| Message ID | 20230327124520.2707537-4-npiggin@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | powerpc: updates, P10, PNV support | expand |
On 27/03/2023 14.45, Nicholas Piggin wrote: > Check to ensure exception handlers are not being overwritten or > invalid exception numbers are used. > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > --- > Since v2: > - New patch > > lib/powerpc/processor.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/lib/powerpc/processor.c b/lib/powerpc/processor.c > index ec85b9d..70391aa 100644 > --- a/lib/powerpc/processor.c > +++ b/lib/powerpc/processor.c > @@ -19,11 +19,23 @@ static struct { > void handle_exception(int trap, void (*func)(struct pt_regs *, void *), > void * data) > { > + if (trap & 0xff) { You could check for the other "invalid exception handler" condition here already, i.e. if (trap & ~0xf00) ... I'd maybe simply do an "assert(!(trap & ~0xf00))" here. > + printf("invalid exception handler %#x\n", trap); > + abort(); > + } > + > trap >>= 8; > > if (trap < 16) { ... then you could get rid of the if-statement here and remove one level of indentation in the code below. > + if (func && handlers[trap].func) { > + printf("exception handler installed twice %#x\n", trap); > + abort(); > + } > handlers[trap].func = func; > handlers[trap].data = data; > + } else { > + printf("invalid exception handler %#x\n", trap); > + abort(); > } > } > Thomas
On Tue Mar 28, 2023 at 12:39 AM AEST, Thomas Huth wrote: > On 27/03/2023 14.45, Nicholas Piggin wrote: > > Check to ensure exception handlers are not being overwritten or > > invalid exception numbers are used. > > > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > > --- > > Since v2: > > - New patch > > > > lib/powerpc/processor.c | 12 ++++++++++++ > > 1 file changed, 12 insertions(+) > > > > diff --git a/lib/powerpc/processor.c b/lib/powerpc/processor.c > > index ec85b9d..70391aa 100644 > > --- a/lib/powerpc/processor.c > > +++ b/lib/powerpc/processor.c > > @@ -19,11 +19,23 @@ static struct { > > void handle_exception(int trap, void (*func)(struct pt_regs *, void *), > > void * data) > > { > > + if (trap & 0xff) { > > You could check for the other "invalid exception handler" condition here > already, i.e. if (trap & ~0xf00) ... > > I'd maybe simply do an "assert(!(trap & ~0xf00))" here. > > > + printf("invalid exception handler %#x\n", trap); > > + abort(); > > + } > > + > > trap >>= 8; > > > > if (trap < 16) { > > ... then you could get rid of the if-statement here and remove one level of > indentation in the code below. Yes that's the way to do it. I feel embarrassed for not thinking of it :) Thanks, Nick > > > + if (func && handlers[trap].func) { > > + printf("exception handler installed twice %#x\n", trap); > > + abort(); > > + } > > handlers[trap].func = func; > > handlers[trap].data = data; > > + } else { > > + printf("invalid exception handler %#x\n", trap); > > + abort(); > > } > > } > > > > Thomas
diff --git a/lib/powerpc/processor.c b/lib/powerpc/processor.c index ec85b9d..70391aa 100644 --- a/lib/powerpc/processor.c +++ b/lib/powerpc/processor.c @@ -19,11 +19,23 @@ static struct { void handle_exception(int trap, void (*func)(struct pt_regs *, void *), void * data) { + if (trap & 0xff) { + printf("invalid exception handler %#x\n", trap); + abort(); + } + trap >>= 8; if (trap < 16) { + if (func && handlers[trap].func) { + printf("exception handler installed twice %#x\n", trap); + abort(); + } handlers[trap].func = func; handlers[trap].data = data; + } else { + printf("invalid exception handler %#x\n", trap); + abort(); } }
Check to ensure exception handlers are not being overwritten or invalid exception numbers are used. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- Since v2: - New patch lib/powerpc/processor.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)