From 54ce1927eb787f7bbb7ee664841c8f5932703f39 Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Wed, 31 Jan 2024 15:55:38 -0800 Subject: cxl/cper: Fix errant CPER prints for CXL events Jonathan reports that CXL CPER events dump an extra generic error message. {1}[Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 1 {1}[Hardware Error]: event severity: recoverable {1}[Hardware Error]: Error 0, type: recoverable {1}[Hardware Error]: section type: unknown, fbcd0a77-c260-417f-85a9-088b1621eba6 {1}[Hardware Error]: section length: 0x90 {1}[Hardware Error]: 00000000: 00000090 00000007 00000000 0d938086 ................ {1}[Hardware Error]: 00000010: 00100000 00000000 00040000 00000000 ................ ... CXL events were rerouted though the CXL subsystem for additional processing. However, when that work was done it was missed that cper_estatus_print_section() continued with a generic error message which is confusing. Teach CPER print code to ignore printing details of some section types. Assign the CXL event GUIDs to this set to prevent confusing unknown prints. Reported-by: Jonathan Cameron Suggested-by: Jonathan Cameron Signed-off-by: Ira Weiny Reviewed-by: Dave Jiang Reviewed-by: Jonathan Cameron Reviewed-by: Alison Schofield Signed-off-by: Ard Biesheuvel --- include/linux/cper.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'include/linux') diff --git a/include/linux/cper.h b/include/linux/cper.h index c1a7dc325121..265b0f8fc0b3 100644 --- a/include/linux/cper.h +++ b/include/linux/cper.h @@ -90,6 +90,29 @@ enum { GUID_INIT(0x667DD791, 0xC6B3, 0x4c27, 0x8A, 0x6B, 0x0F, 0x8E, \ 0x72, 0x2D, 0xEB, 0x41) +/* CXL Event record UUIDs are formatted as GUIDs and reported in section type */ +/* + * General Media Event Record + * CXL rev 3.0 Section 8.2.9.2.1.1; Table 8-43 + */ +#define CPER_SEC_CXL_GEN_MEDIA_GUID \ + GUID_INIT(0xfbcd0a77, 0xc260, 0x417f, \ + 0x85, 0xa9, 0x08, 0x8b, 0x16, 0x21, 0xeb, 0xa6) +/* + * DRAM Event Record + * CXL rev 3.0 section 8.2.9.2.1.2; Table 8-44 + */ +#define CPER_SEC_CXL_DRAM_GUID \ + GUID_INIT(0x601dcbb3, 0x9c06, 0x4eab, \ + 0xb8, 0xaf, 0x4e, 0x9b, 0xfb, 0x5c, 0x96, 0x24) +/* + * Memory Module Event Record + * CXL rev 3.0 section 8.2.9.2.1.3; Table 8-45 + */ +#define CPER_SEC_CXL_MEM_MODULE_GUID \ + GUID_INIT(0xfe927475, 0xdd59, 0x4339, \ + 0xa5, 0x86, 0x79, 0xba, 0xb1, 0x13, 0xb7, 0x74) + /* * Flags bits definitions for flags in struct cper_record_header * If set, the error has been recovered -- cgit v1.2.3 From dad6a09f3148257ac1773cd90934d721d68ab595 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 29 Jan 2024 15:56:36 -0800 Subject: hrtimer: Report offline hrtimer enqueue The hrtimers migration on CPU-down hotplug process has been moved earlier, before the CPU actually goes to die. This leaves a small window of opportunity to queue an hrtimer in a blind spot, leaving it ignored. For example a practical case has been reported with RCU waking up a SCHED_FIFO task right before the CPUHP_AP_IDLE_DEAD stage, queuing that way a sched/rt timer to the local offline CPU. Make sure such situations never go unnoticed and warn when that happens. Fixes: 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier") Reported-by: Paul E. McKenney Signed-off-by: Frederic Weisbecker Signed-off-by: Paul E. McKenney Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240129235646.3171983-4-boqun.feng@gmail.com --- include/linux/hrtimer.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 87e3bedf8eb0..641c4567cfa7 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -157,6 +157,7 @@ enum hrtimer_base_type { * @max_hang_time: Maximum time spent in hrtimer_interrupt * @softirq_expiry_lock: Lock which is taken while softirq based hrtimer are * expired + * @online: CPU is online from an hrtimers point of view * @timer_waiters: A hrtimer_cancel() invocation waits for the timer * callback to finish. * @expires_next: absolute time of the next event, is required for remote @@ -179,7 +180,8 @@ struct hrtimer_cpu_base { unsigned int hres_active : 1, in_hrtirq : 1, hang_detected : 1, - softirq_activated : 1; + softirq_activated : 1, + online : 1; #ifdef CONFIG_HIGH_RES_TIMERS unsigned int nr_events; unsigned short nr_retries; -- cgit v1.2.3 From 853b8d7597eea4ccaaefbcf0942cd42fc86d542a Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Fri, 2 Feb 2024 12:22:58 +0200 Subject: remap_range: merge do_clone_file_range() into vfs_clone_file_range() commit dfad37051ade ("remap_range: move permission hooks out of do_clone_file_range()") moved the permission hooks from do_clone_file_range() out to its caller vfs_clone_file_range(), but left all the fast sanity checks in do_clone_file_range(). This makes the expensive security hooks be called in situations that they would not have been called before (e.g. fs does not support clone). The only reason for the do_clone_file_range() helper was that overlayfs did not use to be able to call vfs_clone_file_range() from copy up context with sb_writers lock held. However, since commit c63e56a4a652 ("ovl: do not open/llseek lower file with upper sb_writers held"), overlayfs just uses an open coded version of vfs_clone_file_range(). Merge_clone_file_range() into vfs_clone_file_range(), restoring the original order of checks as it was before the regressing commit and adapt the overlayfs code to call vfs_clone_file_range() before the permission hooks that were added by commit ca7ab482401c ("ovl: add permission hooks outside of do_splice_direct()"). Note that in the merge of do_clone_file_range(), the file_start_write() context was reduced to cover ->remap_file_range() without holding it over the permission hooks, which was the reason for doing the regressing commit in the first place. Reported-and-tested-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202401312229.eddeb9a6-oliver.sang@intel.com Fixes: dfad37051ade ("remap_range: move permission hooks out of do_clone_file_range()") Signed-off-by: Amir Goldstein Link: https://lore.kernel.org/r/20240202102258.1582671-1-amir73il@gmail.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/fs.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index ed5966a70495..023f37c60709 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2101,9 +2101,6 @@ int __generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, loff_t *count, unsigned int remap_flags); -extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - loff_t len, unsigned int remap_flags); extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, loff_t len, unsigned int remap_flags); -- cgit v1.2.3 From f814bdda774c183b0cc15ec8f3b6e7c6f4527ba5 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 23 Jan 2024 18:58:26 +0100 Subject: blk-wbt: Fix detection of dirty-throttled tasks The detection of dirty-throttled tasks in blk-wbt has been subtly broken since its beginning in 2016. Namely if we are doing cgroup writeback and the throttled task is not in the root cgroup, balance_dirty_pages() will set dirty_sleep for the non-root bdi_writeback structure. However blk-wbt checks dirty_sleep only in the root cgroup bdi_writeback structure. Thus detection of recently throttled tasks is not working in this case (we noticed this when we switched to cgroup v2 and suddently writeback was slow). Since blk-wbt has no easy way to get to proper bdi_writeback and furthermore its intention has always been to work on the whole device rather than on individual cgroups, just move the dirty_sleep timestamp from bdi_writeback to backing_dev_info. That fixes the checking for recently throttled task and saves memory for everybody as a bonus. CC: stable@vger.kernel.org Fixes: b57d74aff9ab ("writeback: track if we're sleeping on progress in balance_dirty_pages()") Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20240123175826.21452-1-jack@suse.cz [axboe: fixup indentation errors] Signed-off-by: Jens Axboe --- include/linux/backing-dev-defs.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index ae12696ec492..2ad261082bba 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -141,8 +141,6 @@ struct bdi_writeback { struct delayed_work dwork; /* work item used for writeback */ struct delayed_work bw_dwork; /* work item used for bandwidth estimate */ - unsigned long dirty_sleep; /* last wait */ - struct list_head bdi_node; /* anchored at bdi->wb_list */ #ifdef CONFIG_CGROUP_WRITEBACK @@ -179,6 +177,11 @@ struct backing_dev_info { * any dirty wbs, which is depended upon by bdi_has_dirty(). */ atomic_long_t tot_write_bandwidth; + /* + * Jiffies when last process was dirty throttled on this bdi. Used by + * blk-wbt. + */ + unsigned long last_bdp_sleep; struct bdi_writeback wb; /* the root writeback info for this bdi */ struct list_head wb_list; /* list of all wbs */ -- cgit v1.2.3 From cd7d469c25704d414d71bf3644f163fb74e7996b Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Fri, 13 Oct 2023 13:55:44 +0800 Subject: libceph: fail sparse-read if the data length doesn't match Once this happens that means there have bugs. Signed-off-by: Xiubo Li Reviewed-by: Jeff Layton Signed-off-by: Ilya Dryomov --- include/linux/ceph/osd_client.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h index fa018d5864e7..f66f6aac74f6 100644 --- a/include/linux/ceph/osd_client.h +++ b/include/linux/ceph/osd_client.h @@ -45,6 +45,7 @@ enum ceph_sparse_read_state { CEPH_SPARSE_READ_HDR = 0, CEPH_SPARSE_READ_EXTENTS, CEPH_SPARSE_READ_DATA_LEN, + CEPH_SPARSE_READ_DATA_PRE, CEPH_SPARSE_READ_DATA, }; @@ -64,7 +65,7 @@ struct ceph_sparse_read { u64 sr_req_len; /* orig request length */ u64 sr_pos; /* current pos in buffer */ int sr_index; /* current extent index */ - __le32 sr_datalen; /* length of actual data */ + u32 sr_datalen; /* length of actual data */ u32 sr_count; /* extent count in reply */ int sr_ext_len; /* length of extent array */ struct ceph_sparse_extent *sr_extent; /* extent array */ -- cgit v1.2.3 From 8e46a2d068c92a905d01cbb018b00d66991585ab Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Thu, 14 Dec 2023 16:01:03 +0800 Subject: libceph: just wait for more data to be available on the socket A short read may occur while reading the message footer from the socket. Later, when the socket is ready for another read, the messenger invokes all read_partial_*() handlers, including read_partial_sparse_msg_data(). The expectation is that read_partial_sparse_msg_data() would bail, allowing the messenger to invoke read_partial() for the footer and pick up where it left off. However read_partial_sparse_msg_data() violates that and ends up calling into the state machine in the OSD client. The sparse-read state machine assumes that it's a new op and interprets some piece of the footer as the sparse-read header and returns bogus extents/data length, etc. To determine whether read_partial_sparse_msg_data() should bail, let's reuse cursor->total_resid. Because once it reaches to zero that means all the extents and data have been successfully received in last read, else it could break out when partially reading any of the extents and data. And then osd_sparse_read() could continue where it left off. [ idryomov: changelog ] Link: https://tracker.ceph.com/issues/63586 Fixes: d396f89db39a ("libceph: add sparse read support to msgr1") Signed-off-by: Xiubo Li Reviewed-by: Jeff Layton Signed-off-by: Ilya Dryomov --- include/linux/ceph/messenger.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h index 2eaaabbe98cb..1717cc57cdac 100644 --- a/include/linux/ceph/messenger.h +++ b/include/linux/ceph/messenger.h @@ -283,7 +283,7 @@ struct ceph_msg { struct kref kref; bool more_to_follow; bool needs_out_seq; - bool sparse_read; + u64 sparse_read_total; int front_alloc_len; struct ceph_msgpool *pool; -- cgit v1.2.3 From 4356e9f841f7fbb945521cef3577ba394c65f3fc Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 9 Feb 2024 12:39:31 -0800 Subject: work around gcc bugs with 'asm goto' with outputs We've had issues with gcc and 'asm goto' before, and we created a 'asm_volatile_goto()' macro for that in the past: see commits 3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation bug") and a9f180345f53 ("compiler/gcc4: Make quirk for asm_volatile_goto() unconditional"). Then, much later, we ended up removing the workaround in commit 43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR 58670") because we no longer supported building the kernel with the affected gcc versions, but we left the macro uses around. Now, Sean Christopherson reports a new version of a very similar problem, which is fixed by re-applying that ancient workaround. But the problem in question is limited to only the 'asm goto with outputs' cases, so instead of re-introducing the old workaround as-is, let's rename and limit the workaround to just that much less common case. It looks like there are at least two separate issues that all hit in this area: (a) some versions of gcc don't mark the asm goto as 'volatile' when it has outputs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420 which is easy to work around by just adding the 'volatile' by hand. (b) Internal compiler errors: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422 which are worked around by adding the extra empty 'asm' as a barrier, as in the original workaround. but the problem Sean sees may be a third thing since it involves bad code generation (not an ICE) even with the manually added 'volatile'. but the same old workaround works for this case, even if this feels a bit like voodoo programming and may only be hiding the issue. Reported-and-tested-by: Sean Christopherson Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/ Cc: Nick Desaulniers Cc: Uros Bizjak Cc: Jakub Jelinek Cc: Andrew Pinski Signed-off-by: Linus Torvalds --- include/linux/compiler-gcc.h | 19 +++++++++++++++++++ include/linux/compiler_types.h | 4 ++-- 2 files changed, 21 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index aebb65bf95a7..c1a963be7d28 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -64,6 +64,25 @@ __builtin_unreachable(); \ } while (0) +/* + * GCC 'asm goto' with outputs miscompiles certain code sequences: + * + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420 + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422 + * + * Work it around via the same compiler barrier quirk that we used + * to use for the old 'asm goto' workaround. + * + * Also, always mark such 'asm goto' statements as volatile: all + * asm goto statements are supposed to be volatile as per the + * documentation, but some versions of gcc didn't actually do + * that for asms with outputs: + * + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 + */ +#define asm_goto_output(x...) \ + do { asm volatile goto(x); asm (""); } while (0) + #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) #define __HAVE_BUILTIN_BSWAP32__ #define __HAVE_BUILTIN_BSWAP64__ diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 6f1ca49306d2..663d8791c871 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -362,8 +362,8 @@ struct ftrace_likely_data { #define __member_size(p) __builtin_object_size(p, 1) #endif -#ifndef asm_volatile_goto -#define asm_volatile_goto(x...) asm goto(x) +#ifndef asm_goto_output +#define asm_goto_output(x...) asm goto(x) #endif #ifdef CONFIG_CC_HAS_ASM_INLINE -- cgit v1.2.3 From 119ff04864a24470b1e531bb53e5c141aa8fefb0 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 8 Feb 2024 14:43:21 +0000 Subject: tcp: move tp->scaling_ratio to tcp_sock_read_txrx group tp->scaling_ratio is a read mostly field, used in rx and tx fast paths. Fixes: d5fed5addb2b ("tcp: reorganize tcp_sock fast path variables") Signed-off-by: Eric Dumazet Cc: Coco Li Cc: Wei Wang Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- include/linux/tcp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 89b290d8c8dc..168f5dca6609 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -221,6 +221,7 @@ struct tcp_sock { u32 lost_out; /* Lost packets */ u32 sacked_out; /* SACK'd packets */ u16 tcp_header_len; /* Bytes of tcp header to send */ + u8 scaling_ratio; /* see tcp_win_from_space() */ u8 chrono_type : 2, /* current chronograph type */ repair : 1, is_sack_reneg:1, /* in recovery from loss with SACK reneg? */ @@ -352,7 +353,6 @@ struct tcp_sock { u32 compressed_ack_rcv_nxt; struct list_head tsq_node; /* anchor in tsq_tasklet.head list */ - u8 scaling_ratio; /* see tcp_win_from_space() */ /* Information of the most recently (s)acked skb */ struct tcp_rack { u64 mstamp; /* (Re)sent time of the skb */ -- cgit v1.2.3 From 666a877deab2bcf8fd11c962d69e687e18168a6f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 8 Feb 2024 14:43:22 +0000 Subject: tcp: move tp->tcp_usec_ts to tcp_sock_read_txrx group tp->tcp_usec_ts is a read mostly field, used in rx and tx fast paths. Fixes: d5fed5addb2b ("tcp: reorganize tcp_sock fast path variables") Signed-off-by: Eric Dumazet Cc: Coco Li Cc: Wei Wang Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- include/linux/tcp.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 168f5dca6609..a1c47a6d69b0 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -224,6 +224,7 @@ struct tcp_sock { u8 scaling_ratio; /* see tcp_win_from_space() */ u8 chrono_type : 2, /* current chronograph type */ repair : 1, + tcp_usec_ts : 1, /* TSval values in usec */ is_sack_reneg:1, /* in recovery from loss with SACK reneg? */ is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */ __cacheline_group_end(tcp_sock_read_txrx); @@ -368,8 +369,7 @@ struct tcp_sock { u8 compressed_ack; u8 dup_ack_counter:2, tlp_retrans:1, /* TLP is a retransmission */ - tcp_usec_ts:1, /* TSval values in usec */ - unused:4; + unused:5; u8 thin_lto : 1,/* Use linear timeouts for thin streams */ recvmsg_inq : 1,/* Indicate # of bytes in queue upon recvmsg */ fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */ -- cgit v1.2.3 From c353c7b7ffb7ae6ed8f3339906fe33c8be6cf344 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 8 Feb 2024 14:43:23 +0000 Subject: net-device: move lstats in net_device_read_txrx dev->lstats is notably used from loopback ndo_start_xmit() and other virtual drivers. Per cpu stats updates are dirtying per-cpu data, but the pointer itself is read-only. Fixes: 43a71cd66b9c ("net-device: reorganize net_device fast path variables") Signed-off-by: Eric Dumazet Cc: Coco Li Cc: Simon Horman Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- include/linux/netdevice.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 118c40258d07..ef7bfbb98497 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2141,6 +2141,11 @@ struct net_device { /* TXRX read-mostly hotpath */ __cacheline_group_begin(net_device_read_txrx); + union { + struct pcpu_lstats __percpu *lstats; + struct pcpu_sw_netstats __percpu *tstats; + struct pcpu_dstats __percpu *dstats; + }; unsigned int flags; unsigned short hard_header_len; netdev_features_t features; @@ -2395,11 +2400,6 @@ struct net_device { enum netdev_ml_priv_type ml_priv_type; enum netdev_stat_type pcpu_stat_type:8; - union { - struct pcpu_lstats __percpu *lstats; - struct pcpu_sw_netstats __percpu *tstats; - struct pcpu_dstats __percpu *dstats; - }; #if IS_ENABLED(CONFIG_GARP) struct garp_port __rcu *garp_port; -- cgit v1.2.3 From 11ba1728be3edb6928791f4c622f154ebe228ae6 Mon Sep 17 00:00:00 2001 From: Jiaxun Yang Date: Fri, 2 Feb 2024 12:30:26 +0000 Subject: ptrace: Introduce exception_ip arch hook On architectures with delay slot, architecture level instruction pointer (or program counter) in pt_regs may differ from where exception was triggered. Introduce exception_ip hook to invoke architecture code and determine actual instruction pointer to the exception. Link: https://lore.kernel.org/lkml/00d1b813-c55f-4365-8d81-d70258e10b16@app.fastmail.com/ Signed-off-by: Jiaxun Yang Signed-off-by: Thomas Bogendoerfer --- include/linux/ptrace.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index eaaef3ffec22..90507d4afcd6 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -393,6 +393,10 @@ static inline void user_single_step_report(struct pt_regs *regs) #define current_user_stack_pointer() user_stack_pointer(current_pt_regs()) #endif +#ifndef exception_ip +#define exception_ip(x) instruction_pointer(x) +#endif + extern int task_current_syscall(struct task_struct *target, struct syscall_info *info); extern void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact); -- cgit v1.2.3 From 68fb3ca0e408e00db1c3f8fccdfa19e274c033be Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 15 Feb 2024 11:14:33 -0800 Subject: update workarounds for gcc "asm goto" issue In commit 4356e9f841f7 ("work around gcc bugs with 'asm goto' with outputs") I did the gcc workaround unconditionally, because the cause of the bad code generation wasn't entirely clear. In the meantime, Jakub Jelinek debugged the issue, and has come up with a fix in gcc [2], which also got backported to the still maintained branches of gcc-11, gcc-12 and gcc-13. Note that while the fix technically wasn't in the original gcc-14 branch, Jakub says: "while it is true that no GCC 14 snapshots until today (or whenever the fix will be committed) have the fix, for GCC trunk it is up to the distros to use the latest snapshot if they use it at all and would allow better testing of the kernel code without the workaround, so that if there are other issues they won't be discovered years later. Most userland code doesn't actually use asm goto with outputs..." so we will consider gcc-14 to be fixed - if somebody is using gcc snapshots of the gcc-14 before the fix, they should upgrade. Note that while the bug goes back to gcc-11, in practice other gcc changes seem to have effectively hidden it since gcc-12.1 as per a bisect by Jakub. So even a gcc-14 snapshot without the fix likely doesn't show actual problems. Also, make the default 'asm_goto_output()' macro mark the asm as volatile by hand, because of an unrelated gcc issue [1] where it doesn't match the documented behavior ("asm goto is always volatile"). Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 [1] Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 [2] Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/ Requested-by: Jakub Jelinek Cc: Uros Bizjak Cc: Nick Desaulniers Cc: Sean Christopherson Cc: Andrew Pinski Signed-off-by: Linus Torvalds --- include/linux/compiler-gcc.h | 7 ++++--- include/linux/compiler_types.h | 9 ++++++++- 2 files changed, 12 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index c1a963be7d28..75bd1692d2e3 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -67,10 +67,9 @@ /* * GCC 'asm goto' with outputs miscompiles certain code sequences: * - * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420 - * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422 + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 * - * Work it around via the same compiler barrier quirk that we used + * Work around it via the same compiler barrier quirk that we used * to use for the old 'asm goto' workaround. * * Also, always mark such 'asm goto' statements as volatile: all @@ -80,8 +79,10 @@ * * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 */ +#ifdef CONFIG_GCC_ASM_GOTO_OUTPUT_WORKAROUND #define asm_goto_output(x...) \ do { asm volatile goto(x); asm (""); } while (0) +#endif #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) #define __HAVE_BUILTIN_BSWAP32__ diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 663d8791c871..0caf354cb94b 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -362,8 +362,15 @@ struct ftrace_likely_data { #define __member_size(p) __builtin_object_size(p, 1) #endif +/* + * Some versions of gcc do not mark 'asm goto' volatile: + * + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 + * + * We do it here by hand, because it doesn't hurt. + */ #ifndef asm_goto_output -#define asm_goto_output(x...) asm goto(x) +#define asm_goto_output(x...) asm volatile goto(x) #endif #ifdef CONFIG_CC_HAS_ASM_INLINE -- cgit v1.2.3