From 27d3313807296c3943a96ceef8c2b7279cb56962 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 18 May 2024 19:39:59 +0200 Subject: Adding debian version 6.7.7-1. Signed-off-by: Daniel Baumann --- ...buffer-Skip-non-finalized-records-in-pani.patch | 67 ++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 debian/patches-rt/0010-printk-ringbuffer-Skip-non-finalized-records-in-pani.patch (limited to 'debian/patches-rt/0010-printk-ringbuffer-Skip-non-finalized-records-in-pani.patch') diff --git a/debian/patches-rt/0010-printk-ringbuffer-Skip-non-finalized-records-in-pani.patch b/debian/patches-rt/0010-printk-ringbuffer-Skip-non-finalized-records-in-pani.patch new file mode 100644 index 0000000000..a92123216f --- /dev/null +++ b/debian/patches-rt/0010-printk-ringbuffer-Skip-non-finalized-records-in-pani.patch @@ -0,0 +1,67 @@ +From: John Ogness +Date: Fri, 13 Oct 2023 10:23:11 +0000 +Subject: [PATCH 10/50] printk: ringbuffer: Skip non-finalized records in panic +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.7/older/patches-6.7-rt6.tar.xz + +Normally a reader will stop once reaching a non-finalized +record. However, when a panic happens, writers from other CPUs +(or an interrupted context on the panic CPU) may have been +writing a record and were unable to finalize it. The panic CPU +will reserve/commit/finalize its panic records, but these will +be located after the non-finalized records. This results in +panic() not flushing the panic messages. + +Extend _prb_read_valid() to skip over non-finalized records if +on the panic CPU. + +Fixes: 896fbe20b4e2 ("printk: use the lockless ringbuffer") +Signed-off-by: John Ogness +Signed-off-by: Sebastian Andrzej Siewior +--- + kernel/printk/printk_ringbuffer.c | 28 ++++++++++++++++++++++++++-- + 1 file changed, 26 insertions(+), 2 deletions(-) + +--- a/kernel/printk/printk_ringbuffer.c ++++ b/kernel/printk/printk_ringbuffer.c +@@ -2107,6 +2107,10 @@ u64 prb_next_reserve_seq(struct printk_r + * + * On failure @seq is updated to a record that is not yet available to the + * reader, but it will be the next record available to the reader. ++ * ++ * Note: When the current CPU is in panic, this function will skip over any ++ * non-existent/non-finalized records in order to allow the panic CPU ++ * to print any and all records that have been finalized. + */ + static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq, + struct printk_record *r, unsigned int *line_count) +@@ -2129,8 +2133,28 @@ static bool _prb_read_valid(struct print + (*seq)++; + + } else { +- /* Non-existent/non-finalized record. Must stop. */ +- return false; ++ /* ++ * Non-existent/non-finalized record. Must stop. ++ * ++ * For panic situations it cannot be expected that ++ * non-finalized records will become finalized. But ++ * there may be other finalized records beyond that ++ * need to be printed for a panic situation. If this ++ * is the panic CPU, skip this ++ * non-existent/non-finalized record unless it is ++ * at or beyond the head, in which case it is not ++ * possible to continue. ++ * ++ * Note that new messages printed on panic CPU are ++ * finalized when we are here. The only exception ++ * might be the last message without trailing newline. ++ * But it would have the sequence number returned ++ * by "prb_next_reserve_seq() - 1". ++ */ ++ if (this_cpu_in_panic() && ((*seq + 1) < prb_next_reserve_seq(rb))) ++ (*seq)++; ++ else ++ return false; + } + } + -- cgit v1.2.3