kernel/git/stable/linux.git/arch/csky/include, branch linux-5.7.y

csky: Coding convention in entry.S

2020-05-28T00:18:36+00:00

There is no fixup or feature in the patch, we only cleanup with: - Remove unnecessary reg used (r11, r12), just use r9 & r10 & syscallid regs as temp useage. - Add _TIF_SYSCALL_WORK and _TIF_WORK_MASK to gather macros. Signed-off-by: Guo Ren

csky: Fixup raw_copy_from_user()

2020-05-14T16:16:30+00:00

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

csky: Fixup gdbmacros.txt with name sp in thread_struct

2020-05-14T16:16:18+00:00

The gdbmacros.txt use sp in thread_struct, but csky use ksp. This cause bttnobp fail to excute. TODO: - Still couldn't display the contents of stack. Signed-off-by: Guo Ren

csky: Fixup remove unnecessary save/restore PSR code

2020-05-13T09:55:06+00:00

All processes' PSR could success from SETUP_MMU, so need set it in INIT_THREAD again. And use a3 instead of r7 in __switch_to for code convention. Signed-off-by: Guo Ren

csky: Fixup calltrace panic

2020-05-13T09:55:06+00:00

The implementation of show_stack will panic with wrong fp: addr = *fp++; because the fp isn't checked properly. The current implementations of show_stack, wchan and stack_trace haven't been designed properly, so just deprecate them. This patch is a reference to riscv's way, all codes are modified from arm's. The patch is passed with: - cat /proc//stack - cat /proc//wchan - echo c > /proc/sysrq-trigger Signed-off-by: Guo Ren

csky: Fixup compile error for abiv1 entry.S

2020-05-13T09:55:05+00:00

This bug is from uprobe signal definition in thread_info.h. The instruction (andi) of abiv1 immediate is smaller than abiv2, then it will cause: AS arch/csky/kernel/entry.o arch/csky/kernel/entry.S: Assembler messages: arch/csky/kernel/entry.S:224: Error: Operand 2 immediate is overflow. Signed-off-by: Guo Ren

mm/special: create generic fallbacks for pte_special() and pte_mkspecial()

2020-04-10T22:36:21+00:00

Currently there are many platforms that dont enable ARCH_HAS_PTE_SPECIAL but required to define quite similar fallback stubs for special page table entry helpers such as pte_special() and pte_mkspecial(), as they get build in generic MM without a config check. This creates two generic fallback stub definitions for these helpers, eliminating much code duplication. mips platform has a special case where pte_special() and pte_mkspecial() visibility is wider than what ARCH_HAS_PTE_SPECIAL enablement requires. This restricts those symbol visibility in order to avoid redefinitions which is now exposed through this new generic stubs and subsequent build failure. arm platform set_pte_at() definition needs to be moved into a C file just to prevent a build failure. [anshuman.khandual@arm.com: use defined(CONFIG_ARCH_HAS_PTE_SPECIAL) in mips per Thomas] Link: http://lkml.kernel.org/r/1583851924-21603-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Acked-by: Guo Ren [csky] Acked-by: Geert Uytterhoeven [m68k] Acked-by: Stafford Horne [openrisc] Acked-by: Helge Deller [parisc] Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Russell King Cc: Brian Cain Cc: Tony Luck Cc: Fenghua Yu Cc: Sam Creasey Cc: Michal Simek Cc: Ralf Baechle Cc: Paul Burton Cc: Nick Hu Cc: Greentime Hu Cc: Vincent Chen Cc: Ley Foon Tan Cc: Jonas Bonn Cc: Stefan Kristiansson Cc: "James E.J. Bottomley" Cc: "David S. Miller" Cc: Jeff Dike Cc: Richard Weinberger Cc: Anton Ivanov Cc: Guan Xuetao Cc: Chris Zankel Cc: Max Filippov Cc: Thomas Bogendoerfer Link: http://lkml.kernel.org/r/1583802551-15406-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds

mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS

2020-04-10T22:36:21+00:00

There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the existing VM_STACK_DEFAULT_FLAGS. While here, also define some more macros with standard VMA access flag combinations that are used frequently across many platforms. Apart from simplification, this reduces code duplication as well. Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Acked-by: Geert Uytterhoeven Cc: Richard Henderson Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Mark Salter Cc: Guo Ren Cc: Yoshinori Sato Cc: Brian Cain Cc: Tony Luck Cc: Michal Simek Cc: Ralf Baechle Cc: Paul Burton Cc: Nick Hu Cc: Ley Foon Tan Cc: Jonas Bonn Cc: "James E.J. Bottomley" Cc: Michael Ellerman Cc: Paul Walmsley Cc: Heiko Carstens Cc: Rich Felker Cc: "David S. Miller" Cc: Guan Xuetao Cc: Thomas Gleixner Cc: Jeff Dike Cc: Chris Zankel Link: http://lkml.kernel.org/r/1583391014-8170-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds

Merge tag 'csky-for-linus-5.7-rc1' of git://github.com/c-sky/csky-linux

2020-04-06T16:55:50+00:00

Pull csky updates from Guo Ren: - Add kproobes/uprobes support - Add lockdep, rseq, gcov support - Fixup init_fpu - Fixup ftrace_modify deadlock - Fixup speculative execution on IO area * tag 'csky-for-linus-5.7-rc1' of git://github.com/c-sky/csky-linux: csky: Fixup cpu speculative execution to IO area csky: Add uprobes support csky: Add kprobes supported csky: Enable LOCKDEP_SUPPORT csky: Enable the gcov function csky: Fixup get wrong psr value from phyical reg csky/ftrace: Fixup ftrace_modify_code deadlock without CPU_HAS_ICACHE_INS csky: Implement ftrace with regs csky: Add support for restartable sequence csky: Implement ptrace regs and stack API csky: Fixup init_fpu compile warning with __init

csky: Add uprobes support

2020-04-03T03:37:51+00:00

This patch adds support for uprobes on csky architecture. Just like kprobe, it support single-step and simulate instructions. Signed-off-by: Guo Ren Cc: Arnd Bergmann Cc: Steven Rostedt (VMware)