1. 19 Sep, 2018 1 commit
    • Vegard Nossum's avatar
      kthread: fix boot hang (regression) on MIPS/OpenRISC · 0d8f2274
      Vegard Nossum authored
      commit b0f5a8f3 upstream.
      
      This fixes a regression in commit 4d6501dc where I didn't notice
      that MIPS and OpenRISC were reinitialising p->{set,clear}_child_tid to
      NULL after our initialisation in copy_process().
      
      We can simply get rid of the arch-specific initialisation here since it
      is now always done in copy_process() before hitting copy_thread{,_tls}().
      
      Review notes:
      
       - As far as I can tell, copy_process() is the only user of
         copy_thread_tls(), which is the only caller of copy_thread() for
         architectures that don't implement copy_thread_tls().
      
       - After this patch, there is no arch-specific code touching
         p->set_child_tid or p->clear_child_tid whatsoever.
      
       - It may look like MIPS/OpenRISC wanted to always have these fields be
         NULL, but that's not true, as copy_process() would unconditionally
         set them again _after_ calling copy_thread_tls() before commit
         4d6501dc.
      
      Fixes: 4d6501dc ("kthread: Fix use-after-free if kthread fork fails")
      Reported-by: 's avatarGuenter Roeck <linux@roeck-us.net>
      Tested-by: Guenter Roeck <linux@roeck-us.net> # MIPS only
      Acked-by: 's avatarStafford Horne <shorne@gmail.com>
      Acked-by: 's avatarOleg Nesterov <oleg@redhat.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: linux-mips@linux-mips.org
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
      Cc: openrisc@lists.librecores.org
      Cc: Jamie Iles <jamie.iles@oracle.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: 's avatarVegard Nossum <vegard.nossum@oracle.com>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: 's avatarAmit Pundir <amit.pundir@linaro.org>
      Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0d8f2274
  2. 17 Feb, 2018 1 commit
    • Eric W. Biederman's avatar
      signal/openrisc: Fix do_unaligned_access to send the proper signal · 498b8b74
      Eric W. Biederman authored
      commit 500d5830 upstream.
      
      While reviewing the signal sending on openrisc the do_unaligned_access
      function stood out because it is obviously wrong.  A comment about an
      si_code set above when actually si_code is never set.  Leading to a
      random si_code being sent to userspace in the event of an unaligned
      access.
      
      Looking further SIGBUS BUS_ADRALN is the proper pair of signal and
      si_code to send for an unaligned access. That is what other
      architectures do and what is required by posix.
      
      Given that do_unaligned_access is broken in a way that no one can be
      relying on it on openrisc fix the code to just do the right thing.
      
      Fixes: 769a8a96 ("OpenRISC: Traps")
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
      Cc: Stafford Horne <shorne@gmail.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: openrisc@lists.librecores.org
      Acked-by: 's avatarStafford Horne <shorne@gmail.com>
      Signed-off-by: 's avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      498b8b74
  3. 20 Dec, 2017 1 commit
  4. 07 Aug, 2017 1 commit
  5. 06 Nov, 2016 1 commit
    • Guenter Roeck's avatar
      openrisc: Define __ro_after_init to avoid crash · 2c7a5c5c
      Guenter Roeck authored
      openrisc qemu tests fail with the following crash.
      
      Unable to handle kernel access at virtual address 0xc0300c34
      
      Oops#: 0001
      CPU #: 0
         PC: c016c710    SR: 0000ae67    SP: c1017e04
         GPR00: 00000000 GPR01: c1017e04 GPR02: c0300c34 GPR03: c0300c34
         GPR04: 00000000 GPR05: c0300cb0 GPR06: c0300c34 GPR07: 000000ff
         GPR08: c107f074 GPR09: c0199ef4 GPR10: c1016000 GPR11: 00000000
         GPR12: 00000000 GPR13: c107f044 GPR14: c0473774 GPR15: 07ce0000
         GPR16: 00000000 GPR17: c107ed8a GPR18: 00009600 GPR19: c107f044
         GPR20: c107ee74 GPR21: 00000003 GPR22: c0473770 GPR23: 00000033
         GPR24: 000000bf GPR25: 00000019 GPR26: c046400c GPR27: 00000001
         GPR28: c0464028 GPR29: c1018000 GPR30: 00000006 GPR31: ccf37483
           RES: 00000000 oGPR11: ffffffff
           Process swapper (pid: 1, stackpage=c1001960)
      
           Stack: Stack dump [0xc1017cf8]:
           sp + 00: 0xc1017e04
           sp + 04: 0xc0300c34
           sp + 08: 0xc0300c34
           sp + 12: 0x00000000
      ...
      
      Bisect points to commit d2ec3f77 ("pty: make ptmx file ops read-only
      after init"). Fix by defining __ro_after_init for the openrisc
      architecture, similar to parisc.
      
      Fixes: d2ec3f77 ("pty: make ptmx file ops read-only after init")
      Cc: Kees Cook <keescook@chromium.org>
      Signed-off-by: 's avatarGuenter Roeck <linux@roeck-us.net>
      Acked-by: 's avatarStafford Horne <shorne@gmail.com>
      2c7a5c5c
  6. 08 Oct, 2016 1 commit
  7. 28 Sep, 2016 1 commit
  8. 18 Sep, 2016 1 commit
  9. 13 Sep, 2016 1 commit
    • Al Viro's avatar
      openrisc: fix copy_from_user() · acb2505d
      Al Viro authored
      ... that should zero on faults.  Also remove the <censored> helpful
      logics wrt range truncation copied from ppc32.  Where it had ever
      been needed only in case of copy_from_user() *and* had not been merged
      into the mainline until a month after the need had disappeared.
      A decade before openrisc went into mainline, I might add...
      
      Cc: stable@vger.kernel.org
      Signed-off-by: 's avatarAl Viro <viro@zeniv.linux.org.uk>
      acb2505d
  10. 04 Aug, 2016 1 commit
    • Krzysztof Kozlowski's avatar
      dma-mapping: use unsigned long for dma_attrs · 00085f1e
      Krzysztof Kozlowski authored
      The dma-mapping core and the implementations do not change the DMA
      attributes passed by pointer.  Thus the pointer can point to const data.
      However the attributes do not have to be a bitfield.  Instead unsigned
      long will do fine:
      
      1. This is just simpler.  Both in terms of reading the code and setting
         attributes.  Instead of initializing local attributes on the stack
         and passing pointer to it to dma_set_attr(), just set the bits.
      
      2. It brings safeness and checking for const correctness because the
         attributes are passed by value.
      
      Semantic patches for this change (at least most of them):
      
          virtual patch
          virtual context
      
          @r@
          identifier f, attrs;
      
          @@
          f(...,
          - struct dma_attrs *attrs
          + unsigned long attrs
          , ...)
          {
          ...
          }
      
          @@
          identifier r.f;
          @@
          f(...,
          - NULL
          + 0
           )
      
      and
      
          // Options: --all-includes
          virtual patch
          virtual context
      
          @r@
          identifier f, attrs;
          type t;
      
          @@
          t f(..., struct dma_attrs *attrs);
      
          @@
          identifier r.f;
          @@
          f(...,
          - NULL
          + 0
           )
      
      Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.comSigned-off-by: 's avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
      Acked-by: 's avatarVineet Gupta <vgupta@synopsys.com>
      Acked-by: 's avatarRobin Murphy <robin.murphy@arm.com>
      Acked-by: 's avatarHans-Christian Noren Egtvedt <egtvedt@samfundet.no>
      Acked-by: Mark Salter <msalter@redhat.com> [c6x]
      Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris]
      Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm]
      Reviewed-by: 's avatarBart Van Assche <bart.vanassche@sandisk.com>
      Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
      Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp]
      Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core]
      Acked-by: David Vrabel <david.vrabel@citrix.com> [xen]
      Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb]
      Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
      Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon]
      Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
      Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
      Acked-by: 's avatarBjorn Andersson <bjorn.andersson@linaro.org>
      Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32]
      Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc]
      Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu]
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      00085f1e
  11. 02 Aug, 2016 1 commit
  12. 26 Jul, 2016 1 commit
  13. 25 Jun, 2016 1 commit
    • Michal Hocko's avatar
      tree wide: get rid of __GFP_REPEAT for order-0 allocations part I · 32d6bd90
      Michal Hocko authored
      This is the third version of the patchset previously sent [1].  I have
      basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get
      rid of superfluous gfp flags" which went through dm tree.  I am sending
      it now because it is tree wide and chances for conflicts are reduced
      considerably when we want to target rc2.  I plan to send the next step
      and rename the flag and move to a better semantic later during this
      release cycle so we will have a new semantic ready for 4.8 merge window
      hopefully.
      
      Motivation:
      
      While working on something unrelated I've checked the current usage of
      __GFP_REPEAT in the tree.  It seems that a majority of the usage is and
      always has been bogus because __GFP_REPEAT has always been about costly
      high order allocations while we are using it for order-0 or very small
      orders very often.  It seems that a big pile of them is just a
      copy&paste when a code has been adopted from one arch to another.
      
      I think it makes some sense to get rid of them because they are just
      making the semantic more unclear.  Please note that GFP_REPEAT is
      documented as
      
      * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
      
      * _might_ fail.  This depends upon the particular VM implementation.
        while !costly requests have basically nofail semantic.  So one could
        reasonably expect that order-0 request with __GFP_REPEAT will not loop
        for ever.  This is not implemented right now though.
      
      I would like to move on with __GFP_REPEAT and define a better semantic
      for it.
      
        $ git grep __GFP_REPEAT origin/master | wc -l
        111
        $ git grep __GFP_REPEAT | wc -l
        36
      
      So we are down to the third after this patch series.  The remaining
      places really seem to be relying on __GFP_REPEAT due to large allocation
      requests.  This still needs some double checking which I will do later
      after all the simple ones are sorted out.
      
      I am touching a lot of arch specific code here and I hope I got it right
      but as a matter of fact I even didn't compile test for some archs as I
      do not have cross compiler for them.  Patches should be quite trivial to
      review for stupid compile mistakes though.  The tricky parts are usually
      hidden by macro definitions and thats where I would appreciate help from
      arch maintainers.
      
      [1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org
      
      This patch (of 19):
      
      __GFP_REPEAT has a rather weak semantic but since it has been introduced
      around 2.6.12 it has been ignored for low order allocations.  Yet we
      have the full kernel tree with its usage for apparently order-0
      allocations.  This is really confusing because __GFP_REPEAT is
      explicitly documented to allow allocation failures which is a weaker
      semantic than the current order-0 has (basically nofail).
      
      Let's simply drop __GFP_REPEAT from those places.  This would allow to
      identify place which really need allocator to retry harder and formulate
      a more specific semantic for what the flag is supposed to do actually.
      
      Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.orgSigned-off-by: 's avatarMichal Hocko <mhocko@suse.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jan Kara <jack@suse.cz>
      Cc: John Crispin <blogic@openwrt.org>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Fleming <matt@codeblueprint.co.uk>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      32d6bd90
  14. 08 Jun, 2016 1 commit
  15. 21 May, 2016 2 commits
    • Zhaoxiu Zeng's avatar
      lib/GCD.c: use binary GCD algorithm instead of Euclidean · fff7fb0b
      Zhaoxiu Zeng authored
      The binary GCD algorithm is based on the following facts:
      	1. If a and b are all evens, then gcd(a,b) = 2 * gcd(a/2, b/2)
      	2. If a is even and b is odd, then gcd(a,b) = gcd(a/2, b)
      	3. If a and b are all odds, then gcd(a,b) = gcd((a-b)/2, b) = gcd((a+b)/2, b)
      
      Even on x86 machines with reasonable division hardware, the binary
      algorithm runs about 25% faster (80% the execution time) than the
      division-based Euclidian algorithm.
      
      On platforms like Alpha and ARMv6 where division is a function call to
      emulation code, it's even more significant.
      
      There are two variants of the code here, depending on whether a fast
      __ffs (find least significant set bit) instruction is available.  This
      allows the unpredictable branches in the bit-at-a-time shifting loop to
      be eliminated.
      
      If fast __ffs is not available, the "even/odd" GCD variant is used.
      
      I use the following code to benchmark:
      
      	#include <stdio.h>
      	#include <stdlib.h>
      	#include <stdint.h>
      	#include <string.h>
      	#include <time.h>
      	#include <unistd.h>
      
      	#define swap(a, b) \
      		do { \
      			a ^= b; \
      			b ^= a; \
      			a ^= b; \
      		} while (0)
      
      	unsigned long gcd0(unsigned long a, unsigned long b)
      	{
      		unsigned long r;
      
      		if (a < b) {
      			swap(a, b);
      		}
      
      		if (b == 0)
      			return a;
      
      		while ((r = a % b) != 0) {
      			a = b;
      			b = r;
      		}
      
      		return b;
      	}
      
      	unsigned long gcd1(unsigned long a, unsigned long b)
      	{
      		unsigned long r = a | b;
      
      		if (!a || !b)
      			return r;
      
      		b >>= __builtin_ctzl(b);
      
      		for (;;) {
      			a >>= __builtin_ctzl(a);
      			if (a == b)
      				return a << __builtin_ctzl(r);
      
      			if (a < b)
      				swap(a, b);
      			a -= b;
      		}
      	}
      
      	unsigned long gcd2(unsigned long a, unsigned long b)
      	{
      		unsigned long r = a | b;
      
      		if (!a || !b)
      			return r;
      
      		r &= -r;
      
      		while (!(b & r))
      			b >>= 1;
      
      		for (;;) {
      			while (!(a & r))
      				a >>= 1;
      			if (a == b)
      				return a;
      
      			if (a < b)
      				swap(a, b);
      			a -= b;
      			a >>= 1;
      			if (a & r)
      				a += b;
      			a >>= 1;
      		}
      	}
      
      	unsigned long gcd3(unsigned long a, unsigned long b)
      	{
      		unsigned long r = a | b;
      
      		if (!a || !b)
      			return r;
      
      		b >>= __builtin_ctzl(b);
      		if (b == 1)
      			return r & -r;
      
      		for (;;) {
      			a >>= __builtin_ctzl(a);
      			if (a == 1)
      				return r & -r;
      			if (a == b)
      				return a << __builtin_ctzl(r);
      
      			if (a < b)
      				swap(a, b);
      			a -= b;
      		}
      	}
      
      	unsigned long gcd4(unsigned long a, unsigned long b)
      	{
      		unsigned long r = a | b;
      
      		if (!a || !b)
      			return r;
      
      		r &= -r;
      
      		while (!(b & r))
      			b >>= 1;
      		if (b == r)
      			return r;
      
      		for (;;) {
      			while (!(a & r))
      				a >>= 1;
      			if (a == r)
      				return r;
      			if (a == b)
      				return a;
      
      			if (a < b)
      				swap(a, b);
      			a -= b;
      			a >>= 1;
      			if (a & r)
      				a += b;
      			a >>= 1;
      		}
      	}
      
      	static unsigned long (*gcd_func[])(unsigned long a, unsigned long b) = {
      		gcd0, gcd1, gcd2, gcd3, gcd4,
      	};
      
      	#define TEST_ENTRIES (sizeof(gcd_func) / sizeof(gcd_func[0]))
      
      	#if defined(__x86_64__)
      
      	#define rdtscll(val) do { \
      		unsigned long __a,__d; \
      		__asm__ __volatile__("rdtsc" : "=a" (__a), "=d" (__d)); \
      		(val) = ((unsigned long long)__a) | (((unsigned long long)__d)<<32); \
      	} while(0)
      
      	static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long),
      								unsigned long a, unsigned long b, unsigned long *res)
      	{
      		unsigned long long start, end;
      		unsigned long long ret;
      		unsigned long gcd_res;
      
      		rdtscll(start);
      		gcd_res = gcd(a, b);
      		rdtscll(end);
      
      		if (end >= start)
      			ret = end - start;
      		else
      			ret = ~0ULL - start + 1 + end;
      
      		*res = gcd_res;
      		return ret;
      	}
      
      	#else
      
      	static inline struct timespec read_time(void)
      	{
      		struct timespec time;
      		clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time);
      		return time;
      	}
      
      	static inline unsigned long long diff_time(struct timespec start, struct timespec end)
      	{
      		struct timespec temp;
      
      		if ((end.tv_nsec - start.tv_nsec) < 0) {
      			temp.tv_sec = end.tv_sec - start.tv_sec - 1;
      			temp.tv_nsec = 1000000000ULL + end.tv_nsec - start.tv_nsec;
      		} else {
      			temp.tv_sec = end.tv_sec - start.tv_sec;
      			temp.tv_nsec = end.tv_nsec - start.tv_nsec;
      		}
      
      		return temp.tv_sec * 1000000000ULL + temp.tv_nsec;
      	}
      
      	static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long),
      								unsigned long a, unsigned long b, unsigned long *res)
      	{
      		struct timespec start, end;
      		unsigned long gcd_res;
      
      		start = read_time();
      		gcd_res = gcd(a, b);
      		end = read_time();
      
      		*res = gcd_res;
      		return diff_time(start, end);
      	}
      
      	#endif
      
      	static inline unsigned long get_rand()
      	{
      		if (sizeof(long) == 8)
      			return (unsigned long)rand() << 32 | rand();
      		else
      			return rand();
      	}
      
      	int main(int argc, char **argv)
      	{
      		unsigned int seed = time(0);
      		int loops = 100;
      		int repeats = 1000;
      		unsigned long (*res)[TEST_ENTRIES];
      		unsigned long long elapsed[TEST_ENTRIES];
      		int i, j, k;
      
      		for (;;) {
      			int opt = getopt(argc, argv, "n:r:s:");
      			/* End condition always first */
      			if (opt == -1)
      				break;
      
      			switch (opt) {
      			case 'n':
      				loops = atoi(optarg);
      				break;
      			case 'r':
      				repeats = atoi(optarg);
      				break;
      			case 's':
      				seed = strtoul(optarg, NULL, 10);
      				break;
      			default:
      				/* You won't actually get here. */
      				break;
      			}
      		}
      
      		res = malloc(sizeof(unsigned long) * TEST_ENTRIES * loops);
      		memset(elapsed, 0, sizeof(elapsed));
      
      		srand(seed);
      		for (j = 0; j < loops; j++) {
      			unsigned long a = get_rand();
      			/* Do we have args? */
      			unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand();
      			unsigned long long min_elapsed[TEST_ENTRIES];
      			for (k = 0; k < repeats; k++) {
      				for (i = 0; i < TEST_ENTRIES; i++) {
      					unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &res[j][i]);
      					if (k == 0 || min_elapsed[i] > tmp)
      						min_elapsed[i] = tmp;
      				}
      			}
      			for (i = 0; i < TEST_ENTRIES; i++)
      				elapsed[i] += min_elapsed[i];
      		}
      
      		for (i = 0; i < TEST_ENTRIES; i++)
      			printf("gcd%d: elapsed %llu\n", i, elapsed[i]);
      
      		k = 0;
      		srand(seed);
      		for (j = 0; j < loops; j++) {
      			unsigned long a = get_rand();
      			unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand();
      			for (i = 1; i < TEST_ENTRIES; i++) {
      				if (res[j][i] != res[j][0])
      					break;
      			}
      			if (i < TEST_ENTRIES) {
      				if (k == 0) {
      					k = 1;
      					fprintf(stderr, "Error:\n");
      				}
      				fprintf(stderr, "gcd(%lu, %lu): ", a, b);
      				for (i = 0; i < TEST_ENTRIES; i++)
      					fprintf(stderr, "%ld%s", res[j][i], i < TEST_ENTRIES - 1 ? ", " : "\n");
      			}
      		}
      
      		if (k == 0)
      			fprintf(stderr, "PASS\n");
      
      		free(res);
      
      		return 0;
      	}
      
      Compiled with "-O2", on "VirtualBox 4.4.0-22-generic #38-Ubuntu x86_64" got:
      
        zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
        gcd0: elapsed 10174
        gcd1: elapsed 2120
        gcd2: elapsed 2902
        gcd3: elapsed 2039
        gcd4: elapsed 2812
        PASS
        zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
        gcd0: elapsed 9309
        gcd1: elapsed 2280
        gcd2: elapsed 2822
        gcd3: elapsed 2217
        gcd4: elapsed 2710
        PASS
        zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
        gcd0: elapsed 9589
        gcd1: elapsed 2098
        gcd2: elapsed 2815
        gcd3: elapsed 2030
        gcd4: elapsed 2718
        PASS
        zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
        gcd0: elapsed 9914
        gcd1: elapsed 2309
        gcd2: elapsed 2779
        gcd3: elapsed 2228
        gcd4: elapsed 2709
        PASS
      
      [akpm@linux-foundation.org: avoid #defining a CONFIG_ variable]
      Signed-off-by: 's avatarZhaoxiu Zeng <zhaoxiu.zeng@gmail.com>
      Signed-off-by: 's avatarGeorge Spelvin <linux@horizon.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      fff7fb0b
    • Jiri Slaby's avatar
      exit_thread: remove empty bodies · 5f56a5df
      Jiri Slaby authored
      Define HAVE_EXIT_THREAD for archs which want to do something in
      exit_thread. For others, let's define exit_thread as an empty inline.
      
      This is a cleanup before we change the prototype of exit_thread to
      accept a task parameter.
      
      [akpm@linux-foundation.org: fix mips]
      Signed-off-by: 's avatarJiri Slaby <jslaby@suse.cz>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      5f56a5df
  16. 04 May, 2016 1 commit
    • James Hogan's avatar
      asm-generic: Drop renameat syscall from default list · b0da6d44
      James Hogan authored
      The newer renameat2 syscall provides all the functionality provided by
      the renameat syscall and adds flags, so future architectures won't need
      to include renameat.
      
      Therefore drop the renameat syscall from the generic syscall list unless
      __ARCH_WANT_RENAMEAT is defined by the architecture's unistd.h prior to
      including asm-generic/unistd.h, and adjust all architectures using the
      generic syscall list to define it so that no in-tree architectures are
      affected.
      Signed-off-by: 's avatarJames Hogan <james.hogan@imgtec.com>
      Acked-by: 's avatarVineet Gupta <vgupta@synopsys.com>
      Cc: linux-arch@vger.kernel.org
      Cc: linux-snps-arc@lists.infradead.org
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: linux-c6x-dev@linux-c6x.org
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: linux-hexagon@vger.kernel.org
      Cc: linux-metag@vger.kernel.org
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: linux@lists.openrisc.net
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: nios2-dev@lists.rocketboards.org
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: uclinux-h8-devel@lists.sourceforge.jp
      Signed-off-by: 's avatarArnd Bergmann <arnd@arndb.de>
      b0da6d44
  17. 22 Apr, 2016 1 commit
  18. 25 Mar, 2016 1 commit
  19. 26 Feb, 2016 1 commit
  20. 15 Feb, 2016 1 commit
  21. 21 Jan, 2016 1 commit
    • Christoph Hellwig's avatar
      dma-mapping: always provide the dma_map_ops based implementation · e1c7e324
      Christoph Hellwig authored
      Move the generic implementation to <linux/dma-mapping.h> now that all
      architectures support it and remove the HAVE_DMA_ATTR Kconfig symbol now
      that everyone supports them.
      
      [valentinrothberg@gmail.com: remove leftovers in Kconfig]
      Signed-off-by: 's avatarChristoph Hellwig <hch@lst.de>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Helge Deller <deller@gmx.de>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Christian Borntraeger <borntraeger@de.ibm.com>
      Cc: Joerg Roedel <jroedel@suse.de>
      Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
      Signed-off-by: 's avatarValentin Rothberg <valentinrothberg@gmail.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      e1c7e324
  22. 10 Sep, 2015 5 commits
    • Christoph Hellwig's avatar
      dma-mapping: consolidate dma_set_mask · 452e06af
      Christoph Hellwig authored
      Almost everyone implements dma_set_mask the same way, although some time
      that's hidden in ->set_dma_mask methods.
      
      This patch consolidates those into a common implementation that either
      calls ->set_dma_mask if present or otherwise uses the default
      implementation.  Some architectures used to only call ->set_dma_mask
      after the initial checks, and those instance have been fixed to do the
      full work.  h8300 implemented dma_set_mask bogusly as a no-ops and has
      been fixed.
      
      Unfortunately some architectures overload unrelated semantics like changing
      the dma_ops into it so we still need to allow for an architecture override
      for now.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: 's avatarChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: 's avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      452e06af
    • Christoph Hellwig's avatar
      dma-mapping: consolidate dma_supported · ee196371
      Christoph Hellwig authored
      Most architectures just call into ->dma_supported, but some also return 1
      if the method is not present, or 0 if no dma ops are present (although
      that should never happeb). Consolidate this more broad version into
      common code.
      
      Also fix h8300 which inorrectly always returned 0, which would have been
      a problem if it's dma_set_mask implementation wasn't a similarly buggy
      noop.
      
      As a few architectures have much more elaborate implementations, we
      still allow for arch overrides.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: 's avatarChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: 's avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      ee196371
    • Christoph Hellwig's avatar
      dma-mapping: cosolidate dma_mapping_error · efa21e43
      Christoph Hellwig authored
      Currently there are three valid implementations of dma_mapping_error:
      
       (1) call ->mapping_error
       (2) check for a hardcoded error code
       (3) always return 0
      
      This patch provides a common implementation that calls ->mapping_error
      if present, then checks for DMA_ERROR_CODE if defined or otherwise
      returns 0.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: 's avatarChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: 's avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      efa21e43
    • Christoph Hellwig's avatar
      dma-mapping: consolidate dma_{alloc,free}_noncoherent · 1e893752
      Christoph Hellwig authored
      Most architectures do not support non-coherent allocations and either
      define dma_{alloc,free}_noncoherent to their coherent versions or stub
      them out.
      
      Openrisc uses dma_{alloc,free}_attrs to implement them, and only Mips
      implements them directly.
      
      This patch moves the Openrisc version to common code, and handles the
      DMA_ATTR_NON_CONSISTENT case in the mips dma_map_ops instance.
      
      Note that actual non-coherent allocations require a dma_cache_sync
      implementation, so if non-coherent allocations didn't work on
      an architecture before this patch they still won't work after it.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: 's avatarChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: 's avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      1e893752
    • Christoph Hellwig's avatar
      dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent} · 6894258e
      Christoph Hellwig authored
      Since 2009 we have a nice asm-generic header implementing lots of DMA API
      functions for architectures using struct dma_map_ops, but unfortunately
      it's still missing a lot of APIs that all architectures still have to
      duplicate.
      
      This series consolidates the remaining functions, although we still need
      arch opt outs for two of them as a few architectures have very
      non-standard implementations.
      
      This patch (of 5):
      
      The coherent DMA allocator works the same over all architectures supporting
      dma_map operations.
      
      This patch consolidates them and converges the minor differences:
      
       - the debug_dma helpers are now called from all architectures, including
         those that were previously missing them
       - dma_alloc_from_coherent and dma_release_from_coherent are now always
         called from the generic alloc/free routines instead of the ops
         dma-mapping-common.h always includes dma-coherent.h to get the defintions
         for them, or the stubs if the architecture doesn't support this feature
       - checks for ->alloc / ->free presence are removed.  There is only one
         magic instead of dma_map_ops without them (mic_dma_ops) and that one
         is x86 only anyway.
      
      Besides that only x86 needs special treatment to replace a default devices
      if none is passed and tweak the gfp_flags.  An optional arch hook is provided
      for that.
      
      [linux@roeck-us.net: fix build]
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: 's avatarChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: 's avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: 's avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      6894258e
  23. 10 Aug, 2015 1 commit
  24. 17 Jul, 2015 2 commits
  25. 25 Jun, 2015 1 commit
    • Laurent Dufour's avatar
      mm: new mm hook framework · 2ae416b1
      Laurent Dufour authored
      CRIU is recreating the process memory layout by remapping the checkpointee
      memory area on top of the current process (criu).  This includes remapping
      the vDSO to the place it has at checkpoint time.
      
      However some architectures like powerpc are keeping a reference to the
      vDSO base address to build the signal return stack frame by calling the
      vDSO sigreturn service.  So once the vDSO has been moved, this reference
      is no more valid and the signal frame built later are not usable.
      
      This patch serie is introducing a new mm hook framework, and a new
      arch_remap hook which is called when mremap is done and the mm lock still
      hold.  The next patch is adding the vDSO remap and unmap tracking to the
      powerpc architecture.
      
      This patch (of 3):
      
      This patch introduces a new set of header file to manage mm hooks:
      - per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h)
      - a generic header (include/linux/mm-arch-hooks.h)
      
      The architecture which need to overwrite a hook as to redefine it in its
      header file, while architecture which doesn't need have nothing to do.
      
      The default hooks are defined in the generic header and are used in the
      case the architecture is not defining it.
      
      In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should
      be moved here.
      Signed-off-by: 's avatarLaurent Dufour <ldufour@linux.vnet.ibm.com>
      Suggested-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Ingo Molnar <mingo@kernel.org>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      2ae416b1
  26. 19 May, 2015 1 commit
  27. 15 Apr, 2015 1 commit
  28. 12 Apr, 2015 2 commits
  29. 13 Feb, 2015 1 commit
    • Andy Lutomirski's avatar
      all arches, signal: move restart_block to struct task_struct · f56141e3
      Andy Lutomirski authored
      If an attacker can cause a controlled kernel stack overflow, overwriting
      the restart block is a very juicy exploit target.  This is because the
      restart_block is held in the same memory allocation as the kernel stack.
      
      Moving the restart block to struct task_struct prevents this exploit by
      making the restart_block harder to locate.
      
      Note that there are other fields in thread_info that are also easy
      targets, at least on some architectures.
      
      It's also a decent simplification, since the restart code is more or less
      identical on all architectures.
      
      [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
      Signed-off-by: 's avatarAndy Lutomirski <luto@amacapital.net>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: David Miller <davem@davemloft.net>
      Acked-by: Richard Weinberger's avatarRichard Weinberger <richard@nod.at>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Guenter Roeck <linux@roeck-us.net>
      Signed-off-by: 's avatarJames Hogan <james.hogan@imgtec.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      f56141e3
  30. 12 Feb, 2015 1 commit
  31. 10 Feb, 2015 1 commit
  32. 29 Jan, 2015 1 commit
    • Linus Torvalds's avatar
      vm: add VM_FAULT_SIGSEGV handling support · 33692f27
      Linus Torvalds authored
      The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
      "you should SIGSEGV" error, because the SIGSEGV case was generally
      handled by the caller - usually the architecture fault handler.
      
      That results in lots of duplication - all the architecture fault
      handlers end up doing very similar "look up vma, check permissions, do
      retries etc" - but it generally works.  However, there are cases where
      the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.
      
      In particular, when accessing the stack guard page, libsigsegv expects a
      SIGSEGV.  And it usually got one, because the stack growth is handled by
      that duplicated architecture fault handler.
      
      However, when the generic VM layer started propagating the error return
      from the stack expansion in commit fee7e49d ("mm: propagate error
      from stack expansion even for guard page"), that now exposed the
      existing VM_FAULT_SIGBUS result to user space.  And user space really
      expected SIGSEGV, not SIGBUS.
      
      To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
      duplicate architecture fault handlers about it.  They all already have
      the code to handle SIGSEGV, so it's about just tying that new return
      value to the existing code, but it's all a bit annoying.
      
      This is the mindless minimal patch to do this.  A more extensive patch
      would be to try to gather up the mostly shared fault handling logic into
      one generic helper routine, and long-term we really should do that
      cleanup.
      
      Just from this patch, you can generally see that most architectures just
      copied (directly or indirectly) the old x86 way of doing things, but in
      the meantime that original x86 model has been improved to hold the VM
      semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
      "newer" things, so it would be a good idea to bring all those
      improvements to the generic case and teach other architectures about
      them too.
      Reported-and-tested-by: 's avatarTakashi Iwai <tiwai@suse.de>
      Tested-by: 's avatarJan Engelhardt <jengelh@inai.de>
      Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
      Cc: linux-arch@vger.kernel.org
      Cc: stable@vger.kernel.org
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      33692f27
  33. 13 Jan, 2015 1 commit