From a6c61e9dfdd0adf8443932cfc43b0c1e25036ad5 Mon Sep 17 00:00:00 2001 From: Daniel Jacobowitz Date: Sat, 19 Nov 2005 10:01:07 +0000 Subject: [PATCH] [ARM] 3168/1: Update ARM signal delivery and masking Patch from Daniel Jacobowitz After delivering a signal (creating its stack frame) we must check for additional pending unblocked signals before returning to userspace. Otherwise signals may be delayed past the next syscall or reschedule. Once that was fixed it became obvious that the ARM signal mask manipulation was broken. It was a little bit broken before the recent SA_NODEFER changes, and then very broken after them. We must block the requested signals before starting the handler or the same signal can be delivered again before the handler even gets a chance to run. Signed-off-by: Daniel Jacobowitz Signed-off-by: Russell King --- arch/arm/kernel/entry-common.S | 3 +- arch/arm/kernel/signal.c | 25 +++-- arch/arm/mm/Makefile | 2 +- arch/arm/mm/blockops.c | 185 --------------------------------- 4 files changed, 14 insertions(+), 201 deletions(-) delete mode 100644 arch/arm/mm/blockops.c diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 066597f434..f7f1830752 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -48,8 +48,7 @@ work_pending: mov r0, sp @ 'regs' mov r2, why @ 'syscall' bl do_notify_resume - disable_irq @ disable interrupts - b no_work_pending + b ret_slow_syscall @ Check work again work_resched: bl schedule diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index a917e3dd36..765922bcf9 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -595,23 +595,22 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, */ ret |= !valid_user_regs(regs); - /* - * Block the signal if we were unsuccessful. - */ if (ret != 0) { - spin_lock_irq(&tsk->sighand->siglock); - sigorsets(&tsk->blocked, &tsk->blocked, - &ka->sa.sa_mask); - if (!(ka->sa.sa_flags & SA_NODEFER)) - sigaddset(&tsk->blocked, sig); - recalc_sigpending(); - spin_unlock_irq(&tsk->sighand->siglock); + force_sigsegv(sig, tsk); + return; } - if (ret == 0) - return; + /* + * Block the signal if we were successful. + */ + spin_lock_irq(&tsk->sighand->siglock); + sigorsets(&tsk->blocked, &tsk->blocked, + &ka->sa.sa_mask); + if (!(ka->sa.sa_flags & SA_NODEFER)) + sigaddset(&tsk->blocked, sig); + recalc_sigpending(); + spin_unlock_irq(&tsk->sighand->siglock); - force_sigsegv(sig, tsk); } /* diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile index 59f47d4c2d..ffe73ba2bf 100644 --- a/arch/arm/mm/Makefile +++ b/arch/arm/mm/Makefile @@ -51,4 +51,4 @@ obj-$(CONFIG_CPU_ARM1026) += proc-arm1026.o obj-$(CONFIG_CPU_SA110) += proc-sa110.o obj-$(CONFIG_CPU_SA1100) += proc-sa1100.o obj-$(CONFIG_CPU_XSCALE) += proc-xscale.o -obj-$(CONFIG_CPU_V6) += proc-v6.o blockops.o +obj-$(CONFIG_CPU_V6) += proc-v6.o diff --git a/arch/arm/mm/blockops.c b/arch/arm/mm/blockops.c deleted file mode 100644 index 4f5ee2d089..0000000000 --- a/arch/arm/mm/blockops.c +++ /dev/null @@ -1,185 +0,0 @@ -#include -#include -#include -#include - -#include -#include -#include -#include - -extern struct cpu_cache_fns blk_cache_fns; - -#define HARVARD_CACHE - -/* - * blk_flush_kern_dcache_page(kaddr) - * - * Ensure that the data held in the page kaddr is written back - * to the page in question. - * - * - kaddr - kernel address (guaranteed to be page aligned) - */ -static void __attribute__((naked)) -blk_flush_kern_dcache_page(void *kaddr) -{ - asm( - "add r1, r0, %0 \n\ - sub r1, r1, %1 \n\ -1: .word 0xec401f0e @ mcrr p15, 0, r0, r1, c14, 0 @ blocking \n\ - mov r0, #0 \n\ - mcr p15, 0, r0, c7, c5, 0 \n\ - mcr p15, 0, r0, c7, c10, 4 \n\ - mov pc, lr" - : - : "I" (PAGE_SIZE), "I" (L1_CACHE_BYTES)); -} - -/* - * blk_dma_inv_range(start,end) - * - * Invalidate the data cache within the specified region; we will - * be performing a DMA operation in this region and we want to - * purge old data in the cache. - * - * - start - virtual start address of region - * - end - virtual end address of region - */ -static void __attribute__((naked)) -blk_dma_inv_range_unified(unsigned long start, unsigned long end) -{ - asm( - "tst r0, %0 \n\ - mcrne p15, 0, r0, c7, c11, 1 @ clean unified line \n\ - tst r1, %0 \n\ - mcrne p15, 0, r1, c7, c15, 1 @ clean & invalidate unified line\n\ - .word 0xec401f06 @ mcrr p15, 0, r1, r0, c6, 0 @ blocking \n\ - mov r0, #0 \n\ - mcr p15, 0, r0, c7, c10, 4 @ drain write buffer \n\ - mov pc, lr" - : - : "I" (L1_CACHE_BYTES - 1)); -} - -static void __attribute__((naked)) -blk_dma_inv_range_harvard(unsigned long start, unsigned long end) -{ - asm( - "tst r0, %0 \n\ - mcrne p15, 0, r0, c7, c10, 1 @ clean D line \n\ - tst r1, %0 \n\ - mcrne p15, 0, r1, c7, c14, 1 @ clean & invalidate D line \n\ - .word 0xec401f06 @ mcrr p15, 0, r1, r0, c6, 0 @ blocking \n\ - mov r0, #0 \n\ - mcr p15, 0, r0, c7, c10, 4 @ drain write buffer \n\ - mov pc, lr" - : - : "I" (L1_CACHE_BYTES - 1)); -} - -/* - * blk_dma_clean_range(start,end) - * - start - virtual start address of region - * - end - virtual end address of region - */ -static void __attribute__((naked)) -blk_dma_clean_range(unsigned long start, unsigned long end) -{ - asm( - ".word 0xec401f0c @ mcrr p15, 0, r1, r0, c12, 0 @ blocking \n\ - mov r0, #0 \n\ - mcr p15, 0, r0, c7, c10, 4 @ drain write buffer \n\ - mov pc, lr"); -} - -/* - * blk_dma_flush_range(start,end) - * - start - virtual start address of region - * - end - virtual end address of region - */ -static void __attribute__((naked)) -blk_dma_flush_range(unsigned long start, unsigned long end) -{ - asm( - ".word 0xec401f0e @ mcrr p15, 0, r1, r0, c14, 0 @ blocking \n\ - mov pc, lr"); -} - -static int blockops_trap(struct pt_regs *regs, unsigned int instr) -{ - regs->ARM_r4 |= regs->ARM_r2; - regs->ARM_pc += 4; - return 0; -} - -static char *func[] = { - "Prefetch data range", - "Clean+Invalidate data range", - "Clean data range", - "Invalidate data range", - "Invalidate instr range" -}; - -static struct undef_hook blockops_hook __initdata = { - .instr_mask = 0x0fffffd0, - .instr_val = 0x0c401f00, - .cpsr_mask = PSR_T_BIT, - .cpsr_val = 0, - .fn = blockops_trap, -}; - -static int __init blockops_check(void) -{ - register unsigned int err asm("r4") = 0; - unsigned int err_pos = 1; - unsigned int cache_type; - int i; - - asm("mrc p15, 0, %0, c0, c0, 1" : "=r" (cache_type)); - - printk("Checking V6 block cache operations:\n"); - register_undef_hook(&blockops_hook); - - __asm__ ("mov r0, %0\n\t" - "mov r1, %1\n\t" - "mov r2, #1\n\t" - ".word 0xec401f2c @ mcrr p15, 0, r1, r0, c12, 2\n\t" - "mov r2, #2\n\t" - ".word 0xec401f0e @ mcrr p15, 0, r1, r0, c14, 0\n\t" - "mov r2, #4\n\t" - ".word 0xec401f0c @ mcrr p15, 0, r1, r0, c12, 0\n\t" - "mov r2, #8\n\t" - ".word 0xec401f06 @ mcrr p15, 0, r1, r0, c6, 0\n\t" - "mov r2, #16\n\t" - ".word 0xec401f05 @ mcrr p15, 0, r1, r0, c5, 0\n\t" - : - : "r" (PAGE_OFFSET), "r" (PAGE_OFFSET + 128) - : "r0", "r1", "r2"); - - unregister_undef_hook(&blockops_hook); - - for (i = 0; i < ARRAY_SIZE(func); i++, err_pos <<= 1) - printk("%30s: %ssupported\n", func[i], err & err_pos ? "not " : ""); - - if ((err & 8) == 0) { - printk(" --> Using %s block cache invalidate\n", - cache_type & (1 << 24) ? "harvard" : "unified"); - if (cache_type & (1 << 24)) - cpu_cache.dma_inv_range = blk_dma_inv_range_harvard; - else - cpu_cache.dma_inv_range = blk_dma_inv_range_unified; - } - if ((err & 4) == 0) { - printk(" --> Using block cache clean\n"); - cpu_cache.dma_clean_range = blk_dma_clean_range; - } - if ((err & 2) == 0) { - printk(" --> Using block cache clean+invalidate\n"); - cpu_cache.dma_flush_range = blk_dma_flush_range; - cpu_cache.flush_kern_dcache_page = blk_flush_kern_dcache_page; - } - - return 0; -} - -__initcall(blockops_check); -- 2.39.5