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author | louis.wang <liang26812@gmail.com> | 2021-02-24 13:25:53 +0100 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-22 11:40:52 +0200 |
commit | ec324393a63cfd28e2182a3efd52c93766b6dcd0 (patch) | |
tree | e6be1f4fbcda48d32894f8056803ea1f3e872e72 /drivers/pci | |
parent | 3029ef71ab227af7c0ffb7956c2da4b1882aa23b (diff) |
ARM: 9066/1: ftrace: pause/unpause function graph tracer in cpu_suspend()
[ Upstream commit 8252ca87c7a2111502ee13994956f8c309faad7f ]
Enabling function_graph tracer on ARM causes kernel panic, because the
function graph tracer updates the "return address" of a function in order
to insert a trace callback on function exit, it saves the function's
original return address in a return trace stack, but cpu_suspend() may not
return through the normal return path.
cpu_suspend() will resume directly via the cpu_resume path, but the return
trace stack has been set-up by the subfunctions of cpu_suspend(), which
makes the "return address" inconsistent with cpu_suspend().
This patch refers to Commit de818bd4522c40ea02a81b387d2fa86f989c9623
("arm64: kernel: pause/unpause function graph tracer in cpu_suspend()"),
fixes the issue by pausing/resuming the function graph tracer on the thread
executing cpu_suspend(), so that the function graph tracer state is kept
consistent across functions that enter power down states and never return
by effectively disabling graph tracer while they are executing.
Signed-off-by: louis.wang <liang26812@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/pci')
0 files changed, 0 insertions, 0 deletions