diff options
| author | bde <bde@FreeBSD.org> | 2003-03-24 10:17:14 +0000 |
|---|---|---|
| committer | bde <bde@FreeBSD.org> | 2003-03-24 10:17:14 +0000 |
| commit | 79afd37295979afa452a4b5ed75ac6a74f9569fe (patch) | |
| tree | 4b95fc998041d683ead48a7c799ac1e529d0f525 | |
| parent | 97be9a96e65371bca742adf3199022c9e8bf0aeb (diff) | |
| download | FreeBSD-src-79afd37295979afa452a4b5ed75ac6a74f9569fe.zip FreeBSD-src-79afd37295979afa452a4b5ed75ac6a74f9569fe.tar.gz | |
Disable interrupts while in kdb_trap() to handle cases where the caller
doesn't do it. This fixes all known causes of "Context switches not
allowed in the debugger" in mi_switch(). The main cause was trap_fatal()
calling kdb_trap() with interrupts enabled. Switching to ithreads for
interrupt handling then made fatal traps more fatal and harder to debug.
The problem was limited in -current because most interrupt handlers are
blocked by Giant, but it occurred almost deterministically for me because
my clock interrupt handlers are non-fast and not blocked by Giant.
| -rw-r--r-- | sys/amd64/amd64/db_interface.c | 7 | ||||
| -rw-r--r-- | sys/i386/i386/db_interface.c | 7 |
2 files changed, 14 insertions, 0 deletions
diff --git a/sys/amd64/amd64/db_interface.c b/sys/amd64/amd64/db_interface.c index f1ba48c..e2b936b 100644 --- a/sys/amd64/amd64/db_interface.c +++ b/sys/amd64/amd64/db_interface.c @@ -77,6 +77,7 @@ rss(void) int kdb_trap(int type, int code, struct i386_saved_state *regs) { + u_int ef; volatile int ddb_mode = !(boothowto & RB_GDB); /* @@ -96,6 +97,9 @@ kdb_trap(int type, int code, struct i386_saved_state *regs) return (0); } + ef = read_eflags(); + disable_intr(); + switch (type) { case T_BPTFLT: /* breakpoint */ case T_TRCTRAP: /* debug exception */ @@ -216,6 +220,9 @@ kdb_trap(int type, int code, struct i386_saved_state *regs) regs->tf_fs = ddb_regs.tf_fs & 0xffff; regs->tf_cs = ddb_regs.tf_cs & 0xffff; regs->tf_ds = ddb_regs.tf_ds & 0xffff; + + write_eflags(ef); + return (1); } diff --git a/sys/i386/i386/db_interface.c b/sys/i386/i386/db_interface.c index f1ba48c..e2b936b 100644 --- a/sys/i386/i386/db_interface.c +++ b/sys/i386/i386/db_interface.c @@ -77,6 +77,7 @@ rss(void) int kdb_trap(int type, int code, struct i386_saved_state *regs) { + u_int ef; volatile int ddb_mode = !(boothowto & RB_GDB); /* @@ -96,6 +97,9 @@ kdb_trap(int type, int code, struct i386_saved_state *regs) return (0); } + ef = read_eflags(); + disable_intr(); + switch (type) { case T_BPTFLT: /* breakpoint */ case T_TRCTRAP: /* debug exception */ @@ -216,6 +220,9 @@ kdb_trap(int type, int code, struct i386_saved_state *regs) regs->tf_fs = ddb_regs.tf_fs & 0xffff; regs->tf_cs = ddb_regs.tf_cs & 0xffff; regs->tf_ds = ddb_regs.tf_ds & 0xffff; + + write_eflags(ef); + return (1); } |
