From 2a01bb3885c9145dbb7583d5aa5f5d5504f6f46f Mon Sep 17 00:00:00 2001 From: Kyle McMartin Date: Wed, 11 Apr 2012 08:15:29 -0400 Subject: panic: Make panic_on_oops configurable Several distros set this by default by patching panic_on_oops. It seems to fit with the BOOTPARAM_{HARD,SOFT}_PANIC options though, so let's add a Kconfig entry and reduce some more upstream delta. Signed-off-by: Kyle McMartin Cc: Andrew Morton Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20120411121529.GH26688@redacted.bos.redhat.com Signed-off-by: Ingo Molnar --- lib/Kconfig.debug | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 6777153f18f3..91858cd8394f 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -228,6 +228,26 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC default 1 if BOOTPARAM_SOFTLOCKUP_PANIC +config PANIC_ON_OOPS + bool "Panic on Oops" if EXPERT + default n + help + Say Y here to enable the kernel to panic when it oopses. This + has the same effect as setting oops=panic on the kernel command + line. + + This feature is useful to ensure that the kernel does not do + anything erroneous after an oops which could result in data + corruption or other issues. + + Say N if unsure. + +config PANIC_ON_OOPS_VALUE + int + range 0 1 + default 0 if !PANIC_ON_OOPS + default 1 if PANIC_ON_OOPS + config DETECT_HUNG_TASK bool "Detect Hung Tasks" depends on DEBUG_KERNEL -- cgit v1.3-14-g43fede From 2aa4ee2a8805ec0260dde971e9e6699917c868a7 Mon Sep 17 00:00:00 2001 From: Jim Kukunas Date: Mon, 28 May 2012 14:10:22 +1000 Subject: lib/raid6: fix sparse warnings in recovery functions Make the recovery functions static to fix the following sparse warnings: lib/raid6/recov.c:25:6: warning: symbol 'raid6_2data_recov_intx1' was not declared. Should it be static? lib/raid6/recov.c:69:6: warning: symbol 'raid6_datap_recov_intx1' was not declared. Should it be static? lib/raid6/recov_ssse3.c:22:6: warning: symbol 'raid6_2data_recov_ssse3' was not declared. Should it be static? lib/raid6/recov_ssse3.c:197:6: warning: symbol 'raid6_datap_recov_ssse3' was not declared. Should it be static? Reported-by: Fengguang Wu Signed-off-by: Jim Kukunas Signed-off-by: NeilBrown --- lib/raid6/recov.c | 7 ++++--- lib/raid6/recov_ssse3.c | 7 ++++--- 2 files changed, 8 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/lib/raid6/recov.c b/lib/raid6/recov.c index 1805a5cc5daa..a95bccb8497d 100644 --- a/lib/raid6/recov.c +++ b/lib/raid6/recov.c @@ -22,8 +22,8 @@ #include /* Recover two failed data blocks. */ -void raid6_2data_recov_intx1(int disks, size_t bytes, int faila, int failb, - void **ptrs) +static void raid6_2data_recov_intx1(int disks, size_t bytes, int faila, + int failb, void **ptrs) { u8 *p, *q, *dp, *dq; u8 px, qx, db; @@ -66,7 +66,8 @@ void raid6_2data_recov_intx1(int disks, size_t bytes, int faila, int failb, } /* Recover failure of one data block plus the P block */ -void raid6_datap_recov_intx1(int disks, size_t bytes, int faila, void **ptrs) +static void raid6_datap_recov_intx1(int disks, size_t bytes, int faila, + void **ptrs) { u8 *p, *q, *dq; const u8 *qmul; /* Q multiplier table */ diff --git a/lib/raid6/recov_ssse3.c b/lib/raid6/recov_ssse3.c index 37ae61930559..ecb710c0b4d9 100644 --- a/lib/raid6/recov_ssse3.c +++ b/lib/raid6/recov_ssse3.c @@ -19,8 +19,8 @@ static int raid6_has_ssse3(void) boot_cpu_has(X86_FEATURE_SSSE3); } -void raid6_2data_recov_ssse3(int disks, size_t bytes, int faila, int failb, - void **ptrs) +static void raid6_2data_recov_ssse3(int disks, size_t bytes, int faila, + int failb, void **ptrs) { u8 *p, *q, *dp, *dq; const u8 *pbmul; /* P multiplier table for B data */ @@ -194,7 +194,8 @@ void raid6_2data_recov_ssse3(int disks, size_t bytes, int faila, int failb, } -void raid6_datap_recov_ssse3(int disks, size_t bytes, int faila, void **ptrs) +static void raid6_datap_recov_ssse3(int disks, size_t bytes, int faila, + void **ptrs) { u8 *p, *q, *dq; const u8 *qmul; /* Q multiplier table */ -- cgit v1.3-14-g43fede From 0cfd32b736ae0c36b42697584811042726c07cba Mon Sep 17 00:00:00 2001 From: Hiroaki SHIMODA Date: Wed, 30 May 2012 12:24:39 +0000 Subject: bql: Fix POSDIFF() to integer overflow aware. POSDIFF() fails to take into account integer overflow case. Signed-off-by: Hiroaki SHIMODA Cc: Tom Herbert Cc: Eric Dumazet Cc: Denys Fedoryshchenko Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- lib/dynamic_queue_limits.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/dynamic_queue_limits.c b/lib/dynamic_queue_limits.c index 6ab4587d052b..c87eb76f2fd4 100644 --- a/lib/dynamic_queue_limits.c +++ b/lib/dynamic_queue_limits.c @@ -10,7 +10,7 @@ #include #include -#define POSDIFF(A, B) ((A) > (B) ? (A) - (B) : 0) +#define POSDIFF(A, B) ((int)((A) - (B)) > 0 ? (A) - (B) : 0) /* Records completed count and recalculates the queue limit */ void dql_completed(struct dql *dql, unsigned int count) -- cgit v1.3-14-g43fede From 25426b794efdc70dde7fd3134dc56fac3e7d562d Mon Sep 17 00:00:00 2001 From: Hiroaki SHIMODA Date: Wed, 30 May 2012 12:25:19 +0000 Subject: bql: Avoid unneeded limit decrement. When below pattern is observed, TIME dql_queued() dql_completed() | a) initial state | | b) X bytes queued V c) Y bytes queued d) X bytes completed e) Z bytes queued f) Y bytes completed a) dql->limit has already some value and there is no in-flight packet. b) X bytes queued. c) Y bytes queued and excess limit. d) X bytes completed and dql->prev_ovlimit is set and also dql->prev_num_queued is set Y. e) Z bytes queued. f) Y bytes completed. inprogress and prev_inprogress are true. At f), according to the comment, all_prev_completed becomes true and limit should be increased. But POSDIFF() ignores (completed == dql->prev_num_queued) case, so limit is decreased. Signed-off-by: Hiroaki SHIMODA Cc: Tom Herbert Cc: Eric Dumazet Cc: Denys Fedoryshchenko Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- lib/dynamic_queue_limits.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/dynamic_queue_limits.c b/lib/dynamic_queue_limits.c index c87eb76f2fd4..0fafa77f4036 100644 --- a/lib/dynamic_queue_limits.c +++ b/lib/dynamic_queue_limits.c @@ -11,12 +11,14 @@ #include #define POSDIFF(A, B) ((int)((A) - (B)) > 0 ? (A) - (B) : 0) +#define AFTER_EQ(A, B) ((int)((A) - (B)) >= 0) /* Records completed count and recalculates the queue limit */ void dql_completed(struct dql *dql, unsigned int count) { unsigned int inprogress, prev_inprogress, limit; - unsigned int ovlimit, all_prev_completed, completed; + unsigned int ovlimit, completed; + bool all_prev_completed; /* Can't complete more than what's in queue */ BUG_ON(count > dql->num_queued - dql->num_completed); @@ -26,7 +28,7 @@ void dql_completed(struct dql *dql, unsigned int count) ovlimit = POSDIFF(dql->num_queued - dql->num_completed, limit); inprogress = dql->num_queued - completed; prev_inprogress = dql->prev_num_queued - dql->num_completed; - all_prev_completed = POSDIFF(completed, dql->prev_num_queued); + all_prev_completed = AFTER_EQ(completed, dql->prev_num_queued); if ((ovlimit && !inprogress) || (dql->prev_ovlimit && all_prev_completed)) { -- cgit v1.3-14-g43fede From 914bec1011a25f65cdc94988a6f974bfb9a3c10d Mon Sep 17 00:00:00 2001 From: Hiroaki SHIMODA Date: Wed, 30 May 2012 12:25:37 +0000 Subject: bql: Avoid possible inconsistent calculation. dql->num_queued could change while processing dql_completed(). To provide consistent calculation, added an on stack variable. Signed-off-by: Hiroaki SHIMODA Cc: Tom Herbert Cc: Eric Dumazet Cc: Denys Fedoryshchenko Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- lib/dynamic_queue_limits.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'lib') diff --git a/lib/dynamic_queue_limits.c b/lib/dynamic_queue_limits.c index 0fafa77f4036..0777c5a45fa0 100644 --- a/lib/dynamic_queue_limits.c +++ b/lib/dynamic_queue_limits.c @@ -17,16 +17,18 @@ void dql_completed(struct dql *dql, unsigned int count) { unsigned int inprogress, prev_inprogress, limit; - unsigned int ovlimit, completed; + unsigned int ovlimit, completed, num_queued; bool all_prev_completed; + num_queued = ACCESS_ONCE(dql->num_queued); + /* Can't complete more than what's in queue */ - BUG_ON(count > dql->num_queued - dql->num_completed); + BUG_ON(count > num_queued - dql->num_completed); completed = dql->num_completed + count; limit = dql->limit; - ovlimit = POSDIFF(dql->num_queued - dql->num_completed, limit); - inprogress = dql->num_queued - completed; + ovlimit = POSDIFF(num_queued - dql->num_completed, limit); + inprogress = num_queued - completed; prev_inprogress = dql->prev_num_queued - dql->num_completed; all_prev_completed = AFTER_EQ(completed, dql->prev_num_queued); @@ -106,7 +108,7 @@ void dql_completed(struct dql *dql, unsigned int count) dql->prev_ovlimit = ovlimit; dql->prev_last_obj_cnt = dql->last_obj_cnt; dql->num_completed = completed; - dql->prev_num_queued = dql->num_queued; + dql->prev_num_queued = num_queued; } EXPORT_SYMBOL(dql_completed); -- cgit v1.3-14-g43fede From 725fe002d315c2501c110b7245d3eb4f4535f4d6 Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Thu, 31 May 2012 16:26:08 -0700 Subject: vsprintf: correctly handle width when '#' flag used in %#p format The '%p' output of the kernel's vsprintf() uses spec.field_width to determine how many digits to output based on 2 * sizeof(void*) so that all digits of a pointer are shown. ie. a pointer will be output as "001A2B3C" instead of "1A2B3C". However, if the '#' flag is used in the format (%#p), then the code doesn't take into account the width of the '0x' prefix and will end up outputing "0x1A2B3C" instead of "0x001A2B3C". This patch reworks the "pointer()" format hook to include 2 characters for the '0x' prefix if the '#' flag is included. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Grant Likely Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/vsprintf.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'lib') diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 5391299c1e78..b8fbd275bc46 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -870,13 +870,15 @@ static noinline_for_stack char *pointer(const char *fmt, char *buf, char *end, void *ptr, struct printf_spec spec) { + int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0); + if (!ptr && *fmt != 'K') { /* * Print (null) with the same width as a pointer so it makes * tabular output look nice. */ if (spec.field_width == -1) - spec.field_width = 2 * sizeof(void *); + spec.field_width = default_width; return string(buf, end, "(null)", spec); } @@ -931,7 +933,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, */ if (in_irq() || in_serving_softirq() || in_nmi()) { if (spec.field_width == -1) - spec.field_width = 2 * sizeof(void *); + spec.field_width = default_width; return string(buf, end, "pK-error", spec); } if (!((kptr_restrict == 0) || @@ -948,7 +950,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, } spec.flags |= SMALL; if (spec.field_width == -1) { - spec.field_width = 2 * sizeof(void *); + spec.field_width = default_width; spec.flags |= ZEROPAD; } spec.base = 16; -- cgit v1.3-14-g43fede From 133fd9f5cda2d86904126f4b9fa4e8f4330c9569 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 31 May 2012 16:26:08 -0700 Subject: vsprintf: further optimize decimal conversion Previous code was using optimizations which were developed to work well even on narrow-word CPUs (by today's standards). But Linux runs only on 32-bit and wider CPUs. We can use that. First: using 32x32->64 multiply and trivial 32-bit shift, we can correctly divide by 10 much larger numbers, and thus we can print groups of 9 digits instead of groups of 5 digits. Next: there are two algorithms to print larger numbers. One is generic: divide by 1000000000 and repeatedly print groups of (up to) 9 digits. It's conceptually simple, but requires an (unsigned long long) / 1000000000 division. Second algorithm splits 64-bit unsigned long long into 16-bit chunks, manipulates them cleverly and generates groups of 4 decimal digits. It so happens that it does NOT require long long division. If long is > 32 bits, division of 64-bit values is relatively easy, and we will use the first algorithm. If long long is > 64 bits (strange architecture with VERY large long long), second algorithm can't be used, and we again use the first one. Else (if long is 32 bits and long long is 64 bits) we use second one. And third: there is a simple optimization which takes fast path not only for zero as was done before, but for all one-digit numbers. In all tested cases new code is faster than old one, in many cases by 30%, in few cases by more than 50% (for example, on x86-32, conversion of 12345678). Code growth is ~0 in 32-bit case and ~130 bytes in 64-bit case. This patch is based upon an original from Michal Nazarewicz. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Michal Nazarewicz Signed-off-by: Denys Vlasenko Cc: Douglas W Jones Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/bitsperlong.h | 4 + lib/vsprintf.c | 281 ++++++++++++++++++++++++++------------ 2 files changed, 194 insertions(+), 91 deletions(-) (limited to 'lib') diff --git a/include/asm-generic/bitsperlong.h b/include/asm-generic/bitsperlong.h index 4ae54e07de83..a7b0914348fd 100644 --- a/include/asm-generic/bitsperlong.h +++ b/include/asm-generic/bitsperlong.h @@ -28,5 +28,9 @@ #error Inconsistent word size. Check asm/bitsperlong.h #endif +#ifndef BITS_PER_LONG_LONG +#define BITS_PER_LONG_LONG 64 +#endif + #endif /* __KERNEL__ */ #endif /* __ASM_GENERIC_BITS_PER_LONG */ diff --git a/lib/vsprintf.c b/lib/vsprintf.c index b8fbd275bc46..c3f36d415bdf 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -112,106 +112,199 @@ int skip_atoi(const char **s) /* Decimal conversion is by far the most typical, and is used * for /proc and /sys data. This directly impacts e.g. top performance * with many processes running. We optimize it for speed - * using code from - * http://www.cs.uiowa.edu/~jones/bcd/decimal.html - * (with permission from the author, Douglas W. Jones). */ + * using ideas described at + * (with permission from the author, Douglas W. Jones). + */ -/* Formats correctly any integer in [0,99999]. - * Outputs from one to five digits depending on input. - * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */ +#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64 +/* Formats correctly any integer in [0, 999999999] */ static noinline_for_stack -char *put_dec_trunc(char *buf, unsigned q) +char *put_dec_full9(char *buf, unsigned q) { - unsigned d3, d2, d1, d0; - d1 = (q>>4) & 0xf; - d2 = (q>>8) & 0xf; - d3 = (q>>12); - - d0 = 6*(d3 + d2 + d1) + (q & 0xf); - q = (d0 * 0xcd) >> 11; - d0 = d0 - 10*q; - *buf++ = d0 + '0'; /* least significant digit */ - d1 = q + 9*d3 + 5*d2 + d1; - if (d1 != 0) { - q = (d1 * 0xcd) >> 11; - d1 = d1 - 10*q; - *buf++ = d1 + '0'; /* next digit */ - - d2 = q + 2*d2; - if ((d2 != 0) || (d3 != 0)) { - q = (d2 * 0xd) >> 7; - d2 = d2 - 10*q; - *buf++ = d2 + '0'; /* next digit */ - - d3 = q + 4*d3; - if (d3 != 0) { - q = (d3 * 0xcd) >> 11; - d3 = d3 - 10*q; - *buf++ = d3 + '0'; /* next digit */ - if (q != 0) - *buf++ = q + '0'; /* most sign. digit */ - } - } - } + unsigned r; + /* + * Possible ways to approx. divide by 10 + * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit) + * (x * 0xcccd) >> 19 x < 81920 (x < 262149 when 64-bit mul) + * (x * 0x6667) >> 18 x < 43699 + * (x * 0x3334) >> 17 x < 16389 + * (x * 0x199a) >> 16 x < 16389 + * (x * 0x0ccd) >> 15 x < 16389 + * (x * 0x0667) >> 14 x < 2739 + * (x * 0x0334) >> 13 x < 1029 + * (x * 0x019a) >> 12 x < 1029 + * (x * 0x00cd) >> 11 x < 1029 shorter code than * 0x67 (on i386) + * (x * 0x0067) >> 10 x < 179 + * (x * 0x0034) >> 9 x < 69 same + * (x * 0x001a) >> 8 x < 69 same + * (x * 0x000d) >> 7 x < 69 same, shortest code (on i386) + * (x * 0x0007) >> 6 x < 19 + * See + */ + r = (q * (uint64_t)0x1999999a) >> 32; + *buf++ = (q - 10 * r) + '0'; /* 1 */ + q = (r * (uint64_t)0x1999999a) >> 32; + *buf++ = (r - 10 * q) + '0'; /* 2 */ + r = (q * (uint64_t)0x1999999a) >> 32; + *buf++ = (q - 10 * r) + '0'; /* 3 */ + q = (r * (uint64_t)0x1999999a) >> 32; + *buf++ = (r - 10 * q) + '0'; /* 4 */ + r = (q * (uint64_t)0x1999999a) >> 32; + *buf++ = (q - 10 * r) + '0'; /* 5 */ + /* Now value is under 10000, can avoid 64-bit multiply */ + q = (r * 0x199a) >> 16; + *buf++ = (r - 10 * q) + '0'; /* 6 */ + r = (q * 0xcd) >> 11; + *buf++ = (q - 10 * r) + '0'; /* 7 */ + q = (r * 0xcd) >> 11; + *buf++ = (r - 10 * q) + '0'; /* 8 */ + *buf++ = q + '0'; /* 9 */ return buf; } -/* Same with if's removed. Always emits five digits */ +#endif + +/* Similar to above but do not pad with zeros. + * Code can be easily arranged to print 9 digits too, but our callers + * always call put_dec_full9() instead when the number has 9 decimal digits. + */ static noinline_for_stack -char *put_dec_full(char *buf, unsigned q) +char *put_dec_trunc8(char *buf, unsigned r) { - /* BTW, if q is in [0,9999], 8-bit ints will be enough, */ - /* but anyway, gcc produces better code with full-sized ints */ - unsigned d3, d2, d1, d0; - d1 = (q>>4) & 0xf; - d2 = (q>>8) & 0xf; - d3 = (q>>12); + unsigned q; + + /* Copy of previous function's body with added early returns */ + q = (r * (uint64_t)0x1999999a) >> 32; + *buf++ = (r - 10 * q) + '0'; /* 2 */ + if (q == 0) + return buf; + r = (q * (uint64_t)0x1999999a) >> 32; + *buf++ = (q - 10 * r) + '0'; /* 3 */ + if (r == 0) + return buf; + q = (r * (uint64_t)0x1999999a) >> 32; + *buf++ = (r - 10 * q) + '0'; /* 4 */ + if (q == 0) + return buf; + r = (q * (uint64_t)0x1999999a) >> 32; + *buf++ = (q - 10 * r) + '0'; /* 5 */ + if (r == 0) + return buf; + q = (r * 0x199a) >> 16; + *buf++ = (r - 10 * q) + '0'; /* 6 */ + if (q == 0) + return buf; + r = (q * 0xcd) >> 11; + *buf++ = (q - 10 * r) + '0'; /* 7 */ + if (r == 0) + return buf; + q = (r * 0xcd) >> 11; + *buf++ = (r - 10 * q) + '0'; /* 8 */ + if (q == 0) + return buf; + *buf++ = q + '0'; /* 9 */ + return buf; +} - /* - * Possible ways to approx. divide by 10 - * gcc -O2 replaces multiply with shifts and adds - * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386) - * (x * 0x67) >> 10: 1100111 - * (x * 0x34) >> 9: 110100 - same - * (x * 0x1a) >> 8: 11010 - same - * (x * 0x0d) >> 7: 1101 - same, shortest code (on i386) - */ - d0 = 6*(d3 + d2 + d1) + (q & 0xf); - q = (d0 * 0xcd) >> 11; - d0 = d0 - 10*q; - *buf++ = d0 + '0'; - d1 = q + 9*d3 + 5*d2 + d1; - q = (d1 * 0xcd) >> 11; - d1 = d1 - 10*q; - *buf++ = d1 + '0'; - - d2 = q + 2*d2; - q = (d2 * 0xd) >> 7; - d2 = d2 - 10*q; - *buf++ = d2 + '0'; - - d3 = q + 4*d3; - q = (d3 * 0xcd) >> 11; /* - shorter code */ - /* q = (d3 * 0x67) >> 10; - would also work */ - d3 = d3 - 10*q; - *buf++ = d3 + '0'; - *buf++ = q + '0'; +/* There are two algorithms to print larger numbers. + * One is generic: divide by 1000000000 and repeatedly print + * groups of (up to) 9 digits. It's conceptually simple, + * but requires a (unsigned long long) / 1000000000 division. + * + * Second algorithm splits 64-bit unsigned long long into 16-bit chunks, + * manipulates them cleverly and generates groups of 4 decimal digits. + * It so happens that it does NOT require long long division. + * + * If long is > 32 bits, division of 64-bit values is relatively easy, + * and we will use the first algorithm. + * If long long is > 64 bits (strange architecture with VERY large long long), + * second algorithm can't be used, and we again use the first one. + * + * Else (if long is 32 bits and long long is 64 bits) we use second one. + */ - return buf; +#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64 + +/* First algorithm: generic */ + +static +char *put_dec(char *buf, unsigned long long n) +{ + if (n >= 100*1000*1000) { + while (n >= 1000*1000*1000) + buf = put_dec_full9(buf, do_div(n, 1000*1000*1000)); + if (n >= 100*1000*1000) + return put_dec_full9(buf, n); + } + return put_dec_trunc8(buf, n); } -/* No inlining helps gcc to use registers better */ + +#else + +/* Second algorithm: valid only for 64-bit long longs */ + static noinline_for_stack -char *put_dec(char *buf, unsigned long long num) +char *put_dec_full4(char *buf, unsigned q) { - while (1) { - unsigned rem; - if (num < 100000) - return put_dec_trunc(buf, num); - rem = do_div(num, 100000); - buf = put_dec_full(buf, rem); - } + unsigned r; + r = (q * 0xcccd) >> 19; + *buf++ = (q - 10 * r) + '0'; + q = (r * 0x199a) >> 16; + *buf++ = (r - 10 * q) + '0'; + r = (q * 0xcd) >> 11; + *buf++ = (q - 10 * r) + '0'; + *buf++ = r + '0'; + return buf; +} + +/* Based on code by Douglas W. Jones found at + * + * (with permission from the author). + * Performs no 64-bit division and hence should be fast on 32-bit machines. + */ +static +char *put_dec(char *buf, unsigned long long n) +{ + uint32_t d3, d2, d1, q, h; + + if (n < 100*1000*1000) + return put_dec_trunc8(buf, n); + + d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */ + h = (n >> 32); + d2 = (h ) & 0xffff; + d3 = (h >> 16); /* implicit "& 0xffff" */ + + q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); + + buf = put_dec_full4(buf, q % 10000); + q = q / 10000; + + d1 = q + 7671 * d3 + 9496 * d2 + 6 * d1; + buf = put_dec_full4(buf, d1 % 10000); + q = d1 / 10000; + + d2 = q + 4749 * d3 + 42 * d2; + buf = put_dec_full4(buf, d2 % 10000); + q = d2 / 10000; + + d3 = q + 281 * d3; + if (!d3) + goto done; + buf = put_dec_full4(buf, d3 % 10000); + q = d3 / 10000; + if (!q) + goto done; + buf = put_dec_full4(buf, q); + done: + while (buf[-1] == '0') + --buf; + + return buf; } +#endif + /* * Convert passed number to decimal string. * Returns the length of string. On buffer overflow, returns 0. @@ -220,16 +313,22 @@ char *put_dec(char *buf, unsigned long long num) */ int num_to_str(char *buf, int size, unsigned long long num) { - char tmp[21]; /* Enough for 2^64 in decimal */ + char tmp[sizeof(num) * 3]; int idx, len; - len = put_dec(tmp, num) - tmp; + /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ + if (num <= 9) { + tmp[0] = '0' + num; + len = 1; + } else { + len = put_dec(tmp, num) - tmp; + } if (len > size) return 0; for (idx = 0; idx < len; ++idx) buf[idx] = tmp[len - idx - 1]; - return len; + return len; } #define ZEROPAD 1 /* pad with zero */ @@ -314,8 +413,8 @@ char *number(char *buf, char *end, unsigned long long num, /* generate full string in tmp[], in reverse order */ i = 0; - if (num == 0) - tmp[i++] = '0'; + if (num < spec.base) + tmp[i++] = digits[num] | locase; /* Generic code, for any base: else do { tmp[i++] = (digits[do_div(num,base)] | locase); @@ -611,7 +710,7 @@ char *ip4_string(char *p, const u8 *addr, const char *fmt) } for (i = 0; i < 4; i++) { char temp[3]; /* hold each IP quad in reverse order */ - int digits = put_dec_trunc(temp, addr[index]) - temp; + int digits = put_dec_trunc8(temp, addr[index]) - temp; if (leading_zeros) { if (digits < 3) *p++ = '0'; -- cgit v1.3-14-g43fede From fffaee365fded09f9ebf2db19066065fa54323c3 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Tue, 5 Jun 2012 21:36:33 +0400 Subject: radix-tree: fix contiguous iterator MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch fixes bug in macro radix_tree_for_each_contig(). If radix_tree_next_slot() sees NULL in next slot it returns NULL, but following radix_tree_next_chunk() switches iterating into next chunk. As result iterating becomes non-contiguous and breaks vfs "splice" and all its users. Signed-off-by: Konstantin Khlebnikov Reported-and-bisected-by: Hans de Bruin Reported-and-bisected-by: Ondrej Zary Reported-bisected-and-tested-by: Toralf Förster Link: https://lkml.org/lkml/2012/6/5/64 Cc: stable # 3.4.x Signed-off-by: Linus Torvalds --- include/linux/radix-tree.h | 5 ++++- lib/radix-tree.c | 3 +++ 2 files changed, 7 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index 0d04cd69ab9b..ffc444c38b0a 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -368,8 +368,11 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags) iter->index++; if (likely(*slot)) return slot; - if (flags & RADIX_TREE_ITER_CONTIG) + if (flags & RADIX_TREE_ITER_CONTIG) { + /* forbid switching to the next chunk */ + iter->next_index = 0; break; + } } } return NULL; diff --git a/lib/radix-tree.c b/lib/radix-tree.c index d7c878cc006c..e7964296fd50 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -686,6 +686,9 @@ void **radix_tree_next_chunk(struct radix_tree_root *root, * during iterating; it can be zero only at the beginning. * And we cannot overflow iter->next_index in a single step, * because RADIX_TREE_MAP_SHIFT < BITS_PER_LONG. + * + * This condition also used by radix_tree_next_slot() to stop + * contiguous iterating, and forbid swithing to the next chunk. */ index = iter->next_index; if (!index && iter->index) -- cgit v1.3-14-g43fede From 8a173b1476d126674104c7c5c6cef0bcd824b001 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Tue, 29 May 2012 11:18:44 +0200 Subject: spinlock: Indicate that a lockup is only suspected On an over-committed KVM system we got a: "BUG: spinlock lockup on CPU#2, swapper/2/0" message on the heavily contended virtio blk spinlock. While we might want to reconsider the locking of virtio-blk (lock is held while switching to the host) this patch tries to make the message clearer: the lockup is only suspected. Signed-off-by: Christian Borntraeger Cc: Rusty Russell Cc: Michael S. Tsirkin Cc: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1338283124-7063-1-git-send-email-borntraeger@de.ibm.com Signed-off-by: Ingo Molnar --- lib/spinlock_debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c index d0ec4f3d1593..e91fbc23fff1 100644 --- a/lib/spinlock_debug.c +++ b/lib/spinlock_debug.c @@ -118,7 +118,7 @@ static void __spin_lock_debug(raw_spinlock_t *lock) /* lockup suspected: */ if (print_once) { print_once = 0; - spin_dump(lock, "lockup"); + spin_dump(lock, "lockup suspected"); #ifdef CONFIG_SMP trigger_all_cpu_backtrace(); #endif -- cgit v1.3-14-g43fede From cbf8ae32f66a9ceb8907ad9e16663c2a29e48990 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Thu, 7 Jun 2012 14:21:13 -0700 Subject: btree: fix tree corruption in btree_get_prev() The memory the parameter __key points to is used as an iterator in btree_get_prev(), so if we save off a bkey() pointer in retry_key and then assign that to __key, we'll end up corrupting the btree internals when we do eg longcpy(__key, bkey(geo, node, i), geo->keylen); to return the key value. What we should do instead is use longcpy() to copy the key value that retry_key points to __key. This can cause a btree to get corrupted by seemingly read-only operations such as btree_for_each_safe. [akpm@linux-foundation.org: avoid the double longcpy()] Signed-off-by: Roland Dreier Acked-by: Joern Engel Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/btree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/btree.c b/lib/btree.c index e5ec1e9c1aa5..5cf9e74ec3f3 100644 --- a/lib/btree.c +++ b/lib/btree.c @@ -319,8 +319,8 @@ void *btree_get_prev(struct btree_head *head, struct btree_geo *geo, if (head->height == 0) return NULL; -retry: longcpy(key, __key, geo->keylen); +retry: dec_key(geo, key); node = head->node; @@ -351,7 +351,7 @@ retry: } miss: if (retry_key) { - __key = retry_key; + longcpy(key, retry_key, geo->keylen); retry_key = NULL; goto retry; } -- cgit v1.3-14-g43fede From 39caa0916ef27cf1da5026eb708a2b8413156f75 Mon Sep 17 00:00:00 2001 From: Joern Engel Date: Thu, 7 Jun 2012 14:21:14 -0700 Subject: btree: catch NULL value before it does harm Storing NULL values in the btree is illegal and can lead to memory corruption and possible other fun as well. Catch it on insert, instead of waiting for the inevitable. Signed-off-by: Joern Engel Signed-off-by: Roland Dreier Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/btree.c | 1 + 1 file changed, 1 insertion(+) (limited to 'lib') diff --git a/lib/btree.c b/lib/btree.c index 5cf9e74ec3f3..f9a484676cb6 100644 --- a/lib/btree.c +++ b/lib/btree.c @@ -509,6 +509,7 @@ retry: int btree_insert(struct btree_head *head, struct btree_geo *geo, unsigned long *key, void *val, gfp_t gfp) { + BUG_ON(!val); return btree_insert_level(head, geo, key, val, 1, gfp); } EXPORT_SYMBOL_GPL(btree_insert); -- cgit v1.3-14-g43fede From f39cdaebb89dc3e6dd4f3e75b6d4e87ef12190af Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Wed, 20 Jun 2012 12:53:03 -0700 Subject: fault-inject: avoid call to random32() if fault injection is disabled After enabling CONFIG_FAILSLAB I noticed random32 in profiles even if slub fault injection wasn't enabled at runtime. should_fail forces a comparison against random32() even if probability is 0: if (attr->probability <= random32() % 100) return false; Add a check up front for probability == 0 and avoid all of the more complicated checks. Signed-off-by: Anton Blanchard Acked-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/fault-inject.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'lib') diff --git a/lib/fault-inject.c b/lib/fault-inject.c index 6805453c18e7..f7210ad6cffd 100644 --- a/lib/fault-inject.c +++ b/lib/fault-inject.c @@ -101,6 +101,10 @@ static inline bool fail_stacktrace(struct fault_attr *attr) bool should_fail(struct fault_attr *attr, ssize_t size) { + /* No need to check any other properties if the probability is 0 */ + if (attr->probability == 0) + return false; + if (attr->task_filter && !fail_task(attr, current)) return false; -- cgit v1.3-14-g43fede