Messages in this thread Patch in this message | | | Date | Fri, 21 Dec 2012 10:02:33 +0800 | From | "tiejun.chen" <> | Subject | Re: [v1][PATCH 3/6] book3e/kgdb: update thread's dbcr0 |
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On 12/21/2012 02:41 AM, Kumar Gala wrote: > > On Dec 20, 2012, at 3:08 AM, Tiejun Chen wrote: > >> gdb always need to generate a single step properly to invoke >> a kgdb state. But with lazy interrupt, book3e can't always >> trigger a debug exception with a single step since the current >> is blocked for handling those pending exception, then we miss >> that expected dbcr configuration at last to generate a debug >> exception. >> >> So here we also update thread's dbcr0 to make sure the current >> can go back with that missed dbcr0 configuration. >> >> Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com> >> --- >> arch/powerpc/kernel/kgdb.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c >> index c470a40..516b44b 100644 >> --- a/arch/powerpc/kernel/kgdb.c >> +++ b/arch/powerpc/kernel/kgdb.c >> @@ -426,8 +426,18 @@ int kgdb_arch_handle_exception(int vector, int signo, int err_code, >> /* set the trace bit if we're stepping */ >> if (remcom_in_buffer[0] == 's') { >> #ifdef CONFIG_PPC_ADV_DEBUG_REGS >> +#ifdef CONFIG_PPC_BOOK3E > > Should this really be CONFIG_PPC64 or CONFIG_PPC_BOOK3E_64?
Yes, I think CONFIG_PPC_BOOK3E_64 is better currently. Because I didn't validate this on power arch since I have no a real machine :)
> >> + /* With lazy interrut we have to update thread dbcr0 here >> + * to make sure we can set debug properly at last to invoke >> + * kgdb again to work well. >> + */ >> + current->thread.dbcr0 = >> + mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM; >> + mtspr(SPRN_DBCR0, current->thread.dbcr0); >> +#else >> mtspr(SPRN_DBCR0, >> mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM); >> +#endif > > Can we code this so we don't need the #else?
I guess you're saying something like this:
--- diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c index c470a40..b2df42a 100644 --- a/arch/powerpc/kernel/kgdb.c +++ b/arch/powerpc/kernel/kgdb.c @@ -409,7 +409,7 @@ int kgdb_arch_handle_exception(int vector, int signo, int err_code, struct pt_regs *linux_regs) { char *ptr = &remcom_in_buffer[1]; - unsigned long addr; + unsigned long addr, dbcr0;
switch (remcom_in_buffer[0]) { /* @@ -426,8 +426,15 @@ int kgdb_arch_handle_exception(int vector, int signo, int err_code, /* set the trace bit if we're stepping */ if (remcom_in_buffer[0] == 's') { #ifdef CONFIG_PPC_ADV_DEBUG_REGS - mtspr(SPRN_DBCR0, - mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM); + dbcr0 = mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM; + mtspr(SPRN_DBCR0, dbcr0); +#ifdef CONFIG_PPC_BOOK3E_64 + /* With lazy interrut we have to update thread dbcr0 here + * to make sure we can set debug properly at last to invoke + * kgdb again to work well. + */ + current->thread.dbcr0 = dbcr0; +#endif linux_regs->msr |= MSR_DE; #else linux_regs->msr |= MSR_SE; -- 1.7.9.5 Tiejun
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