From 598f0a99fa8a35be44b27106b43ddc66417af3b1 Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Mon, 13 Jun 2022 15:05:41 +0100 Subject: ARM: 9210/1: Mark the FDT_FIXED sections as shareable commit 7a1be318f579 ("ARM: 9012/1: move device tree mapping out of linear region") use FDT_FIXED_BASE to map the whole FDT_FIXED_SIZE memory area which contains fdt. But it only reserves the exact physical memory that fdt occupied. Unfortunately, this mapping is non-shareable. An illegal or speculative read access can bring the RAM content from non-fdt zone into cache, PIPT makes it to be hit by subsequently read access through shareable mapping(such as linear mapping), and the cache consistency between cores is lost due to non-shareable property. |<---------FDT_FIXED_SIZE------>| | | ------------------------------- | | | | ------------------------------- 1. CoreA read through MT_ROM mapping, the old data is loaded into the cache. 2. CoreB write to update data through linear mapping. CoreA received the notification to invalid the corresponding cachelines, but the property non-shareable makes it to be ignored. 3. CoreA read through linear mapping, cache hit, the old data is read. To eliminate this risk, add a new memory type MT_MEMORY_RO. Compared to MT_ROM, it is shareable and non-executable. Here's an example: list_del corruption. prev->next should be c0ecbf74, but was c08410dc kernel BUG at lib/list_debug.c:53! ... ... PC is at __list_del_entry_valid+0x58/0x98 LR is at __list_del_entry_valid+0x58/0x98 psr: 60000093 sp : c0ecbf30 ip : 00000000 fp : 00000001 r10: c08410d0 r9 : 00000001 r8 : c0825e0c r7 : 20000013 r6 : c08410d0 r5 : c0ecbf74 r4 : c0ecbf74 r3 : c0825d08 r2 : 00000000 r1 : df7ce6f4 r0 : 00000044 ... ... Stack: (0xc0ecbf30 to 0xc0ecc000) bf20: c0ecbf74 c0164fd0 c0ecbf70 c0165170 bf40: c0eca000 c0840c00 c0840c00 c0824500 c0825e0c c0189bbc c088f404 60000013 bf60: 60000013 c0e85100 000004ec 00000000 c0ebcdc0 c0ecbf74 c0ecbf74 c0825d08 ... ... < next prev > (__list_del_entry_valid) from (__list_del_entry+0xc/0x20) (__list_del_entry) from (finish_swait+0x60/0x7c) (finish_swait) from (rcu_gp_kthread+0x560/0xa20) (rcu_gp_kthread) from (kthread+0x14c/0x15c) (kthread) from (ret_from_fork+0x14/0x24) The faulty list node to be deleted is a local variable, its address is c0ecbf74. The dumped stack shows that 'prev' = c0ecbf74, but its value before lib/list_debug.c:53 is c08410dc. A large amount of printing results in swapping out the cacheline containing the old data(MT_ROM mapping is read only, so the cacheline cannot be dirty), and the subsequent dump operation obtains new data from the DDR. Fixes: 7a1be318f579 ("ARM: 9012/1: move device tree mapping out of linear region") Suggested-by: Ard Biesheuvel Signed-off-by: Zhen Lei Reviewed-by: Ard Biesheuvel Reviewed-by: Kefeng Wang Signed-off-by: Russell King (Oracle) --- arch/arm/include/asm/mach/map.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/mach/map.h b/arch/arm/include/asm/mach/map.h index 92282558caf7..2b8970d8e5a2 100644 --- a/arch/arm/include/asm/mach/map.h +++ b/arch/arm/include/asm/mach/map.h @@ -27,6 +27,7 @@ enum { MT_HIGH_VECTORS, MT_MEMORY_RWX, MT_MEMORY_RW, + MT_MEMORY_RO, MT_ROM, MT_MEMORY_RWX_NONCACHED, MT_MEMORY_RW_DTCM, -- cgit v1.2.3 From cc45b836388f0ccc6831288a08f77a33845f10b0 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Sun, 19 Jun 2022 20:39:29 +0100 Subject: ARM: 9211/1: domain: drop modify_domain() This function/macro isn't used anywhere in the kernel. The only user was set_fs() and was deleted in the set_fs() removal patch set. Fixes: 8ac6f5d7f84b ("ARM: 9113/1: uaccess: remove set_fs() implementation") Acked-by: Arnd Bergmann Signed-off-by: Linus Walleij Signed-off-by: Russell King (Oracle) --- arch/arm/include/asm/domain.h | 13 ------------- 1 file changed, 13 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/domain.h b/arch/arm/include/asm/domain.h index f1d0a7807cd0..41536feb4392 100644 --- a/arch/arm/include/asm/domain.h +++ b/arch/arm/include/asm/domain.h @@ -112,19 +112,6 @@ static __always_inline void set_domain(unsigned int val) } #endif -#ifdef CONFIG_CPU_USE_DOMAINS -#define modify_domain(dom,type) \ - do { \ - unsigned int domain = get_domain(); \ - domain &= ~domain_mask(dom); \ - domain = domain | domain_val(dom, type); \ - set_domain(domain); \ - } while (0) - -#else -static inline void modify_domain(unsigned dom, unsigned type) { } -#endif - /* * Generate the T (user) versions of the LDR/STR and related * instructions (inline assembly) -- cgit v1.2.3 From e5c46fde75e43c15a29b40e5fc5641727f97ae47 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 30 Jun 2022 16:46:54 +0100 Subject: ARM: 9214/1: alignment: advance IT state after emulating Thumb instruction After emulating a misaligned load or store issued in Thumb mode, we have to advance the IT state by hand, or it will get out of sync with the actual instruction stream, which means we'll end up applying the wrong condition code to subsequent instructions. This might corrupt the program state rather catastrophically. So borrow the it_advance() helper from the probing code, and use it on CPSR if the emulated instruction is Thumb. Cc: Reviewed-by: Linus Walleij Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King (Oracle) --- arch/arm/include/asm/ptrace.h | 26 ++++++++++++++++++++++++++ arch/arm/mm/alignment.c | 3 +++ arch/arm/probes/decode.h | 26 +------------------------- 3 files changed, 30 insertions(+), 25 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h index 93051e2f402c..1408a6a15d0e 100644 --- a/arch/arm/include/asm/ptrace.h +++ b/arch/arm/include/asm/ptrace.h @@ -163,5 +163,31 @@ static inline unsigned long user_stack_pointer(struct pt_regs *regs) ((current_stack_pointer | (THREAD_SIZE - 1)) - 7) - 1; \ }) + +/* + * Update ITSTATE after normal execution of an IT block instruction. + * + * The 8 IT state bits are split into two parts in CPSR: + * ITSTATE<1:0> are in CPSR<26:25> + * ITSTATE<7:2> are in CPSR<15:10> + */ +static inline unsigned long it_advance(unsigned long cpsr) +{ + if ((cpsr & 0x06000400) == 0) { + /* ITSTATE<2:0> == 0 means end of IT block, so clear IT state */ + cpsr &= ~PSR_IT_MASK; + } else { + /* We need to shift left ITSTATE<4:0> */ + const unsigned long mask = 0x06001c00; /* Mask ITSTATE<4:0> */ + unsigned long it = cpsr & mask; + it <<= 1; + it |= it >> (27 - 10); /* Carry ITSTATE<2> to correct place */ + it &= mask; + cpsr &= ~mask; + cpsr |= it; + } + return cpsr; +} + #endif /* __ASSEMBLY__ */ #endif diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c index 6f499559d193..f8dd0b3cc8e0 100644 --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c @@ -935,6 +935,9 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (type == TYPE_LDST) do_alignment_finish_ldst(addr, instr, regs, offset); + if (thumb_mode(regs)) + regs->ARM_cpsr = it_advance(regs->ARM_cpsr); + return 0; bad_or_fault: diff --git a/arch/arm/probes/decode.h b/arch/arm/probes/decode.h index 973173598992..facc889d05ee 100644 --- a/arch/arm/probes/decode.h +++ b/arch/arm/probes/decode.h @@ -14,6 +14,7 @@ #include #include #include +#include #include void __init arm_probes_decode_init(void); @@ -35,31 +36,6 @@ void __init find_str_pc_offset(void); #endif -/* - * Update ITSTATE after normal execution of an IT block instruction. - * - * The 8 IT state bits are split into two parts in CPSR: - * ITSTATE<1:0> are in CPSR<26:25> - * ITSTATE<7:2> are in CPSR<15:10> - */ -static inline unsigned long it_advance(unsigned long cpsr) - { - if ((cpsr & 0x06000400) == 0) { - /* ITSTATE<2:0> == 0 means end of IT block, so clear IT state */ - cpsr &= ~PSR_IT_MASK; - } else { - /* We need to shift left ITSTATE<4:0> */ - const unsigned long mask = 0x06001c00; /* Mask ITSTATE<4:0> */ - unsigned long it = cpsr & mask; - it <<= 1; - it |= it >> (27 - 10); /* Carry ITSTATE<2> to correct place */ - it &= mask; - cpsr &= ~mask; - cpsr |= it; - } - return cpsr; -} - static inline void __kprobes bx_write_pc(long pcv, struct pt_regs *regs) { long cpsr = regs->ARM_cpsr; -- cgit v1.2.3