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3705 stack overflow due to zfs lz4 compression

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>
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Sašo Kiselkov Christopher Siden
Sašo Kiselkov authored and Christopher Siden committed Apr 24, 2013
1 parent 4a92375 commit d8fa96c3021236b21f47b84036cbe4f5d4854a06
Showing with 8 additions and 15 deletions.
  1. +8 −15 usr/src/uts/common/fs/zfs/lz4.c
@@ -197,20 +197,17 @@ lz4_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
defined(__amd64) || defined(__ppc64__) || defined(_WIN64) || \
defined(__LP64__) || defined(_LP64))
#define LZ4_ARCH64 1
/*
* Illumos: On amd64 we have 20k of stack and 24k on sun4u and sun4v, so we
* can spend 16k on the algorithm
*/
#define STACKLIMIT 12
#else
#define LZ4_ARCH64 0
#endif

/*
* Illumos: On i386 we only have 12k of stack, so in order to maintain the
* same COMPRESSIONLEVEL we have to use heap allocation. Performance will
* suck, but alas, it's ZFS on 32-bit we're talking about, so...
* Limits the amount of stack space that the algorithm may consume to hold
* the compression lookup table. The value `9' here means we'll never use
* more than 2k of stack (see above for a description of COMPRESSIONLEVEL).
* If more memory is needed, it is allocated from the heap.
*/
#define STACKLIMIT 11
#endif
#define STACKLIMIT 9

/*
* Little Endian or Big Endian?
@@ -240,11 +237,7 @@ lz4_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
#define LZ4_FORCE_UNALIGNED_ACCESS 1
#endif

/*
* Illumos: we can't use GCC's __builtin_ctz family of builtins in the
* kernel
*/
#define LZ4_FORCE_SW_BITCOUNT
/* #define LZ4_FORCE_SW_BITCOUNT */

/*
* Compiler Options

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