kernel/arch/csky/include, branch linux-5.6.y

csky: Fixup raw_copy_from_user()

2020-06-03T06:23:10Z

[ Upstream commit 51bb38cb78363fdad1f89e87357b7bc73e39ba88 ] If raw_copy_from_user(to, from, N) returns K, callers expect the first N - K bytes starting at to to have been replaced with the contents of corresponding area starting at from and the last K bytes of destination *left* *unmodified*. What arch/sky/lib/usercopy.c is doing is broken - it can lead to e.g. data corruption on write(2). raw_copy_to_user() is inaccurate about return value, which is a bug, but consequences are less drastic than for raw_copy_from_user(). And just what are those access_ok() doing in there? I mean, look into linux/uaccess.h; that's where we do that check (as well as zero tail on failure in the callers that need zeroing). AFAICS, all of that shouldn't be hard to fix; something like a patch below might make a useful starting point. I would suggest moving these macros into usercopy.c (they are never used anywhere else) and possibly expanding them there; if you leave them alive, please at least rename __copy_user_zeroing(). Again, it must not zero anything on failed read. Said that, I'm not sure we won't be better off simply turning usercopy.c into usercopy.S - all that is left there is a couple of functions, each consisting only of inline asm. Guo Ren reply: Yes, raw_copy_from_user is wrong, it's no need zeroing code. unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n) { unsigned long res = n; might_fault(); if (likely(access_ok(from, n))) { kasan_check_write(to, n); res = raw_copy_from_user(to, from, n); } if (unlikely(res)) memset(to + (n - res), 0, res); return res; } EXPORT_SYMBOL(_copy_from_user); You are right and access_ok() should be removed. but, how about: do { ... "2: stw %3, (%1, 0) \n" \ + " subi %0, 4 \n" \ "9: stw %4, (%1, 4) \n" \ + " subi %0, 4 \n" \ "10: stw %5, (%1, 8) \n" \ + " subi %0, 4 \n" \ "11: stw %6, (%1, 12) \n" \ + " subi %0, 4 \n" \ " addi %2, 16 \n" \ " addi %1, 16 \n" \ Don't expand __ex_table AI Viro reply: Hey, I've no idea about the instruction scheduling on csky - if that doesn't slow the things down, all the better. It's just that copy_to_user() and friends are on fairly hot codepaths, and in quite a few situations they will dominate the speed of e.g. read(2). So I tried to keep the fast path unchanged. Up to the architecture maintainers, obviously. Which would be you... As for the fixups size increase (__ex_table size is unchanged)... You have each of those macros expanded exactly once. So the size is not a serious argument, IMO - useless complexity would be, if it is, in fact, useless; the size... not really, especially since those extra subi will at least offset it. Again, up to you - asm optimizations of (essentially) memcpy()-style loops are tricky and can depend upon the fairly subtle details of architecture. So even on something I know reasonably well I would resort to direct experiments if I can't pass the buck to architecture maintainers. It *is* worth optimizing - this is where read() from a file that is already in page cache spends most of the time, etc. Guo Ren reply: Thx, after fixup some typo “sub %0, 4”, apply the patch. TODO: - user copy/from codes are still need optimizing. Signed-off-by: Al Viro Signed-off-by: Guo Ren Signed-off-by: Sasha Levin

csky: Fixup get wrong psr value from phyical reg

2020-04-23T08:38:15Z

[ Upstream commit 9c0e343d7654a329d1f9b53d253cbf7fb6eff85d ] We should get psr value from regs->psr in stack, not directly get it from phyiscal register then save the vector number in tsk->trap_no. Signed-off-by: Guo Ren Signed-off-by: Sasha Levin

csky: Add PCI support

2020-02-21T07:43:25Z

Add the pci related code for csky arch to support basic pci virtual function, such as qemu virt-pci-9pfs. Signed-off-by: MaJun Signed-off-by: Guo Ren

csky: Fixup compile warning for three unimplemented syscalls

2020-02-21T07:43:25Z

Implement fstat64, fstatat64, clone3 syscalls to fixup checksyscalls.sh compile warnings. Signed-off-by: Guo Ren

csky: Add flush_icache_mm to defer flush icache all

2020-02-21T07:43:24Z

Some CPUs don't support icache.va instruction to maintain the whole smp cores' icache. Using icache.all + IPI casue a lot on performace and using defer mechanism could reduce the number of calling icache _flush_all functions. Signed-off-by: Guo Ren

csky: Support icache flush without specific instructions

2020-02-21T07:43:24Z

Some CPUs don't support icache specific instructions to flush icache lines in broadcast way. We use cpu control registers to flush local icache and use IPI to notify other cores. Signed-off-by: Guo Ren

csky: Separate fixaddr_init from highmem

2020-02-21T07:43:24Z

After fixaddr_init is separated from highmem, we could use tcm without highmem selected. (610 (abiv1) don't support highmem, but it could use tcm now.) Signed-off-by: Guo Ren

csky: Tightly-Coupled Memory or Sram support

2020-02-21T07:43:24Z

The implementation are not only used by TCM but also used by sram on SOC bus. It follow existed linux tcm software interface, so that old tcm application codes could be re-used directly. Software interface list in asm/tcm.h: - Variables/Const: __tcmdata, __tcmconst - Functions: __tcmfunc, __tcmlocalfunc - Malloc/Free: tcm_alloc, tcm_free In linux menuconfig: - Choose a TCM contain instrctions + data or separated in ITCM/DTCM. - Determine TCM_BASE (DTCM_BASE) in phyiscal address. - Determine size of TCM or ITCM(DTCM) in page counts. Here is hello tcm example from Documentation/arm/tcm.rst which could be directly used: /* Uninitialized data */ static u32 __tcmdata tcmvar; /* Initialized data */ static u32 __tcmdata tcmassigned = 0x2BADBABEU; /* Constant */ static const u32 __tcmconst tcmconst = 0xCAFEBABEU; static void __tcmlocalfunc tcm_to_tcm(void) { int i; for (i = 0; i < 100; i++) tcmvar ++; } static void __tcmfunc hello_tcm(void) { /* Some abstract code that runs in ITCM */ int i; for (i = 0; i < 100; i++) { tcmvar ++; } tcm_to_tcm(); } static void __init test_tcm(void) { u32 *tcmem; int i; hello_tcm(); printk("Hello TCM executed from ITCM RAM\n"); printk("TCM variable from testrun: %u @ %p\n", tcmvar, &tcmvar); tcmvar = 0xDEADBEEFU; printk("TCM variable: 0x%x @ %p\n", tcmvar, &tcmvar); printk("TCM assigned variable: 0x%x @ %p\n", tcmassigned, &tcmassigned); printk("TCM constant: 0x%x @ %p\n", tcmconst, &tcmconst); /* Allocate some TCM memory from the pool */ tcmem = tcm_alloc(20); if (tcmem) { printk("TCM Allocated 20 bytes of TCM @ %p\n", tcmem); tcmem[0] = 0xDEADBEEFU; tcmem[1] = 0x2BADBABEU; tcmem[2] = 0xCAFEBABEU; tcmem[3] = 0xDEADBEEFU; tcmem[4] = 0x2BADBABEU; for (i = 0; i < 5; i++) printk("TCM tcmem[%d] = %08x\n", i, tcmem[i]); tcm_free(tcmem, 20); } } TODO: - Separate fixup mapping from highmem - Support abiv1 Signed-off-by: Guo Ren

csky: Initial stack protector support

2020-02-21T07:43:24Z

This is a basic -fstack-protector support without per-task canary switching. The protector will report something like when stack corruption is detected: It's tested with strcpy local array overflow in sys_kill and get: stack-protector: Kernel stack is corrupted in: sys_kill+0x23c/0x23c TODO: - Support task switch for different cannary Signed-off-by: Mao Han Signed-off-by: Guo Ren

Merge tag 'microblaze-v5.6-rc1' of git://git.monstr.eu/linux-2.6-microblaze

2020-02-04T11:58:07Z

Pull Microblaze update from Michal Simek: - enable CMA - add support for MB v11 - defconfig updates - minor fixes * tag 'microblaze-v5.6-rc1' of git://git.monstr.eu/linux-2.6-microblaze: microblaze: Add ID for Microblaze v11 microblaze: Prevent the overflow of the start microblaze: Wire CMA allocator asm-generic: Make dma-contiguous.h a mandatory include/asm header microblaze: Sync defconfig with latest Kconfig layout microblaze: defconfig: Disable EXT2 driver and Enable EXT3 & EXT4 drivers microblaze: Align comments with register usage