linux

iv/linux

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Steven Rostedt (Google) 4ee7e7dd1f tracing: Use a copy of the va_list for __assign_vstr()

commit 3a2dcbaf4d31023106975d6ae75b6df080c454cb upstream.

If an instance of tracing enables the same trace event as another
instance, or the top level instance, or even perf, then the va_list passed
into some tracepoints can be used more than once.

As va_list can only be traversed once, this can cause issues:

 # cat /sys/kernel/tracing/instances/qla2xxx/trace
             cat-56106   [012] ..... 2419873.470098: ql_dbg_log: qla2xxx [0000:05:00.0]-1054:14:  Entered (null).
             cat-56106   [012] ..... 2419873.470101: ql_dbg_log: qla2xxx [0000:05:00.0]-1000:14:  Entered ×+<96>²Ü<98>^H.
             cat-56106   [012] ..... 2419873.470102: ql_dbg_log: qla2xxx [0000:05:00.0]-1006:14:  Prepare to issue mbox cmd=0xde589000.

 # cat /sys/kernel/tracing/trace
             cat-56106   [012] ..... 2419873.470097: ql_dbg_log: qla2xxx [0000:05:00.0]-1054:14:  Entered qla2x00_get_firmware_state.
             cat-56106   [012] ..... 2419873.470100: ql_dbg_log: qla2xxx [0000:05:00.0]-1000:14:  Entered qla2x00_mailbox_command.
             cat-56106   [012] ..... 2419873.470102: ql_dbg_log: qla2xxx [0000:05:00.0]-1006:14:  Prepare to issue mbox cmd=0x69.

The instance version is corrupted because the top level instance iterated
the va_list first.

Use va_copy() in the __assign_vstr() macro to make sure that each trace
event for each use case gets a fresh va_list.

Link: https://lore.kernel.org/all/259d53a5-958e-6508-4e45-74dba2821242@marvell.com/
Link: https://lkml.kernel.org/r/20220719182004.21daa83e@gandalf.local.home

Fixes: 0563231f93c6d ("tracing/events: Add __vstring() and __assign_vstr() helper macros")
Reported-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2022-08-17 15:16:20 +02:00

acpi

ACPI: CPPC: Do not prevent CPPC from working in the future

2022-08-17 15:16:13 +02:00

asm-generic

asm-generic fixes for 5.19, part 2

2022-07-27 09:50:18 -07:00

clocksource

pwm: Changes for v5.19-rc1

2022-06-01 10:49:11 -07:00

crypto

crypto: blake2s - remove shash module