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Add UserSlicePtrWriter::write. #171

Merged
merged 2 commits into from
Apr 8, 2021
Merged

Add UserSlicePtrWriter::write. #171

merged 2 commits into from
Apr 8, 2021

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wedsonaf
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@wedsonaf wedsonaf commented Apr 8, 2021

This used to be in #117, but I took it out because we had to define a new trait and I didn't want to hold that PR up.

Comment on lines 51 to 52
/// This means that we don't read undefined values when reading the memory contents (which leads to
/// UB). It also ensures that no potentially sensitive information is leaked into the byte slices.
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Should all the "reads" in this paragraph be "writes"?

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I meant reading the memory contents (before writing). I updated the comment, hopefully it's clearer now. PTAL.

@alex alex merged commit 1509393 into Rust-for-Linux:rust Apr 8, 2021
@wedsonaf wedsonaf deleted the write branch April 8, 2021 15:59
fbq pushed a commit that referenced this pull request Dec 28, 2023
Currently, there are two test cases with same name
"ALU64_SMOD_X: -7 % 2 = -1", the first one is right,
the second one should be ALU64_SMOD_K because its
code is BPF_ALU64 | BPF_MOD | BPF_K.

Before:
test_bpf: #170 ALU64_SMOD_X: -7 % 2 = -1 jited:1 4 PASS
test_bpf: #171 ALU64_SMOD_X: -7 % 2 = -1 jited:1 4 PASS

After:
test_bpf: #170 ALU64_SMOD_X: -7 % 2 = -1 jited:1 4 PASS
test_bpf: #171 ALU64_SMOD_K: -7 % 2 = -1 jited:1 4 PASS

Fixes: daabb2b ("bpf/tests: add tests for cpuv4 instructions")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231207040851.19730-1-yangtiezhu@loongson.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
ojeda pushed a commit that referenced this pull request Jun 11, 2024
AudioMix BLK-CTRL on i.MX8MP encountered an accessing register issue
after power up.

[    2.181035] Kernel panic - not syncing: Asynchronous SError Interrupt
[    2.181038] CPU: 1 PID: 48 Comm: kworker/u16:2 Not tainted 6.9.0-rc5-next-20240424-00003-g21cec88845c6 #171
[    2.181047] Hardware name: NXP i.MX8MPlus EVK board (DT)
[    2.181050] Workqueue: events_unbound deferred_probe_work_func
[    2.181064] Call trace:
[...]
[    2.181142]  arm64_serror_panic+0x6c/0x78
[    2.181149]  do_serror+0x3c/0x70
[    2.181157]  el1h_64_error_handler+0x30/0x48
[    2.181164]  el1h_64_error+0x64/0x68
[    2.181171]  clk_imx8mp_audiomix_runtime_resume+0x34/0x44
[    2.181183]  __genpd_runtime_resume+0x30/0x80
[    2.181195]  genpd_runtime_resume+0x110/0x244
[    2.181205]  __rpm_callback+0x48/0x1d8
[    2.181213]  rpm_callback+0x68/0x74
[    2.181224]  rpm_resume+0x468/0x6c0
[    2.181234]  __pm_runtime_resume+0x50/0x94
[    2.181243]  pm_runtime_get_suppliers+0x60/0x8c
[    2.181258]  __driver_probe_device+0x48/0x12c
[    2.181268]  driver_probe_device+0xd8/0x15c
[    2.181278]  __device_attach_driver+0xb8/0x134
[    2.181290]  bus_for_each_drv+0x84/0xe0
[    2.181302]  __device_attach+0x9c/0x188
[    2.181312]  device_initial_probe+0x14/0x20
[    2.181323]  bus_probe_device+0xac/0xb0
[    2.181334]  deferred_probe_work_func+0x88/0xc0
[    2.181344]  process_one_work+0x150/0x290
[    2.181357]  worker_thread+0x2f8/0x408
[    2.181370]  kthread+0x110/0x114
[    2.181381]  ret_from_fork+0x10/0x20
[    2.181391] SMP: stopping secondary CPUs

According to comments in power up handshake:

	/* request the ADB400 to power up */
	if (domain->bits.hskreq) {
		regmap_update_bits(domain->regmap, domain->regs->hsk,
				   domain->bits.hskreq, domain->bits.hskreq);

		/*
		 * ret = regmap_read_poll_timeout(domain->regmap, domain->regs->hsk, reg_val,
		 *				  (reg_val & domain->bits.hskack), 0,
		 *				  USEC_PER_MSEC);
		 * Technically we need the commented code to wait handshake. But that needs
		 * the BLK-CTL module BUS clk-en bit being set.
		 *
		 * There is a separate BLK-CTL module and we will have such a driver for it,
		 * that driver will set the BUS clk-en bit and handshake will be triggered
		 * automatically there. Just add a delay and suppose the handshake finish
		 * after that.
		 */
	}

The BLK-CTL module needs to add delay to wait for a handshake request finished.
For some BLK-CTL module (eg. AudioMix on i.MX8MP) doesn't have BUS clk-en
bit, it is better to add delay in this driver, as the BLK-CTL module doesn't
need to care about how it is powered up.

regmap_read_bypassed() is to make sure the above write IO transaction already
reaches target before udelay().

Fixes: 1496dd4 ("clk: imx: imx8mp: Add pm_runtime support for power saving")
Reported-by: Francesco Dolcini <francesco@dolcini.it>
Closes: https://lore.kernel.org/all/66293535.170a0220.21fe.a2e7@mx.google.com/
Suggested-by: Frank Li <frank.li@nxp.com>
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Tested-by: Adam Ford <aford173@gmail.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/1715396125-3724-1-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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