From 0d9fad91abfd723ea5070a46d98a9f4496c93ba9 Mon Sep 17 00:00:00 2001 From: Kars de Jong Date: Thu, 23 Feb 2023 12:23:49 +0100 Subject: m68k: mm: Fix systems with memory at end of 32-bit address space The calculation of end addresses of memory chunks overflowed to 0 when a memory chunk is located at the end of 32-bit address space. This is the case for the HP300 architecture. Link: https://lore.kernel.org/linux-m68k/CACz-3rhUo5pgNwdWHaPWmz+30Qo9xCg70wNxdf7o5x-6tXq8QQ@mail.gmail.com/ Signed-off-by: Kars de Jong Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230223112349.26675-1-jongk@linux-m68k.org Signed-off-by: Geert Uytterhoeven --- arch/m68k/mm/motorola.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c index 2a375637e007..911301224078 100644 --- a/arch/m68k/mm/motorola.c +++ b/arch/m68k/mm/motorola.c @@ -437,7 +437,7 @@ void __init paging_init(void) } min_addr = m68k_memory[0].addr; - max_addr = min_addr + m68k_memory[0].size; + max_addr = min_addr + m68k_memory[0].size - 1; memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0, MEMBLOCK_NONE); for (i = 1; i < m68k_num_memory;) { @@ -452,21 +452,21 @@ void __init paging_init(void) } memblock_add_node(m68k_memory[i].addr, m68k_memory[i].size, i, MEMBLOCK_NONE); - addr = m68k_memory[i].addr + m68k_memory[i].size; + addr = m68k_memory[i].addr + m68k_memory[i].size - 1; if (addr > max_addr) max_addr = addr; i++; } m68k_memoffset = min_addr - PAGE_OFFSET; - m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6; + m68k_virt_to_node_shift = fls(max_addr - min_addr) - 6; module_fixup(NULL, __start_fixup, __stop_fixup); flush_icache(); - high_memory = phys_to_virt(max_addr); + high_memory = phys_to_virt(max_addr) + 1; min_low_pfn = availmem >> PAGE_SHIFT; - max_pfn = max_low_pfn = max_addr >> PAGE_SHIFT; + max_pfn = max_low_pfn = (max_addr >> PAGE_SHIFT) + 1; /* Reserve kernel text/data/bss and the memory allocated in head.S */ memblock_reserve(m68k_memory[0].addr, availmem - m68k_memory[0].addr); -- cgit From d4b97925e87eb133e400fe4a482d750c74ce392f Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Mon, 27 Feb 2023 21:14:13 +0100 Subject: m68k: mm: Move initrd phys_to_virt handling after paging_init() When booting with an initial ramdisk on platforms where physical memory does not start at address zero (e.g. on Amiga): initrd: 0ef0602c - 0f800000 Zone ranges: DMA [mem 0x0000000008000000-0x000000f7ffffffff] Normal empty Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000008000000-0x000000000f7fffff] Initmem setup node 0 [mem 0x0000000008000000-0x000000000f7fffff] Unable to handle kernel access at virtual address (ptrval) Oops: 00000000 Modules linked in: PC: [<00201d3c>] memcmp+0x28/0x56 As phys_to_virt() relies on m68k_memoffset and module_fixup(), it must not be called before paging_init(). Hence postpone the phys_to_virt handling for the initial ramdisk until after calling paging_init(). While at it, reduce #ifdef clutter by using IS_ENABLED() instead. Fixes: 376e3fdecb0dcae2 ("m68k: Enable memtest functionality") Reported-by: Stephen Walsh Link: https://lists.debian.org/debian-68k/2022/09/msg00007.html Reported-by: John Paul Adrian Glaubitz Link: https://lore.kernel.org/r/4f45f05f377bf3f5baf88dbd5c3c8aeac59d94f0.camel@physik.fu-berlin.de Signed-off-by: Geert Uytterhoeven Acked-by: Finn Thain Link: https://lore.kernel.org/r/dff216da09ab7a60217c3fc2147e671ae07d636f.1677528627.git.geert@linux-m68k.org --- arch/m68k/kernel/setup_mm.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c index 3a2bb2e8fdad..fbff1cea62ca 100644 --- a/arch/m68k/kernel/setup_mm.c +++ b/arch/m68k/kernel/setup_mm.c @@ -326,16 +326,16 @@ void __init setup_arch(char **cmdline_p) panic("No configuration setup"); } -#ifdef CONFIG_BLK_DEV_INITRD - if (m68k_ramdisk.size) { + if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && m68k_ramdisk.size) memblock_reserve(m68k_ramdisk.addr, m68k_ramdisk.size); + + paging_init(); + + if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && m68k_ramdisk.size) { initrd_start = (unsigned long)phys_to_virt(m68k_ramdisk.addr); initrd_end = initrd_start + m68k_ramdisk.size; pr_info("initrd: %08lx - %08lx\n", initrd_start, initrd_end); } -#endif - - paging_init(); #ifdef CONFIG_NATFEAT nf_init(); -- cgit From e36a82bebbf7da814530d5a179bef9df5934b717 Mon Sep 17 00:00:00 2001 From: Michael Schmitz Date: Wed, 1 Mar 2023 15:11:07 +1300 Subject: m68k: Only force 030 bus error if PC not in exception table __get_kernel_nofault() does copy data in supervisor mode when forcing a task backtrace log through /proc/sysrq_trigger. This is expected cause a bus error exception on e.g. NULL pointer dereferencing when logging a kernel task has no workqueue associated. This bus error ought to be ignored. Our 030 bus error handler is ill equipped to deal with this: Whenever ssw indicates a kernel mode access on a data fault, we don't even attempt to handle the fault and instead always send a SEGV signal (or panic). As a result, the check for exception handling at the fault PC (buried in send_sig_fault() which gets called from do_page_fault() eventually) is never used. In contrast, both 040 and 060 access error handlers do not care whether a fault happened on supervisor mode access, and will call do_page_fault() on those, ultimately honoring the exception table. Add a check in bus_error030 to call do_page_fault() in case we do have an entry for the fault PC in our exception table. I had attempted a fix for this earlier in 2019 that did rely on testing pagefault_disabled() (see link below) to achieve the same thing, but this patch should be more generic. Tested on 030 Atari Falcon. Reported-by: Eero Tamminen Link: https://lore.kernel.org/r/alpine.LNX.2.21.1904091023540.25@nippy.intranet Link: https://lore.kernel.org/r/63130691-1984-c423-c1f2-73bfd8d3dcd3@gmail.com Signed-off-by: Michael Schmitz Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230301021107.26307-1-schmitzmic@gmail.com Signed-off-by: Geert Uytterhoeven --- arch/m68k/kernel/traps.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c index 5c8cba0efc63..a700807c9b6d 100644 --- a/arch/m68k/kernel/traps.c +++ b/arch/m68k/kernel/traps.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -545,7 +546,8 @@ static inline void bus_error030 (struct frame *fp) errorcode |= 2; if (mmusr & (MMU_I | MMU_WP)) { - if (ssw & 4) { + /* We might have an exception table for this PC */ + if (ssw & 4 && !search_exception_tables(fp->ptregs.pc)) { pr_err("Data %s fault at %#010lx in %s (pc=%#lx)\n", ssw & RW ? "read" : "write", fp->un.fmtb.daddr, -- cgit