From 39d3454c3513840eb123b3913fda6903e45ce671 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 18 Oct 2020 09:39:21 +0100 Subject: ARM: footbridge: fix dc21285 PCI configuration accessors Building with gcc 4.9.2 reveals a latent bug in the PCI accessors for Footbridge platforms, which causes a fatal alignment fault while accessing IO memory. Fix this by making the assembly volatile. Cc: stable@vger.kernel.org Signed-off-by: Russell King --- arch/arm/mach-footbridge/dc21285.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'arch') diff --git a/arch/arm/mach-footbridge/dc21285.c b/arch/arm/mach-footbridge/dc21285.c index 416462e3f5d6..f9713dc561cf 100644 --- a/arch/arm/mach-footbridge/dc21285.c +++ b/arch/arm/mach-footbridge/dc21285.c @@ -65,15 +65,15 @@ dc21285_read_config(struct pci_bus *bus, unsigned int devfn, int where, if (addr) switch (size) { case 1: - asm("ldrb %0, [%1, %2]" + asm volatile("ldrb %0, [%1, %2]" : "=r" (v) : "r" (addr), "r" (where) : "cc"); break; case 2: - asm("ldrh %0, [%1, %2]" + asm volatile("ldrh %0, [%1, %2]" : "=r" (v) : "r" (addr), "r" (where) : "cc"); break; case 4: - asm("ldr %0, [%1, %2]" + asm volatile("ldr %0, [%1, %2]" : "=r" (v) : "r" (addr), "r" (where) : "cc"); break; } @@ -99,17 +99,17 @@ dc21285_write_config(struct pci_bus *bus, unsigned int devfn, int where, if (addr) switch (size) { case 1: - asm("strb %0, [%1, %2]" + asm volatile("strb %0, [%1, %2]" : : "r" (value), "r" (addr), "r" (where) : "cc"); break; case 2: - asm("strh %0, [%1, %2]" + asm volatile("strh %0, [%1, %2]" : : "r" (value), "r" (addr), "r" (where) : "cc"); break; case 4: - asm("str %0, [%1, %2]" + asm volatile("str %0, [%1, %2]" : : "r" (value), "r" (addr), "r" (where) : "cc"); break; -- cgit v1.2.3 From 538eea5362a1179dfa7770dd2b6607dc30cc50c6 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 15 Dec 2020 16:16:44 +0100 Subject: ARM: 9043/1: tegra: Fix misplaced tegra_uart_config in decompressor The tegra_uart_config of the DEBUG_LL code is now placed right at the start of the .text section after commit which enabled debug output in the decompressor. Tegra devices are not booting anymore if DEBUG_LL is enabled since tegra_uart_config data is executes as a code. Fix the misplaced tegra_uart_config storage by embedding it into the code. Cc: stable@vger.kernel.org Fixes: 2596a72d3384 ("ARM: 9009/1: uncompress: Enable debug in head.S") Reviewed-by: Linus Walleij Signed-off-by: Dmitry Osipenko Signed-off-by: Russell King --- arch/arm/include/debug/tegra.S | 54 +++++++++++++++++++++--------------------- 1 file changed, 27 insertions(+), 27 deletions(-) (limited to 'arch') diff --git a/arch/arm/include/debug/tegra.S b/arch/arm/include/debug/tegra.S index 98daa7f48314..7454480d084b 100644 --- a/arch/arm/include/debug/tegra.S +++ b/arch/arm/include/debug/tegra.S @@ -149,7 +149,34 @@ .align 99: .word . +#if defined(ZIMAGE) + .word . + 4 +/* + * Storage for the state maintained by the macro. + * + * In the kernel proper, this data is located in arch/arm/mach-tegra/tegra.c. + * That's because this header is included from multiple files, and we only + * want a single copy of the data. In particular, the UART probing code above + * assumes it's running using physical addresses. This is true when this file + * is included from head.o, but not when included from debug.o. So we need + * to share the probe results between the two copies, rather than having + * to re-run the probing again later. + * + * In the decompressor, we put the storage right here, since common.c + * isn't included in the decompressor build. This storage data gets put in + * .text even though it's really data, since .data is discarded from the + * decompressor. Luckily, .text is writeable in the decompressor, unless + * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug. + */ + /* Debug UART initialization required */ + .word 1 + /* Debug UART physical address */ + .word 0 + /* Debug UART virtual address */ + .word 0 +#else .word tegra_uart_config +#endif .ltorg /* Load previously selected UART address */ @@ -189,30 +216,3 @@ .macro waituarttxrdy,rd,rx .endm - -/* - * Storage for the state maintained by the macros above. - * - * In the kernel proper, this data is located in arch/arm/mach-tegra/tegra.c. - * That's because this header is included from multiple files, and we only - * want a single copy of the data. In particular, the UART probing code above - * assumes it's running using physical addresses. This is true when this file - * is included from head.o, but not when included from debug.o. So we need - * to share the probe results between the two copies, rather than having - * to re-run the probing again later. - * - * In the decompressor, we put the symbol/storage right here, since common.c - * isn't included in the decompressor build. This symbol gets put in .text - * even though it's really data, since .data is discarded from the - * decompressor. Luckily, .text is writeable in the decompressor, unless - * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug. - */ -#if defined(ZIMAGE) -tegra_uart_config: - /* Debug UART initialization required */ - .word 1 - /* Debug UART physical address */ - .word 0 - /* Debug UART virtual address */ - .word 0 -#endif -- cgit v1.2.3 From 9c698bff66ab4914bb3d71da7dc6112519bde23e Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 29 Jan 2021 10:19:07 +0000 Subject: ARM: ensure the signal page contains defined contents Ensure that the signal page contains our poison instruction to increase the protection against ROP attacks and also contains well defined contents. Acked-by: Will Deacon Signed-off-by: Russell King --- arch/arm/kernel/signal.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'arch') diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 9d2e916121be..a3a38d0a4c85 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -693,18 +693,20 @@ struct page *get_signal_page(void) addr = page_address(page); + /* Poison the entire page */ + memset32(addr, __opcode_to_mem_arm(0xe7fddef1), + PAGE_SIZE / sizeof(u32)); + /* Give the signal return code some randomness */ offset = 0x200 + (get_random_int() & 0x7fc); signal_return_offset = offset; - /* - * Copy signal return handlers into the vector page, and - * set sigreturn to be a pointer to these. - */ + /* Copy signal return handlers into the page */ memcpy(addr + offset, sigreturn_codes, sizeof(sigreturn_codes)); - ptr = (unsigned long)addr + offset; - flush_icache_range(ptr, ptr + sizeof(sigreturn_codes)); + /* Flush out all instructions in this page */ + ptr = (unsigned long)addr; + flush_icache_range(ptr, ptr + PAGE_SIZE); return page; } -- cgit v1.2.3 From 4d62e81b60d4025e2dfcd5ea531cc1394ce9226f Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 1 Feb 2021 19:40:01 +0000 Subject: ARM: kexec: fix oops after TLB are invalidated Giancarlo Ferrari reports the following oops while trying to use kexec: Unable to handle kernel paging request at virtual address 80112f38 pgd = fd7ef03e [80112f38] *pgd=0001141e(bad) Internal error: Oops: 80d [#1] PREEMPT SMP ARM ... This is caused by machine_kexec() trying to set the kernel text to be read/write, so it can poke values into the relocation code before copying it - and an interrupt occuring which changes the page tables. The subsequent writes then hit read-only sections that trigger a data abort resulting in the above oops. Fix this by copying the relocation code, and then writing the variables into the destination, thereby avoiding the need to make the kernel text read/write. Reported-by: Giancarlo Ferrari Tested-by: Giancarlo Ferrari Signed-off-by: Russell King --- arch/arm/include/asm/kexec-internal.h | 12 +++++++++++ arch/arm/kernel/asm-offsets.c | 5 +++++ arch/arm/kernel/machine_kexec.c | 20 ++++++++---------- arch/arm/kernel/relocate_kernel.S | 38 ++++++++++------------------------- 4 files changed, 36 insertions(+), 39 deletions(-) create mode 100644 arch/arm/include/asm/kexec-internal.h (limited to 'arch') diff --git a/arch/arm/include/asm/kexec-internal.h b/arch/arm/include/asm/kexec-internal.h new file mode 100644 index 000000000000..ecc2322db7aa --- /dev/null +++ b/arch/arm/include/asm/kexec-internal.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ARM_KEXEC_INTERNAL_H +#define _ARM_KEXEC_INTERNAL_H + +struct kexec_relocate_data { + unsigned long kexec_start_address; + unsigned long kexec_indirection_page; + unsigned long kexec_mach_type; + unsigned long kexec_r2; +}; + +#endif diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index a1570c8bab25..be8050b0c3df 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -170,5 +171,9 @@ int main(void) DEFINE(MPU_RGN_PRBAR, offsetof(struct mpu_rgn, prbar)); DEFINE(MPU_RGN_PRLAR, offsetof(struct mpu_rgn, prlar)); #endif + DEFINE(KEXEC_START_ADDR, offsetof(struct kexec_relocate_data, kexec_start_address)); + DEFINE(KEXEC_INDIR_PAGE, offsetof(struct kexec_relocate_data, kexec_indirection_page)); + DEFINE(KEXEC_MACH_TYPE, offsetof(struct kexec_relocate_data, kexec_mach_type)); + DEFINE(KEXEC_R2, offsetof(struct kexec_relocate_data, kexec_r2)); return 0; } diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index 5d84ad333f05..2b09dad7935e 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -22,11 +23,6 @@ extern void relocate_new_kernel(void); extern const unsigned int relocate_new_kernel_size; -extern unsigned long kexec_start_address; -extern unsigned long kexec_indirection_page; -extern unsigned long kexec_mach_type; -extern unsigned long kexec_boot_atags; - static atomic_t waiting_for_crash_ipi; /* @@ -159,6 +155,7 @@ void (*kexec_reinit)(void); void machine_kexec(struct kimage *image) { unsigned long page_list, reboot_entry_phys; + struct kexec_relocate_data *data; void (*reboot_entry)(void); void *reboot_code_buffer; @@ -174,18 +171,17 @@ void machine_kexec(struct kimage *image) reboot_code_buffer = page_address(image->control_code_page); - /* Prepare parameters for reboot_code_buffer*/ - set_kernel_text_rw(); - kexec_start_address = image->start; - kexec_indirection_page = page_list; - kexec_mach_type = machine_arch_type; - kexec_boot_atags = image->arch.kernel_r2; - /* copy our kernel relocation code to the control code page */ reboot_entry = fncpy(reboot_code_buffer, &relocate_new_kernel, relocate_new_kernel_size); + data = reboot_code_buffer + relocate_new_kernel_size; + data->kexec_start_address = image->start; + data->kexec_indirection_page = page_list; + data->kexec_mach_type = machine_arch_type; + data->kexec_r2 = image->arch.kernel_r2; + /* get the identity mapping physical address for the reboot code */ reboot_entry_phys = virt_to_idmap(reboot_entry); diff --git a/arch/arm/kernel/relocate_kernel.S b/arch/arm/kernel/relocate_kernel.S index 72a08786e16e..218d524360fc 100644 --- a/arch/arm/kernel/relocate_kernel.S +++ b/arch/arm/kernel/relocate_kernel.S @@ -5,14 +5,16 @@ #include #include +#include #include .align 3 /* not needed for this code, but keeps fncpy() happy */ ENTRY(relocate_new_kernel) - ldr r0,kexec_indirection_page - ldr r1,kexec_start_address + adr r7, relocate_new_kernel_end + ldr r0, [r7, #KEXEC_INDIR_PAGE] + ldr r1, [r7, #KEXEC_START_ADDR] /* * If there is no indirection page (we are doing crashdumps) @@ -57,34 +59,16 @@ ENTRY(relocate_new_kernel) 2: /* Jump to relocated kernel */ - mov lr,r1 - mov r0,#0 - ldr r1,kexec_mach_type - ldr r2,kexec_boot_atags - ARM( ret lr ) - THUMB( bx lr ) - - .align - - .globl kexec_start_address -kexec_start_address: - .long 0x0 - - .globl kexec_indirection_page -kexec_indirection_page: - .long 0x0 - - .globl kexec_mach_type -kexec_mach_type: - .long 0x0 - - /* phy addr of the atags for the new kernel */ - .globl kexec_boot_atags -kexec_boot_atags: - .long 0x0 + mov lr, r1 + mov r0, #0 + ldr r1, [r7, #KEXEC_MACH_TYPE] + ldr r2, [r7, #KEXEC_R2] + ARM( ret lr ) + THUMB( bx lr ) ENDPROC(relocate_new_kernel) + .align 3 relocate_new_kernel_end: .globl relocate_new_kernel_size -- cgit v1.2.3