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shared/efi-loader: remove check that uses absolute tick value

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sd-boot uses rdtsc to set those timestamps. There is no guarantee that the tsc
has any particular absolute value.

On my VM:
$ head /sys/firmware/efi/efivars/LoaderTime*
==> /sys/firmware/efi/efivars/LoaderTimeExecUSec-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f <==
4397904074
==> /sys/firmware/efi/efivars/LoaderTimeInitUSec-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f <==
4396386839
==> /sys/firmware/efi/efivars/LoaderTimeMenuUSec-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f <==
4396392521

$ build/test-boot-timestamps
...
LoaderTimeExecUSec=4396386839 too large, refusing.
Failed to read EFI loader data: Input/output error
Assertion 'q >= 0' failed at src/test/test-boot-timestamps.c:84, function main(). Aborting.

(with patch)
$ build/test-boot-timestamps
...
EFI Loader: start=1h 13min 16.386s exit=1h 13min 17.904s duration=1.517s
Firmware began 1h 13min 17.904074s before kernel.
Loader began 1.517235s before kernel.
Firmware began Tue 2020-05-26 11:04:13 CEST.
Loader began Tue 2020-05-26 12:17:30 CEST.
Kernel began Tue 2020-05-26 12:17:31 CEST.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2020-05-26 21:08:10 +02:00
parent 24b4597064
commit dde5c821bf
1 changed files with 1 additions and 5 deletions
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6
src/shared/efi-loader.c
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@ -531,15 +531,11 @@ int efi_loader_get_boot_usec(usec_t *firmware, usec_t *loader) {
if (r < 0)
return log_debug_errno(r, "Failed to read LoaderTimeExecUSec: %m");
if (y == 0 || y < x)
if (y == 0 || y < x || y - x > USEC_PER_HOUR)
return log_debug_errno(SYNTHETIC_ERRNO(EIO),
"Bad LoaderTimeInitUSec=%"PRIu64", LoaderTimeExecUSec=%" PRIu64"; refusing.",
x, y);
if (y > USEC_PER_HOUR)
return log_debug_errno(SYNTHETIC_ERRNO(EIO),
"LoaderTimeExecUSec=%"PRIu64" too large, refusing.", x);
*firmware = x;
*loader = y;