From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- lib/raid/raid6/powerpc/altivec.uc | 110 +++++++++++++++++++++++++++++++++++++ lib/raid/raid6/powerpc/pq_arch.h | 32 +++++++++++ lib/raid/raid6/powerpc/vpermxor.uc | 82 +++++++++++++++++++++++++++ 3 files changed, 224 insertions(+) create mode 100644 lib/raid/raid6/powerpc/altivec.uc create mode 100644 lib/raid/raid6/powerpc/pq_arch.h create mode 100644 lib/raid/raid6/powerpc/vpermxor.uc (limited to 'lib/raid/raid6/powerpc') diff --git a/lib/raid/raid6/powerpc/altivec.uc b/lib/raid/raid6/powerpc/altivec.uc new file mode 100644 index 000000000..c5429fb71 --- /dev/null +++ b/lib/raid/raid6/powerpc/altivec.uc @@ -0,0 +1,110 @@ +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright 2002-2004 H. Peter Anvin - All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, Inc., 53 Temple Place Ste 330, + * Boston MA 02111-1307, USA; either version 2 of the License, or + * (at your option) any later version; incorporated herein by reference. + * + * ----------------------------------------------------------------------- */ + +/* + * raid6altivec$#.c + * + * $#-way unrolled portable integer math RAID-6 instruction set + * + * This file is postprocessed using unroll.awk + * + * hpa: in process, + * you can just "steal" the vec unit with enable_kernel_altivec() (but + * bracked this with preempt_disable/enable or in a lock) + */ + +#include "algos.h" + +#include +#include +#include + +/* + * This is the C data type to use. We use a vector of + * signed char so vec_cmpgt() will generate the right + * instruction. + */ + +typedef vector signed char unative_t; + +#define NBYTES(x) ((vector signed char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x}) +#define NSIZE sizeof(unative_t) + +/* + * The SHLBYTE() operation shifts each byte left by 1, *not* + * rolling over into the next byte + */ +static inline __attribute_const__ unative_t SHLBYTE(unative_t v) +{ + return vec_add(v,v); +} + +/* + * The MASK() operation returns 0xFF in any byte for which the high + * bit is 1, 0x00 for any byte for which the high bit is 0. + */ +static inline __attribute_const__ unative_t MASK(unative_t v) +{ + unative_t zv = NBYTES(0); + + /* vec_cmpgt returns a vector bool char; thus the need for the cast */ + return (unative_t)vec_cmpgt(zv, v); +} + + +/* This is noinline to make damned sure that gcc doesn't move any of the + Altivec code around the enable/disable code */ +static void noinline +raid6_altivec$#_gen_syndrome_real(int disks, size_t bytes, void **ptrs) +{ + u8 **dptr = (u8 **)ptrs; + u8 *p, *q; + int d, z, z0; + + unative_t wd$$, wq$$, wp$$, w1$$, w2$$; + unative_t x1d = NBYTES(0x1d); + + z0 = disks - 3; /* Highest data disk */ + p = dptr[z0+1]; /* XOR parity */ + q = dptr[z0+2]; /* RS syndrome */ + + for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { + wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; + for ( z = z0-1 ; z >= 0 ; z-- ) { + wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; + wp$$ = vec_xor(wp$$, wd$$); + w2$$ = MASK(wq$$); + w1$$ = SHLBYTE(wq$$); + w2$$ = vec_and(w2$$, x1d); + w1$$ = vec_xor(w1$$, w2$$); + wq$$ = vec_xor(w1$$, wd$$); + } + *(unative_t *)&p[d+NSIZE*$$] = wp$$; + *(unative_t *)&q[d+NSIZE*$$] = wq$$; + } +} + +static void raid6_altivec$#_gen_syndrome(int disks, size_t bytes, void **ptrs) +{ + preempt_disable(); + enable_kernel_altivec(); + + raid6_altivec$#_gen_syndrome_real(disks, bytes, ptrs); + + disable_kernel_altivec(); + preempt_enable(); +} + +const struct raid6_calls raid6_altivec$# = { + .gen_syndrome = raid6_altivec$#_gen_syndrome, + .name = "altivecx$#", +}; diff --git a/lib/raid/raid6/powerpc/pq_arch.h b/lib/raid/raid6/powerpc/pq_arch.h new file mode 100644 index 000000000..ea1878777 --- /dev/null +++ b/lib/raid/raid6/powerpc/pq_arch.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#include + +extern const struct raid6_calls raid6_altivec1; +extern const struct raid6_calls raid6_altivec2; +extern const struct raid6_calls raid6_altivec4; +extern const struct raid6_calls raid6_altivec8; +extern const struct raid6_calls raid6_vpermxor1; +extern const struct raid6_calls raid6_vpermxor2; +extern const struct raid6_calls raid6_vpermxor4; +extern const struct raid6_calls raid6_vpermxor8; + +static __always_inline void __init arch_raid6_init(void) +{ + raid6_algo_add_default(); + + /* This assumes either all CPUs have Altivec or none does */ + if (cpu_has_feature(CPU_FTR_ALTIVEC)) { + raid6_algo_add(&raid6_altivec1); + raid6_algo_add(&raid6_altivec2); + raid6_algo_add(&raid6_altivec4); + raid6_algo_add(&raid6_altivec8); + } + if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP) && + cpu_has_feature(CPU_FTR_ARCH_207S)) { + raid6_algo_add(&raid6_vpermxor1); + raid6_algo_add(&raid6_vpermxor2); + raid6_algo_add(&raid6_vpermxor4); + raid6_algo_add(&raid6_vpermxor8); + } +} diff --git a/lib/raid/raid6/powerpc/vpermxor.uc b/lib/raid/raid6/powerpc/vpermxor.uc new file mode 100644 index 000000000..e8964361a --- /dev/null +++ b/lib/raid/raid6/powerpc/vpermxor.uc @@ -0,0 +1,82 @@ +/* + * Copyright 2017, Matt Brown, IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * vpermxor$#.c + * + * Based on H. Peter Anvin's paper - The mathematics of RAID-6 + * + * $#-way unrolled portable integer math RAID-6 instruction set + * This file is postprocessed using unroll.awk + * + * vpermxor$#.c makes use of the vpermxor instruction to optimise the RAID6 Q + * syndrome calculations. + * This can be run on systems which have both Altivec and vpermxor instruction. + * + * This instruction was introduced in POWER8 - ISA v2.07. + */ + +#include +#include +#include +#include +#include "algos.h" + +typedef vector unsigned char unative_t; +#define NSIZE sizeof(unative_t) + +static const vector unsigned char gf_low = {0x1e, 0x1c, 0x1a, 0x18, 0x16, 0x14, + 0x12, 0x10, 0x0e, 0x0c, 0x0a, 0x08, + 0x06, 0x04, 0x02,0x00}; +static const vector unsigned char gf_high = {0xfd, 0xdd, 0xbd, 0x9d, 0x7d, 0x5d, + 0x3d, 0x1d, 0xe0, 0xc0, 0xa0, 0x80, + 0x60, 0x40, 0x20, 0x00}; + +static void noinline raid6_vpermxor$#_gen_syndrome_real(int disks, size_t bytes, + void **ptrs) +{ + u8 **dptr = (u8 **)ptrs; + u8 *p, *q; + int d, z, z0; + unative_t wp$$, wq$$, wd$$; + + z0 = disks - 3; /* Highest data disk */ + p = dptr[z0+1]; /* XOR parity */ + q = dptr[z0+2]; /* RS syndrome */ + + for (d = 0; d < bytes; d += NSIZE*$#) { + wp$$ = wq$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; + + for (z = z0-1; z>=0; z--) { + wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; + /* P syndrome */ + wp$$ = vec_xor(wp$$, wd$$); + + /* Q syndrome */ + asm(VPERMXOR(%0,%1,%2,%3):"=v"(wq$$):"v"(gf_high), "v"(gf_low), "v"(wq$$)); + wq$$ = vec_xor(wq$$, wd$$); + } + *(unative_t *)&p[d+NSIZE*$$] = wp$$; + *(unative_t *)&q[d+NSIZE*$$] = wq$$; + } +} + +static void raid6_vpermxor$#_gen_syndrome(int disks, size_t bytes, void **ptrs) +{ + preempt_disable(); + enable_kernel_altivec(); + + raid6_vpermxor$#_gen_syndrome_real(disks, bytes, ptrs); + + disable_kernel_altivec(); + preempt_enable(); +} + +const struct raid6_calls raid6_vpermxor$# = { + .gen_syndrome = raid6_vpermxor$#_gen_syndrome, + .name = "vpermxor$#", +}; -- cgit v1.3.1