Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Fix SMP races with thread swap and abort #21903

Merged
merged 7 commits into from
Jan 21, 2020
Merged

Fix SMP races with thread swap and abort #21903

Changes from 1 commit
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
ad44159
Revert "x86: qemu_x86_64: workaround SMP issues in x86"
Jan 16, 2020
5297606
kernel: arch: Clarify output switch handle requirements in arch_switch
Jan 16, 2020
4d98b8a
kernel/sched: Correct IPI usage
Jan 16, 2020
102d28f
kernel/sched: Address thread abort termination delay issue on SMP
Jan 14, 2020
946919c
kernel/swap: Add SMP "wait for switch" synchronization
Jan 17, 2020
78b1402
kernel/queue: Fix SMP race
Jan 17, 2020
dbaf43a
samples/userspace/shared_mem: Fix SMP race
Jan 17, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
21 changes: 9 additions & 12 deletions samples/userspace/shared_mem/src/main.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -78,7 +78,6 @@ struct k_thread ct_thread;
K_THREAD_STACK_DEFINE(ct_stack, STACKSIZE);

_app_enc_d char encMSG[] = "ENC!\n";
_app_enc_d int enc_state = 1;
_app_enc_b char enc_pt[50]; /* Copy form shared pt */
_app_enc_b char enc_ct[50]; /* Copy to shared ct */

Expand All @@ -104,6 +103,15 @@ void main(void)
struct k_mem_partition *dom0_parts[] = {&part0, &part1};
k_tid_t tPT, tENC, tCT;

fBUFIN = 0; /* clear flags */
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

change looks good but I'm still worried about how this was crashing by the emulator suddenly exiting. even with a race it should at least produce an exception that can be handled, if the whole thing triple faults that tells me we might have a bug in arch/x86 somewhere that I should try to investigate more, unless this race somehow got the page tables corrupted. what do you think?

fBUFOUT = 0;
calc_rev_wheel((BYTE *) &W1, (BYTE *)&W1R);
calc_rev_wheel((BYTE *) &W2, (BYTE *)&W2R);
calc_rev_wheel((BYTE *) &W3, (BYTE *)&W3R);
IW1 = 0;
IW2 = 0;
IW3 = 0;

k_thread_access_grant(k_current_get(), &allforone);

/*
Expand Down Expand Up @@ -169,17 +177,6 @@ void enc(void)
{

int index, index_out;
if (enc_state == 1) {
fBUFIN = 0; /* clear flags */
fBUFOUT = 0;
calc_rev_wheel((BYTE *) &W1, (BYTE *)&W1R);
calc_rev_wheel((BYTE *) &W2, (BYTE *)&W2R);
calc_rev_wheel((BYTE *) &W3, (BYTE *)&W3R);
IW1 = 0;
IW2 = 0;
IW3 = 0;
enc_state = 0;
}

while (1) {
k_sem_take(&allforone, K_FOREVER);
Expand Down