA_ENTRY_SET_TOR(5, SOC_IRAM_HIGH, PMA_NONE);
PMA_ENTRY_SET_TOR(6, SOC_IROM_LOW, PMA_TOR | PMA_NONE);
// 5. Gap between D_Cache & LP_RAM
PMA_ENTRY_SET_TOR(7, SOC_DROM_HIGH, PMA_NONE);
PMA_ENTRY_SET_TOR(8, SOC_RTC_IRAM_LOW, PMA_TOR | PMA_NONE);
// 6. Gap between LP memory & peripheral addresses
PMA_ENTRY_SET_TOR(9, SOC_RTC_IRAM_HIGH, PMA_NONE);
PMA_ENTRY_SET_TOR(10, SOC_PERIPHERAL_LOW, PMA_TOR | PMA_NONE);
// 7. End of address space
PMA_ENTRY_SET_TOR(11, SOC_PERIPHERAL_HIGH, PMA_NONE);
PMA_ENTRY_SET_TOR(12, UINT32_MAX, PMA_TOR | PMA_NONE);
}
void esp_cpu_configure_region_protection(void)
{
/* Notes on implementation:
*
* 1) Note: ESP32-H2 CPU doesn't support overlapping PMP regions
*
* 2) Therefore, we use TOR (top of range) entries to map the whole address
* space, bottom to top.
* 2) ESP32-H2 supports 16 PMA regions so we use this feature to block all the invalid address ranges
*
* 3) There are not enough entries to describe all the memory regions 100% accurately.
* 3) We use combination of NAPOT (Naturally Aligned Power Of Two) and TOR (top of range)
* entries to map all the valid address space, bottom to top. This leaves us with some extra PMP entries
* which can be used to provide more granular access
*
* 4) This means some gaps (invalid memory) are accessible. Priority for extending regions
* to cover gaps is to extend read-only or read-execute regions or read-only regions only
* (executing unmapped addresses should always fault with invalid instruction, read-only means
* stores will correctly fault even if reads may return some invalid value.)
*
* 5) Entries are grouped in order with some static asserts to try and verify everything is
* 4) Entries are grouped in order with some static asserts to try and verify everything is
* correct.
*/
const unsigned NONE = PMP_L | PMP_TOR;
const unsigned RW = PMP_L | PMP_TOR | PMP_R | PMP_W;
const unsigned RX = PMP_L | PMP_TOR | PMP_R | PMP_X;
const unsigned RWX = PMP_L | PMP_TOR | PMP_R | PMP_W | PMP_X;
// 1. Gap at bottom of address space
PMP_ENTRY_SET(0, SOC_DEBUG_LOW, NONE);
/* There are 4 configuration scenarios for SRAM
*
* 1. Bootloader build:
* - We cannot set the lock bit as we need to reconfigure it again for the application.
* We configure PMP to cover entire valid IRAM and DRAM range.
*
* 2. Application build with CONFIG_ESP_SYSTEM_PMP_IDRAM_SPLIT enabled
* - We split the SRAM into IRAM and DRAM such that IRAM region cannot be written to
* and DRAM region cannot be executed. We use _iram_end and _data_start markers to set the boundaries.
* We also lock these entries so the R/W/X permissions are enforced even for machine mode
*
* 3. Application build with CONFIG_ESP_SYSTEM_PMP_IDRAM_SPLIT disabled
* - The IRAM-DRAM split is not enabled so we just need to ensure that access to only valid address ranges are successful
* so for that we set PMP to cover entire valid IRAM and DRAM region.
* We also lock these entries so the R/W/X permissions are enforced even for machine mode
*
* 4. CPU is in OCD debug mode
* - The IRAM-DRAM split is not enabled so that OpenOCD can write and execute from IRAM.
* We set PMP to cover entire valid IRAM and DRAM region.
* We also lock these entries so the R/W/X permissions are enforced even for machine mode
*/
const unsigned NONE = PMP_L;
const unsigned R = PMP_L | PMP_R;
const unsigned RW = PMP_L | PMP_R | PMP_W;
const unsigned RX = PMP_L | PMP_R | PMP_X;
const unsigned RWX = PMP_L | PMP_R | PMP_W | PMP_X;
// 2. Debug region
PMP_ENTRY_SET(1, SOC_DEBUG_HIGH, RWX);
//
// Configure all the invalid address regions using PMA
//
esp_cpu_configure_invalid_regions();
//
// Configure all the valid address regions using PMP
//
// 1. Debug region
const uint32_t pmpaddr0 = PMPADDR_NAPOT(SOC_DEBUG_LOW, SOC_DEBUG_HIGH);
PMP_ENTRY_SET(0, pmpaddr0, PMP_NAPOT | RWX);
_Static_assert(SOC_DEBUG_LOW < SOC_DEBUG_HIGH, "Invalid CPU debug region");
// 3. Gap between debug region & IROM
PMP_ENTRY_SET(2, SOC_IROM_MASK_LOW, NONE);
_Static_assert(SOC_DEBUG_HIGH < SOC_IROM_MASK_LOW, "Invalid PMP entry order");
// 2.1 I-ROM
PMP_ENTRY_SET(1, SOC_IROM_MASK_LOW, NONE);
PMP_ENTRY_SET(2, SOC_IROM_MASK_HIGH, PMP_TOR | RX);
_Static_assert(SOC_IROM_MASK_LOW < SOC_IROM_MASK_HIGH, "Invalid I-ROM region");
// 4. ROM
PMP_ENTRY_SET(3, SOC_DROM_MASK_HIGH, RX);
_Static_assert(SOC_IROM_MASK_LOW < SOC_DROM_MASK_HIGH, "Invalid ROM region");
// 2.2 D-ROM
PMP_ENTRY_SET(3, SOC_DROM_MASK_LOW, NONE);
PMP_ENTRY_SET(4, SOC_DROM_MASK_HIGH, PMP_TOR | R);
_Static_assert(SOC_DROM_MASK_LOW < SOC_DROM_MASK_HIGH, "Invalid D-ROM region");
// 5. Gap between ROM & RAM
PMP_ENTRY_SET(4, SOC_IRAM_LOW, NONE);
_Static_assert(SOC_DROM_MASK_HIGH < SOC_IRAM_LOW, "Invalid PMP entry order");
if (esp_cpu_dbgr_is_attached()) {
// Anti-FI check that cpu is really in ocd mode
ESP_FAULT_ASSERT(esp_cpu_dbgr_is_attached());
// 6. RAM
PMP_ENTRY_SET(5, SOC_IRAM_HIGH, RWX);
_Static_assert(SOC_IRAM_LOW < SOC_IRAM_HIGH, "Invalid RAM region");
// 5. IRAM and DRAM
PMP_ENTRY_SET(5, SOC_IRAM_LOW, NONE);
PMP_ENTRY_SET(6, SOC_IRAM_HIGH, PMP_TOR | RWX);
_Static_assert(SOC_IRAM_LOW < SOC_IRAM_HIGH, "Invalid RAM region");
} else {
#if CONFIG_ESP_SYSTEM_PMP_IDRAM_SPLIT && !BOOTLOADER_BUILD
extern int _iram_end;
// 5. IRAM and DRAM
/* Reset the corresponding PMP config because PMP_ENTRY_SET only sets the given bits
* Bootloader might have given extra permissions and those won't be cleared
*/
PMP_ENTRY_CFG_RESET(5);
PMP_ENTRY_CFG_RESET(6);
PMP_ENTRY_CFG_RESET(7);
PMP_ENTRY_SET(5, SOC_IRAM_LOW, NONE);
PMP_ENTRY_SET(6, (int)&_iram_end, PMP_TOR | RX);
PMP_ENTRY_SET(7, SOC_DRAM_HIGH, PMP_TOR | RW);
#else
// 5. IRAM and DRAM
PMP_ENTRY_SET(5, SOC_IRAM_LOW, CONDITIONAL_NONE);
PMP_ENTRY_SET(6, SOC_IRAM_HIGH, PMP_TOR | CONDITIONAL_RWX);
_Static_assert(SOC_IRAM_LOW < SOC_IRAM_HIGH, "Invalid RAM region");
#endif
}
// 7. Gap between DRAM and I_Cache
PMP_ENTRY_SET(6, SOC_IROM_LOW, NONE);
_Static_assert(SOC_IRAM_HIGH < SOC_IROM_LOW, "Invalid PMP entry order");
// 8. I_Cache (flash)
PMP_ENTRY_SET(7, SOC_IROM_HIGH, RWX);
// 4. I_Cache (flash)
const uint32_t pmpaddr8 = PMPADDR_NAPOT(SOC_IROM_LOW, SOC_IROM_HIGH);
PMP_ENTRY_SET(8, pmpaddr8, PMP_NAPOT | RX);
_Static_assert(SOC_IROM_LOW < SOC_IROM_HIGH, "Invalid I_Cache region");
// 9. D_Cache (flash)
PMP_ENTRY_SET(8, SOC_DROM_HIGH, RW);
// 5. D_Cache (flash)
const uint32_t pmpaddr9 = PMPADDR_NAPOT(SOC_DROM_LOW, SOC_DROM_HIGH);
PMP_ENTRY_SET(9, pmpaddr9, PMP_NAPOT | R);
_Static_assert(SOC_DROM_LOW < SOC_DROM_HIGH, "Invalid D_Cache region");
// 10. Gap between D_Cache & LP_RAM
PMP_ENTRY_SET(9, SOC_RTC_IRAM_LOW, NONE);
_Static_assert(SOC_DROM_HIGH < SOC_RTC_IRAM_LOW, "Invalid PMP entry order");
// 16. LP memory
PMP_ENTRY_SET(10, SOC_RTC_IRAM_HIGH, RWX);
// 6. LP memory
#if CONFIG_ESP_SYSTEM_PMP_IDRAM_SPLIT && !BOOTLOADER_BUILD
extern int _rtc_text_end;
/* Reset the corresponding PMP config because PMP_ENTRY_SET only sets the given bits
* Bootloader might have given extra permissions and those won't be cleared
*/
PMP_ENTRY_CFG_RESET(10);
PMP_ENTRY_CFG_RESET(11);
PMP_ENTRY_CFG_RESET(12);
PMP_ENTRY_SET(10, SOC_RTC_IRAM_LOW, NONE);
PMP_ENTRY_SET(11, (int)&_rtc_text_end, PMP_TOR | RX);
PMP_ENTRY_SET(12, SOC_RTC_IRAM_HIGH, PMP_TOR | RW);
#else
const uint32_t pmpaddr10 = PMPADDR_NAPOT(SOC_RTC_IRAM_LOW, SOC_RTC_IRAM_HIGH);
PMP_ENTRY_SET(10, pmpaddr10, PMP_NAPOT | CONDITIONAL_RWX);
_Static_assert(SOC_RTC_IRAM_LOW < SOC_RTC_IRAM_HIGH, "Invalid RTC IRAM region");
#endif
// 17. Gap between LP memory & peripheral addresses
PMP_ENTRY_SET(11, SOC_PERIPHERAL_LOW, NONE);
_Static_assert(SOC_RTC_IRAM_HIGH < SOC_PERIPHERAL_LOW, "Invalid PMP entry order");
// 18. Peripheral addresses
PMP_ENTRY_SET(12, SOC_PERIPHERAL_HIGH, RW);
// 7. Peripheral addresses
const uint32_t pmpaddr13 = PMPADDR_NAPOT(SOC_PERIPHERAL_LOW, SOC_PERIPHERAL_HIGH);
PMP_ENTRY_SET(13, pmpaddr13, PMP_NAPOT | RW);
_Static_assert(SOC_PERIPHERAL_LOW < SOC_PERIPHERAL_HIGH, "Invalid peripheral region");
// 19. End of address space
PMP_ENTRY_SET(13, UINT32_MAX, NONE); // all but last 4 bytes
PMP_ENTRY_SET(14, UINT32_MAX, PMP_L | PMP_NA4); // last 4 bytes
}

8
components/soc/esp32h2/include/soc/Kconfig.soc_caps.in
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@@ -307,6 +307,14 @@ config SOC_CPU_WATCHPOINT_SIZE
hex
default 0x80000000
config SOC_CPU_HAS_PMA
bool
default y
config SOC_CPU_IDRAM_SPLIT_USING_PMP
bool
default y
config SOC_MMU_PAGE_SIZE_CONFIGURABLE
bool
default y

3
components/soc/esp32h2/include/soc/soc_caps.h
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@@ -134,6 +134,9 @@
#define SOC_CPU_WATCHPOINTS_NUM 4
#define SOC_CPU_WATCHPOINT_SIZE 0x80000000 // bytes
#define SOC_CPU_HAS_PMA 1
#define SOC_CPU_IDRAM_SPLIT_USING_PMP 1
/*-------------------------- MMU CAPS ----------------------------------------*/
#define SOC_MMU_PAGE_SIZE_CONFIGURABLE (1)
#define SOC_MMU_PERIPH_NUM (1U)